ok this may be a stupid question......
 

how come no one makes a Big straight 6 like 400-500 cu inch, 400hp +.
seems like it would be easier to work on in a boat with a twin setup,
and reduced weight.

Re: ok this may be a stupid question......
 

Hmmm... interesting thought. And it would sound like a bread truck. Seems that the old pickup trucks with straight six's did pull pretty good.

Re: ok this may be a stupid question......
 

There was an old Mathews that I worked on in the 60's that had a big 6 cylinder (about the size of a vw bug) that had twin plugs in the top for each cylinder. Cant remember the brand name but it was in a very old 40 ft mathews, single screw.

Re: ok this may be a stupid question......
 

What would be interesting is a pair of narrow angle v6's with screw chargers! I'll bet they could get to the 400hp range.

Re: ok this may be a stupid question......
 

There used to be an engine builder years ago that made HUGE gas 6 cylinder engines for trucks... The name of the engine was " Hall-Scott"... They made small engines also for cars back in the late twenties. But... most people don't know that inline 6 cylinder engines of the same cubic inches as a V-8 weigh more... a lot more.
You have 7 main bearings instead of 5. The block and crankshaft are heavier. Instead of only 4 throws for the 8 cylinders.. Each cylinder has it's own crankshaft throw. The only advantage is width. Not too many people make speed equipment for inline 6 cylinder engines. :eek:

Re: ok this may be a stupid question......
 

That is what "Torque" motors was trying to do with their 60 degree V-12... make a narrow, powerful, unsupercharged engine. But they had too many "issues"... :eek:

Re: ok this may be a stupid question......
 

Any update on how callan did with these last race season?

Re: ok this may be a stupid question......
 

I know they installed some ... I learned that from a magazine article... other than that... nada..... :cool:

Re: ok this may be a stupid question......
 

You never heard of a Cummins or Caterpillar? I assure you the narrow-ness of an inline six is a benefit.

As far as a big gas motor, 4 liters is about the high end of the range for a straight six.
Hop up parts? Here you go:
http://www.cliffordperformance.com/

Re: ok this may be a stupid question......
 

Since he didn't mention Diesel... I was assuming he was talking about gas engines. EVERYONE knows there are inline diesel engines.

Re: ok this may be a stupid question......
 

A few yrs back someone was experimenting with using the Mazda twin turbo 1.3B rotary motors and hooking up to an outdrive. Their weight is just a fraction of a BB but of course they made very little torque. Does anyone remember who was doing that and if they had any success?
Rick

Re: ok this may be a stupid question......
 

Just go to an all aluminum engine for the reduced weight.
You still have a lot of horsepower and torque.

Re: ok this may be a stupid question......
 

Some big HP builders are reluctant to go to aluminum blocks.. They tend to twist a little. Also... the weight savings of an aluminum block and heads is offset by the closed cooling system you would have to run if you are using it in salt water. Some builders opt for aluminum heads with an iron block. This is to keep the detonation levels down. But there is still the issue of corrosion with salt water.

Re: ok this may be a stupid question......
 

just don't go in the ocean, duh... :D :evilb: :D

Re: ok this may be a stupid question......
 

Yeah, a couple years ago some guys tried to use a pair of import twin-turbocharged motors in a custom built Reno air racer called the Pond Racer. They had all kinds of temp problems with them and it had an inflight engine fire during a run. A highly experienced pilot by the name of Rick Bricker died in the fire after landing the aircraft.
Tried and true parts are pretty well wrung out and new stuff can bite you.

Re: ok this may be a stupid question......
 

This is correct, but mercruiser is going mostly to closed cooling on all standard production engine packages, so there is no weight savings now. The 496 and 525 packages are all closed cooling systems and still cast iron blocks.