Ello with 383 troubles

[MKCoconuts]

Okay, to start, names Sean and I'm not a Mopar guy, I'm more of a GM guy, but my father is all Mopar all day. He owns a '66 Plymouth Satellite that was originally optioned with a 273. When we got the car, we went through the process of restoring the car. We stuck a 318 poly in it which ran brilliant. We then swapped that out for 318 LA, which also ran flawless. But he wanted a big block and we came across a deal on a 383 with the transmission that he couldn't pass up.

The deal ended up coming with the engine, trans, full rebuild kit, purple camshaft (I'll get specs when I get back home), electronic ignition, and other little things. We purchased a Edelbrock Performer series intake, part #2186, LT headers, a Cloyes Double Roller timing chain. We reused our Edelbrock carburetor 1405 from the 318 which we later found out was a 600 CFM. The car has a 2500-3000 stall converter and we believe 2.93 rear gears.

The trouble we are having is the car is a complete dog off the line, literally, my mothers minivan has more acceleration. Once it gets up in the rpms, it seems to pick itself up and go. I've tried coming with ideas on the issue but haven't found much info.

We are thinking of 3 possible causes:

1) Carb is too small

2) He got the valve timing off when he installed the DR.

3) Rear gears are holding the car back (I'm thinking this is mostly likely it, but he doesn't feel it'd bog the car that much)

Any help/suggestions would be much appreciated. If any one needs/wants more info on anything, I'll try getting it as I've been helping with the car. I'd love to get this figured out for him because it's gotten to the point where I think he's really serious about selling the car, regardless of how much he loves it.

 

[whosyurdaddy]

I would start with a new 750 cfm carb

 

[monaco66coupe]

I would also double check the timing, using a Vacuum gauge to determine the most optimal setting, let us know what it is. Then, see if the distributer is advancing properly. That stall is pretty high,what are the specs for the cam? Personally I don't care for such tall gears with a setup like you have, as it is contributing to the Issue, IMO. 3:23's would help.

 

[mopar 3 B]

The carb is to small and it needs more gear try a 3:54 to 3:90 or else ditch the big cam.

 

[MKCoconuts]

Here's the cam specs off the box, Purple camshaft P4452783, lift of .450/.465, duration 268-284, centerline 115, overlap 26.

When he initially got the big block, I had mentioned him getting a stall and gears, since he was putting a mild cam in it. I picked the stall for him going by a Mopar Performance book a friend has, however, it did not give a recommended carb cfm. I can go over with him on checking the ignition timing and seeing if the distributor is advancing as it should.

Assuming that the timing is okay, the general conclusion would be too small of a carb and too tall of gears? He did get a set of gears but got it for a 489 case where else he has the 741. I'd love to be able to have this figured out for him. He's taken it to one car cruise this whole summer and I'd hate to see him lose his love for the old muscle cars.

 

[monaco66coupe]

That Isn't a radical cam. No need for the stall, and 3:23-3:55 would really help. A Bigger Carb per Mopar 3 B Is also a good idea.

 

[Hemi 354]

Hey, let's wake this puppy up. Yes, increase the carb to a 750, reduce the stall to a 2200-2500, and for heaven's sake, dump those 2.93 gears for something more like a 3.23....preferable to a 3.55. All the other items in previous posts apply as well...timing, etc. Personally, the lift on the cam is not out of line at 4.50/4.64 (I run a .5.01 lift in my 383 to keep it tame, but could go extra if needed).

 

[monaco66coupe]

X2

 

[SlinktRR]

Here's the cam specs off the box, Purple camshaft P4452783, lift of .450/.465, duration 268-284, centerline 115, overlap 26.

When he initially got the big block, I had mentioned him getting a stall and gears, since he was putting a mild cam in it. I picked the stall for him going by a Mopar Performance book a friend has, however, it did not give a recommended carb cfm. I can go over with him on checking the ignition timing and seeing if the distributor is advancing as it should.

Assuming that the timing is okay, the general conclusion would be too small of a carb and too tall of gears? He did get a set of gears but got it for a 489 case where else he has the 741. I'd love to be able to have this figured out for him. He's taken it to one car cruise this whole summer and I'd hate to see him lose his love for the old muscle cars.

I would try rejetting the carburetor richer. What metering rods, springs, and jets are in it now? 600 is small for a 383 but it will be ok for street at <4000rpm. Basic stuff, is the throttle cable adjusted right and timing set?

It's a pretty mismatched combination but should run good enough. My guess would be not enough fuel with metering set for 318ci engine.

 

[mopar 3 B]

Do not think there is enough jetting in the world with the 600 cfm it needs more air flow and your carb just will not due it. The 4000 rpm range would be great for a 440 but is going to kill the 383 from ever reaching it potential. Your combination done right will want to road min. at 2600 rpm with automatic and 3:23's and 2800 rpm with 3:54's with peek power at about 4800 rpm. Do not expect to much before 3200 rpm so why in the world stop it in the middle of the power band. If the 2:94 gears were the real goal should have left it stock were there was plenty of bottom to get things moving.

 

[440roadrunner]

Disagree completely. Might be as simple as winding that cam advanced. I was recently involved with a local kid and a purple shaft, it turned out it needed to be moved something like 6 degrees. Part of this was that manufacturing tolerances put it 2 degrees retard from where it should have been, and the other 4 was to improve low end. Completely changed everything.

That 600 cfm carb should be dynomite out of the hole. What do you think CAME on some of the older stuff? The old AFBs were not very big

WHERE IS THE timing, and what is the advance curve????

 

[MKCoconuts]

There are two reasons he put the purple shaft in, 1) it came with the engine deal free, new in box and 2) factory cam wiped a few lifters.

I will discuss with him about getting a bigger carb as well as the correct steeper gears.

I'll stop by as well and see where the timing and such is at.

Thanks everyone for the help!!

 

[Yatzee]

Well, I run a 383 with a Performer intake, 680 Edlebrock carb, TTI headers and 323's out back. The exhaust is 2 1/2 TTI system with Borla full flows and the tranny is a 727 with TCI shifter body. If you want to ride with me put a dipper on to keep my seats clean. Don't know what you're doing wrong but a 383 is a strong, quick winding engine and should get up and go like stink.

 

[WileE]

Hey, let's wake this puppy up. Yes, increase the carb to a 750, reduce the stall to a 2200-2500, and for heaven's sake, dump those 2.93 gears for something more like a 3.23....preferable to a 3.55. All the other items in previous posts apply as well...timing, etc. Personally, the lift on the cam is not out of line at 4.50/4.64 (I run a .5.01 lift in my 383 to keep it tame, but could go extra if needed).

what he said. Your total combo is way off

 

[383man]

The first thing I want to ask is where is the cam degreed at. You say the centerline is 115 but that sounds more like the lobe separation angle (LSA) to me. If you have the cam on a 115 installed centerline that will make it lazy off the line more. Most of the Mopar cans like that one usually call for about a 108 to 106 installed centerline which is where you would have the cam installed. The LSA is ground into the cam and cant be changed but the installed centerline can be where ever you put it and if it was put at 115 that sounds very late for that cam which will make it feel lazy off the line. Ron

 

[440roadrunner]

The first thing I want to ask is where is the cam degreed at. You say the centerline is 115 but that sounds more like the lobe separation angle (LSA) to me. If you have the cam on a 115 installed centerline that will make it lazy off the line more. Most of the Mopar cans like that one usually call for about a 108 to 106 installed centerline which is where you would have the cam installed. The LSA is ground into the cam and cant be changed but the installed centerline can be where ever you put it and if it was put at 115 that sounds very late for that cam which will make it feel lazy off the line. Ron

..............Which is kinda what I was pretty much 'xactly gettin at earlier,

 

[MKCoconuts]

The original box reads centerline of 115. It does not, however, list the LSA on the box nor does the Mopar performance catalog we have list it. However, if I bring the part number up on Summit Racing, they list 115 as the LSA and do not the list the centerline.

I'm going to get the ignition timing today. I was discussing things with him last night and he's pretty certain that when he installed the timing chain, he got it off a few. As much as he hates too, we will tear it down after we check the ignition timing and see where everything is at. If it is as simple as a timing issue and it helps make the car more what he wants, that will persuade him enough to spend the cash on a bigger carb and steeper gears.

- - - Updated - - -

Another question I should ask, since my dad wasn't sure, but with an aftermarket tach and the electronic ignition that is now installed in his car, does the signal wire for the tach get hooked up the same as it did with the points system?

 

[Garys1969RR]

Also make sure you are running about 20 degrees of initial advance, with 38 total

- - - Updated - - -

My sons 383 was running poorly, no power, slow off the line, no torque. We found the spark looked weak, so we replaced the old elec ignition box, and now it runs great! Lots of power. It starts right up, where before it was hard to start. Runs low 12s at 110 with nitrous.

- - - Updated - - -

Not sure which wire the tach hooks to. Try unhooking it and see if that helps. Pull the coil wire from the distributor, hold it close to ground, and crank it to see if you are getting long, high energy 1 inch blue-white sparks jumping to ground.

 

[440roadrunner]

The original box reads centerline of 115. It does not, however, list the LSA on the box nor does the Mopar performance catalog we have list it. However, if I bring the part number up on Summit Racing, they list 115 as the LSA and do not the list the centerline.

I'm going to get the ignition timing today. I was discussing things with him last night and he's pretty certain that when he installed the timing chain, he got it off a few. As much as he hates too, we will tear it down after we check the ignition timing and see where everything is at. If it is as simple as a timing issue and it helps make the car more what he wants, that will persuade him enough to spend the cash on a bigger carb and steeper gears.

- - - Updated - - -

Another question I should ask, since my dad wasn't sure, but with an aftermarket tach and the electronic ignition that is now installed in his car, does the signal wire for the tach get hooked up the same as it did with the points system?

Somehow I missed, or you didn't say? just what you have for ignition. Mopar breakerless? MSD? other? If it is a "switched" system like Mopar, yes, the tach goes to coil NEG. If it is a CD system like MSD, no it does not. Also MSD and "some" dial up timing lights don't work well togethre.

 

[MKCoconuts]

Ooops. I guess I didn't say! Ha. It's a factory Mopar electronic ignition. I'd like to have it hooked up when we check the timing.