i just started my rebuilt engine. ran it for a few minutes- glowing headers, rough running, and a somewhat slow crank on start up,the cranking acting like advanced timing to me.

Double Checked:

Firing order

Vacum leaks


I'm gonna borrow a friends scanner tomorow to see what code is coming up.

I called my engine builder, he said the cam is straight up, or maybe 2 degrees advanced, doesnt rememebr which.

THE QUESTION!! does this sound like my cam is advanced or what?

i'm trying for some feed back before i take the front of the engine apart this week end.

TIA....Jeff

 

Don't forget that the distributor is timed to the cam. No matter where the cam goes, the distributor goes too. To me it sounds like maybe the knock sensing system is pulling timing out of the distributor and your firing late. This causes the plugs to fire while the exhaust is slightly open. This could be causing your headers to glow. Pretty sure 2 degrees cam advance won't cause your problem.

Could also be programming issue.

Question, how much overlap does your cam have? How much maximum lift do you have at the exhaust lobe?

Have you check vacuum levels since break in? Did you give the engine sufficient time to break in? Compression and therefore vacuum will be low until the rings start to seat.

Just some things to consider.

 

I don't know what all went into your motor but with a stock type cam gear you can't advance the cam 2 degrees. You can only adjust it by one tooth which would be more than 2 degrees.

 

your rocker arms may not be ajusted correctly as in their too tight and farther than zero lash that can be a defenit cause for your problem

 

"i just started my rebuilt engine. ran it for a few minutes- glowing headers, rough running, and a somewhat slow crank on start up,the cranking acting like advanced timing to me.
"

Likely, you tigtened your rockers down, with out thinking about the fact that the lifters wern't pumped up. Loosen them all now back to 0 lash, leave the valve covers OFF and start the car and see how it idles.

 

*Question, how much overlap does your cam have? How much maximum lift do you have at the exhaust lobe?*


cam specs are....I 684 E 660
250 258

26.9 crank degrees overlap.
do you think my knock sensor IS pulling timing and causing this?


It's a solid roller, so not hydrolic JeffSTAR.

I got the long block form the builder, valves lashed as well.

so far, i'm going to wait until tomorow and have my buddy bring his snap on scanner and do a check of all the sensors he can do on that thing, then i'm thinking to re-check the valave lash.

any more input is MUCH APPRECIATED!!

I've called Nu-Tek, Ed Wright Programming, and Speed , Inc....all have been VERY helpful....

Jeff

*also, today i ran it a few minutes, lowest idle i can go, continuous backfiring through the exhaust...*

 

Rockers could still be too tight, and it's what it sounds like on first impressions.