Question for you engine guys from a B28 newbie in SD

[Jay Barnett]

Been a long time reader of this forum and a few months ago just bought a new to me Bertram 28 with Mercruiser 350's. Long story short, Port motor had what I thought was an exhaust leak, but now looks much worse. When the mechanic pulled the manifolds off they were corroded and worse so we're where they mate with the heads. He pulled the heads and said he there is water in the one of the cylinders and trace amount in another.

My question is does it sound like the engine is not salvageable or should I be shopping for a long block? Cash is tight, since I just bought the boat a few months ago, but at the same time I want to do what's right, plan on keeping the boat a long time. The engine was running great, no issues at all except the exhaust leak, so this has been a whole lot of bad news especially considering nothing came up on the engine survey.

Any advice would be really appreciated. Thanks.

Jay
San Diego

[scot]

First question; Are you capable of rebuilding the engine yourself? Or should I say assembling engine parts, as it will be an automotive machine shop that does the real work.

[Jay Barnett]

Probably not with my limited experience and time Scot. I have a feeling I should have it done right and not try and tackle a rebuild myself.

Jay

[Bill Fuller]

Jay,

Did you look at the valve train before the head was removed? If so what did it look like? Oil wise.
Did you look at the cylinders when the head was removed? What did you see? Straight, clear water or coolant? Were the cylinder walls rusty? If so, how rusty, just a little surface rust?
It is very possible that you only had a riser failure and could have simply changed the oil a bunch of times and replaced the rise and been good to go. If things look good in the cylinders, I would clean it up, change the oil a few times ASAP, put it back together with a new riser and run it.

With all that being said, this could be all wrong!!! So try to tell us more about the whole situation. Especially more about the exhaust leak. What was it. Where was it??

Also, I live in San Diego (although currently in Florida until Sunday) and have had my B28 for 25 years. The first 10 years with 350 Chevys.

Also, who is your mechanic?

Bill

[Jay Barnett]

Bill,

Thanks for the reply, appreciate your insight.
I'm out if the country until tomorrow so getting good info from the mechanic is tough via text message.

He just said there was NOT water in the cylinders when he pulled the heads, but evidence of "old damage" specifically scarring in one cylinder and slight scarring in another. Exhaust leaked seemed to be from where the manifold meets the head.

Valves all looked normal (to me) but the heads where they meet the manifolds were badly coroded so I'm sure at the very least I'm looking at new heads for that reason. Exhausts that came on the boat are from "Stainless Marine" with the chrome elbows, etc. Those are actually salvageable looks like, they have been rewelded/machined by a local shop.

Mechanic is a guy named Martine who was recommended by a lifelong friend here in SD. My friend is defacto managing this while I've been awa .

Boat is at the Kona Kai, where do you keep yours Bill? Hoping this doesn't ruin the summer chasing yellows!

Thanks again for your advice.

Jay

[Jay Barnett]

Not sure if these will show much...

[Jay Barnett]

Head to exhaust manifold (rt side)

[scot]

The bores don't look that bad IMHO. Heads (from one pic) look no-bueno, but they may clean up? That's a fair amount of scale buildup in the exhaust port. Might be easier (and better) to just find another set of recon heads, because that scale came from somewhere (the wall of the exhaust port) Best part of your problem is you can find Chevy parts at CVS and Walgreens. The only difference for a marine head is they have ss exhaust valves, assuming casting numbers, etc are the same. But it all depends on what your mechanic says.

Good luck, let us know how it comes out.

[Tony Meola]

Welcome

Maybe if Bruce see's this he will jump in, but depending on how bad the head is they can be milled and new valves and valve seats put in. I would let a good machine shop tell you if the heads are good or not. If they are not good, you can easily find new heads.

The cylinders look good.

MY experience has been that once Salt water hits the oil, nothing food happens. The two times we had risers go bad, and Salt Water hit the oil, even after catching it early, let to valve spring failure. Maybe a coincidence but twice on two different boats, you never know. You will need to get the heads checked out, no if's and or buts about that.

I would Change the oil several times before you put it under a load.

[Jay Barnett]

Thank you Scot and Tony for the input. I'm going to go with the remanufacted heads just to be on the safe side. There's a well known shop out here in San Diego that gave a good quote for heads. Once I get home tomorrow I'll have a better look at the cylinders, but hoping they'll be Ok.

Will definitely take your advice regarding the a couple oil changes before placing under load.

Thanks again and I'll let you know how it turns out.

Jay

[Bill Fuller]

Jay,

I agree with what Tony and Scott said.

Was the oil milky with water in the valve train when the valve cover was removed? This would be a good indication of water in the oil.

I would try to have that head re-worked if possible. There are a lot of different 350 Chevy heads and you want to be sure and have the correct one.

What year and model is this engine? And what year is your boat?

My boat is Marina Village on Mission Bay.

Bill

[Rawleigh]

I am assuming the engines a saltwater cooled?? If so, be sure to use a MARINE gasket kit only. Automobile gaskets will not live long in a saltwater cooled engine. If freshwater cooled they are OK for the headgaskets, as they only see antifreeze. I would still use marine exhaust gaskets as they may at least get some salty condensation on them from air coming back into the manifold when cooled.

[Jay Barnett]

Bill,

Boat is a 1991 B28. Port motor is a carbed 5.7/260 original block. Serial number C385734. According to PO, new main bearing installed Sept 2012.

No water/coolant as far as I could tell in the in the oil, it looked really good. As far as the heads, doesn't look like they can be saved because the corrosion where they mate with the manifolds are real bad. Shop out in Santee has a set of heads with matching casting numbers of mine, so that's the direction I'm going. We'll hopefully have it back together sometime next week. Let you know how it goes. Thanks for the info. BTW, it'll be a long ways off for a repower for me, but curious what motors you went with with your B28?

Raleigh,

Boat is FWC, but still going to go with the marine gaskets, especially on the manifolds as you suggested. Thank you for your input as well, it's appreciated.

Jay

[RAWicklund]

Rawleigh........ The block looks FW cooled to me. Small block Chevys have "wet" head bolts that penetrate the water jackets. The deck of the block .....water passages....threads for head bolts...etc look really clean.
Jay,
I can't see any water damage in cylinder that the mechanic stated..... But note, just the act of pulling the heads will get some water on top of the pistons..... Not saying the mechanic is setting you up....just need a better inspection.

That Ex. Manifold mating surface in the pic should clean up pretty good..... A lot of automotive Mach shops have big, flat deck belt sanders that could have that mating surface cleaned up in a heart beat.... Get some estimates on the heads and machine shop advise.... Advise is usually better in person when they can put their eyes and hands on it.

Good luck

Ray

[Jay Barnett]

Hey Ray,

I should have posted this pic along with the other . Does show some surface pitting on the #7 cylinder wall. Mechanic and another friend said may be OK, just never know. Was running great before the heads came off and not using any old in the limited time I've had the boat. So I think I'm going to have em put it back together with either my heads machined or the new ones and hope I get a few summers out of it.

Thanks for the advice on the machine shop, I'll see what they say.

[RAWicklund]

Jay,
They can cut pretty deep on the exhaust face on the head and it doesn't change the geometry of the engine, like shaving the head or intake does.
The machine shop might want the new manifold on hand to make sure their not causing interference problems if they go really deep....ie + .040 or deeper... My guesstimate..

Ray

[Bill Fuller]

Jay,

The 1991 model should be a really nice boat. They got really nice toward the end of their production run (1993 I think). I assume you have the 240 gallon fuel tank.

My boat is a 1975 model and was delivered from the factory with 351 fords. These were replaced in approximately 1984 with the Mercruiser 260s (350 Chevys). I pulled these in 2000 when they had about 4,000 hours and replaced them with 4LHA-STE Yanmars. I will hit 4,000 hours on the Yanmars in the next couple of weeks. Great motors!!

Bill

[Jay Barnett]

Ray, the machine shop took a look and just too much corrosion to save them and get a good seal. Sort what I expected, the pictures unfortunately don't do it justice how bad it looks. I'm getting some reman heads and a lot of my components, valves, etc looked really good so some will be reused.

Bill,

The 1991 is nice, lots of little touches they seemed to improve upon, but nothing seems too drastic. Still have plenty of wood paneling in the cabin just like your cabin must have been!

[Tooeez]

You need to find out where the water that caused the damage came from, or else it is going to happen again. It looks like most of the damage is at cylinder 5; if you have center riser exhaust manifolds it is a good bet that the leak is in the manifold-riser joint, or the riser itself. I've seen this a couple of times in the 28 years I have had my 28. If you have access to an air compressor it is easy to check; put an air chuck on a hose on the freshwater side, block the outlet hose, put about 30 psi in and submerge the whole assembly in a tub of water. If you don't see any bubbles repeat the process for the saltwater side.

[Jay Barnett]

That's a good idea. Mechanic said it looks like the corrosion was old damage, but can't hurt to make sure the exhaust isn't bad internally. Thanks for the the tip.

Jay

[Rawleigh]

If there is any doubt replace the riser.