car is a fresh rebuild with heads from a 72 chevelle, 86-up block, comp cam 550/540, edelbrock perfrom. intake, holley 3310 (750)

im not sure if its misfiring due to low compression, or if its a fuel delivery problem, ive been trying to diagnose it for days, the plugs dont look all oiled up at all, and it seems like the hottest running cyl. are 2468 and then 1357 are running cooler.

i had a qjet on there and it never wanted to run, with the holley it runs just is loud as hell on on side of the engine from the open headers, and not so loud but definetly is firing, just not sure if i should say f*** it.

im wondering if its burnt valves or possibly scored cyl walls, anyones input is appreciated and if any additional info is needed ill reply quickly.

 

What's the difference in temperature? Intake gasket problem on that side?

 

i have to get one of those thermometer that uses infrared to tell but i checked compression and it was pretty good, i did back off the intake valve and it seemed hotter by floating my hand above the pipe, but ill assume they were a hundred or so off and usually they would be in range of each other within 50 degrees. i will get some carb spray and check the intake gaskets. maybe even carb with the dual plane intake

 

you know what else im gonna check is the spacer, i have a 180* dual plane intake, so with the spacer i have its now a 360* single plane with the open spacer, letting whichever cyl suck gas and air at its convenience. ill try carb spray and putting in the 4 hole insert on the carb spacer.

 

What do the plugs look like on the side running loud/hot vs the cold/quiet side? That will tell if there is fuel distribution issues. Also can you look inside the header to see if there is more exhaust soot/carbon on one than the other?

 

the headers have been used so there is already soot, but i did take it for a test drive today and the tires were spinning after i put the carb spacer insert in and then backed off the exhaust valves a little, i think the reason the one side is so loud is becuase the number eight cyl header pipe is a 90* angle from the port so that would make it considerably louder on that side, but like i said, i have a few more things to tune but for now im actually suprised how well the low end power took with that spacer insert on the performer intake, btw i dont recommend the edelbrock intake...ever.