Hillbilly pressure test setup

[Al Harpster]

For the guy with the Ace B+ low power.

Gage from harbor freight. Hose and other hose fitting came with it.

Tire valve cut from old tube, excess rubber ground off.

Piece of rubber from said tube.

Piece of copper flashing from hardware store to block manifold.

Copper pipe end cap from hardware store.

Rubber adapter & hose clamps from hardware store.

Bicycle tire pump.

Not shown: spray bottle with teaspoon of liquid dish soap & water.

Requires solder, flux & really big soldering tool or a bernzomatic.

Benefits:. It's worked for me.

Cons: I always find leaks.

Any questions please ask.

[Al Harpster]

Sorry, all photos in reverse order.

I must not speak web design too good.

[Bullfrog]

I like it! Do you always find leaks in the hillbilly test system or in the engines you test?

I'd recommend blocking off the intake side where the carb fits up against the heat block (rather than at the cylinder/ manifold juncture).

[Al Harpster]

Only System leak I recall was at the threaded exhaust boss.

A couple turns on the hose clamp screw, maybe a wrap of electrical tape around those threads, solved it.

I found this stuff easily & quickly obtainable, and cheap

Good for a test of overall crankcase seal, cylinder base & head gasket seal.

No good for checking manifold gasket, o-ring or (my least favorite) leaks thru the threaded stud to cylinder interface.

For the fellow trying to get to 4th gear, this might help rule in or out a few more contributing factors to low power.

One more trip to the hardware store for a length of 1/8" aluminum flat stock & a "blank" to go over the intake manifold can be fabricated.

Little more work, but would rule in or out these last three potential concerns.

The more that's ruled out the better you can focus.

[Al Harpster]

Sorry, I said O ring seal at manifold.

Should have said plastic heat block seal.

I guess you could squeeze the O ring in there too if desired.

[Bullfrog]

Al, Iwas only funnin' with you with the leak quip. That is a nifty set-up - and every one should have something like it if they do their own re-builds or tuning.

I don't understand what you meant about it won't find cylinder stud thread leaks. It should find those just fine. As for testing the O-ring at carb/(plastic)heat block juncture, I don't think I'd recommend that. A flat plate squeezing the O-ring would require some balanced finesse on how tight to torque it down. And a visual/feel check on the O-ring should reveal any problems there.
Ed

[Al Harpster]

Oops, I think you're right.

The hillbilly setup should find leaks around the intake manifold threads.

I only found leaks around those threads when I went to an iron super rat cylinder and upped my game to include a manifold cover plate.

So I associated the manifold blocking plate with greater detecting powers.

Pressure testing for me is looking for trouble because I always find a leak where I don't expect it.

Very annoying.

Maybe this winter I'll work on a vacuum test.

I've got a rotary valve Suzuki motor. I don't think I'd get a 6 psi seal on that one.

Ever tried it on a rotary valve engine?

[Bullfrog]

I've never worked on a rotary valve engine, but I would expect that a plug or cap to take the place of the carb would work the same as what we are used to on a Hodie. Rotary valve two strokes have to be air-tight too.