'94 Echelon engine failure

[MalibuNation]

Good luck ... we'll be out tomorrow and Saturday if you need even more distractions

[Michigan boarder]

Good luck ... we'll be out tomorrow and Saturday if you need even more distractions

I'll already have them! 7/8th grade football game tomorrow (my 8th grader is turning out to be a darn good tight end and nose guard). Thursday night is Service League (rule #1 is do not talk about Service League). Friday night my older son is in varsity football. Saturday my wife and I are coaching our daughter in U8, then it's Oktoberfest at the Winter Sports Complex the rest of the day and night.

Sunday = big breakfast and work on the boat day.

[Michigan boarder]

Well, bad news. The piston is destroyed. Looks like the top of it broke apart. What causes that? The cylinder walls feel completely smooth, no scoring. This is #5 piston. The issue with #3 is that the head gasket did go too between those cylinders.

[Michigan boarder]

Here's a pic of the head.

[Michigan boarder]

_{So, based on all that, what are the options?}

[jk13]

Well, bad news. The piston is destroyed. Looks like the top of it broke apart. What causes that? The cylinder walls feel completely smooth, no scoring. This is #5 piston. The issue with #3 is that the head gasket did go too between those cylinders.

Sure it's not scored at the 9:00 position in that photo?

Strange issue to have a piston do that after 20 years. Hard to call it faulty at this point, but if it was a new build that's what I'd lean toward.

[Michigan boarder]

Sure it's not scored at the 9:00 position in that photo?

Strange issue to have a piston do that after 20 years. Hard to call it faulty at this point, but if it was a new build that's what I'd lean toward.

It sure does look like it in the photo, I'll have to check it out a little closer. I did swipe my hand all the way around it and don't recall feeling anything at all.

[Woodski]

Looks like either detonation or pre-ignition took out the piston. Causes are numerous from too much ignition timing to running too hot (failed impeller / passage blockage) or even too low octane (in this case bad) fuel.

If the block is not damaged, you might get away with a piston and cylinder head, but it looks like there might be some damage to the block on the top surface where the gasket failed, check it with a flat ruler to see if it is eaten away. You could always go one size up on the piston(s) to keep the block and do a rebuild on it. You could actually only do the one in question if you wanted. More analysis needed to get the true picture.

[Michigan boarder]

Looks like either detonation or pre-ignition took out the piston. Causes are numerous from too much ignition timing to running too hot (failed impeller / passage blockage) or even too low octane (in this case bad) fuel.

If the block is not damaged, you might get away with a piston and cylinder head, but it looks like there might be some damage to the block on the top surface where the gasket failed, check it with a flat ruler to see if it is eaten away. You could always go one size up on the piston(s) to keep the block and do a rebuild on it. You could actually only do the one in question if you wanted. More analysis needed to get the true picture.

I'll check out the block a little more at lunch today. Boat has about 650 hours on it, FWIW. If I'm into it this far I'm leary to repair 1 piston.

[FastFreddy]

I'll check out the block a little more at lunch today. Boat has about 650 hours on it, FWIW. If I'm into it this far I'm leary to repair 1 piston.

My suggestion is to rip the engine out and bring it to a professional engine re-builder:

If it were me I'd want to replace all bearings, pistons and probably the valvetrain since they are already in there. Looks like they'll be able to re-use most of the main parts including the head.

[Woodski]

650 hours is not a lot of hours, so without a damaging event (looks like something initially causing either the detonation > piston failure > head gasket failure -or- head gasket to fail > hot gases from other cylinder > detonation > piston failure), everything should be in pretty good shape. An SBC should easily go 1500 hours before any major servicing. Just for fun, check to make sure the distributor is tight and did not twist by accident (advancing the timing).

So my suggestion would be to have the good stuff (pistons / valves) checked for cracks then decide if you want to replace. Keeping them will certainly help on the budget! I would certainly put in new rings, they are pretty cheap. The condition of the block will certainly be a big guide on what will need to be replaced. This does present a great opportunity if you want to bump the power level up as it is a perfect window for that and to your previous posts it sounds like you want to do that. Cam / heads / rockers are good starters, bore and stroke might also come along for the ride...you can easily bump to 400 hp if you want.

A lot of your decisions will be guided on your risk tolerance and access to working on the engine / tools etc. Don't forget, many replacement parts are of lower quality than the originals...

At this point, I would put the head back on the engine (with the lifting hooks) and pull it to do more investigation as the pan has to come off anyway to repair.

Edited October 7, 2013 by Woodski

[Michigan boarder]

Here it is with a light behind it and an aluminum ruler for an edge. Looks OK, don't you think? If anything it feels raised up some.

[Michigan boarder]

Close up.

[Michigan boarder]

Fastfreddy - I think I'm going to end up doing just that, taking it somewhere. I'm just not sure yet, have to do some research.

Here's the problem, I don't have the facilities/time/knowledge to do much more than bolt on/off. So when it comes to boring, honing, checking clearances, I think I have left my realm. If the problem was just the head gasket, I'd be pulling the other head too, taking them to a shop for magnaflux and valve inspection/repairs, prepping the block surfaces, buying gaskets and bolting it back together. Too bad that's not the case. If, due to block damage it means replacing the whole block, I actually feel comfortable doing that. Bolt on my components to a crate engine. If I'm going to keep the block and overhaul it...well then II need to take it somewhere. So I think I'm going to start checking with some local places. Here's what is important to me as I look at options:

1. Reliability. I don't want to be "tinkering" with the engine, I want to put it together and forget about adjustments after a few hours of operation. I don't want hard starts. Wife needs to be able to drive it, as well as the kids that are early teens.
2. Resale. Too much customizing may make it hard to sell IMO. I have no intentions of selling it, but things happen...life takes a turn and if I need to liquidate then I want that to go easily. To me it seems the more bolt-on components I use the better.
3. $$$. I have been bracing for a $5k repair bill. The less I spend on it the better
4. Power. I was doing fine with 265hp. We ran close to WOT when barefooting. Never had an issue with surfing or boarding, plenty of power to spare...with the original 13x13 prop too. I'd LIKE to have more, and it seems I'd be a moron not to get at least SOMETHING more out of it, but bearing in mind the above points, at some point there is a downside curve depending on how far I go.

FWIW, I have done this type of thing in the past, in college. The last engine I did this all on was an '84 Fiero in like 1991.

[Michigan boarder]

Here it is with a light behind it and an aluminum ruler for an edge. Looks OK, don't you think? If anything it feels raised up some.

So, what do you guys think from the picture, is this block toast?

[Woodski]

Block looks okay, besides you could always deck straight if needed, but looks like it's fine.

To your footing comment, my setup ends up being 5/8ths to 3/4 throttle for solo footer @ 41 mph.

[Michigan boarder]

Block looks okay, besides you could always deck straight if needed, but looks like it's fine.

To your footing comment, my setup ends up being 5/8ths to 3/4 throttle for solo footer @ 41 mph.

Thanks! We'll see what a local guy can do.