Which engine

[fastkars52]

Is there a concensus of opinion as to which 600cc engine is best for the F6 class?

[jim murphy]

The GSXR 600 is the smallest and, thus, many of us prefer this one to help fit in the engine bay. All four motors are very close in HP/torque.

If you are planning on building/converting to a F600 please let me know so that I can add you to the builders' list (posted on the F500 forum on eformulacarnews site) - need location, type motor & when you go to the first race - then please post your progress as well.


TX,
Jim

[Stan Clayton]

Is there a concensus of opinion as to which 600cc engine is best for the F6 class?

Since the F600 application to the CRB includes provision for an inlet restrictor to cap hp, you may wish to follow Jim's advice about choosing the smallest and lightest 600cc engine available.

[Jnovak]

I originally picked the GSXR engine for my projects after much research. It is extremely tidy & small. Total engine weight including steel tube exhaust system is 134 lbs & it fits very easily in our NovaKar chassis. The other resaon I picked it is that it had the most mid-range & peak torque of the big 4 engines. We will actually be dynoing the engine soon with individual inlet restrictors & will post the results for all to see.

Thanks ... Jay Novak

[Rick Goodwin]

Mid range power means nothing to an f600. Our motor never saw anything under 10k. Pick the Yamaha R6. If your going to restrict it. It already makes the best HP and the oiling system works perfectly right out of the bike due to its top loaded trans. there is no where for the oil to escape too. This saves money on modified pans or dry sumps.We have lots of test data to prove these facts.

[Rick Eskola]

Even though I'm running the Rotax, I'd like to see all four (Yamaha, Honda, Kawasaki, and Suzuki) bike engines allowed. It would give a person more options, and be more cost effective (dealer in your hometown). Someday I may switch to the bike engine, and I would like to make my own choice to what engine I want to run.

Rick

[Jnovak]

Hey Rick, 10,000 rpm is MIDRANGE.

Thanks Jay.

[lancer360]

The proposed rules do allow Yamaha, Honda, Kawasaki, and Suzuki. As far as which one is best, it depends on the year of engine you are looking at and who you ask. I know of Yamaha, Honda, and Suzuki conversions/new builds being done. I don't know of any Kawasaki's yet. Suzuki is probably the most prevalent with the Honda 2nd. I don't think you could go wrong with any of those three though in an '07 on up motor. I know the motors have significantly reduced in size over the past 5 years. I'm still baffled on how Clint managed to shoe horn that '05 Honda into his existing KBS Mark 5. It is a much bigger engine package compared to an '08 GSXR. It is very impressive how Clint and his dad managed to fit it in with and keep the existing bodywork. If you have other 600's being built by people you are friendly enough with to share technical details, I would go with the same engine they are. This will help the learning curve significantly and help you learn from each others mistakes.

[Daryl DeArman]

Since all 4 of the motors are pretty close, and possibly even closer with the restrictor(s), I'd be more concerned with R&D, support, availability, and price of parts. I'd also take a look at how they are geared moreso than their peak HP numbers (what do the 4-5 and 5-6 gear splits look like????)

[Rick Goodwin]

Hey Rick, 10,000 rpm is MIDRANGE.

Thanks Jay.

example: Peak torq. happens for the 07 gsxr600 engine at 11,000 RPM. You will never be more than 500 RPM below this number. To say that its midrange would be fuzzy math at best. When you have a shifter at you command I would trade the 1.2 ft. pd. of torq. differance of the Suzuki for the extra 5HP and 1500 RPM of the Yamaha on a roadcourse any day.

[Jnovak]

Very good discussion guys. Here are some pics of various dyno curves from Sportbike Magazine. There are many more if you care to search around. No doubt the Yamaha generally makes a bit more power & a bit less torque, but not always. I like to look at the power under the curve & if I had the actual dyno data instead of pics an actual PUC could be calculated.

This is for 2006 engines:
http://www.sportrider.com/dyno/146_s.../photo_88.html

This is for 2008 enginea:
http://www.sportrider.com/dyno/146_s...photo_101.html

This is for 2009 engines:
http://www.sportrider.com/dyno/146_s...photo_105.html


Thanks ... Jay Novak
NovaRace

[six6two]

Quick question, why restrict a 600 motor?

[Jnovak]

Quick question, why restrict a 600 motor?

The stock engines make about 15+ HP more than the best F500 motors right now.

Thanks ... Jay Novak

[six6two]

The stock engines make about 15+ HP more than the best F500 motors right now.

Thanks ... Jay Novak

Well since you put it that way, it makes good sense! Are there any plans to make F600 a class of its own, or is this strictly an addition to the F500 class?

[Jnovak]

Well since you put it that way, it makes good sense! Are there any plans to make F600 a class of its own, or is this strictly an addition to the F500 class?

Our goal is to get the restricted 600cc MC engines approved as alternative engines for use in F500. All the othe F500 rules stay the same.


Thanks ... Jay Novak