compression ???

[Normspeed]

So, do I understand it right that if the gasket fails between 3 and 4, your compression is lost from cylinder to cylinder, and not necessarily into the water jacket or the crankcase?

[martybose]

So, do I understand it right that if the gasket fails between 3 and 4, your compression is lost from cylinder to cylinder, and not necessarily into the water jacket or the crankcase?

When I blew the gasket between 5 and 6 a few years ago, it did not get into either the water or the oil. On the other hand, it had ZERO compression in both cylinders, which makes me suspicious of a head gasket diagnosis when you still have some compression showing.

Marty

[wayfarerstranger]

well i went ahead and pulled the valve covers off didn`t see any stuck vavles, spun the engine over & over and they seemed to be working fine . only thing odd i saw was as the valves went up & down the lifters would spin around but not on the cylinder with the lowest compression ? maybe because of low compression ? i don`t know and the lifter on the low cylinder was stuck in place so i soaked it with pb blaster worked it back & forth and it freed up . other than that it all looked fine. so i guess at this point it`something with the rings & pistions or the head gasket , i guess it want hurt to pour some sea foam or miracle oil down the plug holes and let them soak a couple of days just to see what happens , if no luck i`ll start taking the head off .

[Lou Earle]

Remember that the spark plug hole is directly over the valve-Intake I think. I get something usually a small clear tube and wiggle it ihto the clylinder hole and then squirt mm oil into the cyl area.

lou

[wayfarerstranger]

ok now i`m more confussed than ever , after doing every test and checking everything possible , with no results .. i pulled the head guess what the head gasket isn`t blown ,it looks like new ? there are no stuck or damaged valves .. no stuck or damaged pistons they move up & down the same no play in them like the rings are stuck . all the valves & pistons look about the same..and operate about the same , there is no wear at all in any of the piston sleeves they are like new ?? the head looks fine too . where do i go from hear ???

[wayfarerstranger]

Can`t Seem Yo Get The Pic`s To Upload ??

[Lou Earle]

I would put about a cup of marvel m oil in the weak cyls and let them sit a couple of days. I would also inspect the valves very carefully to make sure they are closing completely. check the head to see if any creases etc around where the 2 cyls are closest together. The reality is that you can only loose compression by 1-valves2 warped head, poor sealing of gasket 3 compression or air escaping into the oil pan 4 cracked cylinder wall allowing gas and air to enter the water jacket. I believe it has to be in the rings being stuck or valve worn and not closing completely.

Lou

[Lou Earle]

Another thing check your valve clearance at the valve stem and tappet. Remember a overly close tappet will not make noise but open one will. This forum has a guide for checking them. If this is a new engine and i suspect it is because of the 120 ratings, it could be the valves were set but tappet not tightened.

Lou

[Guest rockabillybassman]

I think Lou's on the right track from the info you've given us.

[RHDSP15C]

Needs a valve grind.

[wayfarerstranger]

do u mean out of the car valve job or just a hand lap valve grind on the 2 low cylinders..

[Guest rockabillybassman]

My thoughts would be to reset the tappets on the low cylinders to 10thou cold on the intake and 12thou cold on the exhaust, and retry, but then I remembered you've got the head off. Sooo, do an examination of the valve seats and the valve surfaces. I'd suggest a strong torch and a little mirror so you can see all round them. If there's no pitting or damage, reset those four tappets, put the head on and try again. If there's mild pitting or damage, do an in the car lap in. If the exhaust valves have been sitting up a few thou due to no tappet clearance, you may see evidence on the seats, in the form of exhaust coloration on the seats. We may be on the wrong track here, but it seems the most likely scenario. If the rings and/or pistons were damaged I think you would still get some compression, and you would likely have visual evidence on the cylinder walls in the form of some discoloration.

[wayfarerstranger]

there was compression #3 @ about 60 #4 @ about 45 ?? i`ll try the little mirror trick & see if i see any pitting ..