What would you run in SCTA Bonneville G & H classes?

[Deuce Rails]

The Bonneville G class is for little 1.51 to 2.00 liter engines. The H class is for even littler 1.01 to 1.50 liter engines.

What engines are the record holders running? What engine and transmission combinations would you recommend?

If you get below 1.00 liters, motorcycle engines make the most sense. If you go bigger, there are a lot of options.

It seems tempting to go with a Japanese engine, and tune it like all the young kids do. There are a lot of 2.0 options, and you could always sleeve a widely-available 1.6 down to a 1.5. But how would you convert a Japanese engine into rear-wheel-drive? What tranny would you use. Or, is the Zetec a good block to build power?

Any suggestions, tips, or websites that have information on making serious horsepower (to the rear wheels) would be very much appreciated.

--Matt

[Rocket88]

Mazda rotary, I'd run a 12A. I played with them 20 years ago when I was in my teens. Had me a 1970 Mazda R100, what a cool little car, back when imports had chrome bumpers too!

[DrJ]

[ QUOTE ]
Mazda rotary, I'd run a 12A. I played with them 20 years ago when I was in my teens. Had me a 1970 Mazda R100, what a cool little car, back when imports had chrome bumpers too!

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Curious,,, In fact I've always been curious about this and haven't yet got an anawer that made sense to me.
Is there a SCTA accepted method for adding up the cc's of a rotary?
How are they figured, since there are no cylinders to use for a simple computation?

[DrJ]

[ QUOTE ]



It seems tempting to go with a Japanese engine, and tune it like all the young kids do. There are a lot of 2.0 options, and you could always sleeve a widely-available 1.6 down to a 1.5. But how would you convert a Japanese engine into rear-wheel-drive?

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Why would you need to convert to rear wheel drive?
Jocko was/is developing a front wheel drive car that at speed lofts the rear wheels off the salt and "flies" the tail of the car like a pub dart.

[28rpu]

I know some people use pinto and vega engines for G classes.
You've got to get more creative for smaller bullets.

Dr J.
SCTA has a formula for figuring rotaries. I don't have the
book right here but I think it's 3x swept volume.

[purple]

<font color="purple"> I haven't worked with Mazda rotarys, but there was a guy using one at the local roundy round. It equates to 1300cc's. The guy had to de-tune the engine, restricter plate and stuff. They would especially be good for all out, because they can go 9000rpm with little work done to them. They acually don't have a specific red line. With very few moving parts, no rods, pistons, valves, etc, they have nothing to crash into each other. </font>

[Rocket88]

First rotary was a 10A, just shy of 1000 cc's. 12A is almost 1200 cc's and a 13B is almost 1300 cc's. Used to rev the shit out of mine. The only problem was thatmy tach only went to 10,000 rpm. I'd pin the tach count to four and grab another gear.
A rotary with a big hair dryer on it could make some serious horsepower. hmmmmmm...
I'm curios about the classes, are they based on weight per cubic inch, or are the also based on factered horsepower?

[Fat Hack]

Datsun B-210....1300cc at it's peak and five speeds available for 1977-78. Rear wheel drive little cars that came in hatchback body styles.

Slam it, build it, strip and run it!

If you gotta pay more than $500 for a good running sample, you ain't trying hard enough!!

[modernbeat]

Rotary engines are absolutely uncompetitive in the SCTA classes. They are hit with a 300% volume penalty and they can't come close to competing with the 3.6 liter japanese engines. Not even close.

If you were competing in the 1-1.5 liter class, I think I'd start with a small Honda engine converted to a Vtec head. You could run it rear engine-rwd, or front engine - fwd, or you could lock the stock fwd diff and use one half shaft as a drive shaft.

For what it's worth, it's not that hard to adapt a Honda or watercooled VW engine to a front engine rear wheel drive configuration. You loose the stock tranny, but that was probally gonna go for a stronger one anyway.

I've got some ideas on lakester bodies with mid engine front wheel drive setups that I'd like to model.

There was a cheap 4wd buggy designed in the late '80s that utilized a fwd engine and tranny. The stock half shafts were used as the front and rear drive shafts.

[Rix2Six]

Just curious, what about running a VW motor in 15-2000cc. Lightweight snd no cooling system to hassle.

[purple]

<font color="purple"> I forgot, there is an adapter made for a VW to a Chevy tranny.

(Psst Fat Hack, it's 1400cc's, I have one in my 59 Datsun) </font>

[Deuce Rails]

[ QUOTE ]
Rotary engines are absolutely uncompetitive in the SCTA classes. They are hit with a 300% volume penalty and they can't come close to competing with the 3.6 liter japanese engines. Not even close.

[/ QUOTE ]

Modernbeat, and 28rpu, nailed this one. Wankels are out.

I should have said that I was interested in the Modified Roadster body class, which means rear wheel drive, and the engine must be set no further back than 50% of the wheelbase.

Rocket88, the engine classes are purely cubic displacement, divided into fuel or gasoline, blown or unblown. Weight doesn't matter, cuz more is usually better for traction. (Acceleration means nothing next to top speed.)

Modernbeat, that's a neat idea about using a half shaft as a driveshaft. If I used a stock transmission, would I need something like a 0.80:1 rear end for top speed? Is there such a thing? How would you do that? Thanks for the idea.

[Rocket88]

300% ! Even the NHRA isn't that heavy handed! http://www.jalopyjournal.com/ubbthreads/images/graemlins/mad.gif

[Dreamweaver]

[ QUOTE ]
300% ! Even the NHRA isn't that heavy handed! http://www.jalopyjournal.com/ubbthreads/images/graemlins/mad.gif

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Thats because they are so friggin fast!

[DrJ]

From what I heard from some one here, they (SCTA) don't accept the French flatheads in the flathead division either.

Rules aren't made to be fair, they are made to be "cheated" on... http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif

OT
(Maybe this is related to Hatch's Hotrod rules question?
Hotrod "rules" are an offshoot of what cars look like, when built to fit within various racing rules.)

[Fat Hack]

Ya gotta do it like my all time Hero Henry "Smokey" Yunick done it...

Pay attention to what the rules DON'T say and work there!!

[modernbeat]

I'd be more likely to cheat if there were more meets, I wasn't likely to set a record, or, if competition was so fierce that with available resources there wasn't any other way to win.

When I raced SCCA, I went to a lot of local races. I had no fear about bending the rules. When I got to go to Salinas for the finals, I made sure that my car was by-the-book safe. The advantages of cheating in my class were small, and the concenquences of losing a once a year opportunity of a win because of a valid protest were just too great.

I think that the SCTA is in the same boat. I think that so much experimentation in the slower non-streamliner classes is still yet to be done. I think that the short list of meets and the penalty of being caught using an illegal car are just too great. The best recent example is the Rocket Science car. The guy had some unique ideas about how to interpret the rules, rules that are certainly open to interpretation. He built the best car he could inside the rules as he read them, and when the dust settled, after making a record setting run, he did not set a record and to continue competing with that car, in that class, he had to rebuild the chassis, the floor, and the grill shell. Mucho initial expense only to be told to go away and come back when fix your car. A more consertive reading of the rules may have allowed the Rocket Science car to set a record the first time out.

In stock car racing the huge number of meets, the huge prizes, and the penalty of minor suspension and cash fines, but not loss of a win promote cheating and creative rule reading.

FWIW, the SCTA has the loosest rule book of any racing organization I've ever seen.

[modernbeat]

And the Rotary thing...the Mazda guys have been asking the SCTA to change the ratio to 250% or 200% for ages. Most other racing organizations use a 200% factor when classing Rotary engines. The SCTA is the only one that handicaps them at 300%.

This goes through the rules committee every year, and every year a staunch group of Rotary racers campaign for the reduction. I suspect that when/if the SCTA ever goes to 200% a lot of Rotary racers that either do not attend LSR events, or have switched engines will start showing up with new Rotary cars. The competition may not like it, and I suspect the SCTA is resisting it because of it's roots in traditional engines and traditional hot rod racing cars.

[Scott B]

Wankel got the patent on the rotary design in '36. Real development on it was going on with NSU in the early 50's. To me, at least, that would make rotary engines about as traditional as SBC's...

[modernbeat]

Built in the '50s you say?

Name a '50s hot rod or successful racing car with a Rotary. They weren't well thought of untill the RX7 came out. Even Mazda's early efforts (RX3 and the Rotary Truck) gave them a black eye.

Anyway, the modern Mazda Rotarys have about as much in common with those NSU engines as late model Honda Vtec engines have to do with Model A bangers.

Just because the tech is old, doesn't mean it's traditional.

Thanks for the flame bait.

[Bruce Lancaster]

Hmmmm...if I extended the wheelbase a foot, I could throw a second mighty 750cc engine into my Austin coupe and be right at the top of H class...think how that little sucker would haul with 34 horsepower!! Oh oh...here comes the nurse..must be time for my nap...

[Rocket88]

Smokey as a smart man, and I'm no Smokey! lol..
I like the challenge of rule bending but there comes a point where the odds are too great, like 300%.
If I had to choose a different engine it would be a destroked iron duke. I've always wanted to play with one of those. The bolt pattern on the back of the block is the same as a small block chev, which would make tranny choices a whole lot easier.

[av8]

Dave Tuttle has been having fun in H/GL with a Kawasaki four-banger in a lakester of his own design and construction (read "small RED"). This is one of several cars Tuttle built about 10 years ago that he attempted to have cert'd by the NHRA as an affordable dragster class. When that didn't happen, Tuttle modded one of the cars with a canopy and other changes appropriate for lakes racing. Dave is the current El Mirage record holder in H/GL at 172 mph, and I think he was high-points Elmo champ last year (or maybe it was the year before) with his simple, effective, and super-reliable racecar.

A sleeved or destroked Honda VTEC would make a killer G-class motor, particularly as a blower (turbo) motor. Guys like Dan Fodge regularly extract 450 dead-reliable horsepower from these little guys based on mostly stock internals. It shouldn't be tough to adapt a simple Yank automatic, like a C4.

There is a caveat about both of these motors: If you get off on rebuilding between events these puppies will bore you silly because they just keep running and running and running . . .
http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[av8]

DrJ -- You're right about the exclusion of the French L-head blocks from flathead record racing. They can run, but only for the amazement and mystification of their builders. The blocks would have been accepted with little notice had it not been for one colorful purveyor or flathead parts-for-sale raising a concern with the SCTA-BNI. The good stewards petitioned all holders of flathead records to gauge their acceptance/prohibition of this fresh source of sound makings for new flatmotors. From what I've heard, there was little resistence to permitting the new blocks to run in record classes, but the original complainer and his crowd were sufficiently vocal to carry the day and keep the French blocks out of record racing.

It's interesting to note that all the serious builders of record flamotors were in favor of including the French block. It's also interesting to note that the fellow who raised the red flag against the French blocks is not a LSR racing participant much less a record holder -- at least as far as I can tell; when the bullshit is deep and old enough, it begins to look like the ground.

[Deuce Rails]

[ QUOTE ]
A sleeved or destroked Honda VTEC would make a killer G-class motor, particularly as a blower (turbo) motor. Guys like Dan Fodge regularly extract 450 dead-reliable horsepower from these little guys based on mostly stock internals. It shouldn't be tough to adapt a simple Yank automatic, like a C4.

[/ QUOTE ]

Thanks for bringing the post back on topic, Mike. That's exactly what I was thinking. It would be pretty straightforward to sleeve a common 1.6 down to 1.5, or to simply use a 2.0.

However, I still have two doubts about doing that easily:

1) Don't those transverse, front drive engines spin in the opposite direction of traditional longitudinal engines? Or am I wrong?
2) How do you adapt a T-5 or T-56 to a smaller flywheel? How do you mate the bellhousing to the engine?

Maybe I also need a lesson in Engine Swapping 101.

Thanks,

--Matt

[Deuce Rails]

Seriously,

Don't Honda engines spin counter-intuitively?

And if they do, or even if they don't, how would you adapt a bell housing to one?

Thanks,

-Matt

[DrJ]

I think the latest generation of engines are spinning the "normal" way. but it's the larger Acura engines, not all. Unless the article I read confused on purpose!

I'm not sure the Vtec technology will be of any help because it's designed to "retard the cam(s) at low RPM for smog.. and advance the curve at higher RPM. the low RPM benefits I don't think would be needed?

[Unkl Ian]

I think I'd destroke the crank to get the displacement.Reducing the bore can shroud the valves costing HP.Honda motors can benifit from raising the deck height to run longer rods.Lots of cutting edge engine theory here: Endyne (http://www.theoldone.com/articles)

[Unkl Ian]

[ QUOTE ]
Just curious, what about running a VW motor in 15-2000cc.

[/ QUOTE ] What is the stock displacement on a Subaru WRX?They make some power.One passed me yesterday like I was standing still,sounded like a V8. http://www.jalopyjournal.com/ubbthreads/images/graemlins/cool.gif

[Rix2Six]

the WRX is 2L twin turbo put's out like 230hp there's also the WRX STi that's 2.5L twin turbo and puts out 300hp

[Deuce Rails]

[ QUOTE ]
I think I'd destroke the crank to get the displacement.Reducing the bore can shroud the valves costing HP.Honda motors can benifit from raising the deck height to run longer rods.Lots of cutting edge engine theory here: Endyne (http://www.theoldone.com/articles)

[/ QUOTE ]

Thanks for the great website, Unkl.