In my group, we have elected to stick with the 4 Japanese manufactures. While I support my club’s decision, I don’t think anybody around here has any problem with the Northeast clubs taking the initiative to try this motor. I think it’s good that someone is trying it & I will definitely be following their progress to see how it performs.

My concern is how the BMW has some similar characteristics to the zx12 (lower availability and higher horsepower). When the zx12 reigned supreme, the availability started declining and the prices increased, & we all know it ultimately started doing more harm than good. We don’t know if the BMW will go down that path, but it is safer to err on the side of caution for now while nobody has a BMW yet. Keep in mind, clubs can always legalize the BMW later on at any point in time, but once you allow it, there’s basically no going back.

Ok DAD take it away….

Ricky


"BANG"

I truthfully believe the BMW is not heavy enough to be a very good "Boat Anchor"

We have been told by competent authority that the Dwarfs & Lites have canned the late models already. Now if we can get them sports racers to do the same thing we are in the drivers seat. I foresee a BMW in every mini sprint race car out there. CHEAP CHEAP CHEAP That is!! except for mine.

Why would anybody want to go "back"-- wards??


Honest Dad himself

4.8 Engine Modifications

Note: In 2014, Non O.E. Surface treatments or surface coatings of
any kind will be prohibited unless specifically approved.
a. Cylinder Head
i. Cylinder heads must remain as homologated with the
following modifications allowed:

1. Porting and polishing of the cylinder head and intake
manifold normally associated with individual tuning
such as gas flowing of the cylinder head, including the
combustion chamber is allowed.
2. Welding or the addition of material is allowed.
3. The compression ratio is unrestricted.
4. Combustion chamber may be modified.
5. Replacement valve seats, guides, and guide seals are
permitted.
6. Cylinder head gasket surface may be machined
to allow the adjustment of compression ratio or
resurfacing to repair a warped cylinder surface deck.
d. Valves, Springs and Retainers
i. Valves must remain as homologated. No modifications
are allowed.
ii. The original number of valves must be maintained.
iii. Valves must remain in the same location and at the same
angle as the homologated model.
iv. Aftermarket or modified spring bases, springs, retainers
and other valve-train components are permitted

e. Camshafts and Sprockets
i. The original camshafts may be modified or replaced from
those fitted to the homologated motorcycle. They must
remain the same material as stock, or steel. They must be
approved and appear on the Eligible Equipment List.
ii. Offsetting the camshaft is not allowed. The camshaft
must remain in the homologated location.
iii. At the technical checks: for direct cam drive systems, the
cam lobe lift is measured; for non direct cam drive systems
(i.e. with rocker arms), the valve lift is measured.
iv. The method of drive must remain as homologated.
v. Cam sprockets can be modified or replaced to allow the
degreeing of camshafts.

They for all practical purpose are open motors.


Can you imagine someone would re machine cam bores and move the cams in a cylinder head, or that someone would change the angle of the valves in the head for a performance improvement. That is serious stuff.

We had a guy in quarter midgets years ago named Carl Shoji his son Richard was the kid that drove the chrome plated Kurtis Craft Quarter Midget made popular in the plastic car model sold by Revell. Shoji would cut away an old cast iron Continental block and braze a straight piece of pipe coming out the side of the block and running to the intake valve, making the intake path a straight shot from the carburetor to the intake valve, much like our motors do today. They called them side ports and they were fast and very hard to come by. But if you had one you was "KING" in AA Quarter Midgets.

Most car racers aren't going to go to that extreme but I guess there have been a few of them bike guys that did or they wouldn't make such rules.

My point has always been there is just not that much horsepower left in one of these little motors without changing the aspiration on them (supercharging), Oxygenated fuels etc. The only engines out there that are making more horse power per CC than us would be the Formula I car motors. We are making 200 hp per 1000cc's a USAC national midget motor make 400 hp per 2700 cc's. They would have to gain a whole lot to match our numbers. That is why we are so darned fast.

In layman's terms the National USAC midget motor produces about 2.4 horsepower per cubic inch. The bone stock late model bike motor produces 3.27 horsepower per cubic inch. SO when they get the USAC midget motor as effecient as our little motors are right now there will be a 540 horsepower midget motor out there racing.

The advantage to the BMW is a very over square bore to stroke ratio, and the use of rocker activated valves instead of buckets.

Because of their over square design, they can run a little larger valve and maybe improve their VE one or two percent at a certain rpm. They also must give up crankshaft stroke to do this. This means at lower rpm's (I hope Don doesn't get a paddle shifter) he will be down in torque or the ability to pull away from the turn as he tries to go under you on exit.

Also just like the little R6 Yamaha did to the F4 Honda we had to SCREAM them to make them work at all.

Hench has his work cut out for him but he also has a driver that can get the most out of that or any other engine. I just wish people were not so up tight about change. The Changing engine designs over the last 12 years or so is what has brought Mini Sprints back from the dead.

We don't need $10,000.00 Orient Express or Hank Scott motors anymore to be fast and to be honest with you these guys aren't going to get a whole lot more horsepower out of these engine either. What they could and can do is make them easier to drive, or de-tune them a little like Kawasaki did in 2008. Did you know that in 2012 BMW put a heaver crank in the 1000rr to try and make them more manageable and reliable.

If we spent more time on our driving and set up and less time worrying about what is under some guys hood the sport would be a lot better off.

Honest Dad himself

Has anyone ? Had success with this motor ? Or is running it?

Shim

Paul Davis has one that seems to work pretty good racing with MMSA, their appears to be a steep learning curve> but Paul seems to have his fingers around it.

Honest Dad himself

We have taken some calls recently, for those who are confused by this, Paul's car grandfathered before the national rules took place. It has been nice to see his car perform to make a better educated descision if this ever comes to a vote again. We will not ban any of the Japanese engines unless it's voted on by all National Series partners. The MMSA does standby the 2 year rule which was voted on in the National Meeting.

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Honest Dad himself

Come on "dad",thought you were smarter than that.most know the main difference is tqs run direct drive drivelines versus the minis chain drive.the costs for our "outdated engines"still don't come close to what it sounds like you guys are spending,in order to be competitive.and you're going through all this for what?peanuts for payout.hmmmm.

Got a ? What does a good top running tq motor cost givin all the machine work to shave off the gear case and such . And how often do they need rebuilt

The machine work isn't all that expensive, I used to do one for $150.00, and like anything else, depends on how much ya want, and how much ya got, and how much you can do yourself, a guy on a budget with some mechanical experience, and a book on the engine, can probably build a good engine for under $3,000.00, but, there are a lot of parts still available, that can be had for a lot less, that's what separates the man and his money, when we were running Honda's, and running full seasons, I could get at least 3 seasons out of an engine, maybe a set of rings and touch up the valves during the winter, rest of it was good to go, a guy like me, with a lot of years in the mechanical and fabrication ends of racing, my costs were a way lot cheaper than the go-karts I had ran since 1958, but then, I was doing my own work on them also, as well as for others, I had as high as 5 guys working 5 nights a week on them! Bob