RedCelica

Amsoil 10w-30

Great actually. A little oil on each around the bases, but nothing crazy

10-4. I scoped cly #4 and the interior looked okay actually. I'll try and go back in and take pics (forgot my SD card) for reference. Good news is there was no smoke on startup, so I guess the oil overnight had a chance to drain back down.

jyeung528

did you try a wet compression test on #4 to see if it bumped up the compression?

HarryD

There's a 20psi variation, which is only 8% between 245 and 265 -- shop manual says a max variation of 28psi.

Personally those numbers look fairly consistent to me, and within the margin of error. Especially since the last cylinder you tested may have been a bit colder in temperature than the first cylinder tested.

I'd let sleeping dogs lie at this point and monitor for smoking if you keep the oil level at the 50% mark moving forward.

jyeung528

that's one of the few instances where i would not rely on the shop manual. 28 psi would cause me to investigate.

DrSideways

While a spinning compression test can tell you something is amiss, a leak down will be more specific. You roll up to TDC on each warm cylinder. Put 80psi in and see what holds. With the throttle plate open a bit you can listen for leakage at each intake valve. Then stick a hose or your handy tubular stethoscope up the tail pipe and listen for air hissing. Then listen to the cam cover vent. Wherever you get a loss of PSI you will hear air.

Air noise from the intake indicates a leaky seat or possibly tight intake valve adjustment. If so check adjustment. If adjustment is correct and you have noise. Proceed to valve job. No passing GO, no $200.00.

Air coming from exhaust pipe, indicates a possible leaky valve seat or a tight valve adjustment. If the adjustment clearance is correct, proceed to the above mentioned valve job. Again, no passing GO or $200.00.

Next, check the Cam Cover vent. Air hissing there will be the rings or worse, a piston issue. Passing GO from here will make $200.00 look like a nice dinner date.

This test is a bit more involved, but much more specific. On true race engine you look for oil PSI at idle or just above and a leak down test. You don't do anything if they pass these tests.

On the face of your tests so far it does look like #4 may have an issue, Warm the engine and do a leak down. Then you will have some comfort in the proper direction of repair if needed.

Tracking a car can be a demanding proposition. No need to make it harder. Sorry to the folks who don't know the Monopoly game. Just wait until you mess with a 7 hour time between overhaul engine Keeping in mind that the Sopwith Camel WW I aircraft had a TBO of around 17 minutes. Brave MFers.....

Laxhero2

Does the smoke continue after warm up? What color is the smoke? Check the head area for gasket leaks and if you do not see any leaks. It could be a piston ring going bad or something in the piston area. Try to do another compression test when the engine is warm.