Duncan_GT

So on a stock engine, the oil pump pickup tube is supported at the #3 main cap. There's a tab on the oil pump pickup w a hole, it attaches to the stud on the cap and is held on by another nut.

So here's the problem. Im currently installing ARP main studs, and I dont see where to attach/support the pickup tube. The new stud is bigger where the tube should attach to, so the tab on the pickup doesnt fit. Should I just modify the tab and drill a bigger hole? But, even if I do that, there's not enough threads to put the tab on and support it with a washer + nut.

Any ideas?

capri debris

I did not use the washer under the nut, the mounting tab for the pickup is serving the same purpose as the washer... and yes, I had to drill the hole out to fit over the stud.

Here's a pic:

Duncan_GT

Did you set the tab in between the main cap and the ARP nut?

tinman

I hope you had that block align-honed before you put those studs in it.........
Studs will change things a little bit.

Duncan_GT

How so? I'm using undersized bearings if you're talking of clearance issues. I know with standard bearings and stock bolts, the engine had about .0015-.0019 main clearance throughout. With the undersize bearings (+.001), I'm hoping to get between .0025-.003" clearance. I know when I installed the studs and the standard bearings, I had about 0015" throughout.

capri debris

When you switch from bolts to studs, you must have the block line bored. The change from bolts to studs positions the main caps in a slightly different place and deforms them differently when torqued down. So what may be a round hole with a bolt will not be round with a stud.

To line bore, the machine shop will shave a little off the cap surface that mates to the block... then mount them to the block and machine a true "new" bore from the front of the block to the back.

If you didn't do this, you run the risk of spun bearings or at the very least, short life out of the bearings.

Duncan_GT

Yeah I looked into it and am going to have it done. Does the shop need the main bearings in order to do this?

tinman

No, I don't think they need the bearings that you are going to use.
Capri Explained quite well about the need for the machine work..........

Duncan_GT

Cool. I got in touch with the machine shop, they priced it at $150. Does this sound like an average/decent price?

Back to the oil pump pickup... I was looking at it today, I have maybe .5" of thread left after the mains are torqued down. Is this enough to put both the pickup's tab and another nut to hold it in place? Doesn't seem like it as I sit and think about it. I was going to get a Grade 8 nut and red loctite it just for assurance

tinman

IO think maybe you could use a 'Jam' nut there and you'd be okay.
Jam nuts are only about half as thick as a standard hex nut, they can be found at any industrial supplier or even a good hardware store.
I'd use a little red locktite on it too.........