Output flange rpm on gs1100g..???

[Mark Harrop]

Mark Mark Mark, the only chance you have is if you fabricate a large ugly cooling shroud. without it the engine will over heat and seize up and likely burst into flames.

the old Henderson's and Indians and several other in-line 4's made back in the early days had at best 30hp, and even then they had problems with over heating the back cylinders. that is why they went the way of the hard tail, it don't work and is un-safe.

know how many people lived to tell their adventure of running 100mph on a motorcycle with no suspension? not very many.

please reconsider, we don't want you to go up in a ball of flames at 100mph.

C'mon man, I'm guessing that at 70-100mph, the turbulent airflow around the engine should be enough to cool it... plus I'll run a large oil cooler.
Great-balls'o fire jokes aside, do you really think it will overheat if I gear it right? I want the lowest possible rpm that will keep it rolling in the 70-100mph zone.

I plan on making it as low as possible and reducing frontal area to cut down on wind resistance....no streamlining/fairings allowed.

What about richening up the rear cylinders a tad, I hear that cools them down. Any other cooling tricks/secrets I should know about?

[uudfourty]

With an award-winning soundtrack.

[Mark Harrop]

The event will be well documented...you can bet on that.

The Smokeout is quite a party, so if you can make it to the Rock, it will be a hoot. Its now going to be a week long.

I won the chopper show the first year I went, but got loaded and passed out before the awards ceremony, so I never knew I won. When I won a trophy with the Kamikaze the next year, they told me I had won the previous year and never picked up my award...

I try to stay a little more clear-headed now. If I win again on a "Stampede" bike, it will be a major coup, especially with a sideways shafty motor!

Of course the GSR will get a plug in the magazine...

[focus frenzy]

C'mon man, I'm guessing that at 70-100mph, the turbulent airflow around the engine should be enough to cool it... plus I'll run a large oil cooler.
Great-balls'o fire jokes aside, do you really think it will overheat if I gear it right? I want the lowest possible rpm that will keep it rolling in the 70-100mph zone.

I plan on making it as low as possible and reducing frontal area to cut down on wind resistance....no streamlining/fairings allowed.

What about richening up the rear cylinders a tad, I hear that cools them down. Any other cooling tricks/secrets I should know about?

I just don't know of any simple cheep way of keeping it cool without major machine work.
without oil jets pointing at the pistons the cooler wont make much differance, and more importantly, turned side ways, you will not be getting anything for air flow between the cylinders.

going very much higher with the gearing will add to the heat issue if you drop it off the cam and try to push it.

the GS1100G engine uses a cam and port profile pretty much just like all the other GS (heck SV1000 also) and comes on the cam strong at 6K rpm and stock will be running about 7K rpm at 100mph.

[MissFabulous]

Why not fabricate some kind of crazy looking baffle with pipes or something that will force air onto the cylinders in the back? Some kind of ram air foil. If you do it just right, you could direct the hot air right towards the seat It could be a "series of tubes" and you could call it The Internets.

As far as torque pulling any vehicle to one side, it still has to be a weight balance issue if it's not pants crapping. In general, a motorcycle isn't a free-moving object so it's not the Coriolis effect!

[Billy Ricks]

If you want a little extra flow around the head you could do a combo carb heat shield/ram air panel between the carbs and head. A flat piece of polished aluminum or stainless with a couple of well placed bends would force some air over the head.

[49er]

Use the KISS principle

Keep it simple.

IMO, you should stay with the 1100G transverse set up and lengthen the frame to accomadate a step up system similar to what you are trying to achieve now.

Run it with the jack shaft at right angles to the output flange, then bring the drive back to the existing postion with a second drive flange bolted to the drive shaft. You will need extra support for the output bearing/shaft assy, and the same at the other end where it comes back to the drive shaft. It will mean far less work in the long run. If you design it right, you will be able to experiment indefinately with your top gear ratio until you're happy with it.

Cooling won't become an issue either, but I would fit a decent oil cooler.

Just my 2 cents worth. Good luck, with your project.

[Mark Harrop]

Well, I guess there is only one way to find out the answers to these perplexing questions...

I'll just build what I have in mind, and if it bursts into flames or siezes up at 100mph, I just hope someone gets it on video...

Anyone ever gotten a cylinder head temp reading on one of these motors?