Ok let me make something clear here. No, i dont know more than probably any of you guys on here about motors but i know enough about them to get them running and running well. I've never had this problem before which is exactly why I'm coming to you guys about this. I am mechanically inclined enough to solve this issue. :banghead:
I have good compression in all 8. #2 and #8 cylinders are giving me problems. I do have spark. I just did the heads on this motor. I know it's not a few valves being larger because I had another set of heads on the motor and the same 2 cylinders were doing the same exact thing.
I HAVE had two people look at the motor that were more mechanically inclined than me and they both said intake problem. Here's why I'm agreeing with them...
First off an intake manifold crack would cause a vacuum leak. The crack is not on the outside. I know this because i sprayed carb cleaner around the intake while the motor was running and i had no sudden climb in rpm. The crack must be underneath the intake, possibly around the runners. This would explain why my air mixture screw on my Holley is not tuning. You can screw that mixture needle in alllllll the way and the motor has no changes. This would ALSO explain why my exhaust burns your eyes when you stick your face around the tail pipes.
I searched Google on symptoms of a bad intake manifold. This one website explained that a cracked or warped intake manifold would not affect compression, it would act like a vacuum leak, and it may in some cases give you a misfire. In this situation, a misfire in 2 of my cylinders. I can understand why my intake would have a crack because it's an LD4B intake manifold. These intakes were made back in the 60's and 70's for the 273 and 318 motors if im not mistaken. In other words, Its OLD. I can understand it being warped or cracked.
Now.... does anyone else have any recommendations or ideas? :happy1::coffee2:
