hey folks,id like to know, if an engine is starting to blow by (head to cylinder) under load,so when i just get into fourth up a slight hill, will it show up in a compression test??or only leakdown or both or niether???

It may show up in one, all or none of the static tests.:jesus
Depends on the severity of the breach that may be small enough to carbon up under light loads and pop thru under hard load.
Bit of a tricky one that.
L8tr
E$

Yes a tricky one... what do you compare it to for a start.

If your engine is down on power then it may be time for a new set of barrells n pistions and new valve guides etc etc

easiest way to fix it

I know mine uses more oil than it should but its just getting time to pull the engine and to the above I can live with it for a while longer.

Hehehe.
Ive always said, where theres smoke theres oil and where theres oil theres lube!!

Prolly the only reliable way to determine leakage at that point is to pull the heads and look for witness marks of blowby.

If there is then you can check the barrels for equal heights and perhaps lap the barrels back into the heads.

Good Luck
L8tr
E

thanks guys, this motor SHOULD not have any leaks!!i guess out she comes for proper inspection.thanks

Who built the engine did you space the ring gaps equally around the pistions, did you fit new valves and valve guides, did you lap the barrells to the heads. run the engine in correctly and with the rings bedded in properly it should last a long time.

All real important points there.

When you get it out pay particular attention to the installed barrel heights.

If there is any difference in heights of the barrels then the heads must pull up unevenly on them leading to dodgey sealing around the barrel to head joint face.

The barrels need to be clamped in place before the heads are removed so when the heads come of the barrels are not disturbed.

Laying a straight edge along the top of the barrels and looking for any clearance between the top of the barrel and the straight edge.

If there is some clearance on one side of the barrel then you will need to determine the amount and then get/make a shim of the appropriate thickness to fit underneath the lowest barrel.

Give the barrels a light lap back in to the head with some valve grinding paste to ensure full width seating of the barrel to the head, bolt her up and all should be sweet!

Have fun dude
E

thanks for the advice tass.. ill let u all know when its out.

Sweet dude
keep us posted.
Good luck with it.
L8tr
E