ring issue

After a dissappointment on the dyno I drug my fairlane home and started looking for reasons why it sucked well I checked timing and it was good valve lash was good everything good until I did a compression ceck number one and four only had 60psi rest of the engine has 175-180 head gasket looked like new so pulled those two pistons only thing I can think is I put the rings on backward the top ring has the dot and chamfer facing up second ring has chamfer down seems right to me they are total seal classic rings 1/16-1/16-3/16 I cant see anything else it could be I filled the intake ports in the head up with diesel while on the bench so far no leaks could it just be the rings not seated

120 psi weak on just 2 holes? Doesn't sound like a ring seat deal to me. Compression gotta be going somewhere else. Broken rings on install? Exhaust valves? Cam lobes...as in...is this a new cam?

Yea this whole deal is brand new has about an hour of run time rings aint broke weird part is it had very very little blowby when running also number one and four header tubes were only about 260 degrees the rest were around 600 holding it about 1300rpm

That's pretty cold. Sounds like the fire wasn't lit on those 2 holes. Dist cap? plug wires? Cracked plug or closed up plug gap?

Msd distributor frpp plug wires and autolite ar3934 plugs figure the ignition is working but the low compression is whats making me wonder

What did the plugs look like in the 2 low comp holes, did you inspect the camshaft.

Put compressed air into the cylinders and find out where it's going. Listen to intake manifold, exhausts, crankcase, cooling system, etc. I'm sure that's part of it, but I still say 260* means the fire ain't lit.

I thought the heads were off and the 2- pistons were removed

Well the motors is apart so take the head that was on that side and put the spark plugs back in and with the heads/chambers facing up poor water or Trans fluid in the chamber and see if they leak past the valve..

Ace

Yea I put air in the cylinder before I pulled it apart couldnt really hear any big leaks seeping air into crankcase weird part was once I took the air off of it I crankrd it over and compression was 160 after a revolution or two it dropped back to 60psi

Did it ever backfire or miss

Right after I took the air off of the cylinder I cranked it up and it did backfire a couple times but never did miss

fordmonsta wrote:Yea I put air in the cylinder before I pulled it apart couldnt really hear any big leaks seeping air into crankcase  weird part was once I took the air off of it I crankrd it over and compression was 160 after a revolution or two it dropped back to 60psi

exhaust valve sticking in the guide...... you put compressed air in the hole it closed the valve then spun it a few times valve stuck open again ( shrugging sholder ) not sure just throwing it out there.

I would check exhaust springs (and cam lobes/p-rods/lifters) very carefully on #1 & #4

Damn up on the brake and got treed

FalconEh wrote:Damn up on the brake and got treed

Thanks for the ideas guys I'm going do definately check the sticky valve deal makes sense about the only thing I havent checked