Cub-reinstall valve guides

Sat Jun 21, 2014 1:37 pm

I'm restoring a 1948 Cub from the ground up.
Got to the point where the valve guides have to go in the block.
Got a few pounds of dry ice at Safeway, acetone from the hardware store for a cold bath.
Chilled the guides for about 20 minutes.
Used a Mayhew tool from Amazon and my Harbor Freight air hammer to install the guides.

Mayhew Pro 32006 Pneumatic Valve Guide Remover and Installer

No problems--the guides went in easily and securely--no wobble or misalignment problems.
I adjusted the air hammer to the lowest setting and didn't bear down on the gun a whole lot--just let the hammer
ease the guides into the block. Seemed to work OK. Set the top of the guides 1 inch below the engine block top deck.

The tool mushroomed the end of the guide about 0.0015 inches (measured with one of those small bore gauges). I used a sharp tapered reamer to remove the burr--a few twists of the reamer and the valve stem slipped easily into the guide.

I measured about 0.0015" clearance between the guide and the stem on all the valves. I'll let it go at that. Save the cost of a new straight reamer or a broach.

Re: Cub-reinstall valve guides

Wed Jun 25, 2014 6:20 am

Interesting topic. Your guides must have been pretty worn for you to replace them. Sounds like the process went well. Was the tool expensive?

Re: Cub-reinstall valve guides

Thu Jul 03, 2014 5:00 pm

$13.97. The guides probably could have been used. But I'm restoring this 1948 Cub completely, so the 66 year old guides had to be replaced on principle.

Re: Cub-reinstall valve guides

Thu Jul 03, 2014 9:39 pm

Curiosity always seems to tickle me interest so I googled and found the Amazon unit - Mayhew Pro 32006 Pneumatic Valve Guide Remover and Installer

Image

Interesting tool.