No compression all cylinders
 

Working with a friend to get his 30 coupe running. Got caught in a fire years ago but it was pulled out by the firemen .

It was running before the fire.


We wired it up. Good spark rotor turning



NO COMPRESSION ALL CYLINDERS. Timing gear good.



Any suggestions as too troubleshooting.

Re: No compression all cylinders
 

Are you POSITIVE the timing gear is good? My only sure check is to pull the gear cover from the front of the engine and spin the crankshaft. If the timing gear CONTINUOUSLY spins, it should be good.... Otherwise valves for all four cylinders could be stuck, but that's pretty unlikely. Good luck!

Re: No compression all cylinders
 

Even if the timing gear turns, the valves could be stuck open. It only takes one in each cylinder and if the motor has been hot, I think itis quite possible they are sticky enough that the cam is able to open them but the springs, maybe weakened by the fire, can't close them.

Re: No compression all cylinders
 

Took the side cover off of the timing gear cover. Could see the timing gear moving when cranking. Plugs out - see valves going up and down. Compression tester and "thumb" test -No compression all 4

Re: No compression all cylinders
 

If the 'valves are going up and down' then check the valve lash and look at the timing gears to make sure it hasn't jumped time for some reason.

Re: No compression all cylinders
 

If the motor got too hot, the rings might have lost their tension or the head warped (unlikely)
Give us some idea on how hot it got. What was the condition of the radiator afterwards, likewise paint, grease running out of the wheel bearings? Distributor body charred or gone?

Re: No compression all cylinders
 

I will try to get a little more info on the fire. He said he changed the head gasket and manifold gaskets. Loose manifold gaskets?

Re: No compression all cylinders
 

https://i.imgur.com/OomuL0E.png?1

This chassis was in a house fire,the coupe body was destroyed,warped and soft as cheese.The engine too a lot of heat from the fuel tank burning..upon disassembly and inspection the entire long block was completely salvageable..
https://i.imgur.com/5RDxJrA.mp4

Re: No compression all cylinders
 

I’ll bet the valves are sticking open from old varnished fuel residue.

Re: No compression all cylinders
 

My guess is that the timing wheel was cooked and damaged and lost a tooth or two .

John in West Drayton London England .

Re: No compression all cylinders
 

https://i.imgur.com/fshIcVZ.jpg?1

https://i.imgur.com/KUDwyG0.jpg?1

Fire was so hot it warped the right front wheel,consumed everything that would burn on the engine but the internals were fine.Whats important is the floor the car was sitting on,this one was on concrete.Heat rises and concrete doesn't burn,tire fire is hot and the interior of the restored coupe burns hot,but the chassis didnt see that kind of heat.

Re: No compression all cylinders
 

'Soft as cheese...' - I believe it.

Re: No compression all cylinders
 

Try adding a teaspoon of oil to each cylinder to seal rings and to up the compression.

Re: No compression all cylinders
 

Your first post after joining 8 years ago. Welcome to the party!

Re: No compression all cylinders
 

You could try diagnosing just cylinder 1.


Get the rotor pointing correctly to spark plug one, Use the timing pin to find TDC cylinder 1 (rotor should still point to spark plug 1/cylinder one). If not pointing correctly, mechanical timing has slipped.


If rotor and timing pin align correctly, with the valve access cover off, use compressed air into the cylinder 1 to locate where the leak is (leak down test). You may have to drop the oil pan. If you hear air in the exhaust, exhaust valve is not seated, if you hear air in the Intake manifold/carb, the intake valve is not closed. if you hear air in the bottom end then it is possible rings, block. If the radiator cooling system is full and bubbles in the radiator or you may hear air in the radiator if radiator is not full, bad head gasket, cracked block. Not sure if I have all the symptoms/causes here.

Re: No compression all cylinders
 

You shouldn't need to remove the oil pan, just remove the oil fill cap! I would only use 60 lbs of compressed air.

Re: No compression all cylinders
 

True, but suggested dropping the pan in this case for an inspection, since it has been through a fire. My feeling is better to check out the bottom end before getting it running. Best to be thorough by dropping the pan, and putting in new pan gaskets may be a good thing due to the fire.

Re: No compression all cylinders
 

My logic I have seen this before and it takes munch heat to damage engine mostly
plastic stuff wires yes . Idea is an engine will not burn, the engine is not fire wood, its
just the burnable stuff. We had a mint 58 Continental covert' house fire, the car
toasted what a shame we salvaged that and a mint Hudson also toasted. The 430 Lincoln
we replaced the melted fuel pump carb and distributor. New oil started up like a champ
same thing with Hudson 6 runs perfectly. and I still have both engines storage...

Re: No compression all cylinders
 

How soft are the valve springs? That motor has been pretty darned hot. I suspect they have lost tension. Piston rings might have done the same.

Re: No compression all cylinders
 

It doesn't take much of a cylinder to produce "thumb compression". Must be stuck valves. They may be moving but not closing. I'd pull the head, the valve cover and the pan and look the internals over. If you plan on salvaging the engine its good to know what it looks like inside.