Pleasanton June 4th & 5th

[dennis68]

Awful lot of credit with that second "1/2" aren't you Vince. :icon_razz



Tony, if those two are coll enough to touch running than you are missing one of the 3; air, fuel or spark. What is the dynamic compression like? Have you run leak down, static compression can be very deceiving? Even low pressure or poor valve train action should result in some fire. I would check for actual spark at the plug (pull the plug and fire the motor to watch the big blue arc) and maybe lift the fuel rail (assuming FI) to watch for fuel injector pulse.

[TonyHuntimer]

It's actually a carb (850 DBL Pumper).

I've pulled the plug and watched it spark it's neat blue spark, so I know it's getting spark.

It's a dual plane Edelbrock Performer RPM intake, so cylinders 1-4-6-7 share one plane and 2-3-5-8 share the other plane. My problem with 1 and 4 have a "plane" in common, but I have a hard time believing that I'm starving 1 and 4 of fuel or air when 6 and 7 are not showing the same "cold" problems. ...but I will take a closer look at that this afternoon.

A preliminary static compression on 1 and 3 were 178 and 182


More later...

Tony Huntimer
RaceHome.com

[TonyHuntimer]

I finally found the problem. The intake lifter on #4 is bad. It was causing #1 to have problems.

Now to see what happens. Crower doesn't make that lifter anymore.



Tony Huntimer
RaceHome.com

[yody]

I'll be with vince, if you want us to come by, he's actually pretty good at trouble shooting, yeah i said it, vince is actually good for something!

[yody]

how in the world does the #4 intake lifte cause the #1 lifter to act funny?

[TonyHuntimer]

The only reason I can think the #4 intake lifter caused the #1 cylinder to be extremely cold is the fact that cylinder #1 and #4 are on the same "plane" on the dual-plane intake manifold. The engine never popped back through the carb or backfired out of the exhaust.

Intake lifter on cylinder #4 was hanging the valve open after startup. ...and it was not mis-adjusted.

I just remembered last night...On my second Hotchkis open track day I had that same lifter come loose when I was out on the track. It must have been going bad. That was before I installed my stud girdles and thought the adjustment nut came loose. Now I know different.

At least I found it. I'll pull it out tonight and send it out to a friend at Comp Cams. He said that his tech department can take care of it. It's great to have friends in the right places.

Thanks guys,
Tony Huntimer
RaceHome.com