Hey guys I need some serious help. My 95 lt1 is in the machine shop atm. Engine had a blown head gasket and bad cam. I am rebuilding the engine to a 383 stroker. Engine is bored already and balanced. Engine has all new piston heads installed.

The engine is ready just need to put a new cam in. I want to put a lt4 hot cam but I have been told that I need to tune the car if I do that. Also my friend told me that the 383 stroker build with a hot cam it needs new lifters and rockers. It won't handle it plus if I put the cam in I will get less vacuum.

I just want to have a 383 stroker with a lt4 hot cam running 400 hp. People tell me I have to get new injectors etc.
I have already put a very good amount of money in this car any help would be appreciated.

 

You're going to need a tune regardless of what cam you put in it.

Any cam entails some valvetrain upgrades. Springs that will handle more lift, hardened pushrods, and roller rockers are all ideal. Stock or stock replacement lifters are probably fine.

The power will really depend on your top end. The LT4 hotcam is really dinky for a 383. You'd also need a decent set of heads to take advantage of the extra cubes.

32 lbs/hr injectors or higher will probably do. You can't just swap injectors without retuning.

It doesn't sound like your build was really thought out. I wouldn't be surprised if your crank is a cast eagle by the way everything sounds. They have a bad reputation.

 

Bored and balanced 383 with new piston heads and a hotcam. Whoever your builder was is an idiot. What's your compression ratio? Are you using a "break any minute" eagle cast crank? Stock unported heads on a 383? A lt4 hotcam is small in a 350, this was a very poorly thought out build. Give us ALL of your details and lets see if we can salvage this for you.

 

Yikes....looks like you didn't plan this out well at all...

Of course you will need a tune for all that work done. I'm worried about what internals are in your motor now....

 

Your engine builder is a you should of before attempting this build. But as said, Let us know of all the details and "Maybe" this build can be salvageable, but it still gonna cost you.. HP = $ no matter how you look at it..

 

Ok I am not a mechanic, I just wanted to do a 383 stroker bored .30 over with a nice cam to produce 400-420 hp. I took my car to a machine shop my friend recommended. The machinist order the kit for the stroker so I guess I should of asked more questions and do more research he charged me 2700 for tg e build so I thought he knew what he was doing.

So I am asking what is the best advice you can give me to do. Right now I have 1200 more to spend. The engine is stroked 383 and it needs a cam.

 

I'd find out what's in the block before you go running it. Added stroke is harder on everything in the bottom end and those cast eagle cranks have a tendency to split. It could be forged stuff for $2700 in all but I would find out for sure.

Getting to 400-420whp with untouched stock heads doesn't seem too realistic, 383 or not. The cam would have to be freakin huge and the RPMs would be beyond what the motor and PCM can handle. You need heads and definitely a bigger cam than the LT4 HC.

 

the LT4 hot cam is not the best pic but would "work" in otherwise a stock motor that is now .030 over with a stroker crank. It just would not make big power but more than "stock". If you have not purchased it yet you would be better off getting a custom cam from Lloyd Elliott that is not to big and will work with stock heads (you didn't note if you have ported heads so I assume they are stock). Lloyd has a few offerings that would work better than the Hot cam and will work with stock heads

you will need better than stock valve springs with any cam. Comp 26918 should be fine but Lloyd could spec other options, even cheaper than the Comps.

your 24 lb stock injectors will work with a small cam.

you will need a PCM tune period, with any cam

you could keep your 1:5 stamped rockers...but I and anyone else would advise getting a set of 1:6 RR. I would not recommend cheap ones..

If you did not wipe the original cam, your lifters should be OK, assume the builder inspected them. your stock push rods....well they will work but getting .080 thick wall ones would help in high RPM's but on a "basic" motor not nearly as critical as good springs. I use Trick Flo

Don't know what machine work was done to block & heads, was block zero decked, were heads milled, what head gasket thickness, etc. Hopefully your builder had a plan.

Did your builder tell you what kind (brand) of crank he used and if it is cast or forged?

 

Sorry if we were a bit harsh but it just sucks seeing people spend money before they plan anything out or spend the money wrong. I'm willing to bet the crank your machinist ordered is the junk cast Eagle crank which is the number 1 problem. Find out what it is.

Now you want to make 400-420 HP. If you still have stock unported heads, you will not get there, the 383 does not add a bunch of power, the power comes from good flowing heads and good cam. A hotcam is way too small for a 383 and won't make good power. You would be lucky to see 320 HP if you tossed that cam in there now. Now this is rear wheel HP if thats what you are after.

$1200 isn't going to finish this build either with your goal of 400 HP in mind. Here's a list of things you would need yet.

Cam $150-400
Ported heads (AI or LE) $1500-2000
Rockers $150-400
Pushrods $100
Injectors $150-$350
Tune $200-$600
Misc $300ish Plugs, wires, fluids, etc etc.

You didn't mention exhaust or headers? You will need those for sure. $500-$1000

A stall would benefit the setup also $500+ for a quality stall if you have an auto.

Making reliable power is not cheap, wish you would have stopped here first...

 

You do understand RWHP vs Flywheel hp correct?

 

With $1200 left sell off what you have and buy a used engine.

The full LT4 HOT kit including heads makes 425fwhp in a perfect world. In a 383 with LT1 heads and no tune you would be lucky to have it survive much less make 400fwhp.

If you want to stick with your mistake throw the stock cam in it so long as the compression was not substantially raised, use the savings to pay for the tune IT HAS TO HAVE. A stock engine benefits from reprogramming, modifying an engine and wanting to use a stock tune is worse than a bad idea.

 

You're going to need a tune for the increased displacement regardless of the cam you choose. The LT4 hotcam is probably the only high perf (!) cam you can run that you could still use the stock rocker arms on with cheap LT4 springs to save some money. I've done it. If you do have a cast Eagle crank maybe it will live keeping the redline around 5500 rpm. I'm just trying to be a optimist. Too bad you didn't ask questions first.

 

For $2700, assuming the block work and balancing alone are $1000, and the machinist has to make money so assume $500 for him to assemble it, leaves $1200 for a rotating assembly, which is the price of the cheap Chinese cast eagle crank rotating assembly on summit, so I think it's safe to say that's what he used. You need to verify this and if it is true, you need to start all over. The crank is garbage, it is about half as strong as the stock crank, with failures happening before 5000 miles, regardless of power and rpm. The crank usually snaps behind the front cap, causing a horrible vibration which people come on here to try to solve after they've thrown all new ignition parts at it, and start noticing metal flakes in their oil. Then someone asks "is your balancer wobbling?" And that's the tell tale sign. Any cast eagle crank from the past 5-7 years is junk. Do a quick search here or google for "lt1 cast eagle crank" and see the carnage for yourself. When it breaks, it takes out the whole bottom end, so that $2700 you just spent is gone.

You need to pull the shortblock apart and put in any FORGED 3.75" 1 piece rear main seal crank. Doesn't matter eagle, scat, Howard's, Ohio, whatever. They are $750 and up. Then put your stock cam, stock valvetrain, stock heads, and everything else stock back on it just so you have a running car again. If anything was truely wiped, there are tons of $25 used stock cams for sale. Then just get a $200 mail order tune. There's your $1200 spent. It won't make more than 300rwhp with a stock exhaust, but at least you will have your foundation built, and as you save up more money, you can get exhaust/heads/cam/valvetrain and go from there.

Really sorry to hear about your situation. It happens wayyyyyy too often. You might as well have asked your wife to build you a motor, she would know as much about lt1s as it sounds like that machinist does.

 

FWIW......I am a member of the "2 piece crank" club. The Eagle cast crank broke exactly as bufmatmotorsports describes...in 2k mi.

Fortunately, in terms of $, the builder promptly rebuilt the motor using a forged Scat crank. He also provided a new block as the cast crank took that out also. Crank broke driving at 30 mph

do many have cast Eagle cranks and get away with it, yeah but unfortunately there are numerous cases with problems from Eagle "cast" cranks. YMMV

 

Here are some pics for you guys does this help at all?

 

it doesn't look like the block or heads were decked....unless these are pics before that happened if they were

looks like the valve seats were cleaned up assume the valves got lapped

don't see any crank so that is still a ?

Scatt rods so "maybe" it is also a Scatt crank...a step above Eagle

KB makes OK pistons, more budget but OK for NA applications. They may be heavier than the comparable Mahle ones

 

I know everyone talks bad about the Eagle cast crank but I know a lot of people running them successfully in higher HP engines too. Just recently I talked to an NHRA C class auto guy with an LT1 Firebird, he spins his motor to 8k RPM's and runs an Eagle cast crank...unless he's lying. I didn't get that impression though. He's a older guy who really seemed to know his stuff.

 

Ok update went to the machine shop in my engine I am running.

383 stroker .040 over 10:1 compression.
Kb pistons
1.5 rockers
stock aluminum heads.

I need to buy a cam to put in and then tune it. Any suggestions?

 

I suggest you punch your machinist in the dick and get your money back. 10:1 is less than stock, stock heads can't feed a 383, thick old school rings, you left about 150 horsepower on the table because of poor part selection. I'd be surprised if it makes more hp than a boltons only motor regardless of what cam you put in it. Punch your machinist straight in the weiner and take your money back.

 

any cam would work better with ported heads...but this one, for your build, would be way better than the Hot cam

•224/230 .573/.568 112 LSA. – 1700-6100 RPM

http://elliottsportworks.com/?page_id=32

If you have gears & stall you could go with one of Lloyds bigger cams

10:1 compression...WTF. is that with a .029 head gasket?

if not, use that thickness of gasket