mcollinstn

Not to mash Cord's idea, but all of the Dominators I've played with have idled better than most of the cheapo vacuum secondary fixed metering plate street Holleys out there (in their out of the box form).

All 4 corner Holleys have good idling manners (some may need the bleeds opened up some).

I'm not saying that the TYPE of exhaust is causing an issue. I am saying that a header air leak CAN do exactly what is happening to you. I had an inline Jeep with 6 into 2 headers that all bolted up with the intake manifold and headers and common gaskets and everything else. NEVER got all the header leaks taken care of no matter how many gaskets I used, how flat the weld rings on the header flange were, or how I shimmed the bolts... That booger would pop and blow flames on decel. Got to where I could "feel" it getting ready to blow a big flame and give it a tiny quick squirt of the accel pump right at the flame and blow a 7 footer out the right side pipe. If I timed it right, I could flatten the flame out against the driver's window of cars in the the right lane. Did it to a kid I went to HS with and it scared him so bad he drove into the ditch with his date. I had 4 buds piled into the CJ and it got all over school. Ah, so fun were those days.

Anyhow, ANY small air leak near the head flange WILL do what you describe.

Try whatever's quicker - careful torquing of new gaskets on the dyno headers - put your mani's on it, whatever.

If you DO run your mani's then don't do it dry - run water thru them. Not worth the cracking you'll likely get in the tailpipes.

mopower

What I figured on doing is hanging them on the engine and filling the with water with the hose on the bottom , then pinch it off with vice grips to hold it in. This will act like a heat sync and give me an extra margin of time and safety. Like I said , it will do this even at a cold start , so 10 seconds will be more than enough.
I had a 68 Camaro (new) and I had a problem with the A.I.R. system and blew a seam out of the muffler.

As for the Dominators , I 've never really had a problem with drivability. These were boogered up last season to try to mask the real problem but have been returned to normal parameters.

38KV

Leaking intake valves?

(caused by soot)

That was my problem a few years ago.

mcollinstn

A main key point here is that it isn't backfiring or popping back thru the carb. It is popping out the exhaust.

mopower

Right

PatriYacht

While I'm not sure your carb is the problem, Holley has a web site full of info. www.holley.com They make 1050's in lots of different configurations. Go to tech support. Look at the pdf chart to find your carb. It lists jet sizes, power valves, boosters, etc for each carb.

I'm using a 1050 on a 540 with no problems. With a Crane 651 hyd. roller, mine idles at 800 rpm all day. Throttle response is excellent. Mine was factory equipped with 88 jets and 6.5 power valves. It was a little lean so I went to 92 primary, 94 secondary. Hope this helps.

mopower

Pat,
Thanks , Already spend 1/2 hour on the phone with Holley . Got 92 around now. Also went over idle ckt (35 fuel and 52 air). Intermediate constant 43 , discharge tube 38 and air bleed 95. Main bleeds are.034 At this point it runs great and egts are fine and idles like a ***** cat (well , maybe a lumpy ***** cat). I think the carb problems are solved. And Holley was a GREAT help.
Just have to solve the popping out the exhaust and I really think mcollinstn is on to something with the leaky dyno headers

mopower

mcollinstn,
Your PM box is full. Now I have to give you a public thankyou.
Thanks for the heads up on the leaky header gaskets
Just got off the dyno with new gaskets and I also removed the probes for the EGTs and sealed those holes.
Quiet as a church mouse
I've had SO many problems with these engines I overlooked the obvious for the more complex. Shame on me.
Thanks again,
Cal (mopower)

mcollinstn

PM box clean now.

You're so very welcome.

In lieu of flowers or praise, please send money or beer or passwords for celebrity porn sites.

mopower