21 stud pressure test help??????

[tubman]

For the '37-'38 engines, the water pumps are the same as the early 24 stud engines, so the block-off plates should be also. For an earlier engine, I found some vinyl pipe caps that worked fine when secured with a worm drive hose clamp.

[JSeery]

I'll have to check, I didn't think you could purchase the pieces seperate, thought they were a "kit/set". Maybe I'm wrong!

[Yoyodyne]

Originally Posted by JSeery

I'll have to check, I didn't think you could purchase the pieces seperate, thought they were a "kit/set". Maybe I'm wrong!

I see you are right. I remember seeing just the block off plates. Has anyone here bought one of these? If they are decent, I might just get one and redrill the head plate for 21 studs.

[JSeery]

I have a set of the Speedway plates. The plates are fine, the problem I have is with the washers that go under the bolts than hold the plates down. They warp and do not seal correctly when tightened down. I replaced them with some of better quality and they work fine. I made some other modifications to incorporate shutoff valves.

[Tinker]

couldn-'t ya just have some plate steal cut and transfer the holes to drill from the heads and pumps? or cut some plate to do so?

[tubman]

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I made this setup to pressure check an 8BA in a car a couple of years back. The piece with the gauge bolts on the thermostat housing, while the black thing is a vinyl pipe cap that goes over the bottom water outlet when the hose is removed. I would think it would be easier to make a similar plate that would bolt to the water pump outlet on an early 21 stud head than a full plate. One other thing is necessary. I have a "gutted" spark plug with a child's balloon attached to it that I move from cylinder to cylinder during testing. These balloons a very sensitive and will start to inflate at the slightest leak. Of course, you have to have the spark plugs screwed into the other cylinders while performing this test. This method allows the engine to be crack tested while still in the car without removing the heads. It does have some shortcomings, but it is good enough to detect the great majority of badly cracked engines.

[Dave/Green Bay]

Flatjack9 does it a little different. He fills the block with water then pressurizes the block. If you see water dripping you have problems. His method found a leak deep inside a exhaust passage on an 8ba that had been magged and all visible cracks pinned. Wish I had Jack test it before I wasted the money. Dave/Green Bay

[JSeery]

Originally Posted by Tinker

couldn-'t ya just have some plate steal cut and transfer the holes to drill from the heads and pumps? or cut some plate to do so?

That's how it's done. A lot of work unless you have multiple blocks to check. You have to have the bolt pattern drilled and the combustion chamber area milled out. You can also mill out the combustion area on an original head and use that. You then need to cut a neoprene gasket to fit. It is all very doable, but a lot of work.

[FritzJr]

I have pressure checked blocks with no special equipment. Just bolt on the heads with old head gaskets and plenty of silicone sealer. Bolt on the water pumps and block off all the radiator hose connections. Fill the block with water and pressurize with an air regulator. The water pumps may weep a bit, but you can set the pressure regulator to keep pressure on the block. With the pan and intake removed, severe block or head cracks will show themselves pretty quickly.

[flatjack9]

It's the small ones that will get you every time.

[msstring]

I made a plate for the front and used the heads for the the top. Made a rubber gasket. Both sides held 15 PSI for over an hour so I think I'm good. Now to find someone to build it for me.

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