Potential Issue with ARP Crank Main Cap Studs

[UrS4boy]

The oil pressure check valve that keeps oil in the head is located behind the lower of the two oil pressure switch/pressure senders, as discussed here: http://forums.quattroworld.com/s4s6/msgs/96161.phtml



*APPARENTLY*, if you install ARP main bearing cap studs and you don't realize that there is a stud length issue in that area, you can ~CRUSH~ the check valve, causing all sorts of nasty oil pressure issues. The potential for this conflict is shown in this annotated photo, showing the approximate location of the crank center line and the short distance to the oil check valve location.

[Error404]

Yes this is a known issue with the off-the-shelf main stud kit.

034 sell their own kit with a single shorter stud to avoid the problem or of course if you have the kit or know someone who does you could just turn one down yourself

In reality though the studs only should be installed hand tight so whoever crushed the valve should have known better and not turned them in by force

[Sonic]

Yep did the same thing and crushed the valve.

[UrS4boy]

Yes this is a known issue with the off-the-shelf main stud kit. 034 sell their own kit with a single shorter stud to avoid the problem or of course if you have the kit or know someone who does you could just turn one down yourself In reality though the studs only should be installed hand tight so whoever crushed the valve should have known better and not turned them in by force

First I heard of it was this AM on my home forum so I thought I would share it here. Turns out it is "known".

Not so "known" that it didn't prevent Sonic from crushing his check valve.

[Sonic]

Mine also happened with OEM main bolts, not ARP.

A80Avant posted a good picture of what happened to the valve on my project thread when i discussed it. Quite a few people knew of the issue then.

[UrS4boy]

034 sell their own kit with a single shorter stud to avoid the problem or of course if you have the kit or know someone who does you could just turn one down yourself

Oh. This:

http://www.034motorsport.com/engine-...-i5-p-343.html

[UrS4boy]

Mine also happened with OEM main bolts, not ARP.
A80Avant posted a good picture of what happened to the valve on my project thread when i discussed it. Quite a few people knew of the issue then.

"Then". Hmmm...I guess people need reminding from time to time. Thanks for the photo. It will be going into my Oil Pressure Sender, etc. post.

[irishs2]

See, now you got me all worried and I will have to check my check valve tonight

[Jamo]

This is well known issue, was originally posted about back in 2004!

http://www.s2forum.com/forum/showthread.php?t=3458

pics at post 10 http://www.s2forum.com/forum/showthread.php?t=16684

[Thuppu]

But how can it happen with OE-bolts?

[Jamo]

It shouldn't this was with ARP bolts

[mcandmar]

Scary i remember those threads when they were posted

From memory when i mocked up my build you dont have to shorten the stud as there is enough clearance. Just make sure you fit the valve after you torque the stud so you don't crush it in the process.

[Thuppu]

It shouldn't this was with ARP bolts

Yes, but look at Sonic's post above.

[UrS4boy]

This is well known issue, was originally posted about back in 2004!

Yeh, once posted in 2004, no need to ever post about it again.

I am such a Noob, I only started posting here in 2006 or 07.

(Never saw this issue come up here since)

[A80Avant]

I actually never had an issue by the way. It may have been that it wasn't that much damaged.