No Compression in #5 345cu.in.

R

Ruper

Member
Did a compression check today, and all cylinders looked good except for #5. No compression on #5 at all. Checked valve function and they were working up and down. Put my finger over the spark plug hole and nothing. Dont hear any rachet so I assume the piston rod is it tact.
I will borescope it Wednesday, so dont know what I will find. If its a cracked or hole in the piston, that is obvious, but if the I dont find a trashed piston, I guess its pull the head and look over the valves.
Any other ideas come to mind?
If I do pull one head probably will pull the other and get the valves done.
Are pistons available in singles?
 
Hard to get a piston to cause 0 compression pressure. I would guess you have a stuck valve.

An easy test it so plumb compressed air into the cylinder after you place it on tdc compression stroke. Use your compression tester hose or rubber end to seal on the plug hole and supply the air. Then go to these 4 places and listen. 1) the oil filler cap hole. Air flow there means rings or piston. 2) remove the air filter and listen at the carb. Flow there is an intake valve. 3) exhaust, thats if you have a bad intake valve.. 4) radiator cap blown head gasket.

If it's a burned valve it will be an exhaust valve. You can take a mallet ans strike the rocker and see if a valve is hanging up.
 
Problem is a broken valve spring intake. Trying to find a single vavle spring will be a pain in the arse I am sure.

Got the tool for installing it in the head with engine assembled but still need the spring hate to buy the hole set, but might have to. Anyone have a vavle spring for a 345 laying around?
 
Sure there are many laying around in garages. I've got a few and you are welcom to one. Shipping will be more then a new spring from a local machine shop. Where are you located?
 
I have a source locally that does our company work, so I will check them Monday. If needed I would appreciate the spring, and will of coarse pay for shipping. I can send a ups number if needed.

I will let you know and appreciate the offer and info.

Have a happy easter.
 
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