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Cal-look/High Performance => Pure racing => Topic started by: airstuff on May 06, 2008, 11:52:10 am



Title: Chromoly case studs
Post by: airstuff on May 06, 2008, 11:52:10 am
I am collecting stuff for the 2276cc project.

Guys,do I need the extra long studs for the 2276 buidl,or are the stock lenght studs adequate?

Or do I need long studs If I step to 5.5 rods in comparison to 5.4?

Thanks,

Cal-look


Title: Re: Chromoly case studs
Post by: airstuff on May 06, 2008, 14:07:49 pm
How's the quality of Genuine VW 8mm studs,some guys prefere these over chromoly,but I would take chromoly so I don't pull anything :)


Title: Re: Chromoly case studs
Post by: airstuff on May 06, 2008, 17:00:30 pm
anyone?


Title: Re: Chromoly case studs
Post by: richie on May 06, 2008, 18:08:43 pm
i would use genuine german 8mm,I had them on my 2332 n/a engine with 5.5 rods,they were still on there when i ran up to 150hp of nitrous and worked fine:-)
cheers richie,uk


Title: Re: Chromoly case studs
Post by: besserwisser on May 06, 2008, 19:53:12 pm
Use this as a rule, if original parts fit use them,aftermarket is only for instances where original parts are not available.A company like VW that made so many cars can afford quality, Aftermarket cant.


Title: Re: Chromoly case studs
Post by: Udo on May 06, 2008, 20:14:55 pm
The originals are no longer avaliable . CSP has some fine for street use !!

Udo


Title: Re: Chromoly case studs
Post by: Fasterbrit on May 07, 2008, 20:54:40 pm
You do not need the extra long cro-mo head studs - just regular cro-mo studs for an 82mm crank engine, assuming you aren't going for a ridiculous rod length.


Title: Re: Chromoly case studs
Post by: Frank LUX on May 07, 2008, 21:00:17 pm
I always used Autocraft 10/12 Chromoly Head Studs on my Motor...

Frank


Title: Re: Chromoly case studs
Post by: besserwisser on May 07, 2008, 22:29:06 pm
OF cause I know that the original are no longer available. YOu have to take them from an original case. If youre lucky they have been baked in hot motoroil for several years so rust is no issue.


Title: Re: Chromoly case studs
Post by: Torben Alstrup on May 09, 2008, 00:35:35 am
Hello.
I tend to disagree. - For the last 5-6 years, when people have come in with leakage between cylinderhead and cylinder on big bore (94 mm) engines, especially busses, they were almost all using stock 8 mm studs. I then resurface the cylinders and the cylinderheads, swop to 8 mm crome moly studs and put it back together with the correct torque for the studs. - End of problem. (Assuming that the case is machined correct too)

My philosophy is that the old german stock ones, simply is exactly that, old. Running less bore, say 90,5 mm seems to lessen the problem too. So it has to be something with clampingforce under load.

Personally I use crome moly studs on every 94 mm bore engine I build. Mild or wild. I do not have time to take it apart 3 months later because of leakage problems.

Also be aware that some companies actually sell a stock replacement. But stay away from them. They are soft as cheese and not worth the money.
T


Title: Re: Chromoly case studs
Post by: besserwisser on May 09, 2008, 04:40:41 am
Could the leakageproblem be determined to be caused by the actuall studs or could it be that the case wasn´t deckt for proper sealingsurface or just not retourqed after camshaft runin. Of course new studs will cure the problem when you put it back together with sealant but that doesnt prove that the original studs are bad. Its just your own theory.


Title: Re: Chromoly case studs
Post by: Roman on May 09, 2008, 19:12:05 pm
I know a lot of people including me that uses the stock 10mm studs in high performance engines including me. I used aftermarket studs on my last engine but that was because it was close to 300 hp an just to be safe. I know some guys like Patte in Sweden uses the stock studs well beyond 400 hp in turbo applications without any problems. 
My 2387 put out 228 hp with fan belt and no problems. Why use the 8 mm studs when you have the stock 10 mm? It is no problem what so ever to use them with 94 mm bore.