In-line engine configuration

[Christopher Crowe]

To the best of anyone's knowledge, has any builder explored an inline engine/drive-shaft/conventional diff set-up for FB?

Has anyone done a study of the respective rotating masses for the two set-ups? What might be the friction/heat loss-comparison between the two systems? Has an in-line config ever appeared in D/SR?

Thoughts on the subject appreciated.

Chris

[RobLav]

A lot of very smart people have thought about this. If the engine is inline, you will need some kind of a driveshaft with a couple universals in it. Those absorb more energy than a chain. You'd want to put the center of mass of the engine in the centerline of the car, and this results in the output shaft not in line with the centerline of the car - hence the need for universals.

That's my take on it. I'm sure others can and will provide more info.

[Rick Kirchner]

Art Smith had a look at it. You'd have to ask him, but one advantage was using Hewland parts as drop gears and the case maintains the suspension pickups.

he has a set up fabbed in his shop.

[RussMcB]

An in-line engine would make header fabrication and routing easier. :-).

But a clutch job could be a pain. :-(.

BTW, one of the best things about a bike-powered car is no more never-ending Hewland gear changes. It's nice. :-).

[Northwind]

Some of the Yamaha Snowmobiles use the R 1 engine but has a case configuration that has the transmission and clutch removed. I think they run the crank to a reduction shaft. Maybe some creative adapting might make this possible. There should be a lot of these engines available also. They stuff these machines in the trees all winter long where I live.

[RobLav]

The case on the R1 based snowmobile engines is very completely different. The top end is more like the FZ1 than the R1 too. I tried to use the snowmobile engine dry sump system on the R1, but it was way way off. I still have the brand new snowmobile engine oil pump and sump in the basement.

[Northwind]

For reference of the above.

http://cgi.ebay.com/ebaymotors/ws/eB...ategory=100456

[Christopher Crowe]

It's been posited that a drive-shaft and u-joint system would lose efficiency due to increased friction and heat.

But. How could two u-joints with eight packed and lubricated needle bearings produce more heat and friction than a (dry-ish, bearing-less) sprocket/chain arrangement?

I DO know that the entire D/SR and F-1000 communities cannot be wrong in having chosen the sprocket and chain system; they've also stuck to it for years.

Might it be that the efficiency bugaboo with the drive-shaft system lies in the additional gears and bearings required to facilitate final-drive gear ratio changes in even a Halibrand-type ("quick-change") system? That would be an additional change in direction for the power being transmitted to the wheels... one more set of gears and bearings to go through. And rotational mass would be increased. But how much would it increase relative to a system of two whirling sprockets and an endlessly angle-changing series of unlubricated chain-links.

Please fire away; I'm a little bamboozeled on this one.

Thanks much -- thanks much already ---

Chris Crowe

[Daryl DeArman]

The legend and Dwarf cars utilize the engines in the configuration you are considering.

The legend group couples the engine countershaft to a u-joint with this part:

http://store.600racing.com/site/prod...B23BFDCCF3BDC3

The dwarf car crowd utilize a variety of powerplants, so you may find ready made parts for a variety of applications through their suppliers.

[Roux]

You are trading off ring and pinion losses for chain losses. turning the power 90 degrees is going to eat up HP. You have to look at the chain as if it is a flywheel with some friction to figure out the heat generated. If the orings and pins had no drag you would conclude that it had no negative impact. In a ring and pinion setup if there was pure rolling and no sliding at the contact you might be in a similar happy state but my understanding is that you don't achieve either. If you run the ring and pinion with the wrong oil you can kill it. Indicative of the cpacity to do work in the gear train. I think the chain wins each time.

the BMW bikes with driveshafts have always had losses that I think were not there in the chain drives. Their Uber Bike has a chain not a driveshaft.

[Jnovak]

Chain frictional losses are optimally in the 1% to 1.5% range. Losses from the best ring & pinions are in the 5% range minimum, more typically in the 7% range.

Thanks ... Jay Novak
NovaRace LLC

[glenn cooper]

bearingless and dry-ish.

The differential in all the m/c engine powered cars have bearings, not just riding on an oil wedge on bare aluminum, THAT'd be our camshafts!

The chain is made with lube sealed inside by O rings.
Some folks have adopted a "Never lube the chain" philosophy that seems to suit them well, all the while turning very quick laps.
I prefer to lube my chain only the slightest bit, in an effort to cushion the chain roller/sprocket tooth interface.
It sure flings off (no matter what brand) quite quickly.

[JakeL]

Also, nobody has mentioned: WEIGHT.

a chain and a coupla aluminum sprockets weigh a bucketload less than a driveshaft, ujoints, ring, pinion, bearings, gear oil, kitchen sink, etc etc.

-Jake

[Christopher Crowe]

First, thank you all for the insightful input.

Jay Novak really put an end to my mental gymnastics with:

"Chain frictional losses are optimally in the 1% to 1.5% range. Losses from the best ring & pinions are in the 5% range minimum, more typically in the 7% range."

Not much else to consider. Thanks again each of you.

Chris Crowe

[martyb]

Having a inline turbo Hayabusa-powered Super Production car with a driveshaft and a quick-change rearend, I would have to add that most of the adapters to connect driveshafts to motorcycle transmissions have a real problem. The straight spline output shaft doesn't normally have to deal with centering the device on it, since it is a sideloaded chain sprocket. A driveshaft, on the other hand, really likes to be centered, as any eccentricity translates to a vibration that can be anywhere from annoying to destructive. We have tried lots of different adapters; we can shatter/strip the aluminum ones, and the steel ones generally don't fit real well on a metric spine shaft. I think we're up to number 6 right now.

Just something to consider, along with the substantial weight and efficiency penalty.

Marty

[dereklola]

one of the best things about a bike-powered car is no more never-ending Hewland gear changes.

The fact that you don't change in a bike engined car (because you can't) means that you could also not change with a Hewland car (even though you can). Right?

Heh - If F1 crews don't change at the track then you don't need to either.