Head ache

F

Flat32

Member
Got my B engine mostly assembled and in the car. Rebuild included replacing a cracked head which had F3 and Made in USA cast into it. I assume aftermarket, but it doesn't matter. What does matter is the new head which is a "C" and looks the same with the three bolt pump mount.

Headache comes from a difference in the recess in the head for the water pump shaft. Bottom of recess is about 3/16" shallower. F3 old head has a copper washer in the bottom of the recess that was contacting the end of the pump shaft. The pump impeller end was contacting the top edge of the recess.

I have no idea how the pump shaft and impeller are supposed to interact with the head. Is the copper washer supposed to be in there? Is the impeller end supposed to ride against the head? With no thrust washer? Is there supposed to be a bushing in the recess?:confused:

Thanks for any help.

Ray
 
I have had a few of the F3 heads and never saw what you describe. My guess is that the copper washer is just a "farmer fix" made to limit axial movement of the shaft. I would avoid the whole issue by installing one of the shaft collar w/set-screw retainers sold by the vendors ($3.50 at Bratton's). THis will control the axial movement and you can forget about the clearance inside the head.
 
I've searched the forum and found a thrust washer mentioned between the impeller and the rear pump bushing that limits forward movement of the shaft. While the collar can fix this particular problem that is not the problem I hav

My problem is not knowing if the end of the shaft is supposed to bottom out in the head recess or if the impeller is supposed to hit the machined surface around the recess and whether or not there's supposed to be a thrust washer at he end of the impeller in the head.


Ray
 
the shaft is suppose to have .010 clearance to the boss on the inside of the head if it is to tight grind the shaft down untill you get the clearance it sounds to me that the boss was wore down and someone added a copper washer to make up for the ware. most of the time anymore people just put the caller on the shaft to keep it from moving,
 
I'd go with the collar and forget about the fit to the head. If it's now too tight, then grind off the end of the shaft for clearance.
 
Awhile back,I installed a new shaft & impeller in a B WP.When I went to install it, the impeller hit the head while the housing was more than 1/4" away from the head.The front side of the impeller was not machined deep enough so I had to reuse the old one & pinned it to the shaft.Just another instance of crappy repop parts.All used cyl heads will have the pump shaft recess worn to some degree.If too much end play,use a 5/8" collar with set-screw or you could use a couple nylon washers behind the fan.You should try for 0 clearance without the pump gasket &you will have correct clearance with gasket installed.
 
If I'm reading this right neither the shaft end nor the impeller is supposed to make contact with the head.

I cut the shaft around 1/4" shorter so it doesn't bottom out. I made a bronze thrust washer and put it between the impeller and pump bushing cutting the shaft end play down from about .200" to about .025" with gasket in place. It just wasn't right.

With fan pulley inline with the crank pulley the shaft is pretty much fully back with the impeller contacting the head, however the running fan will probably pull the shaft forward leaving the clearance between the impeller end and head.

Thanks for the input.

Ray:cool::cool:
 
You must log in or register to reply here.
Back
Top