Is this bad? Damage to Cylinder, 72 Chrysler 70hp

[grabera]

I recently bought this boat for a steal of a price. It is a '72 15' Glasspar. Definitely a cool looking boat worth a little elbow grease.

The 72 Chrysler 70hp (707HE) on it allegedly ran but was running a little rough according to the previous owner. I figured for the price I was paying if it ran at all I would call it a victory.

I got it home and it started right up on muffs. I checked the compression and the compression on the top cylinder was fine but the bottom two cylinders were very low. I checked the head gasket and it was blown between the bottom two cylinders so I am assuming that is the cause of the low compression. The pistons and the interior of the cylinders looked fine from a quick inspection. I am getting a new gasket and see if that fixes the compression.

However, I noticed some damage to the outside of the middle cylinder (see damage on the left side of the cylinder in the picture below). There is a chunk of metal missing. I don't see any damage at all to the inside of the cylinder.

My question is: Is this something that will cause problems and will it have to be fixed? Or since the damage is only on the outside of the cylinder will it have no effect?

Also, what could have caused the blown gasket? Is there something I should take a look at before installing a new head gasket? I don't want to install a new one only to blow it again right away.

***It is probably worth noting that the damage on the cylinder does not align with the damage to the gasket.

Any help is appreciated!

 

[moparman]

Re: Is this bad? Damage to Cylinder, 72 Chrysler 70hp

If the damage doesn't align with where the gasket blew ,I don't know what could have caused it,unless it was from a previous gasket failure.It sure looks like its been torched[ compression leaking past small place in gasket will actually act like a torch if its run a while with it like that]If its flat on the inside next to the piston ,you might be able to epoxy the outer part to add some material to gain some area so the gasket won't have a weak place, but if its not flat you may have problems. Could you post a better pic of the area thats damaged? You might want to look at the impeller in the water pump, carbs could be lean, head may not have been torqued correctly and loose head bolts are a blown gasket waiting to happen, might have a timing issue among other things that might have caused it. But like I said ,if you could post a more detailed pic of the damaged area, it might help.

 

[32251]

Re: Is this bad? Damage to Cylinder, 72 Chrysler 70hp

cool boat!

 

[grabera]

Re: Is this bad? Damage to Cylinder, 72 Chrysler 70hp

Moparman, thanks for your reply. I will try to add a better picture when I get home from work today. The iphone camera doesn't focus well up close.

I think you are right and the damage to the cylinder isn't allowing the gasket to make a tight seal and it's getting torched. I think the flames are shooting out and around the outside of the cylinder (that is probably why the damage to the gasket isn't isolated to only that area. The majority of the damage to the gasket is 1.5-2 inches counterclockwise from the damage to the cylinder).

The inside of the cylinder near the piston is pretty flat so your epoxy suggestion may do the trick. Is there a specific kind of high temp epoxy you would recommend? Would J-B Weld work?

 

[Frank Acampora]

Re: Is this bad? Damage to Cylinder, 72 Chrysler 70hp

That damage will almost always cause a blown head gasket--see, the steel sealing ring sits partially on it and only partially on the steel liner.

DO NOT try to epoxy it--it will not work. Using a Dremel, square the edges of the chip and make a pocket in the cooling jacket wall across from it. Now, cut a plate of aluminum just large enough to need pressing in to the gaps. The head gasket will usually hold it in place but for added security, use a premium epoxy to secure the plate.

OR---spend a hundred bucks and have a welder patch the missing chip.

By the way: unless I miss my guess, those are aftermarket Wiseco pistons indicating that the engine was rebuilt at some time. 3124 was a Wiseco number