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Critique my plan for my engine

Old 02-06-2019, 09:27 PM
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Critique my plan for my engine

So I aquired another car. Itís a 92 Z03 Z28. Itís a nice car, G92, 350 auto car, but it has a knocking motor. The car was so nice and so cheap that I had to buy it. I have a bunch of parts laying around, and I am by no means looking for a rocket ship, but I want to toss a motor together as cheap as I can and make it a little better than stock.

What I have so far;

880 roller 4 bolt block, crank, and set of ďdotĒ or ďhi-proĒ rods. The block has been tanked, honed, main line honed, and cam bearing-ed.

i have a set of 113 aluminum corvette L98 heads, 1.6 comp roller tip rockers, and a stock LT1 cam thatís 205/207 .447/.459 117lsa

I build cylinder heads for a living so freshening up the 113ís and doing some mild porting wonít set me back any money.

I know thereís plenty of heads, and plenty of cams that will make a lot more power, but Iím looking for the idle, drivability, and sound to be as stock appearing as possible.

The cam being a touch better, the rockers giving it a touch more lift, the port work on the heads, and bump in compression should all give it a little more here and a little more there, I feel like instead of doing something fancy for an intake Iíll just go the easy route with an HSR and shut the EGR off in the computer.

What are the thoughts on this combo? I feel like it should run out similar to a stock LT1 at that point right?
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Old 02-06-2019, 10:02 PM
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Re: Critique my plan for my engine

Maybe even a bit stronger. Should be a very nice street engine looking forward to seeing it!
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Old 02-06-2019, 11:19 PM
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Re: Critique my plan for my engine

Iím also putting a set of hold hooker 2460 headers and y pipe on it.

Im thinking stock LT1 24lbs injectors will be plenty, as well as using the stock L98 TB and doing a little port work on the entry, and an air foil.

Behind the motor the motor has a rebuilt trans, I plan on tossing a shift kit in it and a big converter, as well as I have a rear end left over out of my 4th gen that has a set of 3.90ís and the stock 02 torsen carrier that I think Iíll stuff into the 10 bolt.

The end end goal is a laughably cheap et sportsman class car to run out local Wednesday night 1/8 mile bracket class.
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Old 02-07-2019, 10:24 AM
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Re: Critique my plan for my engine

Your plan sounds good. 24lb injectors should be fine and the stock tb as well. I would guess that setup would be 325-350hp with a nice broad powerband. Will be fun.
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Old 02-07-2019, 10:32 AM
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Re: Critique my plan for my engine

You might want to cut down the guides and run a hot cam with 1.6 rockers.
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Old 02-07-2019, 10:44 AM
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Re: Critique my plan for my engine

Originally Posted by Tuned Performance View Post
You might want to cut down the guides and run a hot cam with 1.6 rockers.
Cut the guides, yes. The OP said he builds cylinder heads for a living, so he probably already knows this.

The hot cam would be a good choice for this build too, but the OP also said he wants an idle similar to stock. I think the LT1 cam with the 1.6 rockers fit his goals. It will make good power, smooth idle and easy to tune. Maybe a stock LT4 cam with 1.6 rockers for a few more horsepower, but if the OP already owns the LT1 cam, I would just run it.
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Old 02-07-2019, 11:01 AM
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Re: Critique my plan for my engine

Put a 383 kit in it with everything else you listed..
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Old 02-07-2019, 12:53 PM
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Re: Critique my plan for my engine

Yeah the hot cam sounds like a cam for sure. The LT4 production cam is so close to the standard LT1 cam I canít see if being worth the time and money to buy one when I already have the stock LT1 here. Yes I will definitely be doin bronze guides shelves down low, as well as LS behive springs. I havenít looked too far into it but possibly even do the 8mm valve conversion on the heads.
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Old 02-08-2019, 07:29 AM
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Re: Critique my plan for my engine

Originally Posted by charlie6178 View Post
So I aquired another car. Itís a 92 Z03 Z28. Itís a nice car, G92, 350 auto car, but it has a knocking motor. The car was so nice and so cheap that I had to buy it. I have a bunch of parts laying around, and I am by no means looking for a rocket ship, but I want to toss a motor together as cheap as I can and make it a little better than stock.

What I have so far;

880 roller 4 bolt block, crank, and set of ďdotĒ or ďhi-proĒ rods. The block has been tanked, honed, main line honed, and cam bearing-ed.

i have a set of 113 aluminum corvette L98 heads, 1.6 comp roller tip rockers, and a stock LT1 cam thatís 205/207 .447/.459 117lsa

I build cylinder heads for a living so freshening up the 113ís and doing some mild porting wonít set me back any money.

I know thereís plenty of heads, and plenty of cams that will make a lot more power, but Iím looking for the idle, drivability, and sound to be as stock appearing as possible.

The cam being a touch better, the rockers giving it a touch more lift, the port work on the heads, and bump in compression should all give it a little more here and a little more there, I feel like instead of doing something fancy for an intake Iíll just go the easy route with an HSR and shut the EGR off in the computer.

What are the thoughts on this combo? I feel like it should run out similar to a stock LT1 at that point right?
Are you doing anything to address the Intake? The 3.90's are going to be steep with a factory intake runner and nothing to shove air into the motor above 4600RPMs. You may be getting a bump from the cam, but the runners are not going to support the slight bump in RPM and they never Horsepower well.

On the other hand, if you are keeping the TPI runners and going 3.90 so you have a torque monster that you can light the tires up, I think you are spot on. Otherwise, you should be looking to pick up a mini ram. It's basically and LT1 manifold and will match your cam nicely. Going to a deep gear like that will make a fun car to drive. You will have traction issues due to the added torque, and it will run slower 1/4 mile times. Not going to go down the rabbit hole about gearing in this thread, but 3.90 is too deep to get good ETs out of a factory TPI manifold.
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Old 02-08-2019, 09:45 AM
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Re: Critique my plan for my engine

No Iím definitely going to do a different intake. I think for this car, Iím just going to go the easy way and go stealth ram. I am mid install on a T ram on my other 92, and I actually bought another T ram for this car, but I am now thinking I want to save that other T ram for later.
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Old 02-08-2019, 10:42 AM
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Re: Critique my plan for my engine

Originally Posted by charlie6178 View Post
No Iím definitely going to do a different intake. I think for this car, Iím just going to go the easy way and go stealth ram. I am mid install on a T ram on my other 92, and I actually bought another T ram for this car, but I am now thinking I want to save that other T ram for later.
Then you should be more than fine and I would suggest the LT4 Hot Cam. My brother ran it in warmed over 350, the idle wasn't an issue at all and he was running a carb. With the fuel injection it should be easily manageable.
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Old 02-13-2019, 02:02 PM
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Re: Critique my plan for my engine

Charlie, what is the maximum lift a 113 can handle leaving a good guide seal surface on the guide ?
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Old 02-13-2019, 03:21 PM
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Re: Critique my plan for my engine

Assuming you got all the mechanical parts right... the thing that would concern me most is how you will be tuning it?
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Old 02-13-2019, 08:06 PM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
Assuming you got all the mechanical parts right... the thing that would concern me most is how you will be tuning it?
I think Charlie is sticking with the 90-92 tpi 1227730 speed density ecm. I tuned the hotcam for a member in California last year. It passed the sniffer this year. Not a hard cam to tune for although it took me maybe 8 tries to dial it in.
Another good cam choice
http://www.lunatipower.com/Product.aspx?id=2607&gid=346

Last edited by Tuned Performance; 02-13-2019 at 08:41 PM.
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Old 02-13-2019, 08:25 PM
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Re: Critique my plan for my engine

Its... so... old.

I mean, I know this is getting rote but. LS swap?
A stock LS engine (4.8L or 5.3 or 6.0) is cheap. The computer it comes with is modern as f. Sequential efi, trans mode switching, you can real-time it too. Turn off 1 cylinder at a time for diagnostics etc... fuel AND spark.
I know its expensive to get the motor into the car but... once you put those mounts and stuff in place, you can LS swap it all day for cheap after that. $.02
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Old 02-21-2019, 11:59 AM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
Its... so... old.

I mean, I know this is getting rote but. LS swap?
A stock LS engine (4.8L or 5.3 or 6.0) is cheap. The computer it comes with is modern as f. Sequential efi, trans mode switching, you can real-time it too. Turn off 1 cylinder at a time for diagnostics etc... fuel AND spark.
I know its expensive to get the motor into the car but... once you put those mounts and stuff in place, you can LS swap it all day for cheap after that. $.02
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Old 02-21-2019, 12:05 PM
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Re: Critique my plan for my engine

Looks like the plan has changed. The car is now for sale
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Old 02-21-2019, 12:21 PM
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Re: Critique my plan for my engine

Originally Posted by Tuned Performance View Post
Looks like the plan has changed. The car is now for sale
Well, probably a moot point now then.

Funny though that this thread went down the same predictable path of most motor build discussions. The OP starts out saying he has a bunch of existing parts he wants to use toward a mild engine build that's just a little upgraded over stock and has a smooth idle. Nothing wrong with that and sometimes less is more, but then come the suggestions of stroker kits, bigger cam, etc. and then ends with the inevitable suggestion to just put an LS in it.

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Old 02-21-2019, 12:38 PM
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Re: Critique my plan for my engine

If ppl are discussing replacement heart valves manufactured in the 90's and someone comes in and suggests using one made in the 00's you wouldn't scoff the notion unless there was something wrong with newer versions

and theres nothing wrong with LS engines, the tech is newer and actually much better. Many details have been revised to 'catch' the Japanese engines of 90's.
In other words, Japanese 1992 is like Chevy's 2002. If you want a well designed JDM motor you buy 92+, but for chevy its 02+

The parts to do the swap are expensive, 10k just in motor mounts driveshaft transthis and thats. But if the motor ever gives trouble again you can replace for $300-$1000 another LS engine is currently highly available.
and they support 500-600-700hp some of them 800-1000hp is possible. For a mean street car most ppl will enjoy 500-600 only, such a small bit and can be done on a $100 fuel pump with a $300 engine? Or similar.
I'm not sure I would go through all the trouble to LS swap something without turbo though. There is very little gain if all we are talking about is displacement. In fact anybody'd be crazy to pull a 5.7L in favor of a 5.3L, or even a 6L... all that work to LS swap for .3L? Nah. If you needed it to be a reliable daily driver, then you have to swap it. But if its just a junk toy car then keep the leaky possibly unreliable 5.7L old-tech engine (try to make it reliable though lol) dont drop money on the LS swap... unless you can turbo it. The whole point is LS is to go turbo... now you have access to $300 engines that do at least 500hp reliably and don't spew oil etc... no need to buy heads,intakes,hard valve mods, or worry about is it built right. Is it built right? It just came out of an 02 Escalade/Denali/etc with 120,000 miles hit in the front, you damn sure that motor will go 250,000 to 350,000 miles total. And with 15-18psi of boost it will get there @ 500hp+ and you never took the engine apart except the front cover to put in the cam and springs and new oil pump.
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Old 02-21-2019, 01:54 PM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
If ppl are discussing replacement heart valves manufactured in the 90's and someone comes in and suggests using one made in the 00's you wouldn't scoff the notion unless there was something wrong with newer versions
This is not a heart valve and the consequences, benefits, and desires of the results are no where near the same.

Aesthetics, individuality, what you are comfortable with, and emotional attachment come into play. I can tell you personally I know my L98 will never be as good of a performer as an LS engine apples to apples... but that LS will never look as cool as a TPI. Besides, there is always someone who has spent more to go faster. Build what you like, your smile will thank you.
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Old 02-21-2019, 01:56 PM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
If ppl are discussing replacement heart valves manufactured in the 90's and someone comes in and suggests using one made in the 00's you wouldn't scoff the notion unless there was something wrong with newer versions

and theres nothing wrong with LS engines, the tech is newer and actually much better. Many details have been revised to 'catch' the Japanese engines of 90's.
In other words, Japanese 1992 is like Chevy's 2002. If you want a well designed JDM motor you buy 92+, but for chevy its 02+

The parts to do the swap are expensive, 10k just in motor mounts driveshaft transthis and thats. But if the motor ever gives trouble again you can replace for $300-$1000 another LS engine is currently highly available.
and they support 500-600-700hp some of them 800-1000hp is possible. For a mean street car most ppl will enjoy 500-600 only, such a small bit and can be done on a $100 fuel pump with a $300 engine? Or similar.
I'm not sure I would go through all the trouble to LS swap something without turbo though. There is very little gain if all we are talking about is displacement. In fact anybody'd be crazy to pull a 5.7L in favor of a 5.3L, or even a 6L... all that work to LS swap for .3L? Nah. If you needed it to be a reliable daily driver, then you have to swap it. But if its just a junk toy car then keep the leaky possibly unreliable 5.7L old-tech engine (try to make it reliable though lol) dont drop money on the LS swap... unless you can turbo it. The whole point is LS is to go turbo... now you have access to $300 engines that do at least 500hp reliably and don't spew oil etc... no need to buy heads,intakes,hard valve mods, or worry about is it built right. Is it built right? It just came out of an 02 Escalade/Denali/etc with 120,000 miles hit in the front, you damn sure that motor will go 250,000 to 350,000 miles total. And with 15-18psi of boost it will get there @ 500hp+ and you never took the engine apart except the front cover to put in the cam and springs and new oil pump.
Absolutely the LS is a much better motor than the SBC. My 99 SS has an LS1 and it's a fabulous motor, but that doesn't mean the SBC is a bad motor and doesn't still have its place. If all you are looking for is a mildly warmed over, relatively stock replacement for a car that originally came with a SBC, it's far simpler and less expensive to stick another SBC in there and be on your way. Everything bolts right up and it will be plenty reliable.

If you're looking to build the snot out of it, 500+ horsepower, turbo, etc., LS all the way.
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Old 02-21-2019, 02:08 PM
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Re: Critique my plan for my engine

Originally Posted by TransamGTA350
Absolutely the LS is a much better motor than the SBC.
That's not really true. Members don't want to pony up the expense needed to build a SBC properly, because it gets very expensive, so they are relegated to what is out there. Remember that LS engines have the most appeal because of their cheapness (not quality wise, but in availability, and they already come better in terms of air flow from the factory, obviously), and people also want that newer "technology" (ECU wise) thinking it will give them the edge, and half can't even tune it. I mean a Shafiroff 440-SBC running SB2 cylinder heads is making over 900 horsepower in crate package form. Talk to them about a miniram, monoblade, their patented valvetrain tech, all controlled by a FAST XFI, and watch them put a huge grin on their face, because they already know the outcome. However, that package right there will set you way over twenty grand, so yeah, that's why the LS engines with their ECU's have the edge, easily replaceable when pushed too hard, and never think they don't break, because they do. That is the only reason people lean to LS engines, cost factor. For less than a grand you can have the ECU, harness, the whole damn thing...

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Old 02-21-2019, 03:42 PM
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Re: Critique my plan for my engine

Originally Posted by Street Lethal View Post
That's not really true. Members don't want to pony up the expense needed to build a SBC properly, because it gets very expensive, so they are relegated to what is out there. Remember that LS engines have the most appeal because of their cheapness (not quality wise, but in availability, and they already come better in terms of air flow from the factory, obviously), and people also want that newer "technology" (ECU wise) thinking it will give them the edge, and half can't even tune it. I mean a Shafiroff 440-SBC running SB2 cylinder heads is making over 900 horsepower in crate package form. Talk to them about a miniram, monoblade, their patented valvetrain tech, all controlled by a FAST XFI, and watch them put a huge grin on their face, because they already know the outcome. However, that package right there will set you way over twenty grand, so yeah, that's why the LS engines with their ECU's have the edge, easily replaceable when pushed too hard, and never think they don't break, because they do. That is the only reason people lean to LS engines, cost factor. For less than a grand you can have the ECU, harness, the whole damn thing...

- Rob
I agree with all of this, and there are other reasons too. This is why the custom car hobby is so fun. It would get boring quick if we all built the same thing.
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Old 02-21-2019, 03:56 PM
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Re: Critique my plan for my engine

The LS platform is miles ahead of original SBC. Everything is better. The engine is sealed up properly using factory gaskets which are mostly re-usable. For small samples of limited quantity production models, The LS engines are guaranteed to achieve high mileage. That is two major concerns (oil leaking/seepage and bottom end machining/assembly procedures). The sealing surfaces at the time of production are still used the same way, it hasn't been 'converted' to something else for 'low power' gasoline applications (500~hp).

LS solves all the major unavoidable issues of SBC that make it tedious for 1-engine owners (novices that only have 1 engine at a time as opposed to a wall full of built engines ready to go in, in which case the desirable factor is speed instead of cost) at low power. Sealing one up is no longer a question of permatex and vacuum pumps. The compression ratio is low to begin with and many engines already with 100,000 will have even less compression with slight wear is ideal for turbo applications which scavenge exhaust energy in order to impart some kinetic energy unto incoming air molecules which sort of makes up for the 3-4% the engine lost due to mileage. In other words, mileage will/should be if not restored, improved slightly when the low power engine is turbocharged. (high power engines use such higher weight impellers that low speed kinetic energy imparted to intake air molecules may be reduced).
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Old 02-21-2019, 04:33 PM
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Re: Critique my plan for my engine

As said, the LS based engine is desirable for someone with a smaller bank account because they are readily available and cheap. The LSX only solves the problems associated with the SBC for those who had trouble building a SBC, nobody else, and that is because the heads already flow good. This hobby doesn't revolve around that type of enthusiast though, it's just the enthusiast with his or her own opinion. Same can be said for those unsuccessful with the third gen in general, you'll read plenty of how third gens suck because they failed at building one. Plenty of SBC's out there that flat out annihilate the LSX, whether naturally aspirated or boosted, just takes money to do it, and by money I mean investing in very good parts, not porting stock garbage, and not buying AFR heads used or on sale. Funny how FasterProms just finished building a C6 LSX package for a customer who wants low tens, high nines, yet his dad's C4 from the 90's made less power on their dyno yet runs faster than the LSX he just built.. As for boost, don't imply the LSX will take 30-psi of boost pressure and live after 100 runs being daily driven simply because it is an LSX, they break online all the time when pushed too hard. Meanwhile a Grand National LC2 engine will do just that in terms of boost and then some, and its' LC2 3.8 is a prehistoric old school Buick 350 less two cylinders, with even less head bolts than the SBC. Go figure. But I digress...

Whatever makes the individual happy in the end.

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Old 02-21-2019, 05:42 PM
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Re: Critique my plan for my engine

The piston cast alloy used in turbocharged 2L and 3L engines which traditionally produce 150hp/liter (and in some cases more) from the factory for 300,000 miles. Is more or less the same piston material found in factory truck LS engines. That is, they are brittle materials which fracture without any sign of being about to do so. Therefore I see no problem with 5L engines using the same materials to achieve even 100hp/liter (to 150/liter) for the same mileage. I think the reason we have any reliability list at all is because this is nearly possible the way people run them. However there are a few key features which many build(ers) miss that reduce the lifespan of their LS engines. I will name a bunch now:
1. they run it without an air filter (shudder)
2. they run it without PCV action (reduced crankcase pressure) during boost
3. they let the exhaust gas temperature rise too high/do not monitor
4. they let the piston get too hot/ are not aware

for example;
The 2 and 3L turbo engines making 150hp/L have piston oil squirters.The intended function is to help remove heat from a fragile cast piston.

Done right, the LS turbo has a water system tied to the EGT system to prevent the piston from overheating, to serve as a pseudo replacement for piston oil squirters.
E85 serves this function but at low power there is no need for such extravagant (fuel cost/source method/containment/quality issues) and since water systems are traditionally methanol compliant anyways it makes sense to use 30% (washer fluid) to 50% methanol in the water injection system to improve octane of 93 pump fuel. If more people were careful with these small details the rate of piston failures would be even lower than it is.
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Old 02-22-2019, 08:58 AM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post

The compression ratio is low to begin with and many engines already with 100,000 will have even less compression with slight wear is ideal for turbo applications which scavenge exhaust energy in order to impart some kinetic energy unto incoming air molecules which sort of makes up for the 3-4% the engine lost due to mileage.
You are missing it utilizes enthalpy from the exhaust as well. It is recovering waste heat.

I am not really sure why you are in the TPI section if you are so dead set on the LS. There are sites for that. We get it, it is newer technology. There is also major hurdles in the swap process many do not want to deal with. There is a lot about the Engine Management System the older crowd doesn't know and doesn't want to learn just to have a fun hot rod. This is why to this day, we still have people ripping TPI units off. The LS is an overall an unattractive engine IMO. Parts are more expensive the SBC. If you change something, it often requires a tune. Everyone isn't trying to build a 500+hp motor, and don't care too much about what the potentials are if they are never going that far. They want something they know and trust.

It's not like the LS is the BEST engine in the world either, actually doesn't even appear on the 12 best engines of the last 20 years according to the International Engine of the Year Awards. The new LT's surpass it in technology and everything else you mentioned. So why are you stuck in the past on LS architecture? Move up to LT man.
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Old 02-23-2019, 07:07 PM
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Re: Critique my plan for my engine

Originally Posted by KyleF View Post
You are missing it utilizes enthalpy from the exhaust as well. It is recovering waste heat.
It doesn't 'recover' waste heat like a power plant. The heat isn't used in succession with a second power plant, or fed back into the mouth of the original furnace. All the heat energy recovered is used to spin the compressor wheel. Which in and of itself does absolutely nothing. There is no rule which says the compressor needs to be connected to the engine at all, or that it is even compressing air. Maybe we use it to generate electricity. Or maybe we just want to slow down the flow of exhaust molecules. In other words, there is no 'recovery' of the energy, either implied or guaranteed. None of the extracted heat energy from the exhaust directly functions to increase engine efficiency unless we somehow derive a means (which is what I posted originally, via kinetic energy of intake air, that is the true recovery action which I mentioned already) to put that energy to work somewhere else. In fact just the act alone of having the turbine in the way of exhaust flow acts as a restriction should reduce engine efficiency slightly, by itself is no means of recovery whatsoever.


Everyone isn't trying to build a 500+hp motor, and don't care too much about what the potentials are if they are never going that far. They want something they know and trust.

It's not like the LS is the BEST engine in the world either, actually doesn't even appear on the 12 best engines of the last 20 years according to the International Engine of the Year Awards. The new LT's surpass it in technology and everything else you mentioned. So why are you stuck in the past on LS architecture? Move up to LT man.
I think the minimum power today for a hot rod is 500hp. If you have anything less it won't even compare or keep up with modern 4-cylinder cars.
The LS is the only platform where 500hp base model engines happen to cost roughly the price of a cam swap- around $300-$500 each. Its a cost issue, not a "which engine is better' issue. Some people are busy spending more than that on their intake manifolds to make less power. Ridiculous.
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Old 02-23-2019, 07:28 PM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
It doesn't 'recover' waste heat like a power plant. The heat isn't used in succession with a second power plant, or fed back into the mouth of the original furnace. All the heat energy recovered is used to spin the compressor wheel. Which in and of itself does absolutely nothing. There is no rule which says the compressor needs to be connected to the engine at all, or that it is even compressing air. Maybe we use it to generate electricity. Or maybe we just want to slow down the flow of exhaust molecules. In other words, there is no 'recovery' of the energy, either implied or guaranteed. None of the extracted heat energy from the exhaust directly functions to increase engine efficiency unless we somehow derive a means (which is what I posted originally, via kinetic energy of intake air, that is the true recovery action which I mentioned already) to put that energy to work somewhere else. In fact just the act alone of having the turbine in the way of exhaust flow acts as a restriction should reduce engine efficiency slightly, by itself is no means of recovery whatsoever.




I think the minimum power today for a hot rod is 500hp. If you have anything less it won't even compare or keep up with modern 4-cylinder cars.
The LS is the only platform where 500hp base model engines happen to cost roughly the price of a cam swap- around $300-$500 each. Its a cost issue, not a "which engine is better' issue. Some people are busy spending more than that on their intake manifolds to make less power. Ridiculous.

Where are are you getting the idea that itís only 3-500 dollars for a 500 horsepower engine? Maybe just for the engine itself, but a decent turbo kit, engine mounts, transmission and driveshaft among other things(nevermind tuning) will raise the cost, even if you do all the labor yourself and can fab your own hot and cold sides for the turbo kit.
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Old 02-23-2019, 07:50 PM
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Re: Critique my plan for my engine

Originally Posted by Richardman1992 View Post



Where are are you getting the idea that itís only 3-500 dollars for a 500 horsepower engine? Maybe just for the engine itself, but a decent turbo kit, engine mounts, transmission and driveshaft among other things(nevermind tuning) will raise the cost, even if you do all the labor yourself and can fab your own hot and cold sides for the turbo kit.
Yes, the longblock is the main concern for mileage/reliability. Everything else, the mounts, driveshaft, wiring, etc... is a set and forget deal. You won't ever 'break' a driveshaft or engine mounts or wiring if its done right. Anything that needs maintenance will require the same OEM service whether it has 100hp or 500hp, so take the 500. The engine is the soft spot, the replaceable entity. They pretty much all will handle 500 easily, those $500 engines are rampant.

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Old 02-23-2019, 08:47 PM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
It doesn't 'recover' waste heat like a power plant. The heat isn't used in succession with a second power plant, or fed back into the mouth of the original furnace. All the heat energy recovered is used to spin the compressor wheel. Which in and of itself does absolutely nothing. There is no rule which says the compressor needs to be connected to the engine at all, or that it is even compressing air. Maybe we use it to generate electricity. Or maybe we just want to slow down the flow of exhaust molecules. In other words, there is no 'recovery' of the energy, either implied or guaranteed. None of the extracted heat energy from the exhaust directly functions to increase engine efficiency unless we somehow derive a means (which is what I posted originally, via kinetic energy of intake air, that is the true recovery action which I mentioned already) to put that energy to work somewhere else. In fact just the act alone of having the turbine in the way of exhaust flow acts as a restriction should reduce engine efficiency slightly, by itself is no means of recovery whatsoever.




I think the minimum power today for a hot rod is 500hp. If you have anything less it won't even compare or keep up with modern 4-cylinder cars.
The LS is the only platform where 500hp base model engines happen to cost roughly the price of a cam swap- around $300-$500 each. Its a cost issue, not a "which engine is better' issue. Some people are busy spending more than that on their intake manifolds to make less power. Ridiculous.

You are wrong. Exhaust gas is hot, it's energy left over by the chemical reaction of burning fuel. One of the many reasons ICEs are not 100% efficient. Hot gasses expand and will flow.

It's a law of thermodynamics, conservation of energy. The heat and flow energy is captured by the turbo. Although not 100% efficient either, it uses this energy to do work on the incoming air, it's work is compression. This is also why turbos heat air, it's the energy that goes into the incoming air. Some is compression and some is extra heat due to inefficiencies in the turbo. Can be controlled by staying in the compressors efficiency curve based of PSI and CFM.

Another law is following systems moving to higher states of disorder. Heat expanding gasses is one of these examples and getting to atmosphere is part of this too. Entropy/Enthalpy is part of why Turbos work.

I am not debating you, this is fact.

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Old 02-23-2019, 08:58 PM
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Re: Critique my plan for my engine

Turbos - good link to read.

"Due to expanding the exhaust gas of the engine in the turbine, it generates the turbine power that depends on the mass flow rate of the exhaust gas through the turbine and the isentropic enthalpy drop in the turbine."
Just so we are clear, heat makes gas expand.
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Old 02-23-2019, 10:30 PM
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Re: Critique my plan for my engine

Originally Posted by KyleF View Post
You are wrong. Exhaust gas is hot, it's energy left over by the chemical reaction of burning fuel. One of the many reasons ICEs are not 100% efficient. Hot gasses expand and will flow.

It's a law of thermodynamics, conservation of energy. The heat and flow energy is captured by the turbo. Although not 100% efficient either, it uses this energy to do work on the incoming air, it's work is compression. This is also why turbos heat air, it's the energy that goes into the incoming air. Some is compression and some is extra heat due to inefficiencies in the turbo. Can be controlled by staying in the compressors efficiency curve based of PSI and CFM.

Another law is following systems moving to higher states of disorder. Heat expanding gasses is one of these examples and getting to atmosphere is part of this too. Entropy/Enthalpy is part of why Turbos work.

I am not debating you, this is fact.
You are just missing information, please relax as I am working on PhD mech and graduate teaching assistant, I would not give you bad information knowingly or try to deceive unless I thought it was really really funny and worth the time. Please read,

Just because I put a turbine in an exhaust stream and it spools up, doesn't mean I've recovered any energy. How does that help your engine get better fuel economy? You put a pinwheel in the exhaust, okay great, now what.

If I blow on one of those little toys, does it make my body more efficient? Where is the efficiency really coming from?

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Old 02-24-2019, 08:04 AM
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Re: Critique my plan for my engine

Originally Posted by Kingtal0n View Post
You are just missing information, please relax as I am working on PhD mech and graduate teaching assistant, I would not give you bad information knowingly or try to deceive unless I thought it was really really funny and worth the time. Please read,

Just because I put a turbine in an exhaust stream and it spools up, doesn't mean I've recovered any energy. How does that help your engine get better fuel economy? You put a pinwheel in the exhaust, okay great, now what.

If I blow on one of those little toys, does it make my body more efficient? Where is the efficiency really coming from?

It is because of BSFC that a given displacement uses. Smaller engine = less overall fuel consumption. This is why they use displacement on demand systems now and part of the reason a 485hp 4300lb Challenger can get 25mpg cruising on the highway.

Turbos do the same thing, your little 2.0L starts to move air at a rate much greater than a Naturally Aspirated version. Fuel is also increased for the added air flow.

Most turbo cars are considered more efficient because the car itself uses a smaller engine when you are not using the power.

I don't care if you are working on you PhD. If this isn't your area of study, you may not know any more about a given topic than a Freshman in high school.

I have worked in the Powertrain department for two OEMs. Waste heat from the combustion process heats the exhaust pipes, heads, block, oil... and so on. The engine would be a lot more efficient and produce a lot more power if it didn't have to lose heat. Like I said above, conservation of energy.

The engine itself can't spool a turbo just off the force coming from a piston shoving the exhaust gas out. Every system has inefficiencies, If the engine was both converting fuel into motion and heat, plus spooling a turbo, the turbo would not be receiving enough energy to compress the air enough (put energy in) to increase the output of the engine. The added energy come from expanding gasses and hot gasses trying to vent to atmosphere. You have the piston shoving the gas out, gas expanding, and heat trying to escape that spins the turbo. Turbos are also not 100% efficient either. Nothing is.

Also, I should add their is a velocity component from the piston movement and expanding gas.


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Old 02-24-2019, 08:38 AM
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Re: Critique my plan for my engine

I see you are ignoring the questions.

If you blow on a toy, you do not become more efficient.
The same way an engine blowing on a turbine does not recover any energy. The engine is experiencing exhaust gas backpressure due to the turbine which can actually take energy FROM the engine.

The only thing a turbo does with that energy, is what I said
Originally Posted by Kingtal0n View Post
... turbo applications which scavenge exhaust energy in order to impart some kinetic energy unto incoming air molecules...
It literally says in my quote that turbo application scavenge exhaust gas energy, and why they do it. Now please tell me how this is anyhow misleading or missing information.
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Old 02-24-2019, 09:12 AM
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Re: Critique my plan for my engine

I'll try to summarize

your statement
Originally Posted by KyleF View Post
You are missing it utilizes enthalpy from the exhaust as well. It is recovering waste heat.

A turbo does not utilize heat directly. If you hit a turbo with a torch, it will not spin because of that.
A turbocharger harnesses the kinetic energy of air molecules. The force of them against a turbine while also moving from an area of high pressure to an area of low pressure drives the turbine.
They do not necessarily need to be 'hot'.

Because kinetic energy is lost from air molecules, the temperature could drop as a result. Temp of air molecules is related to their velocity. Even if air simply collides with pipe that is cooler, energy is lost (exhaust radiates heat energy whether there is a turbine or not, and cools gradually). If you consider that the purpose for the heat was necessary to drive the turbine then you might be tempted to say 'the turbine needs the heat' however a turbine could still work fine at low temperature exhaust gas pressure gradients (Such as when the car is started 100% cold in cold weather, the exhaust is barely 300*F and it will still make plenty boost). The only thing that really improves with higher temperature is efficiency, but that goes for every thermodynamics engine. For example the gasoline car engine cruise at 225*F will yield better economy than 180*F. It is the reason the newer cars all seem to rise to higher coolant temperatures (efficiency = reduced emissions).

In performance applications, the heat component isn't completely necessary and in fact heat is often unwanted/discarded. For example Water injection limits EGT on purpose to control turbine inlet temperature and piston surface temp. Water will reduce power because it absorbs energy, it puts out fires. The maximum inlet temperature for modern turbochargers is often around 1380*F (for example that is borg warner's exact number) so if you coat and insulate the system it will need even more auxiliary cooling. The turbine could be configured to work with high OR low temperature exhaust gas, for example they work in rear mounts quite well where there is very low temperature. So whether it was hot or cold, the exhaust gas is expanding (due to volume not temperature, when temp drops the gas shrinks so it needs to expand from volume far more than it shrinks from lost temperature) through the turbine to an area of low pressure (away from the exhaust valve is lower pressure) is driving the turbine, 'recovering energy' from the exhaust gas- but not specifically heat related. The temp may only change from 300*F to 265*F in a rear mount application at 800rwhp. Not very much 'heat' was necessary to achieve the desired compressor wheel speed.

So now we have to talk about the actual efficiency component of turbocharging. I've already said it was all based on kinetic energy of air molecules- but HOW does that actually improve economy? An engine doesn't magically become 'more efficient' just because we put a turbine on it. Like we already know that adding a turbine increases exhaust gas backpressure which would take energy FROM our combustion engine. So we need a really good reason to use one, and how/why does this do anything for us?
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Old 02-24-2019, 03:25 PM
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Re: Critique my plan for my engine

So before I jump to why turbochargers improve economy which I've remember numerous times on other forums so I will link those as well when I find. But before I do that lets talk about BSFC because alot of people throw that word around without realizing a subtle implication.

If you we look on a injector flow paper:


Notice that the turbo application always has a poor BSFC compared to N/A application. And supercharger is even worse.
This is always true for every injector calculator, every fuel quality, every engine. The Brake specific fuel consumption in reality goes down in turbocharger application for every engine.

Why this happens: because the more fuel we throw away (in heat) the safer the engine becomes. It isn't necessarily bad to have a high BSFC- its just wasteful and expensive.

That BSFC rating is intended for wide open throttle. That is not a cruise rating or anyhow involved in highway economy considerations. Maybe highway isn't important for you though. Cruise bsfc might be higher than NA in a cruise situation- but the paper doesn't say that because there are special factors, extremely small insignificant factors involved in why turbochargers might improve economy and its the barest sliver of almost nothing. They depend on the size and construction of the compressor wheel and other things, like if you need an intake system or not. Some cars just have turbo-engine with nothing in between at all. That will put the maximum kinetic energy into the engine intake manifold when the throttle body is wide open (as if it didn't exist, we ran it without a TB) But that is only wide open throttle situations. That is only for the low BSFC situations. In other words, If the engine has ambient temperature air and higher pressure before the throttle body, that means more collisions per unit time on the outside of the throttle blade. It means more air molecules/time get into the intake manifold, so the driver demand will decrease in order to compensate for the additional air, intake manifold vacuum will be higher and the car will return to steady state cruise. If you disconnect the wastegate now and let it flop open the kinetic energy of incoming air will decrease and driver demand will need to increase as the air is less dense, slightly less pressure, pretty much same exact temperature. The difference between pre and post throttle body pressure becomes a greater difference, the more efficient the engine we usually say is overall. It is tempting to say that the increased air density and reduced driver demand makes the engine easier to 'breath', However, with a higher vacuum in the intake manifold now, and less throttle position, the intake valve opens up and experiences a deeper vacuum. Less air molecules enter the cylinder while the intake valve is open. Also there is a slight increase in resistance to pull the piston down, since now it has to pull to bdc against a greater vacuum. So the pumping losses are actually higher when the engine becomes more efficient on the intake stroke it looks like.

Can I remember what the actual benefit was for a minute. Oh right, if you have tons of plumbing like intercoolers and long pipes etc... or an application that NEEDS long pipes like underwater car or something. Then the turbocharger is good at saving the energy costs of moving all that air through those pipes. But that is just ridiculous to say that the engine is working harder without a turbo and it has all that pipe in front of it. You see the intake manifold ALWAYS exists, we take it for granted right. Every engine has an intake manifold. So the system for pressure over intake valves starts and ends there. If there is more vacuum, then the piston works harder to go down. Just like if there is more vacuum in the crank case, its harder for the piston to go up. And isn't it funny that extremely efficient engine oil systems often run a heavily vacuumed crankcase with a very low pressure? Wet sump oil systems can only go down so far before the vacuum in the crankcase affects oil flow through the engine. The benefits are a whole other chapter- but for now realize that having kinetically charged (mv^2)/2 liquid molecules (air is a liquid) being shot at the throttle body when the engine is trying to cruise is going to make it less efficient on the intake stroke. So why then do they get better fuel economy anyways? There is something else helping conserve energy but if not the intake then where? Compression would be the same. We are interested in the cost to rotate the physical parts of the engine (and drivetrain) at this point. Compression/Combustion is the same because driver demand was reduced to compensate for the additional air molecules getting past the throttle body due to the higher pressure of turbocharging so the same number of air molecules are going in still and air-intercooling at low flow rates (highway cruise) will allow near-ambient temp air into a performance engine. The difference with timing would be negligible, every engine wanders with some small error, which is why I never use the same timing number in adjacent cells. I don't see any help yet. Finally exhaust. The exhaust stroke is more difficult in turbo application because of increased exhaust gas pressure most of the time. This is actually the coolest part about turbo though. Higher EGP means there will be pseudo compression on the exhaust stroke, which will help hold the rod to the crankshaft through that cycle. Thus making the engine always have a cushion for every TDC event and achieve high rpm. Although this clearly takes energy (it takes more energy to compress more stuff I am sure of that) the benefit of being able to go high RPM with oem rod and rod bolt is priceless to using stock engines. So every cycle in turbo seems to be a loss, BSFC is worse across the board, but bsfc being poor isn't a bad thing if you can afford it.

A pressure drop AT the intake manifold, AT the throttle body, you can't possible get an closer to the intake valve than that because every engine has a valve and a intake manifold. And the piston creates it so that is where it winds up one the piston is moving/moved down the BDC. It works against intake vacuum. Any/extra vacuum in the crankcase would assist though so that is one way crankcase vacuum might help economy. But it comes at the cost of intake vacuum, since a strong intake manifold vacuum is what drives a strong pcv crankcase vacuum during highway cruise. That is, crankcase vacuum can never go lower than whatever the intake manifold can provide.
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