Bowen Island Paint Job

[Marty Levenson]

head gasket question

The second time I installed the head last night (NOT torqued: just hand tight) there was some slight effect on the lower head gasket. Looks like a tiny bit of the graphite stuck to the block....maybe because of some permatex residue? Looks reusable to me, but would like one or more second opinions...I'm ordering a bunch of items from Moyer on Monday, so adding a new pair of head gaskets wouldn't be hard.

Thanks,
Marty

[jpian0923]

Gaskets are still good. Leave stud in. Just my opinion...

[ILikeRust]

1. A fully seated stud has more threads engaged in the block than one that is only partially threaded in. More threads = more force required to pull it out.

2. I would leave that stud in. Looks like it's in good condition; why take the gamble and try to pull it out?

3. Gasket looks ok to me - I would use it.

[Marty Levenson]

studs

I think I didn't convey the situation well enough! To clarify:

The studs I bought are the correct length, but the coarse thread section is longer than necessary. So, to seat the stud it is screwed in so far that the stud bottom end protrudes almost .25" into the water jacket. When I back the stud out 4.5 turns I can feel inside the water jacket that the stud is now flush with the block. Because the stud's coarse section is longer than needed for the A4, there are then about .25" of coarse threads showing above the block. Here's the main point: all the threads that the block has to offer are still engaged with the stud's coarse threads. With the threads backed out that .25", the top sits high enough to attach the nut, with a couple threads clear above that.

So. I thought the replies I received indicated that the stud needed to be seated, not just all the threads engaged....and I started to wonder why.

Another factor is that the Moyer studs are grade 8: the ones I bought are grade 5. ($1.15 each).

Looks like I'll be leaving that stud in, as planned, and reusing that gasket!

Thanks,
Marty

[Loki9]

My concern with not seating the studs all the way tight is that they might unscrew themselves or otherwise come loose when you don't want them to. If Locktite or permatex is enough to keep them in place, then I guess they'll be fine.

I'd reuse that head gasket without much thought.

[jpian0923]

Marty,

Get the studs from Moyer... no matter the cost! Cheaper in the long run.

[ILikeRust]

The studs I bought are the correct length, but the coarse thread section is longer than necessary. So, to seat the stud it is screwed in so far that the stud bottom end protrudes almost .25" into the water jacket.

What I would do - cut/grind 1/4" off the bottom end of the stud. Then they would be fully seated, without that little tail hanging down into the water jacket.

[ILikeRust]

I'm curious as to where you got the studs from - and did you make sure to get the right lengths? There are three different lengths - (1) the "normal" or "short" length that goes through just the gaskets and the head itself; (2) the "medium" length, which go through the alternator/lifting eye bracket; and (3) the long ones that go through the thermostat housing.

The key is to make sure the fine thread does not end before the nut fully tightens down on the head.

When I did mine, I somehow ended up with the wrong number of short ones and had a few too many medium ones. I don't know if I miscounted when I ordered of if Moyer accidentally sent me the wrong ones or what - but it made no difference anyhow. I have a nice little set of taps and dies, so I simply added about another 1/8" - 1/4" of threading to the studs that were too long and cut off the extra length. Worked fine. Although threading that grade 8 metal took a bit of effort.

[Marty Levenson]

studs again

Hey Bill,

Thanks for your reply. I think you might have missed post #94: the stud lengths were correct, but the coarse section was longer than on the Moyer studs...thus when seated they were screwed down too far.

My conclusion is that having the head off, rebuilding something so essential to the future of the engine, I want to do it the best way possible. I'm not missing any sailing time, so there is no real hurry. If I were improvising a repair up the coast to get me home, I'd be very happy with my workaround....it would likely work fine.

Built the skid last night, and assembled the enlarged water inlet tee. Time to get the FWC parts set up while I'm waiting for the studs!

Thanks,
Marty

[ILikeRust]

Gotcha.

In that case, I probably would have used them, and just screwed them down until the threads were fully engaged in the block, but not bottomed out. With a little Threadlock or Permatex, I'm sure it would have been just fine.

[Marty Levenson]

right!

That's exactly what I did, but worried about what effect not being seated would have, in terms of leaks or vibration. Also like the idea of grade 8 studs: hope to leave the boat to my nephew in 20 years or so....!

-Marty

[ILikeRust]

Well as far as that goes, I wouldn't worry about that. Grade 5 is well more than strong enough for that use. It's not a very high-compression engine, and you're torqueing them down only to 35 lbs. For that matter, you could use plain old mild steel bolts, which would work just fine.

[Marty Levenson]

rust?

It wasn't strength I was thinking about; I have heard that grade 8 is more rust (yes: I know you like it) resistant. The studs I took out were very corroded...about .25" on several.

-Marty

[ILikeRust]

Well, I don't actually like rust. Long story, but suffice to say my wife gave me that moniker as an e-mail ID, and it stuck.

I dunno, really. I think they have a zinc plating, which gives it that gold color, and also helps with some superficial corrosion resistance.

[Marty Levenson]

looking ahead

Waiting for my studs and nuts from MM, and thinking about what comes after getting the head back on!

While the A4 is still n the engne stand, I built a wooden skid with wheels, with an extension for the FWC set up. (see photos). Want to test it when I test start. Gauges will be mounted on the top of the plywood.

On our Tartan 27 the heat ex and cond. bottle will be in the starboard sail locker....about 2.5 feet aft of the transmission.

The engine came with good SW gauges, that were new in 2009. Am I right that G=ground, S=sender, and I=ignition? Wondering what to do for a cheap, easy start switch when I do the testing.

Added some photos of my workshop table: ready for assembly! Stil haven't painted the alternator, but plan to.

Fun!
-Marty