neat

Hi, I've been lurking here for awhile and was looking for some high HP L98 combo's. What I am looking for is a streetable car, that my wife can drive, that makes 425+ RWHP. I just sold a 1992 corvette with an LT1 based 383 stroker that made about 390 RWHP on engine alone, and 475 RWHP with nitrous. Something similar to that, but with some more kick on engine would be great. I would also like the ability to spray upwards of 150 HP of N20. I know that is asking for a lot, but I think it can be done with the right recipe of parts. The ultimate goal is 600 RWHP on juice. No real goals as far as ET or MPH are concerned, just looking to make 600 on the bottle.

MattL98TA made similar numbers to what I am looking on engine, and is one of the few I have found that lists his entire engine combo on a web page. So, what are some reliable and prooven methods to make 400-450 RWHP?

Thanks!

89gta383

iTrader: (5)

Why are you hung up on rwhp numbers? What do you want to run in the 1/4?

The l98 isn't that different from the lt1 you put together if you use a miniram or stealthram or lt1 intake, good heads, and big cam.

neat

I don't go to the track much, and I just want a car that is fun to drive. I street race a little, usually from a roll, so the 1/4 mile ET isn't really that important to me. MPH would be, but that should be pretty good in a stock weight F-body with 600 RWHP. On top of that, I live where the DA is usually about 10k, so any 1/4 mile times I get will be vastly skewed from what the rest of the world see's. My corvette (the one with 370 RWHP) struggled to break into the 12's at 110 mph here. At sea level it would trap 119 pretty consistently, and I even hit 121 a time or 2.

So, any tried and true methods to do what I am looking for?

Stekman

I could list a combo, but I am pretty sure you can't afford it.

Do a search. You aren't the first to post up one of these "show me the high hp combinations. I'm looking for blah blah power"

Here, I'll make things easy for you. Click the smiley. <A HREF="https://www.thirdgen.org/techbb2/search.php?s="><IMG SRC="https://www.thirdgen.org/techbb2/images/smilies/search.gif" BORDER="0"></A>

But, to keep it half-@$$ed fair, what is the budget.

neat

The car is a 1991 Corvette. It's got a McLeod clutch, cryo treated ZF6, and carbon fiber half-shafts so the drive train "should" hold up to the power.

As far as engine budget goes, 10k is probably the limit. Maybe a tad over, but not much. I was really looking onto a 427 stroker kit from lunati, but I think that might be overkill for what I want to do. I have also kind of found that with big inch small blocks, finding heads to support that kind of size is kind of difficult (and expensive). It also get's harder to keep the engine streetable. I don't want something that I have to rev to 7.5k to see the power. Maybe a large displacement SBC with silghtly undersized heads to keep the peak HP down to reasonable RPM is the way to go? Thoughts?

Anyway, I did a search and have been watching the board for a couple months now. I appreciate your trying to help, but the condescending attitude, assuming I can't afford what "you" would build, and treating me like I know nothing beacuse I am "newbie" is uncalled for IMO. I am not new to cars, nor am I new to the internet scene dealing with cars. I am however, new to the L98. Any constructive input would be greatly appreciated.

MrDude_1

brodix 18* heads
hogan FI intake
comp cam solid roller.



then you'll only need a 50shot to make 600

neat

What cam specs? How often would I have to adjust the valve lash on a solid roller car that is driven 1k a month? Untouched or ported Brodix heads? What kind of streetability would that yield me? Compression ratio? Displacement? Brand of and type of rotating assembly?

Gotta get some more details!

Thanks! :thumbs:

MrDude_1

if you're serious, the obvious question is, how much money do you have?

the heads:
out of the box, they should flow almost,if not over, 300cfm. if you have the money to have them ported you will without doubt have heads capable of the power you want.

for the cam:
if you're planning on large doses of nitrous, id go for a split pattern cam..
somthing like a 234/244@.050 with 114LSA and around .600 lift.
10:1 compression to stay pumpgas compatible without pulling timing (and power)
if you wanted a "L98" id assume it would be a 350 or 383.... athough id startout with a 400... and if i had the money, a Motown 415 or 427.

however, the intake alone would set you back more then alot of guys on here paid for their heads... lol.

Stekman

350 block, factory 2 bolt mains
bored .030" over
indexed lifters
vented lifter valley
forged crank (your choice)
forged rods/Carr bolts (your choice on rods)
Choice of bearings
JE lightweight pistons, custom cut to reflect the combustion chamber (18°)
Brodix 18x cylinder heads
~12:1 static compression, ~9:1 dynamic (pump gas friendly)
Solid roller valve train (about 240/250° @ .050", just under .600" lift)
Jesel or T&D shaft rockers
Jesel belt drive
Balancer (fluidamper, etc)
The rest is just parts

Since you want EFI probably, go with a custom EFI setup. Use the Brodix intake and tap the nitrous bosses for fuel injectors. Run something like the Accel 1000 cfm TB. Or get something from FAST or similar company. Run this on a stand alone system. It's nothing flashy, but it get's the job done. Of course, probably not the most cost efficient route. I would build that in an aftermarket block.

The thing about the L98 is this. In the stock form, the intake and the heads do not have the flow ability to support the engine at those power levels. You could have the heads ported and the intake extrude honed, but it wouldn't exactly be worth the cost.

If you want 400+ cubes out of a small block (the 427) Your best bet is an aftermarket block like the Mowtown or Dart block. a 427 is a 4" stroke. With the 6" rods that are required, maybe longer, you've got limited room for compression height before the piston pokes out of the hole. Aftermarket blocks also have tighter machining tolerances than factory blocks.

Other than that, there isn't too much of a difference between the Gen II and the Gen I chevy. if the 350 block is what you have, look to a large hydraulic roller cam and a 383. Don't skimp on cylinder heads. I highly advice AGAINST using the factory castings.

*edit* D*** looks like MrDude was thinking what i was.

Scott 88 GTA

I guess the real question is, what do you define as an L98? IMO, the combinations suggested by the others are so radical that they could not be considered an L98.

What I typically think of as an L98 is the long tube runner (stock style) intakes, or the SuperRam. HSR is borderline. Minirams are too close to an LT1 to be considered an L98 IMO.

If you're looking to make 400 RWHP on motor (NA) with a long runner intake, good luck. I don't believe it's been done yet. With a SuperRam or HSR it's definately possible with the right combination of parts.

What is it you're looking for?

neat

Right now I have an L98 in the vette. I'd like to use the stock block, but I am not opposed to using the miniram or other intakes. The HSR won't clear my hood, so that isn't an option. I don't want to build the engine to just make good numbers on N20. I would rather build the engine to make good power NA, and then just let the N20 numbers fall where they may. After all, 99% of the engine's life is going to be NA.

This is what I was thinking, let me know what you guys think:

Miniram intake
AFR 195's, ported locally by Chapman racing enigines
Hydraulic roller cam, 232/242, .565/.575, 114 LS
Forged 3.75 inch stroke crank
6 inch 4340 rods
Thick crown N20 friendly pistons, final compression ratio of about 10.5:1
.030 overbore
Total seal rings, gapped appropriately for N20 use
Various bearings and gaskets
Assembled by myself

That should get me dang close shouldn't it? I should also be able to come in under 6k, which would be great. Like I said 10k is about the limit of the "fun" money for this year, and having some coin left over for other things that might go wrong would be great.

I am seeing brodix heads mentioned quite abit. I haven't done much reserach in the direction of Brodix, and always assumed AFR was the best head out there, all though outrageously over priced IMO. Trick flow's heads seem to come really close to the AFR's every time I see a comparison on the same engine, and they are a lot less expensive. I'll have to look into the brodix heads.

The main thing that I am not sure on is the heads, and cam shaft selection. I went through hell picking the cam on my old LT1, and never did get it quite right. I tried 2 off the shelf grinds, and 2 custom grinds from comp cams and I never did realize the potential of that engine. I don't want a repeat of that, lol.

Lots of people have told me to flow the heads I choose, and pick a cam based on the flow numbers. Then the same people say that all flow benches are different, and comparing heads from one bench to the next is impossible. If all benches are different, how can I choose a cam based on the numbers my local flow bench gives?

Thanks for the info guys, I really appreciate it!

FWIW, I have spent a bunch of time using the serach engine and haven't come up with anything. Maybe I am using the wrong search terms, anyone got some sugggestions on what to search for?

Stekman

Do a search for a thread titled "Lets talk 500 hp N/A" or something along those lines.

Orr89RocZ

iTrader: (20)

It would probably be best to run a 383 or 396 L98 with superram and a supercharger like Procharger or even better, a twin turbo setup.
The turbo would be custom job and more expensive, but have seen many 80's vettes done this way from Callaway or just custom done. Then spray on that if you need it.

This would ultimately be your best bet for streetability and high horsepower numbers. The fastest pump gas street cars in America run turbos and superchargers and can maintain good enough gas mileage and streetability to drive to the track and run into the 9's. Thats good enough for 700 rwhp+.

neat

I really considered forced induction before deciding on N20. A buddy and I just finsihed up DIY twin turbo on his 331 stroker Mustang. It made 606 at the wheels, and is pretty streetable. His McLeod twin is a bit rough, but not too bad. Other than that, it is basically exactly what I am looking for. BUt...

There are a couple reasons I decided to steer clear of forced induction. Number one is cost. Like you mentioned, it wil cost more. I have an exhuast tube bender, and MIG and TIG welder's but the cost of the turbo's, and the systems to support them adds up quickly. The boost controller, wastegates, igniton system with boost retard, BOV, etc... A supercharger kit is also expensive, especially if you add in the cost of a cog drive system to cure the belt slip issues.

N20 will make just as much power, be easier to install, and the initial investment is considerbaly less. The car will have all the streetability of a 425 RWHP car, and also be able to make 600 RWHP when I want it to. All with the factory AC intact, something that is impossible on a C4 with a custom turbo kit, or a supercharger.

Stekman- NA and HP are too small to work in the search funtion, and "lets see 500" returned no results. I did search for 400, 425, 45, and 500. I found one thread of some value:

https://www.thirdgen.org/techbb2/sho...&highlight=450

If you are able to find more please post the links.

Thanks everyone!

camarojoe

I'd say that a good way to make 400rwhp on a (Dynojet) is my combo or Matt87GTA's combo, which is practically the same. I put down 375 with about 50 degs total timing, so I know there's more power in it once I dyno it again with the right initial timing.

neat

Do you honestly think there is another 50-75 RWHP in the engine by adjusting the timing? The most I have ever seen on a dyno is about a 30 RWHP gain. If there truly is that kind of gain to be had with your combination of engine parts, then I will seriously look at what you and Matt have done. before i commit to copying your set-up though, i would have to see the dyno numbers after the timing was adjusted.

Looking at your combo, the heads are what stick out to me. A 220 cc head seems awfully large for a 383. However, the combo seems to work well, and merits some more research on my part. Anyway, could I get you to send me a copy of your dyno graph? I am kinda interested in the peak HP RPM, and the way the graph looks under the peak.

joshkinzey@comcast.net

If you were looking to squeeze out just a little more power, what would you change in your combo?

Drkhrse89

iTrader: (1)

Matt87GTA is one of my friends and his car is ***** to the wall. His is a all forged 383 with ported Brodix heads that flow like mad, almost 300 cfm on the intake side. Here is his buildup page. He has also done extensive work to every other aspect of his car and tons of prom tuning. But this car does run like a raped ape.

neat

I sent you a PM with a couple questions about Matt's car.

Matt87GTA

Here I am! :lala:

neat

Kick ***, thanks for dropping by. There has to be someone else who has achieved the numbers you have. You can't be the only one, lol.

Is there anything you would change about your combo?

Matt87GTA

A couple small things would complete this package, IMO.

First, stay away from Ross pistons if you don't want to hear piston slap. It seems their pistons are all noisey to some extent and mine are REALLY noisey. I would go with something like the SRPs instead.

Next, get the compression a little higher. Mine is at 10.7:1 and it seems like I could easily run more since I never see any knock at all on 92 octane - never. I would like to have about 11.2-11.5:1.

I also would go with a .040 or .060 bore instead of the .030. Pricing is all the same for .030, .040, and .060 over stuff for the most part and it is just plain "free" horsepower" at that point. I've even heard of people running factory blocks .080 and .100 over before on the street with no cooling problems so there is no worry with going at least a little bit bigger. Maybe do the .040 over so you have room for one more rebuild....

Skip the big hydraulic cam and go with a solid roller. Even with the same specs it would slaughter a hydraulic cam on things like throttle response and peak usable RPM. But I would definately go a little bit bigger. Something in the 250* range with about .620" lift along with the higher compression and the slightly larger bore (hey, every bit helps) would probably put this combo close to 600 Hp at the flywheel......

I will probably be doing all of those things with mine over the winter as I just about cannot stand the damn piston slap of those Ross pistons and I would like to dial in those other changes while I am in there.... I think I could do the solid roller swap and sell off my hydraulic roller stuff and come out pretty much even so the only real cost will be machine work, gaskets, and a set of pistons and rings. Not bad for a possible 100 more Hp and a quiet engine (especially on cold starts!).

Then there is this 150 Hp NX Shark nozzle kit I just happened across.......

D's89IROCZ

I don't mean this as a hyjack .....its a dam good thread ! I was just wondering ( author ) when you set a goal of 600 hp like that ..... what do you feel you base it all on ....a set of heads ....the cam ... the intake . I know they all have to work in a certain way together ..... It's just what is the proverbial "square one " . You mentioned how you have a definate role for the car ...so I was wondering is there more than one way to get to your goal ( N/A ...witha shot of giggle gas) Like a real hyper non streetable setup ....or something alot more civalized . SO how do you pick the comprimise?



Good luck man .... I wanna setup like yours you are figureing out ....I just gotta have a first born son ....so I can give him away for the price of what you are asking

neat

Square one is deciding what you want to do with the car. Then decide what kind of power you'll need to get there. In my case, a certain power level was my goal, associated with good street manners. No ET requirements, no top speed, nothing like that. 425 RWHP on engine, and 600 RWHP on juice. Anything more than that is just gravy.

After displacement is decided, I think the heads are square one. All the power comes from the heads, IMO.

D's89IROCZ, for future reference, a private message would of answered all of your questions, with hijacking my post.



(please don't respond to this guys, let's try to stay on topic)

No one ever did respond to my combo. What do you guys think?

Miniram intake
AFR 195's, ported locally by Chapman racing enigines
Hydraulic roller cam, 232/242, .565/.575, 114 LS
Forged 3.75 inch stroke crank
6 inch 4340 rods
Thick crown N20 friendly pistons, final compression ratio of about 10.5:1
.030 overbore
Total seal rings, gapped appropriately for N20 use
Various bearings and gaskets
Assembled by myself

Is that enough to get me to 425 RWHP NA? And will it hold 600 a couple times a month on juice?

Matt87GTA

It should be pretty close. Probably not much more though.... I think the cam and heads will be a little on the small side for more than 425 RWHp though..... But I could be wrong.... Lots of setups surprise me all of the time.... The LSA seems a bit wide unless you are shooting for a more torque oriented power band or want a smoother idle at the price of some high RPM power...

[Edit: Nevermind, N2O use noted..... cylinder pressure, etc.]

I really would go with a solid roller though (and larger than what you have listed).... Can't stress that enough .

Are the AFR 195s laying around right now or something? Any reason you can't go with something else (cough, Brodix, cough cough....lol)?

What kind of car is this anyways? Transmission, rear axle gear ratio, etc.?

neat

The car is a 91 corvette. Cryo treeted ZF 6 speed, McLeod clutch, Dana 44 rear end, 3.45 gears, and carbon fiber driveshafts. Just like I said a few posts up, lol.

Ok, my problems with solid roller. Getting to the crank bolt on a corvette is a major PITA. There is a bar that runs right infront of the harmonic balancer, that makes it almost impossible to get a ratchet and socket on the crank bolt. Why do I care about the crank bolt acces so much? Because I'll have to adjust the valve lash all the time with a solid roller set-up. That means I'll have to pull the plugs, and fight that bolt. I'd rather just drive the car, lol. I don't know, maybe I'm wrong. I have never had a solid roller set-up before. How often would I have to adjust the valve lash assuuming the car is driven 1k a month?

No reason I couldn't go with the Brodix heads. Everyone always says AFR is the best, so I thought I would spend the money and get a really nice set of heads. I know the thread is long, and some of my posts are novels in themselves, but if you read the whole thread I answered all of these questions all ready.


FWIW, a buddy of mine with a 94 corvette, just made almost exactly the numbers I am looking for. He did it with a 9:1 compression 383, CC305 cam, and home ported LT4 heads and intake. (Its 9:1 because he eventually wants to supercharge it) The engine dyno'd 426 RWHP NA after he tuned it with LT1 edit. I was so upset when he got those numbers with all the small components I almost cried. His corvette passes emissions, gets 26 mpg, and sounds and idles stock. The worse thing is that he is my friend, and I know he is not BS'ing me. If it was a stranger I could tell myself he was lieing about the numbers, or had a small N20 shot.

Thanks for the help Matt! I just got a PM from your buddy that said you were making 460 RWHP now? Is that true, or are the numbers in your sig still accurate?

Kingtal0n

Ive already read that you ditched the idea of Forced induction. But seriouselly, you want to make lots of power on the street, and keep fuel economy, etc...

the money you spend on super-strong aftermarket engine parts that will dish out your 600 horsepower on Juice can easilly be replaced with the cost of a Procharger setup, I bet it would cost close to the same said and Done. and it would be available 100% of the time.

Im getting ready to sell my twin turbo setup on ebay, so keep your eyes open if you would rather have one of those

305RSlc

What exactly are the specs on the CC305 Cam? I have heard of great things with that cam, but have never seen the specs. He got a whole 426RWHP with only 9:1 Compression??? That's pretty damn good. I hope to make that much power, hopefully more since I'll be running more compression, on a 383 HSR buildup, and that cam sounds like it'd be a good choice.

neat

.220/.230, .510/.510 on a 114.

As far as forced induction goes, i don't see why the internals of a 600 RWHP procharged would be cheaper than the internals of a 600 RWHP N20 engine?

The other factor is my wife. She drives the car almost as much as I do, and I'm not sure I want her to have 600 RWHP at her disposal if she decides to plant her right foot.

Kingtal0n

Well for one, I beleive its procharger that powers the world's fastest F-body with stock internals, so you dont need a bullet proof bottom end to work with a properly chosen procharger setup from what I have seen.

and for second, if you dont want 600 horsepower at the right foot, stick a bigger pulley on the thing. its really that simple...

neat

I'm not looking for the fastest stock internal F-body. I want a reliable, fun to drive car. There is no reason an engine that makes 425 RWHP can not be reliable. I'm not looking to run on the ragged edge with a pro-charger set-up. I would much rather spend the money on the internals to make the power I want NA. 425 RWHP is going to be enough for me 99% of the time. But I always want to have the option to open the bottle and do my thing.

As easy a pulley swap is, I don't want to do it 30 times a month. the car is driven about 1k a month. My wife probably drives 400 of that 1000 miles. I'll take the car to work, then she'll go get groceries with it. Then I'll go out with some friends, then she goes here, etc... Flipping a switch is easier than a pulley change.

Anyway, it is pointless to try talk me into a FI set-up. I have given FI all it's due consideration. Some friends of mine have forced induction cars, and I have seen what they are capable of. My buddies 600+ RWHP TT Mustang is a good example. Another friend has a pro-charged ZZ4 crate engine in an 84 Camaro. That car makes 560 RWHP and will occasionally touch the 10's at 130 mph in the 1/4 mile. Having seen these cars that achieve what I want to do, the costs involved to run a FI car that makes that kind of power 12,000 miles a year, and seeing the labor involved in installing and maintaining one of these systems I have decided to use nitrous for my power adder. I'm sorry that you don't agree with me. The costs of a reliable forced induction set-up are greater than that of a reliable N20 set-up. That's just the way it is.

Orr89RocZ

iTrader: (20)

How much more cash does it take to make a reliable blown motor? All forged stuff and strong rods right. Sounds to me that thats what it will take to make 400+ rwhp N/A with added nitrous hit anyway so why not go the extra step and supercharge it.

I am just curious. Doesnt nitrous hurt engine more than boost? What kind of maintainance do you have to do with a supercharger? That much power for a car doing 12000 miles a year or so is insane. Gas mileage, whats that?? You will be flying so you best be careful.
Cost is alittle more expensive due to 3 grand charger and accessories and chip work versus like 500 for nitrous setup. But the power will be there all the time. If you don't want your wife to have so much power then get her a thirdgen and do a mild build. Make sure she dont know how to work the nitrous though, that button would be even more tempting than just 600 blown hp on tap!! . Fast N Furious. Have fun.

MTPFI-MAF

A engine Properly built for Nitrous Or Super charger will be reliable, Hence the GN that are factory turbo charged, also Buick producied the Supercharged buick Regels, It is to build the motor for what you intened to do. The problem With nitrous is that the Ring End gaps need to be set correctly when the enging is built, and little things like a Fuel Pressure saftey switch, RPM windo Switch, Wot Switch, Nitous Filters, A good way of knowing what AFR you are running at what RPM (A good WB02 Helps)Now with supercharging THe compression Ratio is Very Important. you don't want to build a 10.5:1 Compression engine with a super charger producing 10+ lbs of Boost and 93 octane gas. (this was just a example) Just Research, Research, Research, and build the enging for what you intend to do with it. Nitrous Depending on How big of a shot and supercharger I would take some x-tra insurance and Go with a Forged Crank, Rods & Pistons.

Just my .02

neat

None, that is my point. A FI engine and a N20 engine that are set-up to produce 600 RWHP will be almost the same in cost.That "extra step" is an expensive one. Like I said for all the reasons above, I am not going to supercharge the car. It's not a thirdgen, it's a corvette. The supercharger kit is more expensive, the cog drive is expensive, and the way they make power doesn't appeal to me as nitrous.

Quote:

I am just curious. Doesnt nitrous hurt engine more than boost?

No offense intended, but if you have to ask that question you are probably shouldn't be posting here. Nitrous and supercharging accomplish the same thing. Putting more oxygen into the cylinder which allows you to burn more fuel to produce more power. Nitrous has a bad reputation IMO because it is so cheap it allows people who shouldn't have it to buy it. If you are dropping 3k+ on a blower or turbo set-up, you are going to research the hell out of it before you drop the cash. N20 kits can be pieced together for less than $500.

Quote:

Gas mileage, whats that??

There is no reason a fuel injected 383 that makes 425 RWHP shouldn't get decent mileage. The engine will not be constantly producing 600 RWHP.

Quote:

Oh, an LS1 swap build up and nos would be sweeter and may give you better reliability and gas mileage and that cooool factor.

Are you insane? First, this is a C4. There are 2 LS1 C4's in the world right now. Both of them were either built by professional speed shops or by someone who works at a speed shop. Neither of them have been able to get the gauges to work, or successfully mate the LS1 to a ZF 6 speed. They had to fabricate motor mounts, headers, and a plethora of other parts. Thanks, but no thanks.

Second, I am pretty familiar with the LS1 as well. The car I had before the corvette was a 99 TA that wetn a best of 10.81 on nitrous. A LS1 in stock form wll not support 600 RWHP on nitrous. While the stock internals of an LS1 are really stout, especially the crank, they will not reliably support 600 RWHP. The cash outlay to build up an LS1 bottom end is really high, as is any other part for that engine. Why on earth would I want to go from the cheapest engine in the world to modify (the small block chevy) to the third most expensive engine to modify, the LS1. (second only to the V10 in the Viper, and the LT5) LS1's are awesome, but not right for this application.

I'm sorry I'm kind of acting like a jerk, but no one is listening to me. I listed what I want and all anyone wants to do is tell me that I want something else. My goals are perfectly doable, I'm just not familiar enough with fuel injected small block chevy's to compile a list of parts that will get the job done. That's all I was asking for. Not "You should go blower." "You should go turbo." "You should get a fuggen LS1, that would be cooool"

Seriously, this message board is one of the best I have ever been on, but answering the asked question should be the first priority on a tech board, not telling the person what YOU think they need to do. If you feel the overwhelming desire to tell me to go turbo, at least answer my question FIRST. List a combo of parts that will make 425 RWHP NA and will be able to support 600 RWHP on nitrous. Rant to high heaven then about how I should do someting else. Atleast at that point you will have contributed to the thread.

FWIW I started a new thread dedicated to combo's only:

https://www.thirdgen.org/techbb2/sho...hreadid=251732

Orr89RocZ

iTrader: (20)

My bad. Misread your post about the C4. For some reason, I thought you were talking about a thirdgen. Not a C4. In that case, it rules out most everything I have said. I dont know much about nitrous so thanks for the input.

No offense taken. Just trying to learn some more cuz I plan on making high horsepower numbers some day as well.

You should make decent gas mileage but it wouldnt be great. Havent seen anyone with a very stout motor making good mileage except on blown motors. N/A takes bigger stuff to make same power and more fuel is generally used.

New Idea. A 383 is nice. How about a 396 or 401 stroker kit? Same block with more inches. Chevy high performance mag or Hot rod did a 350 to 401 cu inch motor that make somewhere close to if not over 500 horsepower. that was carb though. Those extra cubes would help. Also good heads like 220 cc intake or higher would also be great. Everyone loves AFR and I dont blame them. Good stuff.

400 + cubic inches would be a great help for your goal. They will make an easy 450-600 hp N/A and a 150-200 shot would be all you need.

A ZZx cam should due the trick, maybe larger, or call Comp Cams . They will provide you with a real nice custom hyd. roller cam that will make the power you need. Maybe a nitrous grind??

I know money is alot but for a motor that strong, do it right and have the right parts. I know you already know that. If your real crazy, build a 472 lunati small block off of a Dart or motown block. Big numbers and a one of a kind motor.

Matt87GTA

I wasn't sure if all of this was for that same car or if you got another one from all of this yappin on this thread .

Well I haven't actually owned a solid roller so I can't give you raw data on lash adjustments. But I certainly know a lot of people that run them and will never go back. I am tinkering with the setups so often on my cars I just don't see having to do lash adjustments a little here and there as any more "work" than I already do in some fashion as it is.....

Also, I wouldn't be turning the engine with the crank bolt... It will eventually pull the threads out of the crank - ask me how I know . And you can do them 1/2 at a time - one set at #1 TDC and the other at #6 TDC... not much turning of the crank. I always use the pulley bolts to bump it into place and the starter for most of the cranking with the coil disconnected when I do lash. Just doesn't strike me as something I would really despise doing once or twice a year.

I will be going with a solid roller for this engine eventually (hopefully this winter).

My heads blow even AFR 210s away throughout every lift. Get them. They are even CHEAPER than AFR 210s . The AFR 195s, IMO, are too small for a 383.

Sounds like that C4 is all dialed in. Mine is definately more than 420 now but how much I really don't know. Hard to say with all of the variables involved in a street race, but I ran with and even pulled just a little up high on an 03 Cobra that made 450 RWHP from a ~45mph roll. I need to do a few more things before I spend the money on another dyno session.... My injectors are too close to static for my taste, I still only have a 52mm TB, my air intake is crap, and I still want to check my valvesprings even though backing off my lifter preload made a huge difference in usable RPM. But since my below posted numbers I changed plugs to FR2LSs and gapped them to .035 (had FR3LSs at .050) and backed the lifter preload off to about 1/16 turn past zero lash and the car pulls significantly better up high (above 6k) than it did before.... Well actually it wouldn't go past 6k at all before . With the rest of the changes I have in mind I would bet 450+ RWHp is definately possible.

As for mileage, it is pretty much impossible for me to judge since I am on the throttle so much when I drive the car (its just so fun!), but I bet I could easily pull 20+ on the freeway with highway mode enabled and around 14ish around town with normal driving. With proper tuning any engine can get good mileage though.....

I just worked out a deal for a 150 NX wet kit .

neat

That kicks *** man, I'm glad you are really seeing the benefits of all your work and $$$ outlay.

Sounds like you have almost exactly what I am looking for. Once you get it all dialed in, anyway I can get you to drop me a line via E-mail and lemme know the final numbers?

Orr89RocZ- I considered a 427 SBC kit from Lunati and decided against it for the reasons I stated earlier in this thread. I haven't see to many 400+ cube small blocks that are as streetable as I am looking for. If I was looking to make 500+ NA then I would definitely go for a larger displacement, but all I am looking for is 425 RWHP. A 383 should be more than capable of producing those numbers. As long as the rotating assembly is over-built, then it shouldn't have any problem taking a 150-200 HP shot of N20.

Thanks for all the input guys!

Orr89RocZ

iTrader: (20)

I meant 500 hp on the motor at flywheel. Sorry for confusion. I mean 425 rear wheel ponies is like 500 or so at the motor assuming 20% loss. Wow, thats so much power

If built right, I don't see how a 400 small block wouldn't be as streetable as a heavy built 383. You would need a bigger cam for the 383 to make the power that the extra 20+ cubes would make. That seems right and the fact that alot of people have 383's. A 427 vette just sounds good to me! Like old 60's stingrays.

camarojoe

You guys got me seriously wondering why my car seems to be missing power. I even called TPIS and they said that my car should have around 440rwhp on a dynojet. I believe them when I see modded ls-1's putting down that kind of power with less cubes. And my heads aren't exactly holding me back, since they flow over 300cfm, so what gives? I guess it could come down to a few things like right now, I'm using a stock style oil pan, but with a diamond windage tray compared to a comp. Moroso pan, or it could be my timing isn't where it should be, to things like my intake being restrictive. I guess, I may be doing some investigating when I get this car running again.

Matt87GTA

Not to bring this back from the dead or anything....

But I finally scanned in my dyno graphs from my session this spring. Here is the one with Hp and Tq. You can see from the shape of the curve that it is kind of abruptly ending right at 6k and should continue up towards the 450 mark. But I think the lifter thing and undersized TB and whatnot may have been robbing power throughout so the entire curve may move up some and the TQ might be better.... I guess we will have to see. I have the bigger TB on it now and I should have enough money to get the air intake pieces and injectors by the end of the month.... I think I will be hitting the dyno again without checking the valvesprings though as I really don't want to mess with them and I should have ample opportunity to do so when/if I pull the engine this winter and do all of the stuff I mentioned above.

camarojoe - try running it open TB if you are thinking your air intake is a problem and see how that affects it. A small gain is normal but if it is throwing up another 10 RWHP like my POS system did, it is time to upgrade it.....

jester111

hi, dont mean to hijake the thread, Matt i just looked at the picture of yoiur motor did you have to clearence the block for the stroker crank?

Drkhrse89

iTrader: (1)

Yes you will have to notch the block for the rods to clear. Although I was talking with one of my friends and he mentioned to me that he did not have to. Best thing to do would be to slap on some old bearings and connect the rods to the crank and drop it into place. Rotate the crank around to see if you will have to clearence the block.

Matt87GTA

Exactly. From what I understand, most engine builders will notch the block a little in the usual places for a stoker setup and go from there.... This is because you don't want to remove block material for no reason as it compromises strength and not every block is cast precisely the same and not every stroker setup is the same in its requirements for the clearancing.

TPIS did the block work on mine and they notched it at all of the usual places at least some.

doc

Such a long thread.

I read only the top 10 posts and then checked out Matts dyno curve. Pretty awesome, there Matt!!!

But, I didn't see anyone talk about TORQUE. One famous engine biulder said "biuld for torque, horse power will take care of itself".

If you want a fun street car to drive, then what you want is lots of torque on the bottom end and midrange. IMO, a fun car for driving is one with 450 ft-lbf of torque over a wide RPM band.

Thats my goal with my 395 cu in stroker based L98. Soon I will get it on a chassis dyno.

Matt87GTA

Well yeah... HP is derived from TQ so obviously you want to have a lot of torque and to keep making a lot of torque throughout the RPM abilities of the engine. That is what mine is made to do - have a high redline and a broad and flat torque curve. Perfect for road racing and it also makes it less difficult to hook up on the street considering the power level. Reverse the TQ and HP figures and the car would be much harder to handle on the street or even coming out of slower corners on the road course.

Plus those figures are not really the case anymore for my engine... If you read through my other replies here you will see that I had a number of issues at the time of that dyno session - most of which have been taken care of now. I hope to re-dyno within the next month and I expect TQ and HP to higher and it should rev out to where it should (6500+ RPM) before it hits peak HP.

Matt87GTA

Hit the dyno again a few days ago.... I didn't do the requisite tuning on the VE table with my part throttle stuff and it showed . I ran out of resolution in my VE table and PE WOT fuel table and couldn't get rid of a lean surge right off tip in..... Still, I got it to be mostly safe on the top end now and I will have to hit it again after I change the injector constant and recalibrate the VE table.

Still made alright power . Changes since the last time: 42lb SVO injectors, 4" CAI system, 58mm TB, backed off lifter preload to 1/16-ish turn past zero lash, changed plugs to FR2LS and gapped them to .035, and of course PROM changes (obviously not enough though).

I think I still have a valvetrain issue on the top end as it still doesn't pull any higher power above 6k RPM.... Either way it could use a big solid roller to really shine with this head and intake setup and the lower end being built to handle whatever RPM.

demonspeed

So did this guy ever decide what he was doing? I'm getting itchy to buy another 3rd gen and a good solid N/A setup is what I'm looking at...