Head Leak from Alternator Bracket

[kakers]

Hello all,

I'm a long time lurker, first time poster. I have a '73 Cal 29 with the original RWC A4, owned her about 2 years. We love the boat and the quiet and smooth A4. Best thing the p.o. did was tell us about MMI and this forum. I'm always impressed with how generous everyone is with their time and expertise.

Haven't had any major issues with the engine - it starts first try, runs smoothly at around 160 deg., good batching out the exhaust, no steam. Did an acid and water flush per Don's instructions about a year ago, rebuilt the Orberdorfer pump recently.

Last weekend while heading out I noticed a leak coming out from under the alternator bracket and trickling down the water jacket side plate. Yesterday I cleaned off the head and ran the engine in the slip for 7-8 min with no load = no leak. I put it in gear and within 3-4 minutes the leak had reappeared (see picture). The leak appeared along the forward edge of the alternator bracket. Funny thing is the leak stopped when I took it out of gear.

My plan:
1. Remove the two nuts (I've ordered a can of Kroil and will do the tap and soak with Kroil procedure for several days before attempting to loosen) and see if I can seal the stud hole with Permatex.
2. Check the compression.

I've read that pinholes can appear under the bracket. Anyone have that issue before?

I have reasonable access to the engine (thank you Bill Lapworth!) so I believe I can remove the head in place if need be.

Are there any other things I should try/watch out for?

Thanks in advance,
Ken

'73 Cal 29 "Mana"
SF Bay

[hanleyclifford]

I think in your situation I would make an attempt to remove the two nuts in question without the Kroil in the hope that the studs would come out with the nuts. An examination of the threads coming out of the block should tell you if the studs are leaking via the threads. First prize would be to coat the threads with the thick pasty Permatex and reinstall. A pinhole in the head is also a possibility and may be evident when you pull the bracket.

[roadnsky]

Ken-
You seem to have a good plan in place already, otherwise you'd have waayyyy
more opinions from the crew.
Slow and easy with those bolts though...

Strange with the leak/no leak when in and out of gear?

[sastanley]

I wonder if the alternator loads are producing the leak.

I like Hanley's plan as a first attack. The thick pasty Permatex is #1 or #2. I'd pick #2 for parts I may want to remove later...If I remember my Permatex's correctly, #2 kinda stays pliable, whereas #1 is supposed to get hard and brittle..not so good for sealing water leaks in my opinion.

[ndutton]

I wonder if the alternator loads are producing the leak.

If that's the case this would be an opportune time to shamelessly hawk the new tensioner. I found in prototype testing and have learned from other members who have installed theirs that the necessary tension on the system is far less than what we've been running in the past, it eases the loads on all related components.

I'm just sayin' . . .

[kakers]

Thanks for your helpful suggestions

If that's the case this would be an opportune time to shamelessly hawk the new tensioner. I found in prototype testing and have learned from other members who have installed theirs that the necessary tension on the system is far less than what we've been running in the past, it eases the loads on all related components.

I'm just sayin' . . .

Hanley, I like your suggestion. Would you recommend using MMI's stud remover as the first try? I'm a bit leery about those two studs given the fact that they've probably been exposed to more salt water along their lengths than normal.

Shawn, interesting about increased alternator load causing the leak. It makes sense. I'll also have to try running it in neutral at a cruising RPM to see if that makes it leak, too.

Neil, now I have an excuse to get the new tensioner! If it saves a head removal it's worth every penny.

I'll keep posting pics and updates as things progress.

Ken

[ndutton]

I'm with you Ken

Neil, now I have an excuse to get the new tensioner! If it saves a head removal it's worth every penny.

You should consider it prevention of future issues, not necessarily a remedy for this one. Reading your post, we're on the same page.

Ain't this forum great??

[kakers]

Agreed

You should consider it prevention of future issues, not necessarily a remedy for this one. Reading your post, we're on the same page.

Ain't this forum great??

Yep! You're right - the tensioner can save wear and tear on alternator and acc. drive bearings, not to mention knuckles when trying to replace the belt.

Oh yeah, this forum is a great community.

[hanleyclifford]

The stud remover is a great idea but first just put a wrench on those two nuts and see what happens. If they both come out, nut and stud together you get first prize. If you break a stud you pull the head and you had to do it anyway. If the nut comes off leaving the stud in the block it probably isn't leaking anyway. If that happens remove the alternator and bracket, reinstall and torque the nut using washers to take up the extra stud height, and run the engine looking for leaks under where the bracket was.

[kakers]

The stud remover is a great idea but first just put a wrench on those two nuts and see what happens. If they both come out, nut and stud together you get first prize. If you break a stud you pull the head and you had to do it anyway. If the nut comes off leaving the stud in the block it probably isn't leaking anyway. If that happens remove the alternator and bracket, reinstall and torque the nut using washers to take up the extra stud height, and run the engine looking for leaks under where the bracket was.

Good plan - I'll use a 6 pt. socket for starters.

[Mark S]

If that's the case this would be an opportune time to shamelessly hawk the new tensioner.

Neil, you get royalties?

[ndutton]

Neil, you get royalties?

Nope, no royalty arrangement.

I've been thinking about this leak. Please forgive me kakers but haven't we heard of head cracks in the area of the alternator/lifting bracket before? Usually it's blamed on lifting the engine and a bracket design/center of gravity conflict. I always felt a lifetime of raw water cooling rusting the head from the inside was a contributor as well.

Might want to keep a wary eye out for cracks in the area. I want to be wrong on this one.

[Don Moyer]

Historically, leaks in the area pictured in post #1 of this thread have turned out to be caused by a very thin cross section in the casting directly (and very localized) across the base of the raised boss area on which the alternator bracket (AKA lifting eye bracket) sits. If, before you remove anything, you take a wire brush and thoroughly clean the area just in front and all across that boss area you should be able to see exactly where the first sign of water appears. If you can identify a specific spot where the water appears (it may look like a pin hole) you can usually take an ice pick and poke right through the leak and then discover that the thin area extends to the left and right (again, right along the base of the raised area in the head).

I've never been too enthusiastic over the analysis that lifting an engine will cause a crack in this area due to the geometry of the lifting eye, unless of course there is a flaw in the area already. We've never been able to identify any particular vintage of late model head that has this thinness (after 30 plus years, we can hardly call it a manufacturing defect). They just show up every now and then.