Testing blocks in the home shop
 

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!

Re: Testing blocks in the home shop
 

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

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Re: Testing blocks in the home shop
 

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

Re: Testing blocks in the home shop
 

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.

Re: Testing blocks in the home shop
 

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 !

Re: Testing blocks in the home shop
 

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.

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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

Re: Testing blocks in the home shop
 

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

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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.

Re: Testing blocks in the home shop
 

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.

Re: Testing blocks in the home shop
 

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.

Re: Testing blocks in the home shop
 

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

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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....

Re: Testing blocks in the home shop
 

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.

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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...

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

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Excellent thinking Mart !

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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.

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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....

Re: Testing blocks in the home shop
 

If it's to hold a loose seat in place, bad idea.
It will not transfer heat well and will likely rattle around.
May further damage the block.
If the seat fits tight, won't hurt, but no help.

Karl

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I had a shop with a flame cutter use a head gasket to cut a steel plate for the combustion chamber shapes, then I clamped the plate to a cylinder head to drill the head bolt holes.
Gasket material is a theatrical dance floor rubber like material called "Marley".
This comes in huge expensive rolls. You may be able to hunt up used from a theater.

Karl

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Flatjack9 here on the Barn fills the block with water then pressurizes if you see water anywhere you have a problems makes it easy to check. exhaust posts . Dave/Green Bay

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How many lbs pressure would be considered normal for a machine shop test?

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Just remember to coat the plywood as it could swell if it got too wet too long.

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I have the Speedway kit. I think it works great and I tested a Merc block I tested at 55# for an hour and a half. I figured it was worth working on.......Mark

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My idea is to bolt on the heads and water pumps. Use short lengths of radiator hose with freeze plugs clamped in the ends to block off. Get a cheap leak detector kit that uses florescent dye and a black light. Use the dye meant for oil and mix with Diesel fuel and fill the block. You will need little or no pressure as Diesel is good at wicking its way through tiny cracks. Carefully drain the diesel fuel, pull the heads and use the black light to look for cracks.

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I like this. Sounds like it would be hard to miss a crack with this system. I would still use rubber head gasket and dummy water pumps. This way I'm only testing the block. Amazon has a Mastercraft UV test kit with everything needed for the test. Price is 60 bucks. I have used trailer balls in the past to cap off hoses on my run stand. BUT... With Mark's 55 psi in there the block better be filled with liquid and not much air. Think 'potato cannon'.....

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I made water pump block off plates with a gauge, used heads and head gaskets. I used a bicycle pump to pressurize a water filled system and looked for leakage the next day.

I also pumped up with air only and submerged it in a big plastic tub over night and found no bubbles or burps. Gauge held steady.

I did find the typical "part number" cracks with dye penetrant and that was it. I was lucky.

If I did have bubbles or water leaks with this setup I would not be able to look into the cylinders but, I WOULD know there are cracks to investigate.

I made my test kit with what I had on hand.

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Excellent job there Scotty! I have every reason to believe that your double testing procedure was at least as thorough and accurate as I would get from a machine shop. Maybe on the first test I would use the diesel fuel and dye procedure, as when the heads or plates are removed the light will show just where that pesky crack is. If the block was on a typical engine stand, wouldn't the water/diesel/dye drip onto the floor below the affected cylinder? Another question... Would the block off heads and water pumps be the exact same parts for testing all 24 stud engines?
I almost wonder if it would even be necessary to magnaflux a block that passes Scotty's x2 procedure. Of course there's that part of me that wants to make some kinda coil by wrapping a cast iron sash weight with a thousand turns of copper wire and some diodes and vacuum tubes with a big rheostat and a couple of knife switches.... Obviously I know nothing about magnafluxing (or electricity for that matter.) What test would a typical machine shop perform first, and why?

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Thanks Gary. I had a set of head gaskets that were given to me is why I used them. I don't remember the brand. I sprayed them with white grease to hopefully be able to reuse them for testing purposes. I never tried though. I only had the one extra block. I stuck them in a plastic bag just in case.

My water pump plates are 1/4" plate I had laying around. Rubber sheet gasket material. It's been a few years so I don't remember if I made one water pump plate and checked one side at a time. I think you can flip it and use on both sides. I'd have to go dig out my kit from the shed.

I know my heads aren't cracked either.

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I made a water pump block off plate just so I could fill the block with evaporust. It worked on both sides, although for this purpose I only did one side at a time. 1/4" thick, used silly cone for the seal.

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“What test would a typical machine shop perform first, and why?” you have to come up with a way to really clean the inside too......I’m not sure if that should be done before or after the pressure test....does anyone think that cleaning the scale out could expose a crack., post pressure test. Making the test wrong. I used 55# as a test pressure because someone on here said they used 80# and somebody else said 25# was plenty....I went in the middle...Mark

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Same here. Will be using it for three blocks in a few weeks.

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I would clean as much scale and debris out first before testing.

Re: Testing blocks in the home shop
 

Having done this in an automotive machine shop for years...
1) magnaflux top of block
2) pressure test block, 30 lb. air pressure would be ok.
3) use soap in water to look for bubbles. All over, inside and under block.
4) as a finish, raise air pressure to the point where the pressure
the test plate starts to leak air- 50/75 lbs. Look more.
Karl

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I have a pretty powerful pressure washer. I have an extra wand I could alter if needed. Seems maybe with the flywheel end up high, one could blast down into the head cooling holes, starting in the back, maybe a steel wire too. Drag/blast out loose stuff, then soak with vinegar/evaporust/some kinda acid?

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I found a broken parking brake cable that I used on my drill. I tipped the water pump openings down and ran the spinning cable in every place I could get it. Then used air pressure. A lot of stuff settles in there.......Mark

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Excellent! A rotary whip with ragged ends. I have a couple nice long cables from a tonner. I was thinking it could unwind up there if you spun it in the wrong direction and then I got to thinking you might have the outer casing involved as well. Pretty much a rotor-rooter, I like it! So after this, it's the pressure test. While the test kit is hooked up a good time for a vinegar soak?
Can't wait to learn about magna-fluxing.

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I did like you mentioned and blasted as much as possible with my pressure washer.

Then used cable in a drill and more picking and blasting.

Then a soak with phosphoric acid and it looks like new metal inside. It only dissolves rust. Will not damage the block.

I got it at Home Depot in the paint dept. Kleen Strip I think? It's for paint prep. About $14 a gallon the last time I bought it. I used it straight.