Moparts

need advice

Posted By: coronetkid

need advice - 09/22/09 08:03 PM

ok here we go guys
383 .030 over
Cam *P4529318 320/320 272/272 104 108 0.533/0.533 P5249848 3600–6300 1-Bolt
timing is 33 degree all in at 3000rpm
performer RPM intake
850 dp holley
flat top KIeth black pistons
full MSD ignition
1 7/8 hookers into full 3 in. TTI H pipe into 40 series flowmasters
3500 ATI stall
4.10 gears with 28 in tall M/T slicks
all that said my best run to date is 13.49 with a 1.935 60 ft.....
is this good for my combo? does it sound like something is wrong or missed matched? i was just expecting better.....by the way its in a 68 coronet.. any suggestions?
Posted By: an8sec70cuda

Re: need advice - 09/22/09 08:07 PM

What heads and compression?
Way too much cam and not enough timing. CHIP
Posted By: coronetkid

Re: need advice - 09/22/09 08:15 PM

906 heads..not sure of comp...was told 11.4 to 1 but think the builder was smoking crack...it runs fine on 93 octane....what would you do with timing?
Posted By: 66coronet

Re: need advice - 09/22/09 08:22 PM

We ran our old 383 for years at 38 degrees. How much does the car weigh? Have the heads been worked on any? Is the cam in correctly? ie are the teeth lined up on the timing gears? Was it degreed? Based on our old 383 numbers, I would think you would be well in the 12s with that combo.

Attached picture 5499037-pinkslaunch(Medium).jpg
Posted By: an8sec70cuda

Re: need advice - 09/22/09 08:22 PM

I have a set of KB flat tops in a 383 I built a while back and had to cut the heads .060" (906's) just to get it over 9:1. I seriously doubt you have anywhere near 11:1.

I'd bring the timing up to atleast 38 degrees.

I bet it didn't spin the tires at all did it? What's your mph at the 1/4? CHIP
Posted By: coronetkid

Re: need advice - 09/22/09 08:32 PM

38 degrees in by 3000 rpm? forgive me i'm a newbie this is my first car. and it actually does a pretty good burnout...
Posted By: WILD BILL

Re: need advice - 09/22/09 08:47 PM

I think he was refering to off the line not doing a burout.

I would try 38* all in by 3000 RPM.
Posted By: an8sec70cuda

Re: need advice - 09/22/09 08:57 PM

Yes, 38 degrees all in really early.

Wild Bill is correct, I was referring to not spinning off the line, not the cars ability to do a burnout. That cam in a low compression 383 w/ only 33 degrees of timing won't be a stump puller by any means.

You need more timing, less cam, and more compression.
MUCH more converter if you plan to keep that cam. Less carburetor too...I know the 383 we have ran a lot better w/ a 750 on it than it did w/ an 830.

A few things are mismatched, but if you're having fun with your first car then by all means, run it! I don't mean to sound like I'm tearing it apart, just pointing out why it's not running like you hoped it would. I bet it sounds NASTY with that cam though! CHIP

Attached picture 5499094-cudadriveway.jpg
Posted By: coronetkid

Re: need advice - 09/22/09 08:59 PM

if i go to 38 is thing still going to run on 93 octane? if it starts to detonate how will be able to tell? my exhaust is very loud....so i think i'm goin to steal a 750 dp off my wifes monte carlo and go to 38 degrees. sound good?.....and yes Chip it does sound very nasty...but it's all noise and no go right now. thanks for the advice..
Posted By: an8sec70cuda

Re: need advice - 09/22/09 09:16 PM

You'll hear it if it does, but it should not detonate. I think you'll be fine.
I bet you'll find the 750 and more timing wakes it up, but don't change both at the same time. Reset your timing, then go drive it and get a seat of the pants feel for it. Then swap carbs and test drive it again...or better yet, swap them at the track. CHIP

Attached picture 5499125-hemicudaPGD.jpg
Posted By: coronetkid

Re: need advice - 09/22/09 09:18 PM

Chip the mph was only 99.6
Posted By: DblOJoe

Re: need advice - 09/22/09 09:22 PM

With your compression I'd think you could run 38 - 42 and not have a problem. I'd try the 750 off the other car also.
Posted By: dizuster

Re: need advice - 09/22/09 09:27 PM

Since you're not 100% sure on the compression, I would put a compression gauge on it. It's not perfect, but it will give you some kind of idea where the compression is at. My guess is the cranking compression will show it may even be fine on less then 93 octane...
Posted By: 383man

Re: need advice - 09/22/09 10:25 PM

I ran a 9.6 to 1 comp 383 with 452 heads and the MP .484 in a 383 Dart. I ran 38 total all in by 2000 rpm. I used the RPM intake with a 750 DP. With the 3.91 gears and a full body and interior Dart it ran a best of 12.31 @ 110. And it ran fine on 93 or 92. I have to agree with Chip on this as its too much cam for the combo and not enough converter. But since you have it together try bumping the timing to 38 and see if it likes it. If you can get the combo sorted out your car should be deep in the 12's. Good luck , Ron
© 2024 Moparts Forums