132 big bore sumping
Stage II
Joined: Aug 2024
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From: california
Running the Trask trans vent cover. Plan to vent head breathers to atmosphere. Need to change air cleaners, running the s&s.
Club Member
Joined: Apr 2011
Posts: 5,816
Likes: 7,847
From: SE Louisiana
Something else to pay attention to is the pinion bearing depth for proper operation of the reed seal on the back of the oil pump.
With the cases split, you can bolt the oil pump less the gerotors to the plate to check how much preload there is on the seal by holding the plate to the cam chest and looking at the seal through the main bearing from the inside with a dental mirror, you can see when the seal touches the bearing, and how much crush there is when the the plate is seated.
Theres a spec in the service manual for bearing depth, but I think this is a better way to know the seal preload is not too loose or tight.
The Jim’s M8 main bearing install tool positions the pinion bearing flush on the inside, which was not enough on my engine, I made a .005” shim to place on the bearing outer race when installing to move the bearing to where it needed to be.
Between getting the piston oilers sealed and the oil pump seal working better, my M8 doesn’t play hide and go seek with the oil anymore, the level stays put now.
T-man machined & modified his install tool, I made .005” & .010” shims instead, to adjust bearing position, in case there’s differences in the plate or pump housing. He also adds a reed valve for big bore engines.
With the cases split, you can bolt the oil pump less the gerotors to the plate to check how much preload there is on the seal by holding the plate to the cam chest and looking at the seal through the main bearing from the inside with a dental mirror, you can see when the seal touches the bearing, and how much crush there is when the the plate is seated.
Theres a spec in the service manual for bearing depth, but I think this is a better way to know the seal preload is not too loose or tight.
The Jim’s M8 main bearing install tool positions the pinion bearing flush on the inside, which was not enough on my engine, I made a .005” shim to place on the bearing outer race when installing to move the bearing to where it needed to be.
Between getting the piston oilers sealed and the oil pump seal working better, my M8 doesn’t play hide and go seek with the oil anymore, the level stays put now.
T-man machined & modified his install tool, I made .005” & .010” shims instead, to adjust bearing position, in case there’s differences in the plate or pump housing. He also adds a reed valve for big bore engines.
Last edited by Schex; Sep 8, 2024 at 06:30 AM.
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