g741.org

Here's a pic of the head on a 230 c.i. M37 engine.
What's the extra hole for?
(Posted for HB)
Jerry

I know I'm kind of knew here, but could you post a picture zoomed out some so that at least one other combustion chamber is in view?

I'm sue someone will be around to help.

This device was mounted on top of the cyl. head after removing the 1/8" pipe plug and was used to tell when #6 piston was at top dead center for ignition timing purposes. It used a dial indicator and a low voltage lamp so you would know when the piston was up.

Jimmy: Here's a smaller pic of the # 6 combustion chamber. Better eh?

Carter: Thanks for the info. I originally thought the hole could be used for
some type of compressed air source. The pic is the #6 chamber, wouldn't
TDC normally be checked on # 1 ? Maybe 6 and 1 are the same at TDC ?
Jerry

The simple deal is just a piece of stiff wire in the hole to get TDC. Watch it while you turn the motor by hand.

1 & 6 are the same.

Don't forget to pull the wire and put the plug back in when you're done.

It is a great gag on someone else if they aren't looking.....makes an unholy racket with no harm done

DG

PoW wrote:The simple deal is just a piece of stiff wire in the hole to get TDC. Watch it while you turn the motor by hand.

1 & 6 are the same.

Don't forget to pull the wire and put the plug back in when you're done.

It is a great gag on someone else if they aren't looking.....makes an unholy racket with no harm done

DG

Yep..... I've used coat hangar wire on flat heads for many years. Worked for me then and would probably
work just fine today. You know..... it ain't rocket science.