ARP Studs/MBSP-2001 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 05-26-2009, 01:03 AM   #1
Elite Member
Thread Starter
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default ARP Studs/MBSP-2001

What the hell? Building my motor, I put on main bearing support plate only to find it doesn't clear the arp studs! UHG! Has anyone seen this before?
AbeFM is offline   Reply With Quote
Old 06-05-2009, 03:12 PM   #2
Senior Member
iTrader: (2)
 
dc2696's Avatar
 
Join Date: May 2005
Location: Edmonton Ab, Canada
Posts: 1,176
Total Cats: 13
Default

Odd everything clears on my motor. Didn't notice if anything was clearenced or not though.

Can you just cut down the studs a couple tenths?
dc2696 is offline   Reply With Quote
Old 06-05-2009, 03:16 PM   #3
Junior Member
iTrader: (1)
 
Join Date: Mar 2007
Location: South Florida
Posts: 491
Total Cats: -1
Default

You don't want to modify the studs in any way!

Instead, grind/cut the MBSP to allow for proper fit.

Do you have photos of where the issue lies?
mrtonyg is offline   Reply With Quote
Old 06-05-2009, 04:16 PM   #4
Elite Member
iTrader: (33)
 
RotorNutFD3S's Avatar
 
Join Date: Jan 2007
Location: Newnan, GA
Posts: 2,539
Total Cats: 29
Default

Actually, you can grind down the top of the studs. Machinist did it for my car with the MBSP, and even MiataRoadster.com mentions having to do so.

Quote:
You'll need to have us (or your machine shop) shorten the threads on the ends of your ARP main-cap-to-block studs (available below) so the tops of the studs clear the underside of the MBSP.
RotorNutFD3S is offline   Reply With Quote
Old 06-05-2009, 05:10 PM   #5
Senior Member
iTrader: (2)
 
dc2696's Avatar
 
Join Date: May 2005
Location: Edmonton Ab, Canada
Posts: 1,176
Total Cats: 13
Default

Quote:
Originally Posted by mrtonyg View Post
You don't want to modify the studs in any way!

Instead, grind/cut the MBSP to allow for proper fit.

Do you have photos of where the issue lies?
Why not? Its not going to affect the studs strength or anything.
dc2696 is offline   Reply With Quote
Old 06-05-2009, 05:17 PM   #6
Junior Member
iTrader: (1)
 
Join Date: Mar 2007
Location: South Florida
Posts: 491
Total Cats: -1
Default

Quote:
Originally Posted by RotorNutFD3S View Post
Actually, you can grind down the top of the studs. Machinist did it for my car with the MBSP, and even MiataRoadster.com mentions having to do so.
That doesn't mean it's the right way of doing it. You spend a lot of money on top fasteners to then mess with their metallurgy?

If a lot of grinding is necessary, excess heat is generated and could/will affect the heat treating.
mrtonyg is offline   Reply With Quote
Old 06-05-2009, 05:44 PM   #7
Senior Member
iTrader: (2)
 
dc2696's Avatar
 
Join Date: May 2005
Location: Edmonton Ab, Canada
Posts: 1,176
Total Cats: 13
Default

Quote:
Originally Posted by mrtonyg View Post
That doesn't mean it's the right way of doing it. You spend a lot of money on top fasteners to then mess with their metallurgy?

If a lot of grinding is necessary, excess heat is generated and could/will affect the heat treating.
Well if you use a hacksaw or porta-band or a zip disc you should be fine heat wise.

If you use a grinding disc you might get it hot enough to affect the metallurgy, but I really doubt it would be significant.

We're not building 1000hp motors round here.
dc2696 is offline   Reply With Quote
Old 06-06-2009, 10:58 PM   #8
Junior Member
 
Join Date: Jan 2006
Location: Toronto
Posts: 182
Total Cats: 0
Default

I don't know how it applies to this case, but the biggest reason to leave a certain length of stud (or bolt) sticking out of the nut is stress distribution in the stud/nut joint. If the thread abruptly ends at the nut, the end of the thread has a higher stess concentration and won't take the same load before rupture.

Like I said, dunno if it matters in this case or not. I'd call ARP.
fluke is offline   Reply With Quote
Old 06-07-2009, 05:22 PM   #9
Elite Member
iTrader: (5)
 
Join Date: Oct 2007
Location: Canton, Ga
Posts: 1,707
Total Cats: 19
Default

I had the same issue, and I ground the studs down, and clearanced the MBSP some. Grind slowly, uses lots of oil and it will be fine.
Stealth97 is offline   Reply With Quote
Old 06-07-2009, 07:21 PM   #10
Elite Member
iTrader: (15)
 
Join Date: Dec 2007
Location: San Antonio, Texas
Posts: 4,889
Total Cats: 28
Default

Quote:
Originally Posted by fluke View Post
I don't know how it applies to this case, but the biggest reason to leave a certain length of stud (or bolt) sticking out of the nut is stress distribution in the stud/nut joint. If the thread abruptly ends at the nut, the end of the thread has a higher stess concentration and won't take the same load before rupture.

Like I said, dunno if it matters in this case or not. I'd call ARP.
That is a standard rule of thumb in bolted joint design. At least two threads protruding past the nut, to help with stress distribution.

There was some talk about this at miata.net as well. Go there and do a search on MBSP and you'll find it. I think a solution was IIRC to drill clearance holes in the MBSP for the ARP studs. I do not have a MBSP myself (I do have ARP), but I remember reading about it when researching MBSPs during my engine build.
ZX-Tex is offline   Reply With Quote
Old 06-10-2009, 10:42 AM   #11
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Here's the m.net thread.

APR Studs / MBSP??? - MX-5 Miata Forum
Faeflora is offline   Reply With Quote
Old 06-10-2009, 10:55 PM   #12
Elite Member
Thread Starter
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

uh huh - a little protrusion isn't bad, but these are too much. Some are slightly worse that others, and some holes tapped further than others. Actually, I'd be more tempted to cut off the backs, and let them since in further.

I'll check out the M.net link you posted... Still, it's odd ARP didn't take care of this. Even so, thinner washers might be needed.
AbeFM is offline   Reply With Quote
Old 06-11-2009, 08:33 AM   #13
Junior Member
 
Join Date: Jan 2006
Location: Toronto
Posts: 182
Total Cats: 0
Default

Quote:
Originally Posted by AbeFM View Post
uh huh - a little protrusion isn't bad, but these are too much. Some are slightly worse that others, and some holes tapped further than others. Actually, I'd be more tempted to cut off the backs, and let them since in further.

I'll check out the M.net link you posted... Still, it's odd ARP didn't take care of this. Even so, thinner washers might be needed.
I'd place a call to ARP, tell them you want to cut the studs back to 1/2 bolt diameter protrusion (will this clear w/ holes cut in the baffle plate?), cut w/ a hacksaw, not an abrasive wheel and keep the heat down.

See if ARP agrees w/ that. It's strange that the holes in the block are tapped to different depths, did you run a cleanup tap through them? Use tapping oil if you do, use a bottoming tap. DON'T BREAK THE TAP.
fluke is offline   Reply With Quote
Old 06-11-2009, 11:17 AM   #14
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

Quote:
Originally Posted by fluke View Post
I'd place a call to ARP, tell them you want to cut the studs back to 1/2 bolt diameter protrusion (will this clear w/ holes cut in the baffle plate?), cut w/ a hacksaw, not an abrasive wheel and keep the heat down.

See if ARP agrees w/ that. It's strange that the holes in the block are tapped to different depths, did you run a cleanup tap through them? Use tapping oil if you do, use a bottoming tap. DON'T BREAK THE TAP.
ARP would probably just redesign them and send you new ones if they knew what's good for em.
y8s is offline   Reply With Quote
Old 06-11-2009, 11:16 PM   #15
Elite Member
Thread Starter
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Not breaking the tap is a good suggestion! I did clean them up till I was worried of just that.

I will just have to call arp - tell them it's a common problem, see what they say.
AbeFM is offline   Reply With Quote
Old 06-12-2009, 09:59 AM   #16
Junior Member
 
Join Date: Jan 2006
Location: Toronto
Posts: 182
Total Cats: 0
Default

Quote:
Originally Posted by AbeFM View Post
Not breaking the tap is a good suggestion! I did clean them up till I was worried of just that.

I will just have to call arp - tell them it's a common problem, see what they say.
Few things in this world that are more frustrating than breaking a tap in an otherwise perfect part. Always happens flush w/ the hole too.
fluke is offline   Reply With Quote
Old 09-18-2009, 02:45 PM   #17
Elite Member
Thread Starter
iTrader: (3)
 
AbeFM's Avatar
 
Join Date: Aug 2006
Location: San Diego, CA
Posts: 3,048
Total Cats: 8
Default

Quote:
Originally Posted by y8s View Post
ARP would probably just redesign them and send you new ones if they knew what's good for em.
Funny you should mention that.

https://www.miataturbo.net/forum/t39274/ (for anyone following)

The short answer is "no." I've put in probably 6 months of my time on this. More than ready to just put the motor together and weld my wastegate shut.
AbeFM is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
1991 Turbo Miata partout tottestad Miata parts for sale/trade 18 09-14-2015 08:52 PM
built motor parts all new! Shortpersonbk Miata parts for sale/trade 3 09-12-2015 12:39 AM
H-Beam Rods with ARP 2000 Bolts; Supertech 84.0mm Ring Set, OEM 1.8 Water Pump skou Miata parts for sale/trade 4 09-10-2015 10:44 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 05:19 PM.