I just rebuilt my 347 (due to ignorance of not knowing to seal lower head bolts 
)
And of course I suffer from the uncontrollable need to upgrade my motor
, so I took the opportunity while it was apart to get the AFR185s machined ( a fresh deck surface, cut pockets for upgraded springs (due to the new cam), lapped the valves, honed the valve guides), up’d the cam (previous cam was too smooth), new long tube headers, and decided to go with Cometic head gaskets.
After the build, I apparently didn’t have the timing correct and had a few very rough (Very Rough) starts before getting it running. After that, it idled nicely (with very sweet snappy revs), but would cut out around 3000rpm (figured the timing was still off, oh and no timing light only by ear).
The exhaust smelled pretty rich, so I pulled the plugs, and 7 out of 8 were oily and smelled of gas, #5 was brownish in color and didn’t smell of gas.
I did a quick comp check of all the cylinders, all were around 10:1, except #5, the gauge didn’t even twitch.
First I tried re-adjusting the valves on that cylinder (thinking they may not have been closing all the way), still no reading. Blew air into the cylinder to see if I was getting blow by, didn’t feel anything through the breather, carb or exhaust.
Dropped the oil, it looked good for break-in oil.
Pulled the intake and head, #5 runner on the intake was sooty, no holes in the piston, no gouging or scoring on the cylinder walls, combustion chamber looks good, no cracks, valves look good and seated. Looked for blow-by evidence on the block deck, head and gasket, all looked good.
Upon removal of the head, a small bit of water fell into the #5 cylinder, before soaking it up I observed if it leaked past, but nothing.
Oh and yes, the piston does move through its full stroke.
So that’s where I’m at, and I am stumped.
Any and all help is greatly appreciated,
Gary
And of course I suffer from the uncontrollable need to upgrade my motor
, so I took the opportunity while it was apart to get the AFR185s machined ( a fresh deck surface, cut pockets for upgraded springs (due to the new cam), lapped the valves, honed the valve guides), up’d the cam (previous cam was too smooth), new long tube headers, and decided to go with Cometic head gaskets. After the build, I apparently didn’t have the timing correct and had a few very rough (Very Rough) starts before getting it running. After that, it idled nicely (with very sweet snappy revs), but would cut out around 3000rpm (figured the timing was still off, oh and no timing light only by ear).
The exhaust smelled pretty rich, so I pulled the plugs, and 7 out of 8 were oily and smelled of gas, #5 was brownish in color and didn’t smell of gas.
I did a quick comp check of all the cylinders, all were around 10:1, except #5, the gauge didn’t even twitch.
First I tried re-adjusting the valves on that cylinder (thinking they may not have been closing all the way), still no reading. Blew air into the cylinder to see if I was getting blow by, didn’t feel anything through the breather, carb or exhaust.
Dropped the oil, it looked good for break-in oil.
Pulled the intake and head, #5 runner on the intake was sooty, no holes in the piston, no gouging or scoring on the cylinder walls, combustion chamber looks good, no cracks, valves look good and seated. Looked for blow-by evidence on the block deck, head and gasket, all looked good.
Upon removal of the head, a small bit of water fell into the #5 cylinder, before soaking it up I observed if it leaked past, but nothing.
Oh and yes, the piston does move through its full stroke.
So that’s where I’m at, and I am stumped.
Any and all help is greatly appreciated,
Gary
