To fit a 1275 auto block to a manual, apart from drilling the dipstick hole, there are a few mods needed to oil plumbing:
1. Auto block doesn't have the drilling all the way from the oil pump to the relief valve.
2. Auto block has 2 holes in the relief valve seat `cotton reel' to let oil get into the main gallery, because the normal filter flange is blocked off with a plate- the motor's lube oil comes UP the banjo pipe from the auto trans to the motor.
3. Auto block pump mounting recess is .250" deeper than in a normal 1275 block.
The cotton reel needs to be pulled out & the 2 holes brazed or welded, (or fit a manual one) then a 1/4" spacer plate made and bolted in, then the oil pump's 3/8" dia outlet hole drilled in the block 1/4" deep. Finally the relief valve's oil feed drilling can be extended to the pump outlet hole with a long series 8.5mm drill. Note this hole was offset in manufacture to miss the #4 cylinder bore- it can't be drilled properly with the cotton reel still in the block. The hole is already in there, but is about 20mm short....
Spacer must be bolted in there as the drilling will come thru the joint between spacer and block.
Here's a few pics:
Standard auto block's relief valve seat:
Modified relief valve seat (the 2 holes brazed up) and new alloy spacer plate:
Drilling the pump outlet hole:
Block and spacer plate after drilling oil feed hole from relief valve-
Still needs a little cleaning up with the die grinder...
Finished spacer mounted (temporarily) in block-
Now that the 7/16" dipstick hole is drilled, the block can be bored and hot tanked.
Note: the spacer is a real neat fit & will be sealed with a gasket and `Loctite 515' Master Gasket sealant. Once sealed it will stay in there.
If I ever want to remove it though, there's 2 tapped holes in it for jacking screws.
<edit 1> The alloy spacer won't be fitted until after block is bored and hot tanked.
<edit 2, 7/7/05 > Originally I tried to seal between the pump spacer and block with Loctite 515 Master Gasket sealant, and NO paper gasket- but the pump sucked air. It's fine now with a gasket fitted.
[edit 3, 7/9/15]
re a new oil pump, you can use either an 1100S etc spider drive pump, or a 1275A+ slot drive pump. To use the slot drive pump with spider drive cam, use the laser cut steel adaptor shown below.
Available from Minis Plus, Karcraft, ReadSpeed or Graham Russell.
