I cant get my engine to idle low and smooth enough to set my lash dynamically. engine starts fine after 30 seconds idle drops off and engine wants to stall. I increase the idle and it is too high to set the lash.

I have the advance disconected from the ecm for setting base timing. when I get it to around 6-8 the headers start to glow. so I advance it back to around 20 and heat at headers drop.

I have 355 chevy 10.5 : 1 compression fuel injected with comp cams
224-230 503-510 112 lobe.

cant get it to idle under 1200 need to be about 900 max to accurately set lash.

If I loosen the rockers without engine running valve train is noisy as all heck on start up. tighten them without engine running and I think I have valves slightly open after lifters pump up causing the excessive heat at 6-8 degrees advance. I believe the 6-8 base timming is for a stock cam idleing at about 750 rpm.

what should my base timing be at the minimum idle I am seeing (1200) rpm

I cant statically set the lash cause the lifters bleed down too fast.

I need help!

thank you

jeff

 

Hydraulic lifters? You can set the lash with the car off, "bleed down" has nothing to do with it - the spring will hold it in place.

You can also set your lash at 1200RPM, it doesn't really matter. Well, aside from getting more oil dumped all over you and your engine bay

6-8* timing is basically "retarded", so it'll get hot fast. It needs the throttle body to be opened further to keep it idling. 20* + is fine, whatever it wants to let it idle best. You're right, that's not a stock cam anymore. FI is beyond me though...

You can just tighten them up so it will run, set your idle to whatever it takes to keep it running. It should be running ok now, back one off until it ticks, then tighten it until it just shuts up, then add the 1/2 turn or whatever you like. As you're going the idle speed may change so you'll have to re-adjust it.

 

thanks..I will do that


jeff