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Crankshaft Advice !
noslug - February 19th, 2007 at 12:01 PM

I am wanting some advice on the following... Currently I have...

84mm CB crank Chev journals, 5.5" H beam rods (with arp2000 bolts), CB raised roof case, FK87, modified wedgeports 46 x 38mm, AA forged 94mm pistons, and a 50 - 125 hp n2o kit.

Firstly - I dont know how long the crank and flywheel are likely to stay together (not wedgemated), and 2ndly I have concerns about the chevy journals, especially on the bottle.

Would a wedgemate on what I have work OK ?

And since I have the case, Ive been thinking of going to an 86 mm crank ? Rod length and journal (VW, porsche, chev) with this ? Also are 411 mains a worthy option ?
The goal is to run 12s NA and into 11s on nitrous.

The car wont be strip dedicated and will be used on the street.

Lots of questions I know... Thanks in advance...

[ Edited on 19-2-2007 by noslug ]

dangerous - February 20th, 2007 at 06:21 AM

Hi Adrian,
These are my opinions only so take them at your own risk.

I like Bergs advice when it comes to crankshaft rules of thumb, BUT...

These days there is not a lot of options out there.

If you go past 82mm with VW journals and type 1 mains,
you can consider your crankshaft a CONSUMABLE in my view.

Berg says 78 VW is the limit, and I would agree, for long life.

Unfortunately ONLY BERGS make Porsche jounal cranks from a forging now days so for strokes above 78 the only option is to increase the main size to 411.

I personally would put up with an 82vwrod crank with type one mains if it had QUALITY NITRIDING,
but having 411 mains I think is the answer, especially if yours has Chev rod journals.

84 with cvev rod journals and type 1 mains is no going to serve you well with N2O.
Get 411 mains and a flange(or wedgemate) if you want this.

dragvw2180 - February 21st, 2007 at 03:45 PM

The vw crank suprizes me all the time,my turbo engine is 82 wedgemated, porche rod,vw mains. Was worried about crank flex,but in the passes so far it has shown no damage. !5 psi boost,401 hp. I definately would wedgemate it before trying to spray it. I would also recommend 10 psi oil pressure for every thousand rpm's it will be turned. Mike

humpty - February 21st, 2007 at 10:56 PM

Quote:
Originally posted by dragvw2180
!5 psi boost,401 hp.


My god!.... Please tell me how you have done this!

Boostn - February 22nd, 2007 at 01:17 AM

Quote:
Originally posted by humpty
Quote:
Originally posted by dragvw2180
!5 psi boost,401 hp.


My god!.... Please tell me how you have done this!



Yes and draw through old school!

dangerous - February 22nd, 2007 at 05:55 AM

Quote:
Originally posted by humpty
My god!.... Please tell me how you have done this!


Mikes engine goes well because it was well planned and
had the time and effort spent to get the combination right.
This always includes the final tuning and in this case Mike was lucky
to have the KAWELL's offer to give advice and tuning assistance on the dyno.

Dave and Judy K are super nice people, and even have input with the car set-up
long after the engine has left their shop.

http://i113.photobucket.com/albums/n216/dangerous_05/cid_X.jpg

dragvw2180 - February 22nd, 2007 at 12:06 PM

Exactly as Dave said,Dave and Judy Kawell have no secrets,will gladly give great advice and help before and after buying anything from them. We spent a week setting up my fuel system and dynoing the results. Dave is a mechanical genius and a craftman,he built all the shiny stuff.
http://www.kawellracing.com 
Mike

[ Edited on 22-2-2007 by dragvw2180 ]

humpty - February 23rd, 2007 at 12:50 AM

I have long been a fan of the Kawells work from way back in the drag bus days....(via HotVW's Magazine... I have almost every issue since 1978!).... Man that splitty shop truck was a mover!..... Im sure glad there are peeps in this scene that have that attitude..... Just like some peeps I know of here in Oz!.... You know who you are!

:)

dragvw2180 - February 23rd, 2007 at 02:25 AM

"Blacky" is still sitting in their shop,actually sat in her when I went there,car is exactly as it was the last time it was run. Sorry for getting off topic,I do think your crank will be fine ,just wedgemate it and balance again after having it done. The Chevy journals are pretty much taking over because its hard to find a race quality bearing for the other journals (VW and Porche). I am building a new backup engine for mine ,is 82x94,chevy journals,Vw mains, wedgemated. I know there are better choices,but it all comes down to money. Mike

noslug - February 23rd, 2007 at 10:24 AM

I have found a scat pro comp crank with chev journals and 411 centre main, wedgemated and the flywheel locally.

Thanks for all the advice. I did check into the flanged set ups, but the price is a killer. If I crank the nitrous up and break something Ill eat those words !

Is there anyone in Aus who sells the adaptor bearing for the centre main ? I have heard that the Berg bearing is too wide for an alloy case (hangs over the edge), but scat supply a thinner one.

If anyone is interested in a complete 84mm rotating assembly (less the rods - includes ST1 pressure plate, crank, flywheel and pulley) make me an offer. All new stuff.

dangerous - February 23rd, 2007 at 02:50 PM

Just use BMW 6 cylinder main bearings, and narrow to suit.(in a lathe)
A whole set will cost less than one Berg bearing.
You will have to tang the case as per the Berg Bearing...which is a radiused BMW bearing anyhow.

No, I dont know the part number but any bearing catalogue will have
the specs for 60 shaft and 65 tunnel.
You may have to drill the oil hole also.