#1 cylinder has 36psi compression

T

TomballMottershaw

Member
on the engine we just re-sealed ( gasket job )
has 35psi in cylinder #1 and 55PSI in the other 3.
we added oil to #1 and re-tested the compression, it rose to 50psi.

besides a drop in power,
are there any short term issues with having it like this ?

We are trying to get the car in the 4th of July parade, the radiator is good, along with the rest of the drive line ?

after this we will replace the pistons.
standard bore size. ( sleeved )
 
thanks,
good questions:

re Q1: --> no water bubbling up in Radiator

re Q2.) not a chipped valve as they looked good when we had the head off.
but some sort of valve sealing issue is possible.

-------
I'll do a cylinder leak test next.

But I omitted the puffs of smoke from the oil filler tube tube a low idle speed.

this is why I think it's the rings / Cylinder wall leak.
 
TomballMottershaw said:
thanks,
good questions:

re Q1: --> no water bubbling up in Radiator

re Q2.) not a chipped valve as they looked good when we had the head off.
but some sort of valve sealing issue is possible.

-------
I'll do a cylinder leak test next.

But I omitted the puffs of smoke from the oil filler tube tube a low idle speed.

this is why I think it's the rings / Cylinder wall leak.
Click to expand...

If something did not get under the valves on #1, then, I would venture before new gaskets the compression was 35lbs on #1 and it was puffing smoke out the breather. If not, you need to do more investigation. If something got under the valves in doing the gaskets, then it may work out. To me the tip off in your words is when you oil the cylinder, the pressure rises to 50. That sounds like rings. puffing smoke out the oil breather further enforces the notion of bad rings on #1! Can you ident if it was puffing smoke out the breather before the gasket work?
 
Thank you DHZIEMAN & All,

the engine we re-sealed for a swap was a "used" engine, the history we know it ran before it was removed, but rarely does one just remove a "perfect" engine.
so we knew there was risk of some issue, this why we pulled the head etc.

I'll pressure up #1 @TDC and see if I can hear where it's leaking later tomorrow.
 
TomballMottershaw said:
Thank you DHZIEMAN & All,

the engine we re-sealed for a swap was a "used" engine, the history we know it ran before it was removed, but rarely does one just remove a "perfect" engine.
so we knew there was risk of some issue, this why we pulled the head etc.

I'll pressure up #1 @TDC and see if I can hear where it's leaking later tomorrow.
Click to expand...


Hehe


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Do you have a way to pressurize #1 with air. If you have a n air fitting that will go in the sparkplug hole (leak down of compression tester type) Place #1 at TDC, pump about 10# of air in the cylinder. If you can hear air escaping out the tail pipe, ex. valve, through the carb, int valve. If you can't hear it escaping at all probably rings. Kinda "shade tree" but us country folks have country ways. Chap
 
I don't think I would do any more testing until I put some serious run time on it.Under a load,not just sitting in the yard.Having worked on old tractors and equipment all my life it is something I have seen a lot of.People will put oil in the cylinders of something that is going to sit,then the winter turns into years.As the Kendall oil rep put it to me,that oil turns into asphalt in the piston rings.It will wash with run time.I have a Ferguson-Ford here that the owner tried to do a leakdown test on.It would hold nothing.After about 40 hours of mowing it runs good,and will hold at least some pressure.
 
Sea Foam is a great product for engine problems. I've only used it twice and it did wonders both times. About 1980 I added a can to the oil to free up stuck hydraulic lifters, and within 5 miles, the engine was quiet as new. Two months ago I added a can to the gas to help a carb running like crap. Within 20 miles the engine ran smooth as can be.
 
I fixed a model a engine with 10 psi in one cylinder and 0 in another. Still ran but no power! He had just gone one a one hundred tour with it. It was the valves.
 
We got this resolved last night.
it seems the valve adjustment on cylinder #1 was not properly done, and they were slightly open...( no tapet clearance ) should be closed., we re-adjusted the #1 cylinder valve clearances and all is working well. I will see if I still have the Puffs of smoke from the oil filler tube, once we test drive and get the rest of the bits put back together.

compression test is back at 55PSI. ( stock head )
 
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