When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
That does seem true, as was it seemly true for the 2000 Mercury.
BUT A 281 Ford will not fit into my van.
It's true for virtually any reasonably streetable vehicle. There is nothing special about the 2000 Mercury that made it perform differently than other domestic V8 vehicles.
Not sure why you're explaining the details of how you've added 1500 lbs to your van.
I believe you that the Pulse width was lower at 3000 than it was at 2000. Who knows if it was "same conditions" (you don't), but even assuming that it was, do you think it's possible that the injector is firing more times per unit of time at 3000 RPM than it is at 2000 RPM?? :bigears: THINK, now.... So if it's firing 33% more pulses in a given period of time....is the pulse width greater than 33% shorter?
I can't believe that this needs to be explained, but here goes: the reason why I said to compare pulse width at 2000 and 3500 (or what ever numbers you pull out of your *** for "better fuel economy"), no load/in neutral, is because that is a somewhat controlled situations; The only load on the engine is it's own friction. Therefore, 100% of the fuel being burned is being converted into heat -no work is being done. Therefore, you can compare the diff in engine friction/waste at one RPM and any other RPM....and you know that 100% of the difference, is wasted fuel; it's added fuel that did no work, other than to create more heat. You came back with some cockamamie story of climbing some hill....we don't know that the conditions are the same while you're doing your comparison and you likely don't either, because you've introduced a barrage of variables. But if you KISS and just look at an engine at idle, 2000 RPM, 3000 RPM, 4000 RPM and so on, you can literally SEE with your eyeballs, the increase fuel used to get to those RPM's. And you can see that 100% of that additional fuel is doing nothing but making heat.
A corresponding amount of additional fuel is required to drive down the road at 4000 RPM vs. 2000 RPM (or whatever RPM's you want to pick)....and that is why OEM's have OD ratios in the transmissions. Because the OEM's all know, that at a lower RPM, the vehicle will consume less fuel. Someone (the people who build these vehicles) have already figured this out for us. :yesnod:
Absolutely do not agree...I have owned two Titans. One had 2.96 gears. The other had 3.36 gears. Everything else was identical. Over 50K miles in each the 3.36 geared truck consistantly got better MPG. Lower RPM does not mean better fuel mileage in all cases. But keep thinking the OEMs have it spot on in every case. I assure you they do not. I had a very torquey V8 in my M56S. I never even used 7th gear until 80+ MPH. The engine was too lugged to pull the car against the 2.62 rear gear.
I already told you that I calculated PulseWidth x RPM and got numbers for both. The total number was slightly lower at 3,000 rpm compared to 2,000 rpm on flat road. I only used OD above 75 mph.
Lugging is defined as where the engine does not respond to additional throttle at lower rpm because it cannot overcome the load of the gear it is pulling against.
So if you're pulling a hill in your van, you're at 3/4 throttle, 4000 RPM and you go from 3/4 to WOT...and nothing happens....that's "lugging"? It is, by your definition b/c it does not respond to additional throttle at lower rpm because it cannot overcome the load of the gear it is pulling against.
Right?
Originally Posted by Fast355
Lugging absolutely is a thing. Just because I can put my 6 speed in high gear at 15 mph doesn't mean it has the power to move the car.
I could program my 4L85E to shift into the next gear at 1000 rpm but it would probably stall going into the next gear.
What does that mean? 1000 RPM is "lugging"? Or after it shifts, and "stalls"? IDK what you're talking about here. I don't think you do either. What is lugging? How does that relate to this thread, where racprops said 1700 was "lugging" and going to get worse mileage?
So if you're pulling a hill in your van, you're at 3/4 throttle, 4000 RPM and you go from 3/4 to WOT...and nothing happens....that's "lugging"? It is, by your definition b/c it does not respond to additional throttle at lower rpm because it cannot overcome the load of the gear it is pulling against.
Right?
What does that mean? 1000 RPM is "lugging"? Or after it shifts, and "stalls"? IDK what you're talking about here. I don't think you do either. What is lugging? How does that relate to this thread, where racprops said 1700 was "lugging" and going to get worse mileage?
In your first case it absolutely would be lugging. For example if I were driving my G35 it would downshift and swing the tach toward its 7,500 rpm redline. Car would accelerate like a bat out of hell because it is making alot more torque to the wheels and more HP.
1,000 rpm would be lugging if your torque demand was greater than the engine could output.
The OEMs now use a torque model for drivetrain output. The engine and transmission controllers work together to deliver the desired output torque requested from the drivers foot on the throttle.
I have had a 383 TPI in a low top G20 van with 3.07 gears. 1,700 was lugged. Would have been better with a 3.73 or 4.10 gear.
But keep thinking the OEMs have it spot on in every case. I assure you they do not
Where did I say that? You'll have to quote where I said that so that I can correct it. What I ACTUALLY said was:
A corresponding amount of additional fuel is required to drive down the road at 4000 RPM vs. 2000 RPM (or whatever RPM's you want to pick)....and that is why OEM's have OD ratios in the transmissions. Because the OEM's all know, that at a lower RPM, the vehicle will consume less fuel. Someone (the people who build these vehicles) have already figured this out for us.
They don't have it nailed every time....I didn't say that. Of course you can probably cherry pick some odd ball or BS example. But OEM's spent the money to add OD's in car's 40 years ago...why? B/c it provides better fuel economy....that's why.
.
Originally Posted by Fast355
I already told you that I calculated PulseWidth x RPM and got numbers for both. The total number was slightly lower at 3,000 rpm compared to 2,000 rpm on flat road. I only used OD above 75 mph.
Yes you did. But you haven't comprehended the whole picture. I'm guessing the pulse width number wasn't 33% lower, was it? No, it wasn't. But the injectors are firing that "slightly lower" amount, 33% more times! Which means it's used more fuel. I think your calcs were off. Or your too many variable test. Or something else. KISS. Kiss.
Last edited by Tom 400 CFI; May 13, 2020 at 05:16 PM.
In your first case it absolutely would be lugging.
Yeah? 3500 RPM and it's "lugging"? I don't think that your definition of "lugging" matches mine...or most anyone else's.
Originally Posted by Fast355
For example if I were driving my G35
Holy ***....another anecdotal tall tale! It never ends! You must own a Hertz lot!
Originally Posted by Fast355
it would downshift and swing the tach toward its 7,500 rpm redline. Car would accelerate like a bat out of hell because it is making alot more torque to the wheels and more HP.
No chit? Really? And that tells us....what?
Originally Posted by Fast355
1,000 rpm would be lugging if your torque demand was greater than the engine could output.
What about 7500 RPM? What if your G35 where towing a Semi (at 7500 RPM) got to a hill and started slowing down? Is that lugging? B/c, the "torque demand was greater than the engine could output", right?
Originally Posted by Fast355
The OEMs now use a torque model for drivetrain output. The engine and transmission controllers work together to deliver the desired output torque requested from the drivers foot on the throttle.
IDK WTF this has to do with anything. That true on stick shift cars too?
That is true with Fuel Injection, my old Studebaker would buck at lugging speed which for it was 3rd with OD drive at 40/45MPH and 1200RPMs.
I used to fool other drivers with my seemly having a 6 Speed transmission in 1964, by taking off in First then dropping 1St with OD, Seeming hitting second as I was gear splitting, then shift to the real 2ND gear with OD OFF, so that seemed to be 3RD…then I dropped into 2nd OD or seemly 4th.
OK no big thing 4 speeds were common even then.
BUT THEN I dropped into my real 3RD without OD, or OMG 5TH!!!???
Then to put the icing on the cake I dropped into 3RD OD making that 6 gears.
NOW when I add one of the ODs to my 4L60e it will allow me to have the use of 8 Forward Gears.
Granted I will just normally drive with the standard 4 gears accelerating to speed and just drop into over drive when I can use 5th. BUT say I am climbing a long hill, well then I have a number of lower gears, like 2nd AND THEN OD or 3rd and then OD to select a better gear and RPM for the Climb.
Well I did forget my original question: Lowering the power curve of the TPI...So If I had one inch spacers made to go in-between the tubes to the plenum and the intake so that it added 2 inches to the leanth of these tubes would that push the tuned power band downward??
Well I did forget my original question: Lowering the power curve of the TPI...So If I had one inch spacers made to go in-between the tubes to the plenum and the intake so that it added 2 inches to the leanth of these tubes would that push the tuned power band downward??
Rich
Yes, it should move the tuned rpm lower. Not sure it would fit though. There isn’t much clearance between the runner and valve cover.
That and the two flanges aren't parallel, so the spacer would have to be more complex than a 1" spacer. If this was really important to make happen, then I think an easier approach would be to attach relatively straight runners to the base, that extend out, over the valve covers, then have two plenums and two throttle bodies. Similar to this:
That and the two flanges aren't parallel, so the spacer would have to be more complex than a 1" spacer. If this was really important to make happen, then I think an easier approach would be to attach relatively straight runners to the base, that extend out, over the valve covers, then have two plenums and two throttle bodies. Similar to this:
....but with longer runners like this:
Something like that would not fit. That LH carb would be trying to occupy the same space as the accelerator and the RH carb the same space as the ac box.
To get the kind of torque you want for your setup you really should look at the belt driven intake manifold family.
I had a Weiand 177 on my TBI 350 at one point with the stock cam. Fuel economy was excellent. At lower RPM it made about 5-6 psi of boost instantly and peaked about 10 psi @ 5,500 rpm where the stock swirl ports and stock cam started choking it. I had plenty of torque to pull OD with the 3.07 rear gear. However I can say from first hand experience a 700r4 or 4L60E will not take kindly to abusing the overdrive like that. I blew up 4 very well built units in just over a year. Low rpm + massive torque will fry one very quickly. But hey apparantly I don't know what I am talking about. I am out. Hope your build goes as planned.
Something like that would not fit. That LH carb would be trying to occupy the same space as the accelerator and the RH carb the same space as the ac box.
I can't believe that this needs to be explained to you....but here goes: The pipes could be bent.
Ya know, man? They don't have to look exactly like the pipes in the picture. Right? It was just to share a point. An idea. A design phiolosophy. Do you understand what that means? In the pic that you supplied, I can see a bunch of room over the valve covers. Can you see that space, using your eyeballs? Do you think a smallish plenum could fit above those covers? Then what if you unbolted the TPI runners from the plenum, grabbed them w/your hand and bent them away from the TPI plenum, over to your new plenum? Or maybe bend them away from the stock plenum, just over/clearing the valve cover, then curve up...into the bottom of your new plenum? Can you visualize that? Can you "see it"? The OP was asking about ways to package longer runners. With a little brain activity, a person could see that is a way, that it could be done. I think it's easier than spacers that won't work...but none of this matters b/c it appears that the OP likes his spacer idea.
You said that earlier in the thread, back in post #37 when you admitted that you needed physics lessons:
You should make good on that promise. :thumbs:
I am not the one that needs a lesson. I am up on physics and how EFI works. Also built enough stuff that I understand how this stuff works. My **** runs exactly how I want it to run and does exactly what I built it to do. I am just done trying to explain how GEARING is going to make the single biggest difference in his application.
You keep putting words in my mouth that I never said. Kuddos to you key board warrior.
I am going to sit back and watch this whole build fail in an expensive manner.
Figure on flat land his high top van is going to require atleast 80-100 hp to run 70-75 mph. My Express van is in the 75hp range at 75 mph on flat land to overcome rolling resistance and aerodynamic drag. Calculate the torque required to make that HP at the RPM his tires are turning per mile. That will give you an idea on what the engine will need to make torque wise with whatever gearing he chooses. As I said before it is easier to get to the required torque value with more leverage aka gearing. Less load on the engine means you can run a much leaner mixture which is much less pulsewidth. You argued about that as well when I have plenty of data that suggests otherwise.
My buddies 6.0L Chevelle has gotten close to 30 mpg running 70 mph. It has a 4L80E and 4.10s. Lean cruise engages at 25 mph and doesn't ever shut off unless he is heavy on the throttle.
FWIW...This is a screenshot of a datalog of a high top G-van with 3.42 gears and a 4L60E. Its a 93. Upgraded with a stock vortec 350 and a performer carb intake with a 46mm TBI unit. The guy was having problems after two different tuners worked with it before me. It had a very bad flat spot around 60-70 mph. This was trying to maintain 65 mph up a slight incline. I kept pulling timing advance out of the tune to try to kill the detonation that kept happening. Eventually pulled the timing nearly all the way back to TDC and it still knocked. The only fix was for the trans to downshift to get the engine up into its powerband. It really needs 4.10s. This build is not reinventing the wheel. I have already tried to tune for it with poor results. All more cylinder pressure is going to do is increase the tendency for the engine to knock on 87. Its fortunately not my money or my problem how this build turns out. I would almost suggest a stock TBI 454 before trying to cobble together a 383 with TPI on top. The 454 TBI makes peak torque at 1,600 rpm and in 454 SS trim (dual exhaust and a little more timing) it was 405 ft/lbs worth of it. Grumpys old 454/TH400 truck was getting 17 mpg in lean cruise with no overdrive back in the day when he was an EBL Beta tester. At 7.8:1 compression the TBI 454 will happily make all its torque on 87 octane as well. I mentioned a 500 Cadillac earlier as well. Those blocks are very high nickle and make tremendous off-idle torque. With an aluminum intake the 500 cadillac is only about 50 lbs heavier than a cast iron small block. The only other engines that make great off-idle torque are the 455 buick, pontiac or oldsmobile engines. The Buick was torque king of the muscle car era, next to the daddy of all the 1970 500 cadillac at 550 ft/lbs. I had a 472 cubic inch Cadillac in a 1980 K20 on 35s with 3.73s and a TH400. It was an OEM 5.7 Diesel truck that I bought with a blown up diesel. 472 or better a 500 bolted right to the BOP TH400 in those trucks. With a Q-Jet it frequently saw 17 mpg and would smoke those 35s all the way through 1st gear. Also done a port fuel injected 500 in a GMC Motorhome to replace the weak kneed 403. 500 was better on gas than the 403 and had way more power.
Well this is interesting, after so many years looking and talking about all of these ideas, at this point of having fully committed to this build, NOW I am getting hard data about the engine, load and transmission weakness.
And some info on Lean Cruse.
Seems Fast355 and Tom 400CFI got into a bit of an argument/competitive deal over this.
Interesting. You have made me concerned about what I will get with this engine.
Gentlemen, can I ask if you both can take a really good hard look at the cam specs and variable Rhoads lifters setup I am building along with fully roller 1.6 rockers, stock 193 swill port heads, a stock 400 Crank, Teflon coated skirts KB D shaped Pistons, 9.5 ratio, and ceramic coated piston crowns and combustion chambers and answer a few questions:
Consider that at low 1500 to 3000 RPMs my valve train will be detuned to a milder cam profile, thus at cruse I will NOT be making gobs of torque. I am hoping for enough to pull/push the van at the highway speed it has been able to maintain with the 100K+ stock engine, while drawing 14MPG it seems to get under all conductions.
Granted on a run from Phoenix AZ to Sedona AZ a couple of years ago, which involved a number of hills and she would down shift from OD into 3rd, she did manage to maintain 80 and 85 MPH keeping up with a number of cars and trucks. Running at around 3500 she was all in and at nearly full or at WOT, there was no more power to be had. And of course MPG went out the window then. None the less the overall readings were 14MPG.
Under such conductions I have NO intention of trying to hold her in OD, at least not the stock OD gear, I think I will be running in the 4L60’s 3rd and perhaps running with the hard geared Borg Warner OD or just 3rd alone.
Fast355 points out the weakness of the 4L60’s overdrive, and how he burned up a few. So is a 4L80 Stronger??
How strong is the 4L60s third gear, will it last being run a lot in hill climbing?
I get the impression Fass355 has a very powerful hot rod engine that easily overpowers his 4L60s, and wonder if he upgraded it??
Tom 400 CFI points how he believes my van has a high top, it is only a ½ high top, I even at 5.6 cannot stand fully up in it, and only mostly just behind the front seats, it is a mild streamline top. Plus with the ground effects lower section that unbelievable really works, as this is the only Van I have owned (out of some 4 and over decades) that does NOT GET PUSHED/BLOWN around by Big Rigs at speed. I believe she has less wind resisting than a normal van, at least enough to help.
As for Lean Cruse how lean can I consider to be able to run on this engine?? On my 2000 4.6 291 Ford she peaked at 16.4 and lost ground over that. I seen hints of your Chevys reaching 16/17 and perhaps more, so with iron or aluminum heads?? Any with ceramic coated pistons and heads?
And I am aware lean cruse will be pushing chamber temps high and am looking into adding more EGR at cruse to both lower temps, displace incoming charges, and helping lower pumping loses making the driver to put in more throttle lowering the vacuum loading. I feel this will have to be manually controlled as I do not think the PCM could be tuned for this. I see this as a manual override vacuum controlled system and may need a small vacuum PUMP to allow this control as it will LOWER the engines vacuum thus losing the vacuum needed to maintain this control.
Fast355 said “Figure on flat land his high top van is going to require at least 80-100 hp to run 70-75 mph. My Express van is in the 75hp range at 75 mph on flat land to overcome rolling resistance and aerodynamic drag. (HOW DO you get that reading) Calculate the torque required to make that HP at the RPM his tires are turning per mile. (I cannot do that math, so what is the Torque needed???)
Fast355 also said: “That will give you an idea on what the engine will need to make torque wise with whatever gearing he chooses. As I said before it is easier to get to the required torque value with more leverage aka gearing. Less load on the engine means you can run a much leaner mixture which is much less pulse width.”
I take it by “it is easier to get to the required torque value with more leverage aka gearing. Less load on the engine means you can run a much leaner mixture which is much less pulse width.” (that I do have test gear to read)
Your saying higher gears, IE more RPMs…in other words running your engine at its sweet spot which with most engines would be near its torque peak. Correct??
I am trying to first make that sweet spot lower as in around 2000 RPMs and thanks to the Lifters to have that more or less run in a near flat power curve/band from 1500 to 3000 at which point my cam will switch over to the HP band to say 4500RPMs.
So can both of you, arm chair this setup and give me you best guess’s how this will perform with a TBI and a TPI set up??
Thanks for you for your interest and input.
Rich
Note the front end is a little higher due to bricks under A Frames to lift tires of road.
Here are my numbers for the transmission with the extra Over Drive:
Here is an idea of the customized Borg Warner Over Drive:
OK here are a few picture of what I am thinking will work. Sadly my only set of vale covers are currently in the machine shop's hot tank.
So without them I cannot see the clearance between them and the intake tubes.
BUT using 1/2 inch nuts as spacers I can clearly see that as far as the TPI Intake is concerned, I can clearly add 1/2 inch spacers adding a total of one full inch to the runners.
IF I can add 3/4 an inch making for a 1.5 added to the runners or perhaps adding one full inch to each end of the runners making for a full 2 inches longer runners I will need the valve covers to test for clearance.
And the million dollar question is what effect each of these added spacers will do to the power band??
Well, we've found some common ground. This, I can agree with.
Originally Posted by Fast355View Post
I am going to sit back and watch this whole build fail in an expensive manner.
Major BS: So you really cannot answer my questions...so you say that!!
The ONLY fail I can even think of is it MAY NOT product over 20+ MPG highway.
All other indicators are improve the power to weight/load ratios and you can improve the MPG, as I am building an engine for both low RPM service AND mid and top RPM power I believe I cannot fail to have a better running engine/van.
You guys throw around some impressive BS about your engines but when push came to shove dropped out.
You cannot predict what will happen with this build.
And the million dollar question is what effect each of these added spacers will do to the power band??
Virtually nothing. An additional 1" will lower the 3rd harmonic by 140 RPM. It would put your at 3360 RPM instead of 3500 RPM. You can do the math yourself and find out, but that is precisely why I suggested an entirely different intake configuration; to give you the added runner length that you'd need to get the tq peak down where I think you say you want it.
N x L = 84,000, where N represents the desired engine rpm to tune for and L is the length in inches from the opening of the ram tube to the valve head.
84000/2800 (I think that's the RPM you wanted?) = 30". You'll need to add about 5-6" to get there.
Originally Posted by racprops
You guys throw around some impressive BS about your engines but when push came to shove dropped out.
You cannot predict what will happen with this build. Negative nellies.
I don't think that's the case. I know that I've given you my opinions; DIESEL. I don't think that you're going to get an ROI on this effort. I can't see it happening. As a hobby/project, it could be fun/interesting, but to end up money ahead on fuel saved vs. engine build cost, I don't think it's going to happen.
Originally Posted by Fast355View Post
I am going to sit back and watch this whole build fail in an expensive manner.
Major BS: So you really cannot answer my questions...so you say that!!
The ONLY fail I can even think of is it MAY NOT product over 20+ MPG highway.
All other indicators are improve the power to weight/load ratios and you can improve the MPG, as I am building an engine for both low RPM service AND mid and top RPM power I believe I cannot fail to have a better running engine/van.
You guys throw around some impressive BS about your engines but when push came to shove dropped out.
You cannot predict what will happen with this build.
Negative nellies.
I can absolutely predict what will happen. If you can ever get the engine to pull the load at the RPM you want it to the 4L60E will fail shortly after. They 700r4/4L60E pump is not capable of making enough line pressure at ultra low rpms to keep it from burning up the thing. The extra OD will only be useful on extremely flat roads or downhill. With all the cylinder pressure you plan on running to get this massive amount of low-end torque you will be constantly fighting detonation. Detonation will quickly pound your rod bearings flat and break the ring lands off your pistons.
I have already tried to explain to you that running the RPM you want to cruise at is impratical for your aerodynamic load.
There are some programs you can download and put real life information into that will deliver fairly accurate data. Will provide acceleration graphs, fuel economy graphs, etc. You can even specify ambient temps, weather conditions, road conditions and simulate a multitude of scenarios.
One such program is Car Test. Another one is a fuel economy calculator marketed by the company that created engine analyzer.
If you model your engine with engine analyzer you will see that it will show a knock index. Anything over 1.0 is detonation likely. Your build shows a knock index near 2.0. It will likely need propane or E85 to keep it from detonating.
I almost forgot about an extremely durable engine with an ample reserve of low speed torque. It would likely run on your factory TBI system with minimal changes. It has factory 4 bolt main caps on every main cap. It has a factory forged and nitrided crankshaft. It has factory forged and shot peened rods. It has has cylinder heads that outflow vortec heads by a healthy margin. It also has pistons with 4 rings for better seal and longer life. With its low compression ratio, thick cylinder walls, over built lower end and massive cooling system it would not mind being lugged down to the RPM you are wanting to cruise at. You could probably run it WOT at 1,500 rpm for 500K miles and it would still keep on trucking. What is this engine you ask..How about a tall deck 366. Worked on many in 2 ton trucks that had well over 300K on the odometers. The next best thing to a diesel is a low stressed big block.
Virtually nothing. An additional 1" will lower the 3rd harmonic by 140 RPM. It would put your at 3360 RPM instead of 3500 RPM. You can do the math yourself and find out, but that is precisely why I suggested an entirely different intake configuration; to give you the added runner length that you'd need to get the tq peak down where I think you say you want it.
N x L = 84,000, where N represents the desired engine rpm to tune for and L is the length in inches from the opening of the ram tube to the valve head.
84000/2800 (I think that's the RPM you wanted?) = 30". You'll need to add about 5-6" to get there.
Thanks.
I don't think that's the case. I know that I've given you my opinions; DIESEL. I don't think that you're going to get an ROI on this effort. I can't see it happening. As a hobby/project, it could be fun/interesting, but to end up money ahead on fuel saved vs. engine build cost, I don't think it's going to happen.
IF I was just pulling a good running engine I would agree. BUT I loss a oil cooler line and then lost an engine.
The main part of this engine was started back in 2001.
So I am not spending about $3000.00 to add all the UP grades.
So it was swap in a old used junk yard engine or use what I had already started and add to it want I always wanted.
Overall I totally believe this will be a great engine for the van. And IF it gives me 20+ MPG I will be happy.
I can absolutely predict what will happen. If you can ever get the engine to pull the load at the RPM you want it to the 4L60E will fail shortly after. They 700r4/4L60E pump is not capable of making enough line pressure at ultra low rpms to keep it from burning up the thing. The extra OD will only be useful on extremely flat roads or downhill. With all the cylinder pressure you plan on running to get this massive amount of low-end torque you will be constantly fighting detonation. Detonation will quickly pound your rod bearings flat and break the ring lands off your pistons.
I am aware of the lower limit of running below 1500 RPMs for both the transmission pump and th torque convertor, I have said my plan is 1700 to 1900 RPMs.
I have already tried to explain to you that running the RPM you want to cruise at is impratical for your aerodynamic load.
There are some programs you can download and put real life information into that will deliver fairly accurate data. Will provide acceleration graphs, fuel economy graphs, etc. You can even specify ambient temps, weather conditions, road conditions and simulate a multitude of scenarios.
I have never been able to find those, so please point me to them.
One such program is Car Test. Another one is a fuel economy calculator marketed by the company that created engine analyzer.
If you model your engine with engine analyzer you will see that it will show a knock index. Anything over 1.0 is detonation likely. Your build shows a knock index near 2.0. It will likely need propane or E85 to keep it from detonating.
One: I did debur the chamber and it is getting a cermanic coating
I almost forgot about an extremely durable engine with an ample reserve of low speed torque. It would likely run on your factory TBI system with minimal changes. It has factory 4 bolt main caps on every main cap. It has a factory forged and nitrided crankshaft. It has factory forged and shot peened rods. It has has cylinder heads that outflow vortec heads by a healthy margin. It also has pistons with 4 rings for better seal and longer life. With its low compression ratio, thick cylinder walls, over built lower end and massive cooling system it would not mind being lugged down to the RPM you are wanting to cruise at. You could probably run it WOT at 1,500 rpm for 500K miles and it would still keep on trucking. What is this engine you ask..How about a tall deck 366. Worked on many in 2 ton trucks that had well over 300K on the odometers. The next best thing to a diesel is a low stressed big block.
WOW and what is the cost and can it be found in any junk yard??
Thanks, do wish you have told me all of this last year.
But I am committed come what may.
Rich
PS I also was told the idea of coasting downhill in neutral is also very bad to the transmission.
Last edited by racprops; May 14, 2020 at 01:35 PM.
N x L = 84,000, where N represents the desired engine rpm to tune for and L is the length in inches from the opening of the ram tube to the valve head.
Whoops. My bad. In that case, you'll be looking for a runner that is ~84000/1800 (I think that's the RPM you wanted?) = 46" long. You'll need to add about 20" to get there. Yikes.
Note the base line performance. This set up made GOOD torque at 2000 RPMs. In fact only 32FT LBs LESS that at its peak of 328FT LBs at 3000 and all the way to 3500 RPMs.
This engine also made 112HP at 2000RPMs.
Now it seems to the torque peak IS at 3000 to 3500RPMs.
Torque ranges and peak is mainly controlled by the cam.
I will have a cam that will lower that peak to closer to 2000RPMs.
The TPI intake works great from 2000 to 3500RPMs.
I just want to help lower that 3000 downward, so I get a crude reading of the tubes running about 20inches from the plemium to the intake valve. That is not including the space from the throttle body its self.
I have seen all kinds of raiser blocks for carbs, and throttle body injectors (even for the TBI injectors them self's)and another throttle bodies, all claiming to improve power, most of these wonder devices avg. about 1 inch.
SO I kind of think (Unless all such stuff is PURE BS) adding 1 to two inches to this intake should have more effect that that.
Note the base line performance. This set up made GOOD torque at 2000 RPMs. In fact only 32FT LBs LESS that at its peak of 328FT LBs at 3000 and all the way to 3500 RPMs.
This engine also made 112HP at 2000RPMs.
Now it seems to the torque peak IS at 3000 to 3500RPMs.
Torque ranges and peak is mainly controlled by the cam.
I will have a cam that will lower that peak to closer to 2000RPMs.
The TPI intake works great from 2000 to 3500RPMs.
I just want to help lower that 3000 downward, so I get a crude reading of the tubes running about 20inches from the plemium to the intake valve. That is not including the space from the throttle body its self.
I have seen all kinds of raiser blocks for carbs, and throttle body injectors (even for the TBI injectors them self's)and another throttle bodies, all claiming to improve power, most of these wonder devices avg. about 1 inch.
SO I kind of think (Unless all such stuff is PURE BS) adding 1 to two inches to this intake should have more effect that that.
Please re-figure your numbers.
Rich
If you were still able to make 296 ft/lbs @ 1700 rpm that is only 95 hp at the crank. Turn on your a/c, your headlights, your stereo to put a load on the alternator and throw in the driveline loss. See the problem, because I do.
"If you were still able to make 296 ft/lbs @ 1700 rpm that is only 95 hp at the crank. Turn on your a/c, your headlights, your stereo to put a load on the alternator and throw in the driveline loss. See the problem, because I do."
Dude!! I am NOT running a old '99 Corvette 350. I will be running a brand new 383, which just that change gives noted 10% MORE HP and Torque. So by that alone I could have 325 FT LBs of torque and 105HP@ 1700 RPMs.
Of course that is at WOT on a Dyno. real world power to be seen at cruse, but the van, as all cars/trucks and Vans seem to get down the road nicely on light throttle, as did this van. With the A/C running full blast along with all the electrical stuff as well.
I am only looking for 6 more MPG.
By the way how long is the runners for say a standard TBI intake??
The numbers my be slightly off, the the formula is still a good tool. Things like temp, atmospheric density and other factors can more the resonant frequency one way or the other, slightly, but "every thing being equal. the tool works. If you want to make peak tq at 1800 Rpm like you claim....and you want to take advantage of the "TPI TORK monster" effect, then you're going to been longer runners. A LOT longer.
Also, IDK what motor was in that test....not a stock one. Changing parts, cam especially, will move the power peaks...but may not move the resonant frequency of the intake manifold. So that motor may well have made peak tq at a slightly different RPM (250) than the resonant frequency of the intake. No enough info on the motor and test.
Originally Posted by racprops
Note the base line performance. This set up made GOOD torque at 2000 RPMs.
See below. The LT1 short runner intake made more tq at 2000 RPM and below, than the TPI intake? Why? B/c the TPI intake doesn't "work" or do anything any better than any other intake at those low speeds.
Originally Posted by racprops
The TPI intake works great from 2000 to 3500RPMs.
No...the TPI intake works great from ~2800 RPM to about 3800 RPM. It doesn't work at all, at 2000 RPM. How can we tell? By comparing it to an intake that is tuned out of the operating RPM range; the TPIS mini ram or the LT1 intake. Let's have a look....
....You can see the benefit of the TPI/long tube intake here; it runs from ABOUT 2500 up to ABOUT 3500. Below and above, it's doing nothing any differently or special, than any other intake.
Originally Posted by racprops
I have seen all kinds of raiser blocks for carbs, and throttle body injectors (even for the TBI injectors them self's)and another throttle bodies, all claiming to improve power, most of these wonder devices avg. about 1 inch. SO I kind of think (Unless all such stuff is PURE BS) adding 1 to two inches to this intake should have more effect that that.
Two things wrong with this:
1. your deductive process is broken and doesn't work.
2. Those part ARE mostly worthless BS. They can work on carbs and TBI....but for totally different reasons that what we're talking about here. Here, we're talking about the resonant frequency of a tube (runner) of a specific length, from the intake valve, to the mouth of the tup where it mets a box (aka "Plenum"). Note that I said nothing about the TB or the length of the plenum, b/c those dimensions aren't meaningful to this discussion.
Originally Posted by racprops
Please re-figure your numbers.
No. You refigure them. I gave you the formula. Time for you to "fish" on your own.
By the way how long is the runners for say a standard TBI intake??
What's that got to do with anything? They're not tuned to any specific RPM in the normal operating range. It's not a "tuned" intake. You need to read this article for yourself. READ THIS
If you’re trying to make more power at low rpm under partial throttle openings you have to concentrate on reducing pumping loss. These are two pretty good reads.
I can’t find the info, but I’m pretty sure it was a guy that was on the GM R&D and engineering team back in the day that said the reason for the change from the long runner TPI to the short runner intake was twofold. One, the shorter runners had less pumping loss compared to the TPI and was more fuel efficient at the RPM used for testing fuel economy. Two, the shorter runners made more top-end power so the marketing department could advertise a 300HP Vette. Which kinda goes hand in hand with the dyno comparison Tom posted.
If you’re trying to make more power at low rpm under partial throttle openings you have to concentrate on reducing pumping loss. These are two pretty good reads.
I can’t find the info, but I’m pretty sure it was a guy that was on the GM R&D and engineering team back in the day that said the reason for the change from the long runner TPI to the short runner intake was twofold. One, the shorter runners had less pumping loss compared to the TPI and was more fuel efficient at the RPM used for testing fuel economy. Two, the shorter runners made more top-end power so the marketing department could advertise a 300HP Vette. Which kinda goes hand in hand with the dyno comparison Tom posted.
WOW great info. THANKS
I have read that adding EGR can help with pumping losses by forcing more throttle dropping engine vacuum.
Also do you know what the RPM that was used for MPG testing?
I have read that adding EGR can help with pumping losses by forcing more throttle dropping engine vacuum.
Also do you know what the RPM that was used for MPG testing?
Rich
I am guessing its a drive cycle similar to an IM240 emissions test where the vehicle is driven on the dyno in cycles of acceleration, steady throttle, coasting and deceleration to duplicate both urban and highway driving. The dyno applies the appropriate load to simulate vehicle weight, hills, etc.
I have read that adding EGR can help with pumping losses by forcing more throttle dropping engine vacuum.
Also do you know what the RPM that was used for MPG testing?
Rich
EGR can help mileage by helping reduce pumping losses however when using lean cruise it will contribute to misfiring and not allow you to run as lean as you could without it. Lean cruise itself greatly reduces pumping losses. The mixture burns slower, reducing torque, which makes you increase throttle to compensate.
Here is a current production marine L31 350 power chart from Kodiak marine. Uses the cross ram L31 marine intake, 395' roller cam and cast marine shorty style header manifolds with cats. Torque curve is very flat and well above what an OEM TPI or LT1 makes. Marine engines are net rated very similarly to cars/trucks however they have less restrictive intakes and exhauat systems that typically have 4" piping although cooling water also exits with the exhaust.
If you’re trying to make more power at low rpm under partial throttle openings you have to concentrate on reducing pumping loss.
Originally Posted by racprops
help with pumping losses by forcing more throttle dropping engine vacuum.
This is the opposite of using higher RPM and a more closed throttle to achieve better mileage. Higher gearing/lower RPM and a greater throttle opening reduces pumping losses. And friction.
Here is a current production marine L31 350 power chart from Kodiak marine. Uses the cross ram L31 marine intake, 395' roller cam and cast marine shorty style header manifolds with cats. Torque curve is very flat and well above what an OEM TPI or LT1 makes. Marine engines are net rated very similarly to cars/trucks however they have less restrictive intakes and exhauat systems that typically have 4" piping although cooling water also exits with the exhaust.
Agree...as well as less accessories with typically "under driven" pulleys (compared to typical cars), virtually no intake system and are run at much lower temps. The only meaningful diff between the "Net" marine method and GROSS hp is the flame arrestor, water pump and alternator.
That thing IS making a lot of tq above about 1500 RPM to ~3800 though. What is a 395' cam?
Agree...as well as less accessories with typically "under driven" pulleys (compared to typical cars), virtually no intake system and are run at much lower temps. The only meaningful diff between the "Net" marine method and GROSS hp is the flame arrestor, water pump and alternator.
That thing IS making a lot of tq above about 1500 RPM to ~3800 though. What is a 395' cam?
Boats have a power steering pump, 2 water pumps, and alternator as well as a fairly restrictive wet exhaust system.
395 is the GM marine cam that was recycled by GM performance into the Ramjet 350 and HT383.
It is 196/206 @ .050, .431/.451 lift, 109 LSA and 106 ICL. The earlier versions of the Ramjets got 1.6 full roller rockers with it.
My MasterCraft doesn't have a steering pump. No inboards do, that I'm aware of. Good point about the two water pumps though.
Looks very close to the stock L31 Vortec cam.
I wonder if the water cooling the exhaust, offsets the volume and/or restriction that the water itself, presents?
I have messed with stern drives not inboards for the most part. The Alpha and Bravo drives use GM power steering pumps.
Not sure on the exhaust it is certainly possible.
The couple of marine engine setups I have run in vehicles with a recalibrated GM 0411 have both run well above their marine ratings. It is entirely possible my road tunes run more timing than a marine tune allows.
My 496 H0 cammed 8.1 with headers makes about 450 crank. The 350 Marine setup in my Express van with a little head work and 1.7 rockers made about 340 hp or so. 8.1 was rated about 425 hp. 350 was rated 300.
Boats have a power steering pump, 2 water pumps, and alternator as well as a fairly restrictive wet exhaust system.
395 is the GM marine cam that was recycled by GM performance into the Ramjet 350 and HT383.
It is 196/206 @ .050, .431/.451 lift, 109 LSA and 106 ICL. The earlier versions of the Ramjets got 1.6 full roller rockers with it.
Interesting:
My cam will be:#806 cam’s Specs; 207/214 @.050 117 440/454 lift with 1.6 Rockers (milder rockers)
I will be running Rhoads V-Max roller lifters, and with Rhoads Lifters running at 10% reduction the cam will be:
180/192 117 .396/408 at low RPMs yet at 3000/ 3500 will be running the full cam’s 207/214 @.050 117 440/454.
This will give me a variable cam, mild at low RPMS and HOT at higher RPMs.
I think such a set up should lower the torque peak near 2000RPMs at low RPMs and open up the cam around 3000 RPMs which will give me a big power boost.
Next to a custom grind cam the best thing that one can do is run the GM 395 marine cam and TBI heads. Lots of low-end torque with that cam and TBI heads. Dual plane intake with TBI will make more off-idle torque than the TPI.
Earlier you said the above: Can you provide any charts showing Dual plane intake with TBI will make more off-idle torque than the TPI??
Most MPFI domestic ~5.7L V8's from the '80's and '90's make just shy of 300 ctq at 1000 RPM. To me, tq at 1000 RPM is "off idle", because it's just, you know....off idle. The ones that came with dual plane intakes (L05's and Ford EFI 5.8 truck motor) were not exceptional in any way. If anything, they were consistently worse.
The original purpose and continued use of the dual plane philosophy for V configuration engines was to improve air/fuel mixing, throttle response, and drivability by improving signal at the carb. I believe the 180*, or dual plane intake was developed on/for the Ford Flathead V8 in 1934, to solve low speed tq, throttle response and drivability issues with the obvious carburetor fuel mixer of the time. SEE PAGE 13 & 14. That's a lot of history, but the purpose is to clarify the reason for the dual plane's existence; the carburetor. Once you move to EFI and you don't need a "signal" at a carb booster, there is no reason to plumb the 4 runners into 1/2 a plenum, and 1/2 a TB.
Note that by "long runners" they're contrasting that to the carb'ed single plane intake. Looking at a typical SBC dual plane intake, you can clearly see that the runners are about 5" long or so....not at all what we would call a "long tube runner" intake where the TPI uses 21" runner IIRC, from runner mouth to head flange. Additionally the dual plane is not "tuned" for a 3rd harmonic in a typical operating range. Certainly not "off idle". The tq building characteristics are;
1. In comparison to a single plane intake with carbs and due to the stronger signal through the carb (when using a carb)
2. Due to runner cross section.
Last edited by Tom 400 CFI; May 15, 2020 at 11:23 AM.
So does a dual plane intake help with a TBI system?? And adding spacers also help with such a set up?
As I will be running a TBI system for break in, IF it works great overall I will more likely leave it as a TBI. The swap to TPI will be major.
Thanks for still helping.
Rich
Originally Posted by Tom 400 CFI
^2
:bigears
Most MPFI domestic ~5.7L V8's from the '80's and '90's make just shy of 300 ctq at 1000 RPM. To me, tq at 1000 RPM is "off idle", because it's just, you know....off idle. The ones that came with dual plane intakes (L05's and Ford EFI 5.8 truck motor) were not exceptional in any way. If anything, they were consistently worse.
The original purpose and continued use of the dual plane philosophy for V configuration engines was to improve air/fuel mixing, throttle response, and drivability by improving signal at the carb. Once you move to EFI and you don't need a "signal" at a carb booster, there is no reason to plumb the 4 runners into 1/2 a plenum, and 1/2 a TB.
Note that by "long runners" they're contrasting that to the carb'ed single plane intake. Looking at a typical SBC dual plane intake, you can clearly see that the runners are about 5" long or so....not at all what we would call a "long tube runner" intake, and also not "tuned" for a 3rd harmonic in a typical operating range. Certainly not "off idle". The tq building characteristics are;
1. In comparison to a single plane intake and due to the stronger signal through the carb (when using a carb)
2. Due to runner cross section.
BOTH have tuned port intakes very much the same as GMs TPI.
Pretty much all OEM's have been using a "TPI" or a tuned intake manifold since the 90's. There are a few exceptions, but they are....few.
Originally Posted by racprops
So does a dual plane intake help with a TBI system?? And adding spacers also help with such a set up?
As I will be running
How could a dual plane intake help, compared to a LTR intake? It's got shorter runners that aren't tuned in the engine's operating range. It's got a convoluted path for the fuel to follow. It forces cylinders to inhale through only one bore of the TB. Doesn't seem like a winner, to me. They dual plane TBI system was/is clearly a BUDGET system/recycling of parts/design, to meet criteria. They didn't make TQ and they didn't make HP. Not low, not high, not anywhere. A spacer could help by allowing cylinders to pull through both TB bores but all the other problems remain.
You're not Phoenix, are you? You sound a LOT like. Penix...
Pretty much all OEM's have been using a "TPI" or a tuned intake manifold since the 90's. There are a few exceptions, but they are....few.
How could a dual plane intake help, compared to a LTR intake? It's got shorter runners that aren't tuned in the engine's operating range. It's got a convoluted path for the fuel to follow. It forces cylinders to inhale through only one bore of the TB. Doesn't seem like a winner, to me. They dual plane TBI system was/is clearly a BUDGET system/recycling of parts/design, to meet criteria. They didn't make TQ and they didn't make HP. Not low, not high, not anywhere. A spacer could help by allowing cylinders to pull through both TB bores but all the other problems remain.
You're not Phoenix, are you? You sound a LOT like. Penix...
I am in Phoenix AZ but I am not Penix...
So a Dual Plane Intake will not make a better feed for a TBI which is just a pair of injectors on top of a carb like throttle??
