So i just got done with the leak down test on my flattie and here is what I found. #1=20%, pulled the intake and the valve is not seated #5=8% #4=7% #8=8% #6=8% #3=9% #7=8% #2=7% I am just getting tired of my breather smoking, more during a load less when i push the clutch in. I am going to pull that head but i don't know if i should lap the valve in and replace the rings on that cylinder?
I'd correct the problem with the valve and install new guides first. Once thats done put it back together and get a compression test. I can't see rings in only one cylinder unless they were installed incorrectly or broken.
That's my thing, i never did a compression test, and i don't know if i should do that before I pull it apart. Also can i do a compression test with the intake off?? I know i have to get the valve to seat, but i don't want to pull it all apart fix the valve and find out it's a ring and pull it back apart again.
You already know that there is a valve problem. It's only a matter of pulling the head since you already have the intake off. Repair the valve, put the head back on and take a compression test. After doing the valve repair the compression test will tell you which , if any, cyliners have a low compression.
Well the problem is I am already going to buy new head gaskets and i spray copper coat on them for a good seal. I don't want to spray them and find out it's a ring and destroy the gasket again while pulling the head. Really don't have alot of money to be throwing around on gasket's.
Does it have adjustable lifters in it? Perhaps it just needs the lifter adjusted to get the valve closed. You can put air on it when you try to adjust it without having to initially pull the head.
If you don't fire the engine, you can install the heads without sealer, torque the bolts, and do a compression test. The gaskets can be reused if they're not heated and hot-torqued. I did it quite often when I was fitting a set of Offy heads to a dome-piston engine 40 years ago. The pistons had a nasty habit of bumping the heads, so I had the heads off several times while I reshaped the combustion chambers and CC'd them. Jerry
Yes it has adjustable lifters in it, there is no pressure on the valve. That was my first thought that's why i pulled the intake. Can anyone tell me what a normal leak down may be (pressures) I called H&H and they told me it's time for a ring job? I know i need to get that valve to seat.
Anything under 10% leakdown is great! The rest of the engine looks good, if you can get that one valve to seat. Jerry
Confused about your statement "no pressure on valve". Can you get a 0.012"-0.014" feeler gauge between the top of the lifter and the bottom of the (intake) valve stem with #1 on TDC? If the clearance is much greater than that the valve may be stuck open. If so some Kroil or other penetrant may free it up.
Yes that is what i meant by no pressure on the valve, i can get a .014 feeler gauge between the valve and top of the lifter. When i got the cam reground the lash was set at .011 in, .013 ex. That's what was on the cam card.
Sounds like you need to pull that head and see what's holding that valve up. Don't know what else you can do. Since it's an 8BA the valve guides are one piece not split like the earlier guides I believe.
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