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 Head and main studs
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Joshinator99
Starting Member

USA
34 Posts

Posted - 22 Sep 2017 :  01:35:41 Show Profile Visit Joshinator99's Homepage Reply with Quote
I'm assuming that most (if not all) V4 engines out there are just using the 40-50 year old OEM Ford head and main bolts in them. As many of you who read my blog know, I'm going a little over the top with my Sonett III resto-mod. Tripling the factory horsepower levels makes using the old OEM bolts an issue that I would like to dig into further. Instead, I'd like to use racing-quality studs since their clamping force and metallurgy is superior to OEM bolts. Has anyone here done this? If not, I'm happy to be the guinea pig and come up with a solution. Guess I'm just wondering if anyone else has already done this homework?

1972 Sonett III

Derek
V4 Guru

United Kingdom
1778 Posts

Posted - 22 Sep 2017 :  10:42:49 Show Profile Reply with Quote
Over there I think I would be talking to the Ashcrafts or Jack Lawrence, but I'm sure you'll get some answers here. I think new head bolts would be OK plus maybe ARP for big ends and maybe mains?
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Joshinator99
Starting Member

USA
34 Posts

Posted - 22 Sep 2017 :  11:38:39 Show Profile Visit Joshinator99's Homepage Reply with Quote
quote:
Originally posted by Derek
Over there I think I would be talking to the Ashcrafts or Jack Lawrence, but I'm sure you'll get some answers here. I think new head bolts would be OK plus maybe ARP for big ends and maybe mains?



No to Ashcraft and Jack Lawrence. I've got catalogs from both of them and I've spent a ton of dough with Jack Lawrence (forged pistons, new cam, valvetrain, etc) and neither one offer them. Boosted applications benefit from improve head clamping power, so I'm not using "new head bolts". I'm already using new ARP rod bolts for the big end of my rods.

ARP doesn't make any bolt or stud kits for the V4 either (not surprisingly). Also, ARP does not recommend their standard M12x1.75 bolts for head and/or main use, so that rules that out. So I was hoping someone else had gone down this path previously... if not, I will take the necessary measurements and have custom studs made.

1972 Sonett III
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UK_Sub
Moderator

United Kingdom
2103 Posts

Posted - 22 Sep 2017 :  12:05:34 Show Profile Reply with Quote
Have you tried Tom Donney?
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Joshinator99
Starting Member

USA
34 Posts

Posted - 22 Sep 2017 :  12:25:26 Show Profile Visit Joshinator99's Homepage Reply with Quote
quote:
Originally posted by UK_Sub
Have you tried Tom Donney?



Two stroke guy...! Those parts aren't going to work.

1972 Sonett III
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melle
V4 Guru

United Kingdom
2252 Posts

Posted - 22 Sep 2017 :  16:17:41 Show Profile Visit melle's Homepage Reply with Quote
I don't know much about fasteners, only joining the discussion because I'm interested in learning something new.

Are the OEM head bolts different from ordinary high tensile (12.9) bolts? I don't think they are stretch bots or anything special? What other qualities do racing spec bolts have?

For more info on what to use I would definitely try and find people who build/ tune Ford Cologne V6s for race/ rally use as they're very similar engines to our V4s and all fasteners are interchangeable. Are you using the standard con rods or V6 race spec items?

www.saabv4.com
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Woody
V4 Guru

United Kingdom
2373 Posts

Posted - 22 Sep 2017 :  20:23:43 Show Profile Reply with Quote
My yardstick is what did the Competitions Dept use?
I haven't heard of there being problems with head gasket failures, once they had sorted the HD gasket and copper ring inserts, which were used with all stages of engine development from 1531 to 1740 and 1815. They used six of the standard thread tapped earthing head bolt to secure the alloy rocker arm bridge.
Best to put a question on the Facebook Saab Sport & Rally group to see what the guys rallying in Sweden are using. Bengt-Erik Strom built the works engines and still does engines now.
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Joshinator99
Starting Member

USA
34 Posts

Posted - 23 Sep 2017 :  02:15:39 Show Profile Visit Joshinator99's Homepage Reply with Quote
quote:
Originally posted by melle

Are the OEM head bolts different from ordinary high tensile (12.9) bolts? I don't think they are stretch bots or anything special? What other qualities do racing spec bolts have?

For more info on what to use I would definitely try and find people who build/ tune Ford Cologne V6s for race/ rally use as they're very similar engines to our V4s and all fasteners are interchangeable. Are you using the standard con rods or V6 race spec items?

www.saabv4.com



Racing fasteners have a laundry list of improvements over any typical fastener. Superior metallurgy, stronger threads, 200,000 psi strength, etc. Tons of good info on ARP's website. Using the standard con rods with ARP rod bolts (same as 289/302 Ford).

1972 Sonett III
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Joshinator99
Starting Member

USA
34 Posts

Posted - 23 Sep 2017 :  02:20:22 Show Profile Visit Joshinator99's Homepage Reply with Quote
quote:
Originally posted by Woody
My yardstick is what did the Competitions Dept use?
I haven't heard of there being problems with head gasket failures, once they had sorted the HD gasket and copper ring inserts, which were used with all stages of engine development from 1531 to 1740 and 1815. They used six of the standard thread tapped earthing head bolt to secure the alloy rocker arm bridge.
Best to put a question on the Facebook Saab Sport & Rally group to see what the guys rallying in Sweden are using. Bengt-Erik Strom built the works engines and still does engines now.




Given that the Competitions Dept was 40+ years ago, not running 20 psi of boost, not running methanol injection, etc it's hard to really want to follow what they did... . I'm not a Facebook guy, but I like your idea of seeing what the current rally guys are using. That said, I think I'll just plan on developing main and head studs using ARP raw stock. Their stuff is simply too good not to use.

1972 Sonett III
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fuling
Starting Member

Sweden
20 Posts

Posted - 24 Sep 2017 :  11:31:47 Show Profile Reply with Quote
Nothing new with overcharging :)
http://www.saabveteranernatrollhattan.com/Arkiv/V4-motorn_ENG.htm
http://www.saabnet.com/tsn/bb/sonett/?bID=5678

Joshinator99:
How much power is the target?

These fit in V4
Rod Bolt Kit:
ARP Kit #: 153-6001

Flywheel Bolt Kit
ARP Kit #: 151-2801
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Joshinator99
Starting Member

USA
34 Posts

Posted - 25 Sep 2017 :  03:02:46 Show Profile Visit Joshinator99's Homepage Reply with Quote
quote:
Originally posted by fuling
Nothing new with overcharging :)
http://www.saabveteranernatrollhattan.com/Arkiv/V4-motorn_ENG.htm
http://www.saabnet.com/tsn/bb/sonett/?bID=5678

Joshinator99:
How much power is the target?

These fit in V4
Rod Bolt Kit:
ARP Kit #: 153-6001

Flywheel Bolt Kit
ARP Kit #: 151-2801



Fun read, thanks for the links. :)

225+ HP is the goal (approximately triple factory power). Given the dramatic improvements in turbo technology, should be able to get there without too many issues.

I already have both of those ARP bolt kits... ;). The question at hand is main and cylinder head studs.

1972 Sonett III
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fuling
Starting Member

Sweden
20 Posts

Posted - 25 Sep 2017 :  08:53:21 Show Profile Reply with Quote
I use standard head screws and 12.9 for main with bridge.
http://rejsa.nu/im/256-2003-19-08-motor_under1.jpg
The engine only have about 140HP ;)

Screw length is equal, main and head, standard.
Standard length is 80mm, I guess studs 100mm

ARP has studs (M12x1.75), so ask ARP
http://tgmotor.com/?page_id=1661

The Saab Rally-cross engine had
Billet steel crankshaft
Modified 99 can rods
M12x1 flywheel screws
Steel flywheel with 200mm clutch.

225+ HP, I would take HP at high rpm.
The gear box does not like much torque.

It is not HP that is a problem with overcharging.
The problem is getting a motor to not explode ;)
That is the challenge.
Go for it :)
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Joshinator99
Starting Member

USA
34 Posts

Posted - 25 Sep 2017 :  21:54:29 Show Profile Visit Joshinator99's Homepage Reply with Quote
quote:
Originally posted by fuling

225+ HP, I would take HP at high rpm.
The gear box does not like much torque.

It is not HP that is a problem with overcharging.
The problem is getting a motor to not explode ;)
That is the challenge.
Go for it :)



Sounds good fuling, we'll see how it goes. . I'll let you guys know how I make out.

Nice thing about turbos is that the power usually comes on in a way that is livable for the bottom end and gearbox. I'll pass on my instinct to powershift it.

1972 Sonett III
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gorselands
Starting Member

United Kingdom
22 Posts

Posted - 26 Sep 2017 :  17:30:16 Show Profile Reply with Quote
V4 turbo - I used standard bolts and studs with copper O rings to reinforce head gaskets. 117 bhp at wheels, 15 lb boost. 12 sprints and hill climbs - no problems.
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