Water intrusion. Is it too late for BlackMax?

[MarshMan73]

Ran my BlackMax this weekend and noticed it a little harder to idle at first crank but then ran great. Idle was a little rough and it used more gas when at WOT. Brought it home and noticed a little water on the plug for #3. Took the head off and to my horror I found a little sliver of chrome missing at the top of the cylinder where the head gasket had been leaking water and letting a little water in. Also on the back of this is a little v-shaped peice of water jacket missing. Compression was 98 on this cylinder before I took it apart. Also broke and had to extract the lower cylinder head bolt. Hope I can find one. I am thinking of what to try to repair the water jacket with and then put on a new head gasket and run it till she blows. Inside the cylinder walls are smooth but have a few little tiny dark specks. #5 also has a few dark specks, but overall look very shiny and not gouged in any way. The head on #3 looks like something got sucked up in there and scratched it up real good. Piston top looks good though. Wonder if this head was replaced from a block that grenaded? How long can I expect before this one grenades running it with a new head gasket and JB-Welding the water jacket?
Sorry wasn't able to get a good picture under the worklight, so have to wait until tommorow to get pics.

 

[MarshMan73]

Re: Water intrusion. Is it too late for BlackMax?

Here's the pics of the damage

 

[j_martin]

Re: Water intrusion. Is it too late for BlackMax?

Don't know if you can get away with JBWeld on that. Pinholes in the plating are considered normal, and do no harm.

Looks like it was damaged putting in the sleeve. Probably been like that since then.

The head damage is from a blowup that occurs when a ring locater pin is lost, and the ring turns and catches a port and breaks up. Obviously it's past history.

hope it helps
John

 

[MarshMan73]

Re: Water intrusion. Is it too late for BlackMax?

So what are my options now? Priced new Mercury O/B yesterday at 15k! Don't have that kind of money to put in this rig. Is there any sort of cold weld I can use that will buy me some more time?

 

[j_martin]

Re: Water intrusion. Is it too late for BlackMax?

I'm pretty sure the gasket seals on the sleeve. You can probably just bolt up a new gasket and run the heck out of it.

It looks like that sleeve could be replaced. You can have a steel sleeve put in one hole if you put the right rings on that piston. I don't think any epoxy or JBstuff would work long. I don't think you could weld it without distorting the sleeve, but maybe it can be.

The guys over on screamandfly.com have more experience abusing and blowing up these engines that anywhere else on the web that I know of. Some of them are in the habit of making 10,000 rpm dragsters out of junk parts. A couple on the site weld up motors that you wouldn't believe could live again and they are fine. I'd ask on their tech forum, and you'll probably get led right.

If you can do your own work, 1-2G for parts is a lot cheaper than a new motor, and it would probably last as long as you want to run it.

There's a real rush to getting good at maintaining these motors that are quite intimidating, till you find out just how simple they are.

hope it helps
John

 

[MarshMan73]

Re: Water intrusion. Is it too late for BlackMax?

Put everything back together yesterday with new gasket and bolts. Didn't use gasket sealer on head gasket because it was already coated with something that was sticky. Hope this was right. My JB Weld repair of the cylinder water jacket looks real good and planed it flat with sandpaper. Ran it on the hose until the thermostats opened and shut it down. Let it cool a few hours and did it again. After it cooled 2nd time I retorqued the bolts. Hope she holds for a weekend trip out of Venice into the Gulf. I have a good friend taking his boat in case I have to get towed back in.
Oh I forgot to say I rechecked the compression and now am dead even across all cylinders. Yea!