Checking blocks for condition Pressure testing

[deuce5wndw]

Mine is 3/8 with 1/8 rubber glued to it. While they are cutting do the water pump plates also.

[GB SISSON]

Thanks all! I feel this is a very important topic to be discussing on the forum. With these blocks, testing is Everything. With today's labor rates a couple of cracks means a throw away, but success on a proper mag test, pressure test, and good bores, and you have something!

[Mart]

The extra hole on an 8BA is a simple passage from the head face to the water pump face. It doesn't go to the water jacket as such, so shouldn't need blocking. You don't need coolant holes so it should be universal 59A/8BA.

[Ronnieroadster]

Mart is correct that small hole on the deck at the front edge of the block is simply a bypass hole to the water pump housing. So if you pattern the plate from the 59 type head gasket the pressure plate will work perfectly.

[Bored&Stroked]

Hey Ronnie, I like the "universal" idea of a plate that does both 21 and 24 stud blocks. Thanks!

Another idea would be to make a thicker aluminum plate that could also be used as a honing plate when the bores are honed. I have about a 3" think one that we made for the FlatCAD - though when we recently used it, the bores showed no signs of distortion (shadowing) in the stud locations - so not really sure that it provides value. What it did help us find was some weak stud threads! Yikes! We were fortunate to find them before the block was assembled and was still at the machine shop.

We used "RockMount" inserts in a couple locations - really a cool product. They are harder than Hell and really should be put in on a big Mill. But, they also would be ideal for aluminum situations.

https://rockmountwelding.com/product...l/?sku=90402-2

Do you use a honing torque plate - what have you seen with shadowing when you first start the hone process?

[deuce5wndw]

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Well. I'm not as smart as I thought!!! lol

[glennpm]

[GB SISSON]

Originally Posted by Ronnieroadster

Here's some pictures of the universal Ford flathead pressure testing plate for 21 and 24 stud blocks. Note along the front and rear edges the various holes required to accommodate the differences of the water holes and bolt patterns between the 21 and 24 stud blocks. Three holes on each end require a pipe plug thread to seal the plate correctly against the water hole differences.
Ronnieroadster

Ronnie, how was this plate made? Is it an actual head with portions cut away? If I had one cut from plate and had a handful of spacers like hex nuts or pipe cuttoffs, I should be able to leave the studs in place when necessary, correct?

[Mart]

GB, if you have any scrap steering boxes, the column shaft tube would make good standoffs. It's 3/4" diameter and the bore should clear a 7/16" stud. You'd have to check and maybe drill it a bit, but I think it clears.

Mart.

[Bored&Stroked]

Originally Posted by Mart

GB, if you have any scrap steering boxes, the column shaft tube would make good standoffs. It's 3/4" diameter and the bore should clear a 7/16" stud. You'd have to check and maybe drill it a bit, but I think it clears.

Mart.

Or just order some DOM steel tubing - cut to length and finish the ends.

[Ronnieroadster]

Originally Posted by GB SISSON

Ronnie, how was this plate made? Is it an actual head with portions cut away? If I had one cut from plate and had a handful of spacers like hex nuts or pipe cuttoffs, I should be able to leave the studs in place when necessary, correct?

No this plate was made for the testing it may be by KR Wilson but I'm not sure the name and part number are not readable. Its cast iron and very heavy.
Ronnieroadster

[Ronnieroadster]

Originally Posted by Bored&Stroked

Hey Ronnie, I like the "universal" idea of a plate that does both 21 and 24 stud blocks. Thanks!

Another idea would be to make a thicker aluminum plate that could also be used as a honing plate when the bores are honed. I have about a 3" think one that we made for the FlatCAD - though when we recently used it, the bores showed no signs of distortion (shadowing) in the stud locations - so not really sure that it provides value. What it did help us find was some weak stud threads! Yikes! We were fortunate to find them before the block was assembled and was still at the machine shop.

We used "RockMount" inserts in a couple locations - really a cool product. They are harder than Hell and really should be put in on a big Mill. But, they also would be ideal for aluminum situations.

https://rockmountwelding.com/product...l/?sku=90402-2

Do you use a honing torque plate - what have you seen with shadowing when you first start the hone process?

Hi Dale
We definitely use a torque plate for the competition flathead blocks there's definitely shadowing around the bores where the threaded holes are located. Considering the bore we run 3-5/16 that's enough to cause the distortion when tightening the torque plate.
Ronnieroadster

[Bored&Stroked]

Thanks Ronnie! Was wondering what you saw with the torque plate and hone - appreciate the info.

[KiWinUS]

I too use my Honing Torque plate to pressure test.

[supereal]

Our shop is equipped with a device that tests the cylinder bores with ultrasound to determine the thickness between the cylinder bore and the surrounding water jacket, and any "sand" spots that may cause failure. It has saved us from spending time on blocks that are likely to fail.

[Yoyodyne]

Here's my combination 21 and 24 stud plate. I use a 1/16 rubber gasket, it holds 60 psi in open bolts holes no problem. You can see where it stretched but it hasn't failed. I didn't put every hole in the rubber gasket so I didn't need to put a bolt or stud in every hole.


For the pump blockoff plates I tried 3/16 plate, that bent and leaked at under 30 psi. So I grabbed a thick piece of aluminum, faced it and put holes in it. You don't need pretty to be effective.

[GB SISSON]

Originally Posted by Mart

GB, if you have any scrap steering boxes, the column shaft tube would make good standoffs. It's 3/4" diameter and the bore should clear a 7/16" stud. You'd have to check and maybe drill it a bit, but I think it clears.

Mart.

Scrap steering box? Funny you should ask. I replaced the jailbar steering box on my shop built snow plow today. You'll have to stay tuned for that in a seperate thread. Back to our regular scheduled feature, pressure testing.