The V8 Owners Forum -

Finally got my engine running (3.9 hotwire), however whilst running the cam in (around 2000rpm) about 2mins in all the stainless steel headers started to glow bright red apart from no1 cylinder, obviously I stopped straight away, but I'm now scratching my head to why its happening. Presumeably this is not normal and its caused thru too leaner mixture , if this was the case it would be on all cylinders would'nt it?. I'm now in the process of checking all electrical connections, hoses for air leaks etc.

Any of you knowledgeable chaps got any ideas because I haven't

Thanks

Leigh

Retarded ignition?

Mechanical cam, tappets too tight, or with a Hyd cam lifter pre load incorrect, Massive air leak, Ign timing,
On the negative side, blowby on the rings, leaning out the engine, I have only seen it on a Blown SBC but the engine had 2 pipes that would glow almost white in a few seconds of starting, due to shagged rings.

Leigh

I had similar very high temperatures on the headers - discoloured the stainless badly and at £800 they are not likely to get replaced for a shiny set soon!

As it ran more it calmed down but I did loadsa checking and had it to numerous "specialist" to check the EFi which is what I thought was faulty but nobody came up with a definative answer.

I also got a can of "quick start" and when the engine was idling spryed it around the inlet connections - no leaks (engine will run faster if it sucks the stuff in)

Yes recheck the timing as it could be out
Yes recheck the electrical connections
And specially recheck the connectons on cylinder of the header that did not glow - check the spark plug on that one with the others - should not be too much difference - if sooty it ain't running.

If you can also get a spare Ecu and try that - not that easy to get hold of for a quick test but they do ome up on evilbay

What part of the country are you in - there may be someone close who has a spare

Cheers
ian

Leigh

Another thought is your tune resistor correct for the setup? Running lambda sensors or not?

Ian

Cheers, for all the replies guy

Ian, the tune resistor I've got is the green version (I'm not running cats), I'm based in sunny North Wales - Wrexham

So far I've checked for air leaks - none, electrical connectors -seem good, set the timing with the strobe light (haynes recommend between 4 -8 atdc), Will put the plug out of No1 cylinder and check that and will be taking the multi meter to the ecu/afm etc and checking them out.Pretty sure its not blowby as I fitted new pistons and new oe rings

The stainless headers themselves (from simpsons exhausts)are brand new items and seem thinner gauge material than my previous mild steel ones , would they be more prone to heating up or am I clutching at straws with this reason

This engine building lark is more frustrating than building the rest of the car!

Leigh

if you have set your timing to atdc its wrong and retarded it should be btdc

Still could be blow by, as the rings wont have bedded in yet, Unlikly to be the problem, as long as they were gapped correctly and you are not using synthetic oil,