Author Topic: crack head, now what? (Read 8142 times)

commuter boy · « **Reply #15 on:** January 25, 2009, 01:40:21 pm »

I haven't seen a head yet without some cracks between the valves, holding pressure or not. It seems it would have to be awfully deep to hit the water jacket.

If I had to guess I'd say once the crack propagates right across from side to side it's relieved the stress and doesn't go any "deeper" up into the meat of the head. That thicker area wouldn't be flexing as much as the thin web between the valves so the crack won't wiggle it's way up.

1.6Lmarine · « **Reply #16 on:** January 25, 2009, 04:46:41 pm »

Thanks.

Thats what I figured.

I'll let you know what happens.

Rabbit TD · « **Reply #17 on:** January 25, 2009, 10:58:03 pm »

Quote from: "jtanguay"

doesn't matter how big the cracks are, if they leak they leak.. if they dont leak, then you're fine. getting it pressure tested isn't too much coin if you want some peace of mind.

would suck if you bought a new head and your head was fine. but if you have the money for it, it's not a bad thing. only if you buy an inferior product.

Yes I also agree that the size can't be the determining factor, just a rough guidline. The thing I would like to know is how they actualy do pressure test a head in the first place. I've had some tested for myself and we sent them to the machine shop all the time when I was a mechanic but I never ever saw a pressure testing tool. I just can't visualize a tool that would be adaptable enough to be able to seal virtualy every kind o head there is considering bolt patterns, coolant ports and such. It's probably a pretty simple tool in reality if ou could see a picture of one. I just wonder if it is something we could rig-up for at least just our VW heads. We all seem to have the same problems like this and it could save us a lot of time in the shop, money and worries if we could do it ourselves.

Rabbit TD · « **Reply #18 on:** January 25, 2009, 10:58:31 pm »

Quote from: "jtanguay"

doesn't matter how big the cracks are, if they leak they leak.. if they dont leak, then you're fine. getting it pressure tested isn't too much coin if you want some peace of mind.

would suck if you bought a new head and your head was fine. but if you have the money for it, it's not a bad thing. only if you buy an inferior product.

Yes I also agree that the size can't be the determining factor, just a rough guidline. The thing I would like to know is how they actualy do pressure test a head in the first place. I've had some tested for myself and we sent them to the machine shop all the time when I was a mechanic but I never ever saw a pressure testing tool. I just can't visualize a tool that would be adaptable enough to be able to seal virtualy every kind o head there is considering bolt patterns, coolant ports and such. It's probably a pretty simple tool in reality if ou could see a picture of one. I just wonder if it is something we could rig-up for at least just our VW heads. We all seem to have the same problems like this and it could save us a lot of time in the shop, money and worries if we could do it ourselves.

jtanguay · « **Reply #19 on:** January 26, 2009, 12:02:58 am »

Quote from: "Rabbit TD"

Quote from: "jtanguay"
doesn't matter how big the cracks are, if they leak they leak.. if they dont leak, then you're fine. getting it pressure tested isn't too much coin if you want some peace of mind.

would suck if you bought a new head and your head was fine. but if you have the money for it, it's not a bad thing. only if you buy an inferior product.

Yes I also agree that the size can't be the determining factor, just a rough guidline. The thing I would like to know is how they actualy do pressure test a head in the first place. I've had some tested for myself and we sent them to the machine shop all the time when I was a mechanic but I never ever saw a pressure testing tool. I just can't visualize a tool that would be adaptable enough to be able to seal virtualy every kind o head there is considering bolt patterns, coolant ports and such. It's probably a pretty simple tool in reality if ou could see a picture of one. I just wonder if it is something we could rig-up for at least just our VW heads. We all seem to have the same problems like this and it could save us a lot of time in the shop, money and worries if we could do it ourselves.

you know... i never really thought about what the pressure testing tool would look like. and yes it would need to be able to seal very well. perhaps the best testing method would be to bastardize a 1.6/1.9 block, seal up the piston side, and the coolant ports, and do it that way? wouldn't need a new gasket each time because its not under combustion pressures. this could also test valve leakage as well.

does anyone have any input on what the whole pressure testing procedure is? i'm very curious now! :lol:

edit: a quick search revealed this site. looks like a universal tester. and also this tester. looks to be quite elaborate and very adjustable for any kind of head.

Rabbit TD · « **Reply #20 on:** January 27, 2009, 01:08:24 am »

Quote from: "jtanguay"

Quote from: "Rabbit TD"
Quote from: "jtanguay"
doesn't matter how big the cracks are, if they leak they leak.. if they dont leak, then you're fine. getting it pressure tested isn't too much coin if you want some peace of mind.

would suck if you bought a new head and your head was fine. but if you have the money for it, it's not a bad thing. only if you buy an inferior product.

Yes I also agree that the size can't be the determining factor, just a rough guidline. The thing I would like to know is how they actualy do pressure test a head in the first place. I've had some tested for myself and we sent them to the machine shop all the time when I was a mechanic but I never ever saw a pressure testing tool. I just can't visualize a tool that would be adaptable enough to be able to seal virtualy every kind o head there is considering bolt patterns, coolant ports and such. It's probably a pretty simple tool in reality if ou could see a picture of one. I just wonder if it is something we could rig-up for at least just our VW heads. We all seem to have the same problems like this and it could save us a lot of time in the shop, money and worries if we could do it ourselves.

you know... i never really thought about what the pressure testing tool would look like. and yes it would need to be able to seal very well. perhaps the best testing method would be to bastardize a 1.6/1.9 block, seal up the piston side, and the coolant ports, and do it that way? wouldn't need a new gasket each time because its not under combustion pressures. this could also test valve leakage as well.

does anyone have any input on what the whole pressure testing procedure is? i'm very curious now! :lol:

edit: a quick search revealed this site. looks like a universal tester. and also this tester. looks to be quite elaborate and very adjustable for any kind of head.

Yea a block probably would be a good place to start with to make the tool, assuming its not cracked too :lol: I wonder what kind of pressures would be required to do this that would reveal the leaks, use with an air compressor and water maby. Mine only goes to 110 I think. But then again since we're only concerned with the coolant passages an they're pressures, 20 psi might do it. Hell I think I got enough stuff around here to do this including an old N/A block, new 3 notch fiber gasket I'll never use for anything else, plenty of head bolts 11 and 12 m/m and a couple heads too. The pressure hookup shouldn't be too difficult. I believe I might do some experimenting with this idea soon, I would like to know what pressures the machine shop uses though but I'd be ashammed to tell them what I'm doing :lol:

1.6Lmarine · « **Reply #21 on:** January 30, 2009, 04:27:29 pm »

Head:

Head has some serious problems. Valves are so loose that you could use them as a kitchen blender! Valves and guides are gone...and the seats. There is quite a bit of stress showing on the cylinder plugs - lines showing up some pre-crack warnings. And then he didn't even do a pressure test or check for warpage. For the price of doing all this he already found a factory re-built/re-conditioned head (including cam) without all the stresses. He's putting it back together for a core trade-in. I'm sure it would work...but then again I don't want to have to pull it after a couple of years on the water. Put the best on that I can afford...and after all, in comparison with a new outboard, for example, it's still a steal...

Pressure Testing:

I asked him his method. Like he said they do tests on everything from CATs to VWs and there's no one machine that could do it all. Over the years they have cut small 3/8" plates that match most engines and are bolted into the head studs. Between the plates and the head they place a piece of rubber innertube just larger than the holes and tighten them down. They have an inflateable plug for the outlet and another one for the inlet which fits around an airhose fitting. They inject the water jacket with 110 psi of air and then slather on a water-soap mix that readily shows any leaks. Pretty ingenious and straight-forward if you ask me. Wouldn't take much to make up something like that for your 1.6s!

fdnyguy · « **Reply #22 on:** January 30, 2009, 07:58:02 pm »

... minus 45 windchill here now - gotta go plow - dreaming of summer!

Summer is like 4-5 days that far north, right? :lol: :lol: :lol:

1.6Lmarine · « **Reply #23 on:** February 02, 2009, 10:28:53 am »

Lots of people here say that we have two seasons. 9 months of winter and 3 months of tough sledding!

Taking the block in for assessment this a.m..

1.6Lmarine · « **Reply #24 on:** February 02, 2009, 06:10:08 pm »

Looks like the block checks out very well. Makes me crazy-happy!

A word on caution on pressure-testing to follow up on the discussion here...

IF YOU PRESSURE TEST YOUR OWN HEAD MAKE CERTAIN THAT YOU DO NOT STAND IN FRONT OF THE ENGINE PLUGS!!! The machinist showed me a place where one had shot out of a damaged engine he was testing. Went right through the wall...

Rabbit TD · « **Reply #25 on:** February 02, 2009, 08:12:50 pm »

Quote from: "1.6Lmarine"

Looks like the block checks out very well. Makes me crazy-happy!

A word on caution on pressure-testing to follow up on the discussion here...

IF YOU PRESSURE TEST YOUR OWN HEAD MAKE CERTAIN THAT YOU DO NOT STAND IN FRONT OF THE ENGINE PLUGS!!! The machinist showed me a place where one had shot out of a damaged engine he was testing. Went right through the wall...

Thank's for the heads up about the plug coming out. I will definately keep that in mind if I get to experimenting with this.

Smokey Eddy · « **Reply #26 on:** February 03, 2009, 04:19:08 am »

If you haven't decided what to do yet here is some inspiration...

:twisted:

1.6Lmarine · « **Reply #27 on:** February 03, 2009, 12:28:59 pm »

THAT is BEAUTIFUL!

I'm waiting to see how the bottom of the cyinders check out. But they should be fine. I'll get a rebuilt head.

Is this head your own or a rebuild?