ARP main stud and oil pump clearance

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mopar4x4stroker

mopar4x4stroker

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I've done some searching, but not sure what my best option is. A) Run stock bolts B) Run 12pt bolt w/o washer and slightly clearance pump C) Grind down stud and use a 12pt nut w/o washer and clearance pump D) Spot face cap enough to use the std stud and 6pt nut w/ washer, and no pump modification. I choose D since it retains the strength of the studs, and torque accuracy w/ the washer. I don't like the idea of unequal torque, nor inaccurate torque w/o the washer. Anyone know how much needs to be removed and still clear the washer? Is this not a good idea? What do you all suggest? Thanks
 
Excuse the runon paragraph, my laptop is broke so I'm using my PS3 and it wont allow me to shift... I have two more question that are relevant. After an align hone, do you need undersized bearings, or a shorter chain? Also, wouldn't the machine shop leave the studs and caps installed? I picked up the block empty. How can I tell if they did a quality job? After all their name IS quality engine, but you can never be too sure. This is my first motor so any help is greatly appreciated.
 
This was ns1rm21's (Troy) idea for the Milodon main studs in my motor.

Cut stud to exact length. Ever so slightly dress oil pump body. Chamfer nut.
 

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I cut my stud down, and cut my 12pt nut down (but kept the washer), and clearanced the pump a little with my grinder to make it fit.

In hind site, I should have just picked up 1 quality main bolt and I would have been done.
 
The #5 cap has a larger mating surface and is more bulky because of the oil pump mounting. I just trim the stud and use the 12pt nut because I think there is enough strength difference between the factory bolt and an ARP stud and because the block was main honed with the ARP stud.
In regard to the bearings or chain - if the block was properly honed there will be no difference in the crank centerline, and no need for the longer chain or any special bearings. That being said, a chain tensioner IMO is always a good idea.
 
Is it not a good idea to machine the cap to clear the 6pt nut and washer? I realise the 12pt is slightly shorter, but I was told 12pt sockets flex. I also was told that the torque wont be accurate w/o a washer, so ideally I would like to clear the 6pt nut and washer w/o grinding the pump.
 
moper said:
The #5 cap has a larger mating surface and is more bulky because of the oil pump mounting. I just trim the stud and use the 12pt nut because I think there is enough strength difference between the factory bolt and an ARP stud and because the block was main honed with the ARP stud.
In regard to the bearings or chain - if the block was properly honed there will be no difference in the crank centerline, and no need for the longer chain or any special bearings. That being said, a chain tensioner IMO is always a good idea.
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X2 My 360 is done this way making a little over 600HP at 7200RPM aint broke yet.
 
I just used an ARP bolt. The stud doesn't center the cap and ARP bolts are very strong. I have 3 trips to the track and 2000 miles on my 410. No problems
 
Spend the time and spot face the cap down to clear the proper nut and washer.
 

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raymond said:
Spend the time and spot face the cap down to clear the proper nut and washer.
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Yes, thank you! Thats exactly what I was thinking? Do you know how much needs to be removed from both the cap and stud? Does this weaken or possibly distort the cap requiring a re-hone? Thanks for the pic.
 
Sorry - I'm not on here much due to "life" at the moment... But yeah, you can. Just like above...lol.
 
mopar4x4stroker said:
Yes, thank you! Thats exactly what I was thinking? Do you know how much needs to be removed from both the cap and stud? Does this weaken or possibly distort the cap requiring a re-hone? Thanks for the pic.
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The figure is .200" but that was only giving just enough clearance for the particular nut and washer in the pic. You may need to measure your nut and washer, it may be a little different, and just shorten the stud to suit.
 
I did a combination of all on the 2 I've done with studs. Spot faced the cap .080" which made the cap the exact same thickness in that area as the other side of the cap was (not sure why it was thicker on one side anyway but you know Ma Mopar), clearanced the pump a little (approx. .050"), ground the stud down a little, and found a thinner grade 8 nut and washer to use on the stud. In the end I had approx. .040" clearance without taking very much off each part. Maybe overkill but it didn't take very long.
 
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