neat

This is a continuation of this thread:

https://www.thirdgen.org/techbb2/sho...hreadid=250638

I have a budget of 10k to build an engine for my 1991 corvette. 10k is the upper limit and if I could come in under that it would be great. The car has an L98 in it right now, and I would like to use the stock block. The car also has a cryo treated ZF6 six speed, McLeod clutch, Dana 44, 3.45 gears, and carbon fiber half-shafts, so the drive train should be squared away.

I want to make 425+ RWHP NA. The car must drive well, as my wife drives it almost as much as I do. The engine must be stout enough to handle a healthy dose of N20. The goal is 600 RWHP. No ET goal, no mph goal, just 600 RWHP on juice. MPG is not a concern.

Forced induction is out of the question for reasons listed in the other thread.

A solid roller might also be out of the question. I do not want to be adjusting valve lash once a month on this car. I've never had a solid roller set-up before though, so I might be off base on this one. How often would I need to adjust the valve lash if the car is driven 1k a month?

This is what I had planned:

Miniram intake
AFR 195's or Brodix Track 1 heads
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

Thoughts?

89gta383

iTrader: (5)

http://www.wheelermotorsports.net/en...83/prices.html

89gta383

iTrader: (5)

Your combo will make the power, just go with it.

Z69

Well just a thought, but a turbo setup with an electronic boost controller would meet all your criteria. And make more power if you wanted. Just tell your wife it's the rev limiter and set it for 5 lbs. Then turn it up when you want. Just a few keystrokes...
Need to shop and do a lot of the fabrication yourself to make the 10k though. Not sure, but I'm confident mine will cost less than 10k when I'm done. But I have more room to work with.
With a good setup, 5 lbs might make 475hp at the crank.
And drive like a stocker at part throttle.

neat

600 is not the primary goal, 425 NA is. 600 is secondary to the 425 NA.

I knwo it's long, but please read the other thread. Forced induction is not a possibility. For those to lazy to scroll back up and click the link, I will paraphrase here:

Its a C4. There are no turbo kits available for them. I have a MIG and TIG welder, and I even have an exhaust tube bender, but I do not want to go this route. Building headers is not my idea of fun. A friend and I just finished doing a custom TT set-up on his 91 Mustang. Its a 331 stroker, forged internals, etc... By the time the fuel system was complete, all the custom piping was built, and the car was running we each easily had 100 hours into the project. With buying the turbo's, enigne components, drive train stuff, etc... he is into it just over 15k. And it still doesn't do everything he wants it to. His car made 606 at the wheels, and drives really great. Unfortunately he has to take aprt the entire kit to change his spark plugs. The engine compartment in a C4 is a TON more cramped than a Fox body Stang. A nitrous set-up will make just as much power, is easier to install, does not require massive modifications ot the engine bay, and the initial investement is a TON cheaper.

A supercharger kit is expensive, and it's really expensive after you add in the cog drive system to eliminate belt slip issues. Agian, N20 is cheaper, easier to install, and will make just as much power.

IMO, a bottom end that will handle 600 N20 HP is going to cost the same as a bottom end that will take 600 forced induction HP. If I spend the money on the bottom end, and can make just as much power with a power adder that costs 10% of a superchargr kit, why would I go with a blower? the obvious answer is "Beacuse a blower doesn't run empty" or "the blower will be there all the time." 425 RWHP will be enough for me 99% of the time. All I want to be able to do is crack the bottle every now and again for some more fun.

I'm not new to cars, so please don't give me "You'll want more." "You'll get used to it." I have considered all this, and have decided for the way I use the car, and what my goals are this is the best route for me. Please don't debate this with me, I am the one most qualified to decide what I would like the most.

neat

I checked this out. The combo's seem plenty stout, but they don't list estimated HP that I can see. What kind of power is their dyno tested engine supposed to produce?

Orr89RocZ

iTrader: (20)

I have posted alittle bit of stuff in the previous thread. Consider a 396 or 401 build. Think it is a 3.875 in stroke. should get some more out of it due to more inches. Miniram and maybe a little bit bigger cam. Comp cams, call them up and see what they think. Might be able to set you up with nice grind. AFR 195s ported to hell would help alot. May be go 220s? Shouldnt be to big at all. Your combo sounds right, just chip tuning is where you will have to optimize your parts to make the numbers you want.

Motown 427 and 454 shortblocks are like $4000-5000. Alot of cash, but rock solid foundation. With heads and miniram with matching bumpstick, should easily put you above 500 natural aspirated. The 454 crate makes 600 hp alone! Nitrous shot of 150-200 should get it done.

neat

I appreciate the advice, but I am not looking to make 500 HP NA. Like I keep saying, I am looking for a solid 425 RWHP small block, that will handle a healthy dose of N20. There is no reason the stock block can't make that power. If wanted monster power out of a small block, then a 400+ cube engine based on an aftermarket block would be the way to go. That's not what I want to do though. I am looking for a nice streetable combo that nakes decent power. I don't want to shatter any records or anything like that. All I am after is a fun car to drive.

Comp Cams selected the cam for my last 383 vette. I made 360 RWHP with the LT4 hotcam (.525/.525, 218/228, 112 LS). After giving comp cams all the details on my enigne, including head flow numbers from .100 to .700 they recommended a .565/.575, 232/242, 114 LS cam. I bought the cam, tuned the computer and made 11 more RWHP, for a total of 371. I then tried picking my own custom grind, .550/.550, 228/236, 113 LS. I made 31 more RWHP than the hotcam combo, a total of 391. After that I kinda lost faith in comp cams ability to select the right cam.

As far as stroking more than a 383 with a 4.0XX bore I personally don't think that is a great idea for a street machine. Look at the ford 302 and 306 engines. The stroke is 75% of the bore for a 302, and really close to that for a 306. Those engine produce awesome HP numbers when built right. All Nascar engines follow the same pattern, stroke is almost 75% of bore. The more you look into it, the more often you see that commonality. Engines that last a long time, making great numbers all seem to have this in common. Get a 3.875 inch stroke in a 4.030 bore and your bore to stroke ratio is incorrect. This is all my personal preference, so don't take it as gospel or anything. Lot's of guys are making great numbers with engines that have nearly equal bore and stroke. I just see more long lived high HP combo's with the 75% theme.

Orr89RocZ

iTrader: (20)

Sorry I meant 500 flywheel motor horses. Wow, comp cams didnt select the right stick? Well I heard good things about them. i guess when piecing together a big combo like that, you need to select the perfect match of parts to make the full potential. your cam is inbetween comps and hotcam. Wierd how the middle one made the best horses.
What about a single pattern cam? like a 230/230 or the zzx 240/240? For nitrous I guess that wouldnt work too good. I mean if your heads flow well on exhaust side it should work. Superram likes the 219/219 and its runners are longer than LT1 style What about trying a 112 or 111 lsa to squeeze out some extra power?

Your last 383 combo is still short by 25-30 rwhp to make your numbers you want. I would try AFR or some other heads with 210+ cc runners. Looking at my AFR catalog, the 210 cc competition cnc'd head flows like 288 cfm at .600 lift. Some minor port work probably could be done and may see 300 cfm. The 220's flow 298 at .600. Thats alot of air. The cam is where you will make or break your combo. Maybe comp cams cam will work better with the larger heads. That will get you the 425 rwhp.

Also, those motown guys using their aluminum 220 cc heads making big numbers on their 415+ inch motors. Those numbers are what you are looking for. Those heads would need work but are a cheaper alternative to AFRs or the like. Also Pro Lightning heads are good stuff and cheaper. Like 950 pair and less. Possibilities are endless. Hope I could help some.

neat

Thanks for the advice, but this thread was kinda intended for combo's. Do you have a specific combo of parts that will accomplish what I am looking for?

I don't mean to sound like an ***, but I am getting tired of reading through everyone else's opinion. I appreciate what you "think" and what you would do if it were you, but what I am really looking for is people who have first hand experience with a combo that makes the power I am looking for. Conjecture and good guesses are great as long as you aren't the one dropping the cash.

I appreciate the advice/help.

89gta383

iTrader: (5)

https://www.thirdgen.org/techbb2/sho...hreadid=249277

There is another 383 miniram, zzx cam combo here, do a search, I think he put down 419 at the wheels.

neat

Thanks!

Orr89RocZ

iTrader: (20)

I see you already tried the corvette forums. Those guys dont seem too optimistic about the 383. But it can be done. Like I said, the world products shortblocks are hard to beat or even a 396 or 400+ but its your car and it is not necessary to do. I am just a little jealous that I am not doing the same thing right now.
I found one for you. Its a 385 miniram with 480 horses on motor.

385 miniram

Pretty much the same as you and everyone else was thinking. Maybe some minor tweaking and you will have 500 easy on the motor. I know you want some hardcore numbers/list of parts, but how many people are running such a hot combo? A good educated guess based on other combos is all you can go on. Its your motor and alittle experimentation and risk taking is needed to see what works. Alot can be done with 10K if you shop around. Yeah its not my money but if it was, I would still do my own made up combo. I searched yahoo and found the 385 combo but havent found anything else. Keep you posted if something comes up.

Carcraft ZZ 450. 350 based zz4 with miniram III and fastburns made 452 hp on motor with ZZ409 cam (226/226). Those heads dont flow as much as AFRs according to their charts and with a 383 and maybe a bigger cam, should be over 500 hp on the motor.

ZZ450

neat

Thanks man, I appreciate all your help. Especially your candid response.

PHAT89TA

heres another website u can check out.
http://www.golensengineservice.com/