Header tubes glowing on cam break in

[RustyCrankshaft]

Just me trying to learn here so no  retaliation please. But some one explain how timing could effect one side of the engine and not the other ?  More than double the temp ??   I would have went with one side of the carb lean but he has a dual plane intake kinds of rules that out too
Thanks Russ

Sort of off topic, but even with a dual plane you can get some cylinders lean and not others pretty easily. On a lot of boat engines I've built they end up with 4 different jet sizes to get the A/F and EGT evened out on all the cylinders. Obviously a far different application than a 4 tired application, but a good demonstration of fuel distribution. A lot of Mercuiser 454's and early 502's came from the factory jetted that way with iron dual planes (aluminum on a few "Magnum" ratings). 

[nandoz]

I really wish it was the timing. That would have been a much easier fix. If none of the cylinders on the right bank will hold pressure, the timing is kind of a moot point. I agree timing and bad carb tuning probably account for the vast majority of idle quality/drivability/ general malfunctions. I double checked my carb settings, and the plug readings backed them up. Unfortunately the top end has to come off the engine. I will pull it apart this weekend, and post my findings. If I can't find anything visible to point at, I have another set of heads to try. By the way static compression is 9.23:1. The cam is 228/228 @ 50 with a 114LSA, so not a ton of overlap there.

[My427stang]

I missed your air leak test was thinking you were just fighting the hot pipe.  RTFQ Ross....LOL

[nandoz]

I'm not sure how/why it started and ran good with four out of 8 cylinders not sealing.

[My427stang]

If you had access to a leakdown tester it would likely tell you more.

However, with a compression check I'd be looking for common numbers more than anything, do one bank and the other, best way is plugs out, battery charger on, and throttle wide open.  I'd guess 165 psi or so, but the key is, all 8 within 10% or so.

As far as what happened if the air leak you hear is greater than just normal air blowing past the rings....who knows, valves can get pretty close if rebuilder type pistons and kiss, maybe deck is crooked.  I'd say a leak down test and disassembly would be your friend

[Falcon67]

Agree - just blowing 40 psi in there isn't much of an indicator of anything.  Compression test, then repeat test with some 30wt squirted in the cylinders - significant change would indicate a ring issue.  No change could indicate valve issues.  Leakdown check is usually run at 100 PSI.