Hey guys went to install my oil pump into my L05 block this evening and ran into a problem. With the stud installed finger tight and torqued to 55 ft-lbs with ARP fastener lube under the washer and nut, the stud does not protured above the top of the nut. You can see that the stud is about 4 or 5 threads short to stick out above the nut. I used ARP kit #230-7001 which is for the standard oil pump which is what my machine shop told me I would need for my M55a oil pump. My gut tells me I should run a longer stud (kit # 230-7003) to achieve this but is it all right to loosen the stud a few turns to achieve what I want. Or should I just get the longer stud?

Thanks.

PS: I measured the depth to ensure the stud wouldn't bottom out on the main bearing. I have about 1/16 to 1/8" clearance with the stud bottomed in the taper. FWIW.

 

Did you have the stud and pump body on when the crank bore was checked? or did you have the factory bolt on the pump?
I haven't used the pump stud before.
Maybe calling ARPs tech line will help you..

 

Yeah, I'd call ARP and ask them.

I agree that anything that uses a nut should have enough threads to go all the way through the nut.

 

The original setup before the rebuild was the factory pump with a bolt. I phoned ARP they instructed to get the longer stud kit (230-7003). Install instructions are what I listed above: install stud finger tight, can back it just off the taper if desired, loctite not necessary. Put ARP fastener lube under the nut and torque to 55 ft-lbs.

 

If the block was machined with the factory bolt holding the pump, thats prolly what you should use.
If you had the stud on when it was machined then use that.
"supposedly" the stud and bolt pull different and could cause the bore to go outa round. You may be fine if its a street motor..

 

Use the HV stud from ARP, the standard one is to short for the new body standard volume melling pumps.

 

You are correct about the stud having a different effect on the cap then a bolt, when we cut the align bore on a block we have a cut off oil pump that we torque on with either a stud or a bolt depending on the customers application. As it can enlarge the housing bore by as much as 0.0005" This also applies to when I do bearing clearance as it will have the same effect...