Thread: how do i wake up my stroker

Tweet

I have a new 383 stroker with 10:1 comp. forged srp pistons, nitrous hp cam, .496 int. lift, .509 exhaust lift, 1.6 roller rockers, stock heads with 2.02 intake valves, street dominator intake manifold, speed demon 650 mech secondarie carb, mallory unilite distributor, msd 6al box, im running 18 degrees advanced initial timing, plus a 100 shot of nitrous, all mated up to a muncie m21 4 speed and my question is how do i get a better time than a 16.2 at the local race track [LACR]

any suggestions on timing or carb adjustments would be greatly appreciated

Hmmmm.....I am inclined to say Heads or if not heads maybe cam?

Who built the engine for you? Seems like an odd combination of parts to me, but I could be wrong. Just does not strike me as a well thought out or matched set.

Please don't take offense I am not bombing you just offering my thoughts. I takes alot more than just putting in a bigger cam and a shot of nitrous to make an engine work properly.

is that cam designed for the compression you are running?

What exactly are the heads? a 383 needs air flow.

Many questions,but something is obviously not working right if you are only running 16's with a 383 and 100 shot of nitrous.

I am sure there are alot more knowledgable guys here to help you out.

good luck,
Dan

What gear ratio do you have-posi?- tires?
What is the RPM recomendation for the cam and were are you stifting.
paul

my first thought would be cylinder heads! Something with good mid lift flow numbers if you want to stick with the cam you have!
What is your trap speed? 60ft? 1/8 mile? What does the car weigh?

Well i ordered all the parts from P.A.W and then i put the engine together myself. when i bought the engine i tried to match up the parts as best i could. the techs at paw were the ones who suggested all the parts.

i still have the stock 6 cyl. rear end with about 3.28 gears but no posi. im not sure on the rpm of the cam but the engine was built to have power from 1200 to 7200 rpm. however it runs out of power at about 6700 and thats where i shift

Im not sure of the 60 ft. or 1/8 mile, but i know the 60 ft was somewhere around 2.6 and i know the tires spin almost all through 1st. and im not sure of the weight, my guess would be 4000 lbs.

i dont know a whole lot about building a high perf motor but i do know you can cam it all you want but witout the right head and good exaust it won't amount to much. and whats your total advance timing.

i also dont want to insult your perf but my stock 77 T/a will run that in the quarter without nitrous. my brother had a 69 chevelle with a 350 that was camed good ( dont know the specs ) 650 holley carb ,edelbrock performer II intake, and Dart II heads and when i raced him with my T/A he blew my doors off bad. so all in all i would look into some heads. i better add that his chevelle had a 2.73 rearend and was a one wheel wonder.

Spinning could be a big part of your slow times. What do you have on it for tires? Put some sticky tires on for racing. Is this a street car or just race (As in can you chop it up to make it lighter)? Go with a lower ring & pinion (change 12 bolt). If it's stock the rear suspension is proble'' worn. Rebuild with poly bushings.

I don't know when you are hittin' the nitrous but, 18 degrees of initial timing is pushing it for a aspirated motor. Blower motors usually run 12 to 15 degrees initial. I would revaluate your timing. If the heads, cam and intake are pretty well matched and the combo is good for 7200 you could have a total timing issue. Just some things for you to think about.

You absolutlely have a traction problem,that one leger aint gonna cut it.If your spinning though first gear that is the first think to fix. (Read much better gears/posi/good drag tires) Remember that the 1/4 mile is a specific race and such the chassis needs to be tuned for it. Seems to me that although the motor goes flat at 6700 RPM, with your gears your not through 4th gear., are you? Think of the 1/4 mile race as an 1/8 mile, but the second 1/8 your just pushing the loud pedal, not really but think this way. I would not run any laughing gas untill you can launch very hard and get to the top end of 4th gear before the end of the race.
paul

HMMMMMMMMMMMMM

I personally think you have a problem, it should run much quicker than that. DONT USE YOUR NITROUS NO MORE, you have problems bigger than that, ill give you some things i would check

Check fuel pressure-WOT and at idle
Check timing- are you setting it right? what is your overall timing? advance working?
Check plugs- see what they are burning like, possibly too lean, are your secondaries working properly??
Check for weak spark
CHeck to make sure when your pedal is mashed, that the butterflys are completely open

these are simple things but i think its a timing issue or carb prob also, yes gears would help and traction is critical but 16s is not what you should be getting. I think your gonna grenade that motor if you dont find out what the deal is first ESPECIALLY if your carb isnt tuned properly. good luck and keep us posted

-nova

your four barrels are opening arent they?

woah woah woah, this combo is NOT matched at ALL!!! You're shifting a stroker motor at 6700 RPM on stock heads? There's your problem right there buddy, your heads flow for those cubes only to about 5000 RPM, and you're done. THe rest of that spinning you're doing is just wasted ET. Furthermore, your cam is too big for the heads that you have, you have an RPM range that carries way on past what your heads can flow. I'll bet you pick up a second shifting the car at 5500 from now on. If you put a set of 215cc dart pro1 heads on this motor, tuned your chassis to hook up, put a 4160 carb on it and some 373 gears you'd be making friends with the 11 second bracket.

K

If I remember correctly The 300 is the lighter ,Cheaper version of the Chevelle. With a stock 327 the car should have easly turned in the mid to high 14s. Not trying to hurt your feelings,but you need help. I would not spend one more dime at this point. You are so far out in left field,that I would find someone, even if I had pay them $100 to go to track with me for the day to evaluate what I had and then he could make recomendations. Who knows? he might have You running 2 to 3 seconds faster in a few minutes.Make sure You select someone with a proven track record so You dont waste Your money. None of us are there with You and you're so far off its very difficult for anyone to say what the problem is. It could be something simple.I hope so!

well let me try to redeem myself a little bit infront of u guys. First off the nitrous was only on for a few seconds in second gear and even then it was only in spurts. so thats why the time wasnt very much better. question do u guys know of any kind of a respectable dyno tune shop in the valencia, santa clarita area. I could really use some helpo as u can tello. ho ho ........ anyways. u guys have definately made it obvious that i have a problem. im hoping to race tomarow night at LACR w/out nitrous so i can tell u more hopefully some other time. thanx for the suggestions. WOW i feel like an IDIOT.

66 Chevelle 383

First of all, your no idiot. You were able to build the engine yourself and thats more than many can say. As for the suggestions above, most are right on in most cases...so take all of this in stride.

Remember a 383 Stroker Chevrolet was created to deliver big block torque from the size of a small block. And if combined with complimenting internals, it will. But as with any combination for any engine size...if you have things fighting each other you won't be happy with the results.

I agree with Killer Formula above. The 383 is designed for torque in an RPM range which usually ends around 5000-5500. Most of the cams designed for torque will show this. That doesnt mean you can't build an engine to turn faster than that...it only means you have reached the point of diminishing return. When this happens, you simply have to shift into the next gear and start the process over again.

Stroker motors have been designed to reach peak performance depending upon what the goal was. "Stroked" engines were designed for torque while "Destroked" engines were designed for RPMs. Both have their benefits and their weaknesses.

From what you have described, you are losing momentum trying to turn RPMs. I would use your 383 to do what it was created for: Quickness. So simply set the chassis to work with the strategy of getting off the line quick, then accelerate through the "correct" RPM range (up to 5500 or very close to it...just look at your cam specs to determine where the point of diminishing return is), and then shift. Finally only add nitrous after you have perfected the tuning. Otherwise you are just amplifiying a bad set-up and eventually you will pay the price.

His point about the heads is right on as well. If you can't get the air into the cylinder, you wont get the maximum benefit from the 383 (or any engine size for that matter). You will be surprised what airflow will do for you. I would also take the exhaust into consideration(headers, tubing diameter, restriction or lack thereof...etc). Highflow exhausts are for RPM motors(Destroked)...Chevy 302, or the Chevy 327. Since Strokers are designed for lower RPMs the power range is weakened by huge exhaust and large headers. Even I learned this the hard way, but I ain't gonna admit to being an idiot just yet. Its just comes with the territory. If it were easy, and we all new the secrets...we wouldnt need this great website.

Don't give up...you'll get there faster than you think.