Help diagnose these symptoms, PLEASE!

[YGETV8]

HELP! Well, long story long (I can never tell a short story!), last June I THOUGHT I had blown a headgasket on my WE4 on a 28 psi 1/4 mile blast. Heard a "pop" on the run and let off after that. Still running so I went back to my pit space and first thing I see is the oil dipstick up out of it's tube. No coolant in oil, or vice versa but had a slight miss and was puffing some smoke. Looked more like oil smoke, so given those factors I figured that I had blown into the valley, and vacuum was pulling oil into the cylinder and that was the smoke. Knew I only wanted to take it to a couple of shows over the summer, so it got driven very gently a few times after that. Same symptoms. Even did a compression check and cylinder 5 (or was it 6?) was down like 30 psi compared to the others. Headgasket, right?!

SOOOOOOOOO... today I finally get the motor apart and the heads off. BUT, there are NO SIGNS of headgasket failure on the gaskets themselves! Granted, they got pretty "wasted" during removal, but the fire rings are intact and I can't make out any carbon tracks anywhere.

Any ideas? Please? Last thing I need is ANOTHER TR motor that needs rebuilt! Thanks in advance.

Other than that, Happy New Year to all!

 

[TR Custom Parts]

Bent valve, cracked piston rings? Can you see the cylinder bore?

 

[YGETV8]

Hi Mark,

Well, I looked over the valves and couldn't see any abnormalities, but I know it doesn't take much "bend" to ruin one. I'll have to check the cylinders over again. Didn't see anything there, either, but just wiped them out and oiled them. Wouldn't a broken oil ring score up the cylinder wall?

Thanks, Jay

 

[WarpSpeed]

Bent push rod?

 

[TurboJim]

Hook a vacuum gauge to it...oh ****, its apart....

Check for a broken valve spring.... would cause a pop, a miss AND could cause smoke...

 

[Chuck Leeper]

Bent Valve??

Easy check for a bent valve: lay the head on a clean newspaper. Shoot some WD into each port. Let it sit for a few minutes. Lift off the paper and check for WD on the paper.
Obviously, the location of the WD will tell you where to look for the valve problem.
Take those valves out and put them in a drill motor and spin them up. Wobbles??Whoops!! No wobble?, most likely a burned seat, either in the head or on the valve face.....

Back under my rock!!!

 

[YGETV8]

Thanks for the help, Guys! I'll check the heads/valves this weekend. I hope that's all it is because I've got the fresh P/P/big valve heads off my T-Type just dying to be put to good use!

 

[equalizer442]

Bent valve, cracked piston rings? Can you see the cylinder bore?

if you had bad rings you would be blowing oil out of the breather(s) and your not saying any thing about that so i would doubt its your rings. there is a easy way to check that but your going to have to bolt the heads back to the block, put alittle oil down in the cly. if its the rings when you do the compression check it will seal the rings and your psi will raise, if you do that and your psi dont come back up then your looking at something wrong with the valves like there bent. also make sure to look at the 1st and 4th time the engine turns over, if the first stroke is lazy then you have a bad/broke valve spring.

in the case that there is something wrong with your valves do a compression leakage test. if the intake valve is bent you will be forceing air out the intake, exhaust valve will be forceing air out of the pipes if the valve is bent or burnt. if air comes out of the breather its bad rings and if its comeing out of your radiator its a blown head gasket, i know in your case its most likely not the rings or the head gasket so i would put my money on a bent or burnt valve.

 

[YGETV8]

Well, I did the "WD40" test and saw seeping in both rear cylinders' valves. Looked to be mostly the exhaust valves. Didn't really "flow" onto the paper beneath, but was definitely wet in the combustion chamber, whereas the other four remained bone dry. I'm guessing that would be where my problem was then, eh? Thanks for all the input! Jay