bad block

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Jun 25, 2005 | 11:35 PM

roger dowty

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From: western montana

bad block

So I finally have a chance to tear my donor motor down. I was told that it ran-was overheating and, after I got it- had water in the oil. I get the heads off and find that the # 1 cylinder ran hot and is rusted, however there is no indication that the head gasket failed. Then I look down at the piston and see 060 stamped on it and scoring in the bore. I know the whole 040 as max and tend to believe that is true.

Bummed out...I got the motor and a matching c-6 for $300. I guess I need to get a head off before i buy?

Jun 27, 2005 | 11:04 AM

beartracks

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From: Albuquerque

I don't think you could ever go over .060 bore so you probably have a nice piece of metal scrap.

Jun 27, 2005 | 09:48 PM

3/4T man

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i bored mine 060 in my 81 f250 80000 miles ago no problems yet but you are right 040 is the maximum suggested overbore. had mine sonic tested at my machine shop and was told my block would be ok at 060

Jun 28, 2005 | 01:20 AM

roger dowty

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From: western montana

Since it doesn't have a lot of miles on it and the bore looks good- I'd be tempted to re-bearing the lower end , put in a cam- rebuild heads to match and then use it to replace my other motor that's in the truck and rebuild it for what i want.

But the #2 cylinder has a nice scar in it like maybe the rings didn't have enough clearance or something- still might check it out but doubtful- I'm hoping the crank is ok cause I may end up with with a 351 block to work on.

I also would need to find why the oil was hydrated- the head gaskets look good but #1 has a prob.

Again- this is the motor that had the front and rear water jackets blocked purposefully with silicone. I don't get that.

Jun 28, 2005 | 03:47 PM

3/4T man

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using silicone to block the water jacket could very well have kept the head gasket from fully seating on the block. head gaskets are desighned to seal by smashing a metal ring tight against the block and head in effect creating a solid piece but if any silicone got on the gasket and began to set up prior to torqueing the gasket it could have held that edge of the gasket up off of the block and created a leak in the gasket when the engine warmed up and pressurized the cooling system

Jun 28, 2005 | 05:57 PM

roger dowty

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From: western montana

Good point- I didn't see any silicone on the gasket-it was placed down into the jackets. Also did not see any evidence of water breach on the gasket which i have always seen before.

Can the gasket fail w/o leaving evidence?

Jun 29, 2005 | 04:57 PM

3/4T man

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i have a tachnician for ford motor co. for 15 years and have seen stranger than that happen. but to answer your question yes a new or fairly new gasket can fail and leave no visible evidence of its failure iv'e found that one of those lighted magnifying glasses can show a water breach not evident to the naked eye. but maybe my eyes ain't what they used to be.. the reason that a new gasket may not show water breach is because the coolant never had time to discolor and in effect never had time to discolor the gasket in the area of the breach. also if the breach was large enough at the time it may have just filled the cylinder and stopped at that make sure you check the connecting rod from that cylinder to see if it shows signs of being bent.