How Much HP Can Be Made

[badbait]

I want to put a V-4 on a ultra lite Allison. How much dependable HP is possible out of a V-4? It needs to be dependable for long runs. What RPMs will they run, and what gears are available?

 

[Rusrog]

With a little bit of welding & machine work, I would say 200 would not be out of the question on a Yamaha V-4 on carbs. Cut up a horizontal front case half, add some good carbs, a bit of compression, and a finger ported block... Should be no problem at all to get 200 and and probably over 8500RPM with some work and some tuning.

 

[badbait]

How many cubic inches are the V-4 Yamaha's?

 

[John Richied]

Badbait

 

[aaronmt]

:shock:Bob Kottman can make the V-4's flat run.I think 200 is fairly easy.

 

[Lotus 50]

From 1987-2001, and probably beyond, they were 105 CID

 

[whatsamerc??]

i am a yamaha fan from the word go but dont overlook the omc looper v4s especially with a brucato efi setup.........benji

 

[badbait]

The motor needs to have 99 ci or less to run in the class I'm interested in.

 

[whipper]

The motor needs to have 99 ci or less to run in the class I'm interested in.

Bill check out the twin Allison thread that Scott G just put up!! Those guys are a someone you need to talk to about the V4,s for sure!!

Lots of good pics and info. There getting 80mph with the V4 on the little 76 15R A Crafts.

 

[Mr. Scary]

Then you're talking something like a cross flow OMC. Jerry Sellner in Minnesota holds the Formula V world record and his cross flows were really trick. He had 60 degree fast strike carbs on these cool intakes. Probably around 185 HP if you kept the compression reasonable for long runs like you're talking.

 

[Darth VMAX]

I agree. Pretty sure the Yammie and 90 Degree Looper OMC's (122ci) are ruled out in that case. Not sure what the 60 degree OMC V4's are but I would imagine the X-Flows could be hopped up a lot more anyway. Too bad, those big Looper OMC's while heavy can put out a lot of power

 

[froggy]

Badbait,

Talk to Al Stoker about the V4 OMC's that fit in your class of less than 99 c.i. They will turn it up; and now with Brucato's fuel injection setup, ought to live too. BTW, Tony B. is running a V4 OMC so he has "real world" experience.

froggy

 

[Yamonster]

:shock:Bob Kottman can make the V-4's flat run.I think 200 is fairly easy.

I can personally vouch for this. 200 YES

 

[Waterdigger]

:shock:Bob Kottman can make the V-4's flat run.I think 200 is fairly easy.

Catfish Kottnum! Hawk Point Mo. 636-338-4080

 

[badbait]

Thanks guys for the info. My plan has been put on hold for the moment.