Transplant

[FHPREMACH at aol.com]

In a message dated 5/4/99 9:18:31 AM Pacific Daylight Time, 
gderian at oh.verio.com writes:

<< That was the Hirth roller cranks for the Porsche 356.
 
 If there are too many rod journals between the mains, it  difficult to oil
 them.  Ferrari F1 flat 12 engines from the mid 70's had only 5 main bearings
 and used rollers for the rods.
 
 Gary Derian <gderian at oh.verio.com>
 Subject: Re: Transplant >>
I think the common VW ones were actually SPG's. Also, they were only rollers 
on the rods, with plain main bearings as I recall. The main advantage as I 
recall was that they were availible in stroker lengths without the problems 
of early welded strokers. A friend of mine with a bug shop had one and said 
it didn't really have any affect on performance. I think Crower still makes a 
roller bearing camshaft. Smokey Yunick remarked about that after a lot of 
machine work to make a roller bearing cam it netted no horsepower difference 
on the dyno. Unless you have a desire to drastically reduce the amount of oil 
circulating inside a motor as I recall John Lingenfelter did a few years ago 
with a 30psi at max rpm motor, there isn't a lot of reason for to look at 
rollers. Motorcycles use them a lot just to reduce the amount of machine work 
and remove the oil pumps which become a problem when things get too small. If 
you want to see the roller bearing idea taken to an extreme, look up the 
Husky four stroke motorcycle motor that used a reed valve to pump air/oil 
mist around the motor for a pumpless system. Smart them Swedes!!
Fred