I have been looking through alot of post related to 383 strokers. Though I cant seem to find the info I'm looking for. There's alot of mixed gains. Some are saying 450 some are around 500. The ones that come to my local track and say "oh its a stroked ls1 383", then run 11:6~12.0's just make me think if it's stroked, that was a waste. I figure I'm right at 425~430 hp now on motor to run 11.6's with my race weight at 3,655 lbs.

First off, I have a 98 camaro, stock cubes. Dart 225 heads, fast 90, stock injectors 28lbs, FM-14 cam 114 lsa with .598 lift. Th400, 4,00 stall, 9in with 4.11 and 28x10.5-15 goodyear slicks. I bracket race this car every weekend, from April to November. I really don't give a damn about dyno number. I want et. I currently run 11:66 @ 115mph on motor and 10:89 @124mph on dry 100 shot.

I'm throwing the idea around in my head now, if I stroke my motor what et gains will I see. I'd really like to see it run a 10.5~10.6 on motor and close to 9.90 on spray. But and here's the thing that gets me. I have seen alot of "383 Ls1's" run right around 11.6's. So I'm more or less wondering if it's even worth it to stroke and still be at the same et I was prior. Yes, I would have better parts in the block, but the gain of et would not account for the cost. I get it, alot of people will say stroke it for the peace of mind, well I have the peace of mind now"knock on wood" I have the clearnces checked every winter. I make sure the motor is gone thur with a fine tooth comb so to speak.

I guess what I'm trying to say is, people who have stroked their motor what gains in et did you see. I don't want to here stroke it and be done. I'd like to weigh my options now, so I can determine if stroking the motor would gain in areas I want to see gains. The way I look at it, I could stroke it but if it doesnt gain the et I'm looking for then I kinda wasted money I could of used towards traveling this season.

 

ET gains are made by MPH increase, your MPH on motor is very low for the setup. The setup the way it is should be a 120+ mph car. Whats the car weigh? Is it tuned by a good tuner? More cubes wont really help anythin if the way it is its not performing like it should, IMO. What was the DA when you ran those times? Whats the duty cycle on the injectors? Id expect them to be maxed out by now very maxed out.

 

I honestly think that is because people go broke from the money they put into the bottom end, and then put a crappy set of heads on it and a weak intake and make no power. If you keep the same heads/cam and stroke the bottom end to a 383, you will pick up a good amount of torque, but only somewhere between 5-10WHP. If you go with a larger sized cam to match the cubes, then you will start to see some good gains. As for track times, I doubt you will get any good info that applies to your setting here.

 

I used to own a 99 Z28 with a 383 that I built. It had afr 205's, fast intake and TB, compstar rotating assembly with diamond pistons, and a comp cam ground to my specs (236/238@050 112LSA). It ran 11.1s all day at 3650lbs with a m6. This car definitely had more in it though. I think 10.6-10.8s would have been easy with an auto, stall, and maybe take a little weight off. I'm not too far from you so the DA may be similar to what you are used to racing in.

 

what do your heads flow ?looks like you have a great top end.you should pick up at least 40 hp/tq using your current cam,and you should see .4-.5 faster times .consider a custom cam to get more power.

 

Race weight is 3,655 lbs, 3/4 tank of gas, and a full 15lb nitrous bottle. DA 809.0. As for injector I cant remember if they were maxed, but I do have a set of 42 lbs sitting here for it. Tuner is Bryan Herter.

Now on the spray I hit the limiter (6600) around 1,260 ft. I usually tag it at the 1/4 mph cone on track.

 

http://s69.beta.photobucket.com/user...f9b27.mp4.html

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I've heard a few people talk about 383's and the engine geometry. Something about they don't run as hard as they should. I was always recommended to do a 370 or go larger than the 383.

Has anyone else heard of this?

 

My other option I been more or less just keeping in my mind for now has been 427ci lsx. But I know once I build that I would be done with this car. Or building a big cubic inch small block and go have some cheap fun.

 

I would suggest doing the 427. If its what you really want. No sense of spending money on a motor you are just going to pull out to replace.

 

Right now I dont have the budget for a 427 lsx build. Maybe after I graduate. Right now I'm paying for college and I have a ok budget to work with for the 383 build. More or less I'm just playing with it till I have a better budget. But I know once I have that budget, I'll have another project.

 

Engine geometry has nothing to do with how "hard" a setup runs. Engine geometry only plays a roll in how reliable the setup is. Ive seen less than favorable bore to stroke ratios make great power.

Edit:

Heres a good example of a proper 38xci setup.

 

I tend to agree here.
What is the cam duration and lobe sep?
What are the specs on the heads?
Your estimate of RWHP is way off.

There are more than a few Camaros here going bottom 11's with simpler combinations.

I would sort out what you have first.
FWIW, a 383 with the correct cam will simply make more HP and tourque everywhere in the curve. It's 37 CI bigger.

TH400 sucks some power for sure.

Ron

 

cam 232"/234" .598"/.598" 114LSA
Just a set of Dart 225's
2.05/1.60, 62cc, CNC Bowl Blended, 313cfm intake / 214 Exhaust @.550 lift
My rwhp guess is based off fellow old drag racers saying "you should be making 425-430 on motor" But then again all the old drag racers I know dont use dyno's. They use the track to tune.
I would be happy with 10.7.

 

People crack me up with the whole "undersquare" crap, or saying a 383 isn't going to be reliable because the bore diameter is slightly smaller than the length of the stroke. Hell, a 5.4 liter is 3.55 x 4.165 as designed by Ford! I see plenty of them with 250K+ miles on them, doesn't seem to be an issue at all.

 

Thanks for the info.
Hmm, I'm wondering if those heads are maybe too big?
Cam sounds excellent to me....would run nice in my car.
Maybe the old drag racers were referring to crank hp? BTW....I'm an old drag racer.

So, those heads just might really like to be on a 383, with a bigger cam with more exh duration.

Maybe you said, but where do you shift?

BTW, I've not been on a dyno either. In the spring I hope.

 

No one said a less favorable bore to stroke ratio engine isn't going to be reliable. I simply said bore to stroke ratio (engine geometry) only plays a factor in reliability, that is all it effects.

 

his heads aren't too big.

 

The reason the 383 LS1s aren't popular is because they're a waste of money. For the same cost (or less in many cases) you've a 402"+ engine with a 4" bore.

 

How do you figure a 382 costs less when you have to purchase a new block to get anything with a 4"+ bore?