Page 1 of 1
78.4 ?
Posted: Sat Jun 24, 2006 4:19 pm
by Santas Brother
Jake: where did the 78.4 mm stroke come from ?
All other sizes are in whole mm sizes.
Seems like a strange number.
My guess is that is the max stroke
that will clear the stock base circle cam.
Yes,no ?
Thanks.
Posted: Sat Jun 24, 2006 8:53 pm
by tuna
Actually the 78.4 stroke is a holdover from the Type 1 days. Why that particular number, I don't know. I think it may have started with the Okrasa cranks, but I could be wrong.
Tuna
Posted: Sun Jun 25, 2006 6:37 am
by R2.0
IIRC, it is what one winds up with when a crank is offset gound to Chevy bearings.
R2.0
Posted: Sun Jun 25, 2006 9:28 am
by Kelley
Deck height?
Posted: Sun Jun 25, 2006 9:43 am
by MASSIVE TYPE IV
actually it came from Oettinger in the early days of VW stroking... I used to remember the story but I had to "Recycle bin" some of that old memory to make room for the new stuff or my brain would have locked up from overload!
Posted: Sun Jun 25, 2006 12:27 pm
by Santas Brother
90 x 78 = 1985
90 x 78.4 = 1995cc
If you were racing in a class with a 2000cc limit,
some people would want that extra 10cc.
Posted: Sun Jun 25, 2006 12:42 pm
by MASSIVE TYPE IV
Yes, back in the day the 90mm NPR piston kit was very popular in the 2.0 class and used with this crank
Posted: Sun Jun 25, 2006 11:06 pm
by Wally
MASSIVE TYPE IV wrote:Yes, back in the day the 90mm NPR piston kit was very popular in the 2.0 class and used with this crank
I think it is more likely that the 90,0mm Oettinger Nikasil cylinders/Mahle pistons were used for that size 'back in the day', but I'am talking type 1 here
The Oettinger type 1 Nikasils were 90,0mm, not 90,5mm, so thats rather distinctive
(the porsche 2,7 911 engine has 90,0mm alu barrels as well
)
Walter
Posted: Mon Jun 26, 2006 4:58 am
by MASSIVE TYPE IV
Here in the states the 90mm NPRs were very typical with the Type1. I used these all the way up to 1993 when the supply dried up.