RED HOT HEADERS WHEN IDLING

[pfcvdv]

hey guys, i got a quite concerning problem...

i was trying out my new sbc 355 in my buick for the first time. i was running the engine @ 1000/1500 rpm when i noticed the headers where red hot. a few seconds later the engine backfired and stopped immediatly.
im concerned about the abrupt stop. because i had backfires before but that didnt kill the engine.
what was going on and how can i help it?

thanks

 

[custom442]

lean backfiring.

fuel + timing issue

 

[pfcvdv]

lean backfiring.

fuel + timing issue

im running the engine on lpg so mixture is always right...

 

[khan0165]

sounds like it was running very lean... caused by either, lack of fuel or too much timing, or both.
I hope you didn't melt anything...

take out the spark plugs and inspect them. Check your timing.

 

[pfcvdv]

could it be that my valves arent closing? i do run a hot cam...

 

[khan0165]

could be... are you using solid or hydraulic lifters? If solid, what did you set your lash too? Did you set it on Hot lash, or Cold lash? If hydraulic, did you soke your lifters in oil before motor build? How tight past 0 lash did you set them?

your pushrod length could also be incorrect... how did you measure the correct length? I hope you didn't just re'use the stock ones.

 

[pfcvdv]

could be... are you using solid or hydraulic lifters? If solid, what did you set your lash too? Did you set it on Hot lash, or Cold lash? If hydraulic, did you soke your lifters in oil before motor build? How tight past 0 lash did you set them?

your pushrod length could also be incorrect... how did you measure the correct length? I hope you didn't just re'use the stock ones.

i have a complete performer rpm hydrollic roller kit i set the valve lash when the engine was running cold because i wasnt capable off installing the water hose (ran over valve cover) i installed the lifters only coated in tpfe (teflon) i set valve lash 3/4 past 0 .

 

[RITTER]

Coated the lifter with PTFE :?: That's new to me. I have always installed and been informed to install lifters using the camshaft installation lube :idea:

I had a 454 BBC skip timing and was making the cast iron exhaust manifolds cherry red :shock: That thing still ran after we shut it down :lol:

 

[custom442]

lean backfiring.

fuel + timing issue

im running the engine on lpg so mixture is always right...

that wouldve been a nice thing to add to the first post

bump timing back, give more info on the fuel system.

 

[custom442]

i have a complete performer rpm hydrollic roller kit i set the valve lash when the engine was running cold because i wasnt capable off installing the water hose (ran over valve cover) i installed the lifters only coated in tpfe (teflon) i set valve lash 3/4 past 0 .

3/4 is too much lash for hydr roller. should be closer to 1/4 turn. no more than 1/2