up date on cub compression

bass · Jul 5, 2015

i rechecked the valves; all are opening and closing when the valve is open there is some slop

checked the compression tester on my SC Charlie and it is working

so here's the plan:

taking the head to the shop monday, gonna replace valve train assemble, rings and rod bearings.

question: can a head bolt hole be drilled out. one of the head bolt holes in the block has been retapped to 1/2"-13 NC can the hole in the head be drilled to match.

any other options are welcome!

bass
53superC

J.Wondergem · Jul 5, 2015

Can you put in a Heli coil and go with the original size?

Janicholson · Jul 5, 2015

The valves are in the block. If the head is warped, it will need machining to flat. other than that, the resurfacing of the valve seats will require working on the block. Do you have guide drivers and seat grinding equipment? Jim

David G · Jul 6, 2015

Take some pictures....

Buzzman72 · Jul 7, 2015

New valves + worn seats = an invitation for trouble.

The best thing to do is to have the seats cut and narrowed, and then hand-lap each
valve.

To keep the metal fragments out of the engine, you'd best have the block disassembled to
do a proper valve job with seat regrinding. If you're also doing rings and talking
about rod bearings [how much clearance/wear do you have on the bearings?], may as well
check the mains, too. If wear is excessive, have the crank ground...as in a propwer
overhaul.

On the oversized bolt hole in the block...I second the motion on the Heli-coil.

OBVIOUSLY, the only thing a shop can do on a Cub head is to 1) resurface it, and 2)
Magna-flux it for cracks...since the valves are in the block.

up date on cub compression

bass

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J.Wondergem

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Janicholson

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David G

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Buzzman72

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