H6 Motor, the next new thing
For several years now one of the most popular motors for the sand has been Subaru's
2.5 liter 4 cylinder
boxer motor. You have probably seen them in the dunes, DOHC versions
in Subaru cars up to 1998, and the SOHC version used in cars 1999 and later.
These engines are referred to as EL25 motors, both very similar, except for the
heads. At Outfront the DOHC version
has produced over 600HP at the crank, which is quite a thrill ride for such a small 4
Subaru has also produced a 3.3L 6 cylinder motor for many years, also with 4
valves per cylinder. But in 2003 Subaru released a new version of their 6 cylinder
that has put a gleam in the eyes for many duning enthusiasts. The older
3.3L motor has been reduced in physical size, and the displacement was set at
3.0L. The good news is this motor is not much bigger than the 4 cylinder
cousin, minimizing the weight as compared to the heavier 3.3L six cylinder.
As you may know, weight plays a huge part of the handling characteristics of
a sandcar. The Subaru 4 cylinder motor has one of the best power to weight ratios around,
weighing in at around 300lbs with exhaust, turbo, and intercooler. The placement of that weight is just as important
as the amount of weight. Subaru's flat
boxer layout keeps the weight low, closer to the axle centers, minimizing car lean and roll. V6 and V8 motors place much of their weight
above the axle line, which promotes car lean and roll. In addition to weight
height, the length of a motor in rear engine cars will increase the "weight
leverage", which affects the handling characteristics. The farther the
weight of the motor hangs behind the rear axle, the more
leverage that weight has to lighten the front end of the car. And as
everyone knows a light front end is bad for handling in the
dunes. A light
front ends cause steering push, a symptom that comes from less grip of the front wheels.
The bottom line..... too
much weight behind the rear axle is a bad thing. So lighter and shorter
motors (on rear engine cars) are best for
good for handling.
Enter the Subaru H6 SOHC 3.0 & 3.6L motor with 6 cylinders. These motors
1" longer than
Subaru's 2.5L 4-cylinder motor, and it's only 75lbs heavier. Since the weight
increase is small, and the increase in length is small, this is ideal if you
want to increase your displacement beyond 2.5L. The new H6 gives you a 20-44%
displacement increase for a 25% weight increase. The important thing to
remember is this additional weight of the H6 is only 1" longer than
EL25 motors, which minimizes the leverage factor. And if you mate
this motor to our brand new Subaru bellhousing for the Mendeola MD4-2D, it's actually 1/4" short than an EJ25 motor with the normal VW to
Subaru adapter kit.
John is currently building a car with this new H6 motor, connected to the new
Mendeola S5 transmission (good for up to 900HP). John believes Subaru's H6
will be the next big thing in "GO FAST" engines. John has big plans for
this engine with all kinds of racing parts in the works. Over the next
couple of years you will be seeing some exciting developments taking place.
Watch for John at the drags at Glamis, the mean
green machine (as people call it).
How much horsepower can be squeezed out the H6 and stay reliable? Time
will tell, but currently John has pumped 900HP out of his current motor.
He's working on a 1000HP version. This one may require the driver to wear
diapers to drive wide open!