Heimeken
This engine had been sitting in storage for years but ran pretty good when I took it out of my wagoneer. I cleaned it up for use in my 77 J10 and did the following "upgrades".
Summit cam, lifters and new rods
Edelbrock intake non-egr
Edelbrock 1406
New plugs, wires on existing MSD/TFI
New dual exhuast
After putting all back together and at TDC, started right up. Broke in the cam as instructed. I get lots of ping at high rpms on medium to heavy load. Idle is very rough and the carb cannot be tuned. I have tried timing between 8 and 12 with not much difference except that lower than 10 I get crappy power and higher I get ping at lower loads. Vacuum is very low and ranges from 7 to 9 HGs at Idle(600RPM). Engine feels like it's missing a few cylinders but all the plugs look good.
I went in and re-checked the timing mark alignment but it was right. I removed the intake and re-did the valley pan in case I had leaks but nothing improved. I am now thinking I got a bad cam.
Any help is appreciated.
tufcj
Simplest things first. Have you verified that the firing order is correct, and you have the right plug wires on the right plugs? It's easy to get 5-7 reversed. Firing order is 1-8-4-3-6-5-7-2. Second I'd check that the vacuum and centrifugal advances are both working smoothly and not sticking.
The vacuum advance should be hooked to the ported vacuum. On an Edelbrock, it's the port on the passenger side front. Did you plug the large vacuum port on the back side of the carb?
Just some thoughts.
Bob
tufcj
Heimeken
thanks for your input.
All AMC V8s have the same firing order right? I've verified it several times but for some reason the one you posted looks different than what i got from Chilton's. Won't hurt to check again. I did try stronger springs on the mechanical advance and even with the vacuum advance disconnected I get lots of ping. I have plugged every vacuum port I know of, both on the carb and on the manifold without any improvement.
tufcj
I must have been snoozing.... 1-8-4-3-6-5-7-2.... DUH. I read it again and I don't know what I was thinking, I edited the original post.
:razz: :razz: It was a long day of conferences at work.
I need a beer. :razz: :razz:
fuzz401
Heimeken
Yip, that's what I thought.
Order is correct :smile:
Heimeken
Update: Just replaced the summit cam with a stocker.
Engine is now running fine. :?
I can't see anything obviously wrong with the summit cam :-|
tarior
At the risk of beating this subject to death; stay away from those Summit cams, they are no good!! I had two in a row go flat on me :(: , and know some of the other guys on the forum have had trouble with them. Stick with a name brand (Crane, Comp, Reed, Crower, couple others I can't think of) and you will be just fine. :t:
