Testing blocks in the home shop

[GB SISSON]

I have 9 or 10 V8 blocks here and the majority came to me as bare blocks. The rest I stripped down myself. All are 24 stud blocks. Approximately half are early style, mostly 59ab, the rest 8ba style. As many of you know I live on an island with no machine shop. I would really like to check all these blocks, none of which are more than .040 over. Back story is they came from a neighbor who is a mechanic and owns 5 or 6 'tri-five' chevys and "not a fan of the flatheads". The engines had belonged to his father in law (one of us), but he sold his farm and moved into a small space so off they went. I was told that the FIL had scrapped 13 bad blocks but kept these because they were good builders. I see one visible crack in the whole lot, typical valve to cylinder, and one block with a valve seat peened around the circumference that looks like it was run that way. I wouldn't.
About 5 years ago I used a pressure test kit that was loaned to me by a fellow barner. It was simple and worked well on the one engine I had at the time. Apparently these are no longer offered so I would like to build one. The borrowed one had steel plates to block off heads and pumps. (too much work to build)...My thought is use actual heads with an 1/8" epdm rubber sheet gasket, gutted water pumps with a solid sheet gasket, also rubber. I have probably 30 heads and 20 water pumps kicking around. Pipe plugs and expansion plugs where needed. I even thought the water pump gaskets could be made from inner tubes containing the valve stem. Anybody made a home pressure tester kit? Any and all ideas welcomed as long as I don't have to bother a machine shop....Maybe I will start a seperate thread on home brewed magnaflux afterwards. Thanks!

[Ken/Alabama]

Gotta ask, so is peening around a valve seat a bad idea? I’ve never done it but I have a Kwik-Way tool for that very purpose. Just curious

[petehoovie]

Originally Posted by GB SISSON

I have 9 or 10 V8 blocks here and the majority came to me as bare blocks. The rest I stripped down myself. All are 24 stud blocks. Approximately half are early style, mostly 59ab, the rest 8ba style. As many of you know I live on an island with no machine shop. I would really like to check all these blocks, none of which are more than .040 over. Back story is they came from a neighbor who is a mechanic and owns 5 or 6 'tri-five' chevys and "not a fan of the flatheads". The engines had belonged to his father in law (one of us), but he sold his farm and moved into a small space so off they went. I was told that the FIL had scrapped 13 bad blocks but kept these because they were good builders. I see one visible crack in the whole lot, typical valve to cylinder, and one block with a valve seat peened around the circumference that looks like it was run that way. I wouldn't.
About 5 years ago I used a pressure test kit that was loaned to me by a fellow barner. It was simple and worked well on the one engine I had at the time. Apparently these are no longer offered so I would like to build one. The borrowed one had steel plates to block off heads and pumps. (too much work to build)...My thought is use actual heads with an 1/8" epdm rubber sheet gasket, gutted water pumps with a solid sheet gasket, also rubber. I have probably 30 heads and 20 water pumps kicking around. Pipe plugs and expansion plugs where needed. I even thought the water pump gaskets could be made from inner tubes containing the valve stem. Anybody made a home pressure tester kit? Any and all ideas welcomed as long as I don't have to bother a machine shop....Maybe I will start a seperate thread on home brewed magnaflux afterwards. Thanks!

[tomcarman]

Gary,
Probably a stupid idea on my part since I'm not a diagnostics mechanic (I can only wrench and do a bolt in replacement) but years ago I worked running HVAC equipment and natural gas lines. Upon completion of the install we pressure tested the components and looked for leaks using a simple spray bottle with liquid soap mixed up. If it bubbled there was a leak. If not, it was sealed. You could tell right away. If you plugged everything and tested for leaks this way at least you'd know if it was your install or the pressure was exiting elsewhere. Inner tubes to my way of thinking would seal quite well assuming the curvature of the membrane wouldn't interfere under compression. Getting something air tight can be quite a challenge. Give it a try, you're not out much if anything except your time.
Tom

[A bones]

Found 2 post in the archive that speak of making plates.
Head gasket as pattern to cut combustion chamber shape.
One flame cut steel plate. Looks bad works good. Plus plate to cover W-pump hole.
Other one sawed some thick aluminum plate.

[cas3]

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I like the idea, and have always wanted to do the same. Inner tubes is a good idea. Maybe sacrifice a couple bad heads and close them off with epoxy or braze? I have some heavy rubber belting from a conveyer that was going to be the gasket, but tubes would be easier I believe. I wont sleep tonight thinking about the home made magnafluxer !

[ford38v8]

I’m thinking inner tube thickness varies too much, and curvature if the tubes would also compromise the seal. A lot of wasted effort trying to make inner tubes to seal if good flat rubber sheeting is available. Time is money even when retired.

[cas3]

Old truck tubes are thick and wide. The tubes I took out of my army jeep last year probably weigh 8-10 pounds each, the tire was dated 1952, and I would not be afraid to use them again ! perfect for head gaskets I believe

[Bored&Stroked]

On the plate itself, you need to be able to easily inspect the ports, chambers and bores for leaks (and spray a soap-based solution and look for bubbles). What this means is that you need access to the ports and bores while pressure testing.

So, take an old head and if you have access to a really good drill press of better yet milling machine, then you can use a good ole' hole saw at slow speeds to bore through a stock head - in the bore areas and valve areas (two cutters) to make a pressure plate. Is it a lot of work . . . sure . . . but unless you want to have a machine shop make you one, there isn't much other choice. Just a thought . . .

B&S

[FritzJr]

You can do a simple Pass/Fail test just using the heads. Just install some heads so that are known to be good and block off all the water openings. Fill the block with water and pressurize. If the assembly will hold pressure, you are good to go. If it does not, it may be difficult to determine the source of the leak.

[marko39]

Originally Posted by FritzJr

You can do a simple Pass/Fail test just using the heads. Just install some heads so that are known to be good and block off all the water openings. Fill the block with water and pressurize. If the assembly will hold pressure, you are good to go. If it does not, it may be difficult to determine the source of the leak.

i tested my 51 block with the heads and water pumps and found air leakage around the gaskets at 20 psi. i replaced the pump gaskets with thick rubber and copper coated the head gaskets and got it to hold pressure for 2 hours which i considered a success. i was spraying soapy water everywhere and the only bubbles were around the gaskets. air will leak easier than water.

[tubman]

Originally Posted by marko39

i tested my 51 block with the heads and water pumps and found air leakage around the gaskets at 20 psi. i replaced the pump gaskets with thick rubber and copper coated the head gaskets and got it to hold pressure for 2 hours which i considered a success. i was spraying soapy water everywhere and the only bubbles were around the gaskets. air will leak easier than water.

I had the same problem with the setup I made. The water pump block-off was 1/4" aluminum and would leak with the regular gaskets. I made special gaskets from thick rubber which solved the problem. I see no reason for special head block-off plates when there are a lot of extra heads around. My setup is for an 8BA type engine. The plate with the gauge bolts on in place of the thermostat housing; it also has a Schrader valve. The vinyl cap can be used to block off the water pump outlets and allows testing without removing the water pumps (which allows testing in the car). Bad water pump seals complicate the process, but usually it works. I would imagine something similar could be cobbled up for the earlier engines using some radiator hose and the proper sized tubing.

[deuce5wndw]

https://www.speedwaymotors.com/Offen...Kit,25045.html

I bought one of these and it works like a charm!
edit: I just noticed they are on backorder! Sorry

[GB SISSON]

Originally Posted by deuce5wndw

https://www.speedwaymotors.com/Offen...Kit,25045.html

I bought one of these and it works like a charm!
edit: I just noticed they are on backorder! Sorry

Gotta say that speedway set looks pretty nice with the added plus of viewing of valve pockets. That's about 30 bucks per block when a guy has ten of em! I have two friends on the island that have plasma tables. I don't really understand how they work, except that they work remarkably well. They scan an object (head?) and it goes into the computor, at that point it can be altered, then the thing cuts out your steel plate into whatever is on the program. It is mind boggling seeing this apparatus cut 1" steel plate with no slag and all the cuts are perfectly plumb etc, etc.... I can talk to them. On the hillbilly front, I wonder if my bosch jig saw with a good lenox blade would cut the heads open? I suppose I should start with the solid sheet of rubber under a stock head anb see what I find. I assume I will need to at least put a knife cut through each cylinder location on my rubber gasket....

[ursus]

I made gaskets from scrap pieces of vinyl flooring. Easier to cut and punch out stud holes compared to rubber sheeting and the cost was zero. This went under a stock head which was magnafluxed separately by the same shop that performed the pressure test. The machinist said the vinyl flooring gasket worked well for the test. Separate gaskets were made from the same material for the water inlet/outlets.

[GB SISSON]

Originally Posted by Ken/Alabama

Gotta ask, so is peening around a valve seat a bad idea? I’ve never done it but I have a Kwik-Way tool for that very purpose. Just curious

Mine was done quite randomly by hand with punch. I can see that the cast iron of the block actually deformed from the blows. Maybe it's fine, but if it turns out not to be, well you get it...

[Mart]

Just an idea, but do you think some nicely made wooden block offs would work? Might be up your alley, GB.

[cas3]

Excellent thinking Mart !

[B-O-B]

How about using some really thick say 3/4" maybe 1/2" clear plexiglass or some other strong clear plastic. You could use your jigsaw & hole saw. Lexan that is what I was thinking of. Made side windows for my roadster from using this.

[GB SISSON]

Some really good ideas flowing in here. I am almost finished with a recent biography of Thomas Edison. He and his 'boys' worked long hours in the lab and constantly bounced ideas off each other. We don't need no stinkin' lab!

With plywood or lexan I could fasten a head down and drill through the stud holes as a template guide. Water pumps too! If the sheet gasket was already in there, all the better....