Cast vs Forged Crankshafts

Thorkhild · Post by **Thorkhild** » Mon Apr 02, 2001 3:51 pm

I'm trying to decide if i should use a stock (forged) Welded CW crank or a new Cast CW crank from SCAt in my new engine. ive heard that cast is bad, but then i heard its okay just not over 5500 rpm (if i want it to last). The prices are about the same, but i want to get what is better

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Thorkhild
1968 VW Blue Fastback
http://www.edinboro.edu/~e153916n/darkside_resto.htm

James2 · Post by **James2** » Tue Apr 03, 2001 6:46 pm

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Thorkhild:
<B>I'm trying to decide if i should use a stock (forged) Welded CW crank or a new Cast CW crank from SCAt in my new engine. ive heard that cast is bad, but then i heard its okay just not over 5500 rpm (if i want it to last). The prices are about the same, but i want to get what is better

</B><HR></BLOCKQUOTE>

Forged!!!!

Ed Brewer · Post by **Ed Brewer** » Wed Apr 04, 2001 3:49 pm

I have heard all the same about the cast cranks. In a nutshell, a cast piece has a grain structure that is brittle, while a forged piece is much more ductile. Meaning a forging can handle a lot bigger impact without cracking. I would go welded stroker (in fact I did on my 2110). They can handle high rpms and drag race starts, just don't use slicks. Another option is the CB forged cranks for about $430. They are new forgings and I have heard a lot of good about them.

Glenn · Post by **Glenn** » Wed Apr 04, 2001 7:17 pm

One word... FORGED. Do it right the 1st time

superdrag73 · Post by **superdrag73** » Fri Feb 01, 2002 11:53 pm

forged

petevw · Post by **petevw** » Sat Feb 02, 2002 12:14 am

forged for sure

GDRBO · Post by **GDRBO** » Sat Feb 02, 2002 12:31 am

Castings were available and cheaper and VW still chose forged cranks. What does that tell you?

Glenn · Post by **Glenn** » Sat Feb 02, 2002 7:32 am

We all know that forged are stronger and cast is cheaper.

Beetles made in Mexico now have cast cranks... what does that tell you?

[This message has been edited by Glenn (edited 02-02-2002).]

JohnConnolly · Post by **JohnConnolly** » Sat Feb 02, 2002 10:54 am

we don't even sell cast cranks.

I think a cast crank is good to 4500RPM, OR 85-90hp.

who builds a stroker engine with a limit of 90hp? Not me!

John
Aircooled.Net Inc.

farmer · Post by **farmer** » Sat Feb 02, 2002 12:53 pm

According to SCAT, when squeezed them into a corner, they say on the 78 mm one:
130 hp, 140 MAX. and not too many dragstarts with fast biting tyres. Rev limit 6500 rpm.
So If you want to biuld a torqey type big cc dayli driver, I do´nt see anything wrong in using them. (Have done that myself a couple of times) But honestly, I prefer the welded edition or one like CB´s to the cast.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Sat Feb 02, 2002 1:58 pm

John does not sell them, and I WILL NOT use one, no matter what.

Put one on a dynamic balancer and you will see why, had one over 70 grams out of balance (one gram @ 6,000 RPM = 100 pounds of weight in the engine)

Also if you are using one in a newer case than an AE series you will have to clearance the center main web for the narrow cheeks of the crank, otherwise you wil have insufficient end play and after the engine runs it will become excessive..

I have seen 3 of them snap right beehind the #3 main, one of them was in a bus and never went above 4,500 RPM...he decelerated and heard a clunk, SNAP!

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Jake Raby
Raby's Aircooled Technology
www.aircooledtechnology.com

evil_vw · Post by **evil_vw** » Sat Feb 02, 2002 11:11 pm

ummmm, i would go with a Scat cast crank. i mean, they are "scat", right? and scat only makes really good stuff, right? because scat is like -THE- performance leader, are'nt they? they would'nt steer ya wrong. an industry giant like Scat would never lower themselves to use tricky marketing scams on unsuspecting patrons. Cast all the way cuz its made by Scat!!! (if you detect a certain sarchasm in the previous statements, dont worry- it was intentional.)

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OK, got the duct tape, JB weld, bailing wire, and a big hammer- everything should be fine.

Empified · Post by **Empified** » Sun Feb 03, 2002 2:15 am

Now you all got me curious. How can you tell the difference between a forged and a cast crank? I've got a CB performance 82 mm crank with VW mains and Porsche rod journals. Supposedly this used to be the hot crank to get about 10 or more years ago. Was forging big back then? I finally located some porsche 356A rods for it. Oh and while I'm pickin your melon. AS21 fuel injected case versus AS41 case. Which is the better of the two? I'm not going to be using a stock fuel pump anyhow. Thanks, Empified.......

evil_vw · Post by **evil_vw** » Sun Feb 03, 2002 3:42 am

well, as far as im aware, CB has always made their own cranks, and they are forged-- even as far back as 20 yrs ago, especially in an 82mm stroke. (they may have made a cast in 69mm form, correct me if im wrong) typically type 1 as41 dual relief case is superior to the as21 in performance applications or otherwise. Hot VWs did a thing on the two cases 6 issues or so ago-- lots of good info there.

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OK, got the duct tape, JB weld, bailing wire, and a big hammer- everything should be fine.