Octane modifications

[Bill2001]

One of the things I had to do to my Beemer when 100+ Octane leaded gas became unavailable in the late '70's was tp lower the compression with "low test base gaskets" to run on Regular gas. Years later I did internal engine mods so I raise the compression back up and still burn regular.

I wonder if "internal mods" could be done to the Hodaka 2-strokes so they would burn the more-available Regular without harm? Below is a page from Klemm vintage on mods to run regular and the Rich Gagnon page on Torque Grooves.

What do we think?

http://www.klemmvintage.com/91oct.htm

http:// richstaylordporting dot com

[Hydraulic Jack]

I doubt Klemm has build data for a Hodaka. He tend to focus on Yamaha and Kawasaki vintage bikes, but I suppose you could ask. I don't doubt his results, or his experience. He has worked hard to get where he is. Whether he could take his experience and apply it to a Hodaka would be a question for Mr. Klemm.

Torque grooves work. Just how they do work might be a matter of speculation more than science, but I think it has to do with turbulence in the squish band.

[Bill2001]

Today I ordered a (used) spare Wombat cylinder head from SH. The plan is to make internal engine mods and ignition timing changes so that the engine can be operated on a Regular grade of gasoline, just in case my normal Premium grade is not available.

The first step will be to add "torque grooves" to the squish band of the head,
as well as evaluate the squish band itself. I'll send the head off to richestsylordporting for that work since Rich has done the R&D on that. Then I need to check with Klemm and see what setup he has available for his low-test mods for the Hodaka engine.

Does anyone have firsthand experience, or thoughts, on this mod?

[socalhodaka]

I would email Greg and Diane at [email protected] , they are friends with Klemm and talk about stuff.

[Hydraulic Jack]

The torque grooves work. And until recently, I was running regular gas without issues. Better on premium, better yet on premium non-ethanol. But can't get it within 100 miles, so.... use what I can find. Premium w/10% ethanol and stabilizer, or 87 alcohol free. Octane can be raised chemically but not with the store bought stuff which is worthless. I use toluene, but it isn't really necessary just to run pump gas.

Klemm reconfigures combustion chambers to run on pump gas. If you want to try him, give him a call and talk. I think his name is Harry. I have only spoken with him once long time back.

[Bill2001]

The spare cylinder should be here tomorrow. I'll contact Rich about cutting the torque grooves and explain what I am wanting to accomplish. He may have squish zone or combustion chamber shape changes he recommends. As I've said, my goal is not a performance increase as much as to break reliance on needing to use Premium grade gasoline.

I'll get in touch with CA Hodaka soon. My email is a tad funky right now, I'm making some changes and I'm not sure where everything is going.