ARP Main Studs vs MBSP vs BP05 - 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 06-18-2012, 12:52 AM   #1
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Feb 2012
Location: Marietta Ohio
Posts: 45
Total Cats: 1
Default ARP Main Studs vs MBSP vs BP05

I was wondering if anyone else has had this problem. I bought ARP Main Studs for a Miata, and they're too tall, causing an interference issue with the MBSP. I had to drill holes in the MBSP to clearance the studs and let them protrude through so that the MBSP would sit flat on the block and main bearing caps.

ARP main stud interference
http://i844.photobucket.com/albums/a...d/IMAG0784.jpg

What it causes
http://i844.photobucket.com/albums/a...d/IMAG0787.jpg

drilled holes in MBSP and it sits flat and the bolt holes now line up.
http://i844.photobucket.com/albums/a...dclearance.jpg


Anyone else ever had an issue like this? I'm building a 93 protege BP05. The MBSP has BP01 stamped on it, and the main studs were for a Miata BP. Yes, I did put the studs in the block until they bottomed out.


Very sorry about the bad pics, my camera lens is scratched up pretty bad, I'm trying to fix that too..
zoom zoom is offline   Reply With Quote
Old 06-18-2012, 12:31 PM   #2
Senior Member
iTrader: (1)
 
BogusSVO's Avatar
 
Join Date: Mar 2012
Location: Pensacola Fla.
Posts: 590
Total Cats: 191
Default

Did you clean and chase the bolt holes first?
BogusSVO is offline   Reply With Quote
Old 06-18-2012, 12:46 PM   #3
Elite Member
iTrader: (33)
 
RotorNutFD3S's Avatar
 
Join Date: Jan 2007
Location: Newnan, GA
Posts: 2,539
Total Cats: 29
Default

Yes, many of the Miata vendors have a disclaimer up with the ARP studs, this one taken from MiataRoadster:

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.
The machine shop that built my engine used that method without issue. Although the other accepted method is to add holes in the MBSP as you did.
RotorNutFD3S is offline   Reply With Quote
Old 06-19-2012, 01:47 PM   #4
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Feb 2012
Location: Marietta Ohio
Posts: 45
Total Cats: 1
Default

Ah hah, well it is very good to know I'm not the only one who has ran into this problem. Thank you sir, props given for good info.


@bogussvo, yes I did chase EVERY bolt hole on the block and head, and every bolt I've put back on this engine has been cleaned. There's alot of 10x1.25's ! I think I ran through 4 different 10x1.25 tap and dye bits, probably an overkill but they tend to dull out.
zoom zoom is offline   Reply With Quote
Old 06-19-2012, 07:35 PM   #5
Junior Member
iTrader: (6)
 
Join Date: Dec 2008
Location: Boulder, CO
Posts: 291
Total Cats: 7
Default

You should be using special thread chase taps and not regular cutting taps. You have to be very careful with regular cutting taps to not cut into the metal and loosen up the thread fit.

--Ferdi
ftjandra is offline   Reply With Quote
Old 06-23-2012, 12:52 AM   #6
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Feb 2012
Location: Marietta Ohio
Posts: 45
Total Cats: 1
Default

Woops.. maybe by next time ill know the difference. I don't think I cut much metal out of the holes, it was .mainly just old oil/gunk and fresh paint I got in the holes.
zoom zoom is offline   Reply With Quote
Old 05-31-2017, 01:14 PM   #7
Junior Member
 
Join Date: Apr 2011
Location: Oregon
Posts: 278
Total Cats: 7
Default

I had already assembled my shortblock before finding this interference.

I called up ARP to find out if they could supply bolts 0.120" shorter. They didn't stock anything. I asked if I could trim the bolts by using a grinder and then chase the threads. He thought that this could be done as long as I was careful not to heat up the bolt (which would ruin the heat treat) and warned me not to use a standard tap/die ti chase the threads (as thes threads are rolled and a die would cause sharp edges which would weaken the bolt; instead, he said to use an extra nut to chase the threads. A better pan would be to chuck them in a lathe and turn them to shorten them.

After reading this thread, I decided to just clearance my tray/saddle-brace. What a bad idea... first, it took all morning to get the holes right and the saddle cleaned of metal shavings. second, did I get it all cleaned out? I don't know... I think so. The problem is that the saddle consists of two pieces of sheet metal that are spot welded together. This creates a potential space between the layers that might trap metal shavings. clearanced tray



I guess the oil filter would catch the shavings before they hit the bearings, ...but what about that nice new billet pump?
gtred is offline   Reply With Quote
Old 05-31-2017, 01:18 PM   #8
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 17,999
Total Cats: 1,466
Default

Yup. I had the same annoyance. I used lots of water, air and a tried my best to make sure there were no shavings.
aidandj is offline   Reply With Quote
Old 06-04-2017, 12:19 AM   #9
Junior Member
iTrader: (6)
 
Join Date: Feb 2011
Posts: 422
Total Cats: 9
Default

I grind the bottom part of the stud and chase it. i dont think you are going to weaken it at the last 3 threads in the block enough to matter. Id be afraid that if you messed with the top part, your nut torque could be affected by any burrs that are left behind.
Twibs415 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 59 12-15-2017 09:00 PM
Another Cast Manifold Corky Bell Prefabbed Turbo Kits 18 11-22-2016 10:01 PM
OTS Bilstein to motorsports ASN conversion stoves Suspension, Brakes, Drivetrain 5 04-21-2016 04:00 PM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 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 03:29 AM.