Recently put a Hughes Whiplash cam in a 71 383 and I'm having some problems. According to their website, you should be able to use a stock converter with this cam. It kept choking down the engine and dying when put in gear, so I replaced the stock converter with a 2800 stall unit. It's better, but I still have trouble keeping it running in gear. It acts almost like there is a vacuum leak somewhere. It is a 71 383 that was freshened up. 8.5 to 1 compression, fresh set of 346 heads with valve springs to match the cam, torker intake, Hooker super comps, 3310 Holley carb, factory single point distributor. I have replaced the intake gaskets using a new bathtub with the Fel-pro sandwich gaskets. I checked the carb base to make sure it isn't warped. This engine ran fine with the same set up before, the only difference was a factory cam and a Carter AVS carb. I have tried the avs with this cam and it runs the same as the Holley. I installed the cam straight up,should I advance it a couple degrees? I'm drawing a blank here.

yes you should advance the cam, prob 4*.
you are also going to want to run alot of initial ignition advance, you have to modify the advance plates in the dist so your total timing will be proper.

Agreed, & rework the timing first (& if you adv the cam then the timing needs to be reworked again). bump up the initial for a start, what are you running now?

I'd put the stock dual plane intake back on first before any other changes

Trouble keeping it running in gear , how many Rpms does it drop in gear versus park , you mentioned vacuum leak - Did you spray looking for leak

Factory single point distributor , with the 1971 electronic retard box on distributor ?


I would bee looking at dwell versus timing versus points versus distributor springs especially if factory original


Distributor intermediate shaft and rotor position versus spark plug wiring order

Timing set position dot to dot , double check if you only replaced the camshaft

Sounds like your overlooking something simple

Torque Converter would have been the last thing I would have thought of based on what your saying

The motor came with the Torker on it and unfortunately I don't have a dual plane for a low deck engine. The distributor is an older unit, doesn't have the factory retard box, I believe it's a 67 unit. It also has lighter springs in it. I have sprayed all around the intake and carb with no change in idle. Don't have a tach hooked up, so I am not sure what the difference in rpm from park to in gear is. The carb is one that I rebuilt. I have always had good luck when rebuilding Holleys, but I have a new carb on my pickup that I will try. I know that one works well. Timing is set at 14 btdc. I am going to change to factory electronic system. Also, I degreed the cam when I put it in, so I know the cam was ground to the specs Hughes said it was. This car has been one big pain since I started working on it. I seem to get one thing fixed and find two more things messed up. A simple cam change shouldn't be this much trouble.

The torquer is a really poor intake and hard to tune a carb to work on IMHO, need a performer or perf rpm, or a stock intake. The only good single plane is Holley street Dominator.

I love it when people start changing out carbs..... "I just did this and now it runs terrible" did you use any real diagnostic tools or are you just going to keep changing parts till you find something that fixes it? did you check lifter preload? did you put a vacuum gauge on the motor to see where it is? doesn't sound like it. keep changing carbs....

I think the whiplash cams already have the extra advance ground into them so I don't know if you really should need to advance it more. 14° is not enough initial timing. Bump it up to 20 and retune your idle rpm and mixture and I bet it will run great. You will have to recurve your distributor after.

I'd also try 20. Do you have the correct power valve for the amount of vacuum you have? If you turn up the idle will it stay running when you put it in gear? I had good results with the torker intake on b engine I wouldn't blame it for this.

may need more initial timing; which the distributor should be reworked to reduce centrifugal degrees in it. single plane intakes/low vacuum cams/low compression/high overlap aren't a good mix for something your going to drive. power valve in carb may need changed. to me this is the perfect example for not over camming a 383.

just looked at hugh's website. that cam has 21 degrees of overlap at .050". that's nearly identical to the 284/.484 cam. in my opinion, over cammed for 8.5:1 compression 383 and definitely won't run thru stock exhaust manifolds (if they're being used).

I'd get it running with points. Each change made adds another variable. Find the reason its got no power.

http://www.hughesengines.com/Index/produ...mp;partid=30172

over 230* on a 383, it will want at least 16* initial and maybe up to 20*.
Once that's done and off idle is OK, the rest of the curve can be corrected;
either by moving the both spring perches out, and if needed by also shortening the slots. Depends on what the factory curve looks like to begin with.

Tach - for idle with points or a simple ECU, a tach/dwell is the easiest. Easy to find at garage sales, etc.

Vacuum gage - really handy - totally worth it. Mityvac silverline also really handy and a good investment. With that you can figure out what the vac advance is doing.

Timing Tape - Black with white or yellow numbering.

Things thing s will help you. There's still a learning curve, but it takes a guy with tons of experience to do it by sight sound and smell. Even then, those guys will still use instruments to fine tune and write in their notebooks.

you installed the cam at 102* like that hughes link ^ suggests ??

^^This^^ Start with the timing. As someone else posted I think the advance is ground into the Hughes cam, but verify where it is anyway. I also agree that the intake is not a good choice for this engine.

The point about the power valve is a good one as well. Those whiplash cams are designed for low vacuum at idle for that rumpety rump sound that everyone wants. With low vacuum your power valve might be dumping fuel at idle.

In his initial post he said he also tried the Carter AVS with this cam

He said it ran the same as the Holley

those cams have 5 degrees of advance ground into them. I wouldn't advance the cam any more. the website also states low vacuum. low vacuum needs serious distributor and carb recalibrations. it's just plain the wrong cam. everything else is putting band aids on the problem.

Yella71, it's because of dicks like you that more people don't post questions on here. If you don't have anything productive to add, kindly keep your pie hole shut.

Initial timing...

FBO sells a plate to limit the amount mechanical advance in the distributor so you can run a lot more initial ...the plate is pretty cheap.

http://www.manciniracing.com/fbomodilipl.html

I see you are in Oregon..so is FBO

http://www.4secondsflat.com/Mopar%20Mechanical%20timing%20limiter%20plate.htm