Proven lt1/lt4 combo`s

[ThreeHonks]

It disappointing to see any car have a big budget 383 or 396 bottom end thats topped off with stock heads.
The same goes for the LSx platform, there are plenty of guys with 400+ CID strokers that have stock heads.

These cars routinely get outrun by stock displacement cars that are built correctly with a well matched top end.

[Phantom409]

There are so many options out there to pick from it's crazy.

Yes, there are people out there that drive 383's or a 396 daily but the amount of money that it takes isn't budget friendly
Engine work alone will run you 1200 and you don't even have parts yet.

I like Joel's idea
You can easily build a 12 sec motor with just some simple upgrades and ported heads.
You have the LT-4 stuff so you have a good start.
Get a Cam & Spring pkg with new lifters and nice port job and you will be well on your way to your goal.

You can also do a 1.6 rocker to help get more air/fuel into the motor too

Just a remember to do it right and don't try any short cuts, it could end up costly.

[Phantom409]

There is no replacement for displacement but remember that stroked displacement < bore displacement. A 383 isnt a huge increase in CI, if youre going to spend all the money on the build make it worth it and do a 396. However i stick with my original statement, a stroker isnt the most cost effective way to make power. With matched heads and cam they are monsters, but still expensive. He only wants to run mid-twelves... my car is capable of that cam only on street tires.

Old Farts (Red) 383 that we did this spring ran upwards of 7g's just to get what she has, 400 RWHP and if there was more money we could have done some other things to make even more but the kicker is money.

Stock heads on a 383 just don't work well at all and aftermarket one will run you in the area of 15-1800.

The question i ask is, do you want to spend money on heads and a cam? (headwork even option with LT4s) or build an entire engine?

Something else to think about

The HP ratings for my motor are not "tuned" # either.
I did a mail order tune and tweaked it so she would run.
There are big plans for the winter/spring for me and then I will have it tuned on a dyno.

[ThreeHonks]

^^ What heads are you running on that car!? 377RWHP? A4 or M6

[kyleozzie]

Thanks Guys for the responses,My car has 113k on it ,so I know its going to be freshed up,Just trying to do it right the first time. whats your opinion on the pm rods a local machinist told me the wouldn`t resize or put bolts in them that they are throw aways. I am looking at keeping the rpms below 6400/6500. I know 12`s are do able with heads and cam just looking for someone who has a similar combo

Thanks Kyle

[ThreeHonks]

If you're going to be N/A and on a budget:

1.) Re use the stock crank and PM rods
2.) Put ARP rod bolts in the PM rods have have them reconditioned
3.) Get a GREAT balance job on the entire shortblock
4.) Keep the 2 bolt mains with ARP studs
5.) Use a stock volume/high pressure oil pump with GM white relief spring (Melling M155 pump is a good choice)
6.) Bore block .030" over and get some aftermarket pistons and rings
7.) Recondition the crank
8.) Obviously you will need new cam bearings, freeze plugs installed, block hot tanked, etc. etc.
9.) A quality align bore is a MUST

This is the basis for a budget friendly/strong 355 bottom end. You can spin this combo to about 6800-7000 rpm no worries. If you have any other questions PM me

[JoeliusZ28]

great advice ryan.

i would either take that path or just slam H/C on the stock block and run it til it breaks. Some go a long time, others dont. mileage is pretty meaningless on these cars. Its a big gamble. If its been taken care of it should hold for a good while.

[ThreeHonks]

I thought he was wanting to rebuild the bottom end...

but yeah, mileage is pointless. Mine spun a bearing at 54K miles and the engine was VERY clean when we tore it down. If you just decide to run the stock shortblock, use thicker oil, like 10w40 or even 20w50. The factory bearing clearances are too wide for such a thin oil like 5w30

[Phantom409]

^^ What heads are you running on that car!? 377RWHP? A4 or M6

AFR 195's with a M6, 9" w/ 4.10's & a locker.
Needs a good tune though

[JoeliusZ28]

AFR 195's with a M6, 9" w/ 4.10's & a locker.
Needs a good tune though

Definitely invest in a good tune and youll see alot more. I thought you were running a little rich friday, i was gettin kinda happy on the exhaust Youd also dyno better with a 10 bolt in there, but you knew that. What is your compression ratio?

Im shooting for 360-375rwhp with my setup, but then again im not really after dyno numbers... as long as it runs the times and gives me trap speeds I could care less about a dyno sheet.

I also agree with ryan on the 40 weight. I swear i noticed a difference switching from 5w30 M1 to 0w-40 M1.

If you want to preserve a stock bottom end another tip is to upgrade to the "white" oil pressure relief spring.

[ThreeHonks]

9" rear usually sucks up about 10-15 RWHP

but we all know that we race at the track and not on the dyno

[Phantom409]

Definitely invest in a good tune and youll see alot more. I thought you were running a little rich friday, i was gettin kinda happy on the exhaust Youd also dyno better with a 10 bolt in there, but you knew that. What is your compression ratio?

I was going to ask you about that

I took Red's tune after TJ got done with the whole car and put it in mine and saw a big difference in pwr and fuel mileage.
I pulled 22MPG going to & from Woodward Friday

I know shew is a bit rich yet but I'm good with that for now.
Next year will be the real test

[c0ncEpT]

Nitrous is not any more stress than any other power adder.

I will have to slightly disagree with this statement.

Nitrous beats the shit out of your bearing because it brings so much torque in at such a low RPM. When spraying a 100RWHP shot you might pick up say 105RWTQ and 160RWHP. Now when you have thats all coming in at say 3000RPMs it really puts some stress on your bearings.

With that being said if you have a nice motor with some fresh bearings it still shouldn't be a problem. Its these guys like Jon(Phenomic) that have 100K motors and bearings that you see failures on.

[JoeliusZ28]

jon doesnt have much more than 50k on his. It is in the low 60s at the most.

He was however, winding that sucker to nearly 7k all the time... on and off the nitrous. Not to mention he broke a valve spring without knowing it (a dual) and chunks of metal were floating around in the oil for a while without any indication. He was not very surprised when it let go. he was aware of the risks.

[PWND3r]

you could just toss my cam on those heads and intake as they are and run mid-twelves. and it would be really friendly doesnt take much to get mid 12s as long as you can drive. you do not get much additional power out of a stroker, id leave it alone.

I disagree with your stroker statement. Me and a buddy came up with this on my old Merkur forum. This is for a turbo motor, but it's the same thing for a nitrous set-up. I know nitrous isn't going to provide pressure like a turbo or supercharger but it's the same concept.


I hear this a lot. Remember that little air pump sitting next to the motor? Ya, that helps a lot. On a N/A motor, 0.2L is just that. On a turbocharged motor, 0.2L at 14.7psi is holding twice as much air, so it's really 0.4L. At 20psi that's about 0.5L.

You know our motors are really 4.7L, right? Let's do some math:

Atmospheric Pressure: 14.7psi @ sea level
Standard displacement: 2.3L
Standard boost level: 15psi

First we need to figure out the ratio of pressure in to pressure out of the turbo. In this case it is 14.7 to (14.7+15=29.7), or 2.02:1. So we multiply our displacement by this ratio to figure out how much air it is really holding. 2.3L x 2.02 = 4.646L, or roughly 4.7L of air at 15psi. That's a pretty decent sized V8.

So let's change some figures here. For a 2.5L motor, and 15psi, we still have the same air ratio, but a larger displacement. Now we have a motor that is holding 5.0L. And what happens if you turn up the boost to 20psi? Your input/output ratio changes to 2.36:1, so now you have a motor holding 5.9L of air!!! Holy crap! Hello 'Vette beater, good-bye gas mileage.

P.S. I am not pulling these figures out of my ass.