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Discussion Starter · #1 ·
After 25+ years of clean fingers I am back in the grease while installing a new headgasket in Eugene's B18B (1968 122S wagon). Life is good.

While running with the rabbits on IH35 in central Texas Eugene developed a stumble due to coolant sneaking into the #3 cylinder through a tiny split in the head gasket.

This engine has 70k original with the thin (10.5:1 CR) headgasket so I am going with the low-compression kit and fat gaskets.

This car has the original Volvo BRRRRRRRRR AC unit and two front head bolts are used to mount the brackets.

What was the question? Oh, yeah - head bolts.

The existing bolts appear to be ok and came out smoothly. The locally-available options are grade 5 or grade 8 replacements in a 5/8" wrench size (originals are 11/16"?). These are 1/4" in longer than stock.

Should I use the old bolts are replace? Which grade? If I use new bolts will I need hardened washers to offset the extra 1/4" length or will the thicker head gasket allow me to skip the washers?

Please offer other options as well.

Thanks,

George Dill

Temple, Texas, USA.
 

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Re: Head bolts - replace or reuse? (gdill2)

George, I'd reuse the head bolts. Give them a very thorough cleaning and inspect them first, but they should be fine.

I really recommend against using a thicker head gasket, really, really. Moving the head further from the pistons makes it ping *worse* inherently, and reduces combustion efficiency beyond the reduction you'll already get from lowering the compression. You'll have less power and economy, and you'll still have to use premium fuel.

Volvo used the same .030" gasket on all B18s. The high-compression head is shaved .040" thinner, that's all. Shaving the head does not move the head further from the pistons -- that's an entirely different proposition.

A B18B is 10.0:1, not 10.5:1. I've never had trouble running one on 92-octane unleaded. If you do, something's off in the tuning.

If you want to lower the compression and run regular fuel, it's much, much better to use a B18D head. They're common enough...
 

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Re: Head bolts - replace or reuse? (Phil Singher)

Phil;

That's good enough for me - now I am out on the www seeking the stock B18B head gasket and pump O-rings.

Thanks for the sage advice - again!

George Dill
 

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Re: Head bolts - replace or reuse? (gdill2)

George:

Are all the head bolts the same length? When I sell the idler for the B18, I include the longer grade 8 bolts to replace the ones where the bracket mounts. I'd suggest you do the same.
 
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