cfgioja

iTrader: (2)

looking at building a 383 stroker, I do not want a loping muscle car that stalls and will produce over 400ft/lbs of torque low end, that will destroy my transaxle.

I am looking to install this engine in my 944, the ls1 already was running but found out I had a bad set of pistons and bad block.

I have a set of rebuilt ls6 heads with dual springs and want the engine to be smooth and have a good highway power to fuel the speed the car can make.

any advice, I figure the idle is related to the cam, so I just want to know the facts if its possible to have a smooth running 383 and not a rough loping engine.

fatmat80

yes that is posible..the cam is usualy the reason for the choppy idle, but sometimes a **** tune is the reason.you can still make good power with a 383 and something in a 228 range on the cam.goodluck

BAD2000TA

iTrader: (6)

I have a 383 and the cam I'm using is very mild, as this is my daily driver. The cam is a custom Comp Cams, with 224 intake, 230 exhaust, with a little over .600 lift. It's on a 114 so the idle is pretty smooth. I've never had an issue with stalling, surging, etc. Perfect cam, but a lot of that is in the proper tune. Credit for that goes to Mike at G-Force. Good luck.

cfgioja

iTrader: (2)

thanks for the info. With the increased CI I will get increase power correct? so even if I am running a smooth idle I should get more power especially running ls6 heads with comp dual springs.

One other question, What is the top end rpm that a 383 stroker can hit? I dont want to drop below 6500.

BAD2000TA

iTrader: (6)

More horsepower, but notebly more torque! I'm at 420 foot pounds and still do not have headers, ported heads, or FAST intake. My upper RPM limit is set to 7,000 rpm, but since I'm not making power that high (due to the intake and exhaust restrictions), I don't run much more than 6,300 rpm.

SOMbitch

iTrader: (8)

GENERALLY when you increase ci by stroke, peak horsepower will be similiar to to a smaller ci engine with the SAME bore diameter but it will produce more torque at earlier rpm.

cfgioja

iTrader: (2)

Kool, I am running ceramic coated custom headers and a 91mm TB with LS6 intake and LS6 heads.

This is all inside my 86 944 turbo/951 porsche. So that will be about the limit of the transaxle as far a torque goes. It will be sick once I get it together

SOMbitch

iTrader: (8)

It'll be fun for sure Just don't break that transaxle. You can buy a 4th gen F-body for the cost of that thing

cfgioja

iTrader: (2)

I am still doing research. The guy I am looking at buying this from said the setup is for a 3.905 cylinder. So what exactly is the stock bore of an LS1?

I am new to engine building so this is my first engine and I just want to make sure i do it right.

trx250r

If you are looking for top end power why go stroker at all? You could do a forged stock stroke setup and spin it up a lil harder and make the same power while being easier on your trans axle. A shorter stroke at high rpm will be more reliable as well because you wont have to move the pistons as fast. Choppy idle and high rpm power is going to be a conflict of interest for an off the shelf cam, call up one of the sponsors on this site about a custom grind that will make power up top with minimal lope.

franksaltz28

iTrader: (1)

My 383 has an ms4 cam and its not to bad of a dd. Alot depends on the tune.

Mine revs to 6800, with a stroker motor you dont have to rev it that high to make good power.

BAD2000TA

iTrader: (6)

3.898". The 3.905" set-up assumes a hone to the cylinders. LS1 blocks do not get bored. Contact a good local machinist to prep your block. Best to bring the pistons and rings to him and hone to match perfectly.

cfgioja

iTrader: (2)

This is my first true engine build, so I am open to any advice that is given.

I know true sports cars displace rotating mass by smaller ci with more pistons. I really want a smooth idling highway monster. I hope to rev out to 7k or just above. Is the rotating mass of a 383 stroker offset so much that this can not be done?

also I was under the impression if I went this route I can get a cam that would move my torque curve up to 2-3k and all for more power top end.

I look at the CI and see that bigger is not always better but it brings more power possibility to the engine.

what do I need for a smooth idling drive able, highway car that can spin to 7k and not have issues?

venom99

iTrader: (32)

your best bet is to call comp cams and talk with them for your cam to get a cam custom made by the sounds of it thats what you want

cfgioja

iTrader: (2)

So looking at the 383 might not be the best idea for me since the torque is increased over the hp.

Diving further into getting forged and balanced stock sized internals, is it possible and what would be needed to spin the rpm to 7k redline, with a power band up to 6500-7000 area.

I already have ls6 heads with dual comp springs, that seat at 150 or so. their
#26921 comp cams.

I dont have any other upgraded parts anywhere else.

venom99

iTrader: (32)

with to power your looking for putting a cam in it will over shoot it

racer7088

If you are worried about exceeding the torque capacity of your transaxle I'd just stay 347 and save the money by getting an oem crank. The you can put that money on some better valvetrain and turn a lil more rpm with ease.