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henrys57wagon 04-27-2014 09:08 PM

headers glowing red
 
On our 350" NHRA stock engine we removed the crappy HEI distributor the other night and installed an MSD with a small cap.
Last year you could not stand near the car without your eyes watering. We fired up the Nova(after sitting all winter) and set the timing to 15* at 2000RPM which is idle for this set up and checking the max timing which is 31*, we just wanted to get it running and then tune the dist after.
I noticed the headers glowing red. We shut it down and I removed the carb, by the way the exhaust was not the bit irritating this time.
Our thought is that the old dist was not igniting all the fuel which caused the crappy exhaust smell and now with the new dist it seems lean and needs to be richened up. I must add there is a 1/8" hole in each primary throtle plate and the idle screw is in to where the idle circuit is not functioning. I am going to try a non modified carb but would like some direction to head towards.
The carb is one I did about 20 years ago and when last run the car ran in the mid to low 12's.
So where would you direct me to look to get this thing back on track, we are not racing it this year but would like to drive it now and then, it is street legal(more or less) . Thanks, Henry

M&M Motorsports 04-27-2014 10:45 PM

Re: headers glowing red
 
Try setting total timing to 38 degrees. Looks like fuel is being burned after exhaust valve is opening causing extra heat. Hope this helps.

Ed Wright 04-27-2014 10:53 PM

Re: headers glowing red
 
Fifteen degrees @ 2000 will sure warm them up. Put some timing in it.

Alan Roehrich 04-27-2014 11:12 PM

Re: headers glowing red
 
Yeah, a small block Chevy is going to like closer to 36 degrees total. And at 2000 RPM, you should be at least 2/3 of the way there, if you're going to run with a mechanical curve instead of a locked distributor.

henrys57wagon 04-27-2014 11:26 PM

Re: headers glowing red
 
Thanks for the help, we used to set it up around 40*, never bothering to set it lower, amazing how much you forget when you don't do these thing for a while. I will clean out the carb and try it this weekend and let you know, Henry.

rod butcher 04-28-2014 09:05 AM

Re: headers glowing red
 
Lock the distributor out and set timing at 36 degrees and test moving 2 degrees at a time up.

Jody Lang 04-28-2014 11:13 AM

Re: headers glowing red
 
Is it a Q Jet with primary metering rods?

Greg Reimer 7376 04-28-2014 12:02 PM

Re: headers glowing red
 
Back in the early/mid '70s, the era of the most horrible performing cars on earth, a guy backed his '74 Cadillac out of his garage, got out to close and lock the door, and he left his car running on fast idle-around 2000 RPM or so. The phone rang, he ran inside to take a call, which lasted about fifteen minutes, and the car ran at that speed the whole time. He got off the phone and came out to find the cars' exhaust manifolds, the Y pipe, and the head pipe to the muffler cherry red hot. He panicked, shut the engine off, whereupon it dieseled like crazy for several minutes, and then backfired and quit. He had no idea that a by product of retarded ignition timing and a late closing camshaft was excessive exhaust heat. He's lucky he didn't burn the whole place down. Set the timing to 36-38 degrees at 3000 like everybody says, and I bet you find that the engine's idle improves significantly as well. Good luck, let us know what happens.

njk53 04-28-2014 03:16 PM

Re: headers glowing red
 
Agreed too little timing. SBC should stand 40 degrees of total timing. But, all engines are different set it at 36 degrees and raise it in 2 degree increments.

henrys57wagon 04-28-2014 08:35 PM

Re: headers glowing red
 
Thanks again guys;) As far as the primary throttle plates go what size hole do you have/ recommend, ours are 1 in each primary plate and 1/8" dia?
The throttle plates are well past the idle slots and am wondering if I should drill another hole in each primary plate to get the plates back to where they allow the idle circuit to work? Or keep increasing the size of the one hole?

Quote:

Originally Posted by Jody Lang (Post 429447)
Is it a Q Jet with primary metering rods?

We are still running the front metering rods. The car will be mainly a street car. We have kept our 69 Stocker engine but with a 2800 stall and only a 373 street gear in it now, but LOVE how the engine performs on the street:D


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