312 Crank Grinding down to 292 size

Hot Rod Reverend

Hot Rod Reverend

Well-known member
Got a call from the crank grinder today. They have my 312 crank all ready on the main journals and rod journals but they are concerned about the rear seal area. They are telling me that their crank grinding machine will "grab" the rear seal journal if they use the machine to turn that journal down. They want to use their lathe to turn down the rear main seal journal and then polish the journal to match the 292 crank I left in the shop for them to compare.


I have not heard of doing this, but they have been in business for over 50 years and have an excellent reputation and have done top notch work for me in the past. They believe by turning the rear main seal area down this way they will be able to keep the rear slinger also.


Any of you guys have any words of wisdom on this one? 312 cranks are drying up and I don't want to lose this one
Crying.gif
 
The rear slinger helps with sealing the engine, though 55s didn't have this feature.
What they are saying is probably correct. There is no reason why they couldn't turn it in a lathe and then polish it. Most people getting the crank ground down lose the lip. Your choice really. What does Ted Eaton, Tim McMaster, or John Mummert say?
 
A few crank grinders have a stone narrow enough to grind down the rear seal journal thereby saving the oil slinger. I was lucky to find such a shop. Most people have to go with the loss of the slinger.
 
I had my rear seal turned down with a lathe because they didn't have a wheel narrow enough and I didn't want to lose the slinger.next time I will just grind the whole mess off.never heard of a stone to rough for the rear seal but if that's what they want to do let them.
 
I let the crank grinder remove the slinger. Big mistake. You will have rear main leakage once you get a few miles/years on the seal. The '54 Y-block taught Ford that they need a slinger. Cutting down the seal journal with a lathe is a good alternative as long as they polish the surface to a fine finish afterward.

My opinion and mayby worth just what you paid for it. :-)
 
Motorhead6 said:
I let the crank grinder remove the slinger. Big mistake. You will have rear main leakage once you get a few miles/years on the seal. The '54 Y-block taught Ford that they need a slinger. Cutting down the seal journal with a lathe is a good alternative as long as they polish the surface to a fine finish afterward.

My opinion and mayby worth just what you paid for it. :-)
Click to expand...

See my recent post on the forum here about the 55 Ford refresh, etc. I just got my crank back and we did keep the slinger!
 
You must log in or register to reply here.
Back
Top