383 stalls when warm, please help

[jackn440]

hi, i have a 1970 challenger with a 383. it is not the original engine, and i have had it in the car for almost a year. it ran strong, but was getting some blow by and loss of compression, so i yanked it out and did a re-ring. while i was at it, i added a slightly larger cam, new lifters, new timing set, new h.v. oil pump. i got it fired up for the first time today, dialed in the timing, ran it at 2000 rpm for 15 minutes or so, good oil pressure, 10 degrees btdc, etc. the engine fires right up and runs fine until it reaches operating temp. as soon as it's good and warm, it dies instantly as if the key were shut off. i have good fuel pressure to the carb, the filter is full of fuel all the time. at first i thought that the coil (msd blaster 2) might have been getting too hot (let's face it, right on top of the intake is not the best place for it), so i moved it over to the inner fender well. same deal. runs fine for a while, then just suddenly stalls and has trouble starting again. after the engine stalled, i checked for spark and still had plenty. if anyone has any ideas, please let me know. (keep in mind, the car ran just fine before i pulled the engine and did not change the carb settings.)

 

[djwhog]

no huge vacuam leaks buddy?

Can you put a gauge on it to see what it is.

But are you saying that even if you hold the rpms off it just dies when warm?

If so you said it has spark, but maybe only in crank mode and not run mode, you check to make sure it is getting fuel still when hot?

 

[burdar]

Were the rings gapped properly? It is a longshot but the rings could be expanding and the ends could be touching. That may cause enough pressure against the cylinder wall to stall the engine. Does it crank over fine right after it dies?

I would still put a different coil on it just to see how it acts.

 

[beepahh]

try this take a can of brake kleen and spray around the intake manifold and carb right after you star to check for vaccum leaks will show you real fast if there is one......

 

[djwhog]

Or use WD 40 brake kleen may be to flamable buddy, be carefull!

 

[burdar]

DON'T use brake clean. Use carb clean or WD like was said above. Some cheaper brake cleaner can turn to mustard gas when exposed to heat. There was a big thread on Moparts awhile back reguarding the brake clean issue.

 

[jackn440]

Thanks for all the advice, guys. I finally got it to stay running. Like burdar suggested, my coil was no bueno. I had a spare flamethrower coil sitting in the shelf, so i threw that on and she hasn't stalled on me yet. The msd coil was still building a lot of head, even mounted way over on the fender well. Thanks again guys!

 

[djwhog]

Are you using or bypassing the balast circuit for the MSD?

Glad it is running..