MTFCA Forum

I just noticed there is a missing bolt on the top of my rebuilt 1927 timing cover. It is a large diameter, fine thread bolt. It was installed before rebuild but now can't find it and need to order a replacement bolt but do not know that to order. Would appreciate guidance from those in the know.
Also curious to know the purpose of the bolt; why a larger diameter bolt with larger boss on the timing cover? Its a 1928 engine based on serial number so uses the eccentric fan belt pulley mounted to the upper water jacket. Perhaps its not the original 26-27 timing cover?

The large bolt hole was used to hold the fan arm on pre '26 engines - I believe it's a 1/2 - 20 thread - when the fan adjustment was moved to the water outlet, the bolt length was modified.

1/2" nf bolt. You can measure for length. Lock washer? Dont think so.

I can’t remember if an original bolt has a cotter pin hole or not. It’s raining hard here so I can’t go out now look at one of my cars to see!

No cotter pin hole. bolt just reaches past the end of the hole. 3/4" long?

Mike,
This is what mine looks like. 11/16 socket fits on the head.

Thank you Steve, John and Ken for the description and details. Turns out it is not a bolt Lang's or Chaffin's normally stocks. Rats!

Hopefully, I overlooked it in the old parts from the rebuilder or they still have it. Otherwise, will post a WTB in the classifieds. Thanks again for providing the information and photos.

A good hardware store has em. Like McMaster carr , Ace. Head will be 3/4". You can remove the grade marks & paint.