Headbolts

[bobross]

Im doin a light rebuild on my m20 with future plans of boooooost. I just got in on the MLS Headgasket GB and i was wondering what you turbo guys were successfully running for headstud hardware?

[nando]

I have no idea, but I'm definitely NOT using stock headbolts again. I'd be interested to know what people have had success with as well.

[mcgrath]

http://www.mcmaster.com/

serach for 91303A306 and get 3 packs. It comes out to like under $35 with shipping.

I got this info from www.e30tech.com

They have a wright up on the torque procedure. I think you torque them down to 30Lbs they after every 15 minutes torque them down 10 more Lbs untill you get up to 70 or 80 Ft Lbs. It's what I will be doing on my head in a few days.

Steven

[DrMcDave]

i have raceware headstuds. Used by the porsche guys a lot. They are expensive but if you want boost you need to upgrade them.

[AndrewBird]

http://www.mcmaster.com/

serach for 91303A306 and get 3 packs. It comes out to like under $35 with shipping.

I got this info from www.e30tech.com

They have a wright up on the torque procedure. I think you torque them down to 30Lbs they after every 15 minutes torque them down 10 more Lbs untill you get up to 70 or 80 Ft Lbs. It's what I will be doing on my head in a few days.

Steven

Honestly, those kind of scare me. They are more then likely just mild steel and might not be able to handle the stress. Especially in a boosted engine.

I would check out ARP studs. They make all kinds of different studs and are supposed to be really good.

[mcgrath]

Part Number: 91303A306
$10.56 per Pack of 5
ANSI Specification
ANSI B18.3.1M
ASTM Specification
ASTM A574M
ASME Specification
ASME B18.3.1M
Head Style
Standard
Material Type
Steel
Finish
Blue-Coated
Class
Class 12.9
Drive Style
Hex Socket
System of Measurement
Metric
Thread Size
M10
Metric Thread Pitch
1.5 mm
Length
150 mm
Hex Key Size
8 mm
Thread Style
Right Handed
Thread Length
Partially Threaded
Head Diameter
16 mm
Head Height
10 mm
Rockwell Hardness
C38-C44
Minimum Tensile Strength
176,900 psi
Thread Fit
Class 4g6g
Specifications Met
American National Standards Institute (ANSI) and American Society of Mechanical Engineers (ASME) and American Society for Testing and Materials (ASTM)


They are a 12.9 class bolt. Alot of the turbo guys on e30tech use them and have had no issuse with them. Plus they are reuseable unlike the stock bolts.

[nando]

I went ahead and ordered them, they are cheap and the reusable part is a definite plus. I've already gone through 2 sets of stock headbolts ($$$ down the tubes), and torquing them down is a major PITA. thanks for the tip!

[318driver]

nando what happened to your stock bolts?

[James Crivellone]

nando what happened to your stock bolts?

yeah? i've been using the stock oem headbolts on tons of motors without issue.

[AndrewBird]

Part Number: 91303A306
$10.56 per Pack of 5
ANSI Specification
ANSI B18.3.1M
ASTM Specification
ASTM A574M
ASME Specification
ASME B18.3.1M
Head Style
Standard
Material Type
Steel
Finish
Blue-Coated
Class
Class 12.9
Drive Style
Hex Socket
System of Measurement
Metric
Thread Size
M10
Metric Thread Pitch
1.5 mm
Length
150 mm
Hex Key Size
8 mm
Thread Style
Right Handed
Thread Length
Partially Threaded
Head Diameter
16 mm
Head Height
10 mm
Rockwell Hardness
C38-C44
Minimum Tensile Strength
176,900 psi
Thread Fit
Class 4g6g
Specifications Met
American National Standards Institute (ANSI) and American Society of Mechanical Engineers (ASME) and American Society for Testing and Materials (ASTM)


They are a 12.9 class bolt. Alot of the turbo guys on e30tech use them and have had no issuse with them. Plus they are reuseable unlike the stock bolts.

Oh, ok. When I searched by part number, it didn't give me those specs and it looked like they were just plain mild steel.

[nando]

nando what happened to your stock bolts?

nothing happened to them, I've just had my head off a couple times, and having to replace them with new ones every time sucks. I'm also not a big fan of the stretch style bolts and getting them torqued correctly.

[SoopaGhetto]

Would these bolts fit a m10? im redoing my head and i need some head bolts...but i dont feel like getting them from the dealer.

[nando]

I actually ended up using stock bolts for my stroker.. I didn't understand the advantages to the torque-to-yeild style bolts. basically, because they stretch, they are able to hold tension despite changes in temperature. I also made a nice torque angle gauge with a sharpie and a CD-R :D

I would order your bolts online. call BMA and they will hook you up..

[SoopaGhetto]

I actually ended up using stock bolts for my stroker.. I didn't understand the advantages to the torque-to-yeild style bolts. basically, because they stretch, they are able to hold tension despite changes in temperature. I also made a nice torque angle gauge with a sharpie and a CD-R :D

I would order your bolts online. call BMA and they will hook you up..

are you talkin about stock bolts for the M10? any sites where i could order them from? im sorry but what is BMA <--

[Sean]

are you talkin about stock bolts for the M10? any sites where i could order them from? im sorry but what is BMA <--

BMAParts.com - only one of the best parts suppliers for E30s! :D