Head differences

[Lew Mayer]

Does anybody know the diferences  between the "butch" heads and the head with the more rounded fins like on Mr. Erikson's bike in "Featured bikes". These are on the cast iron cylinders. Upon a recent comparison, the head with the rounded fins seemed to be a higher compression head with roughly half the combustion chamber volume of the "butch" head. Can anyone shed light on this? Mr Wilford,maybe?

Lew Mayer

[peter kane]

Lew, The 10/72 Fichtel & Sachs Repair Instructions No. 336.8 E/4 lists the cylinder and head on Jerry Erickson 152cc Wassell as the type used on the 1251/5 B NHW-Military.  It is an aluminum cylinder and head.  If you look on page 2 of Featured Bikes "Owner Unknown" (top row 4th from the right) the Wassell with the shiny aluminum tank has the same cylinder and head. The picture I have is identical.  But I'm probably way off.  You'll soon hear I hope!

Peter Kane
V3442
Plainville, Massachusetts
[email protected]

[Dennis Jones]

Good find on the high compression head Lew, they are very rare.

Dennis Jones

[Doug Wilford]

The radial fin "Sunburst" Sachs head is higher compression than the Butch or original head.   The first High compression heads used on the Penton were made by Puch.   Sachs was soon to follow with the sunburst head.

[Lew Mayer]

Would I need to retard the timing to,maybe,2.5 mm for a trials bike?

Lew Mayer

[Doug Wilford]

I think you are going to have the best performance at 2.8  Using the Bosch points ignition.