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I wonder what kind of bearings they used or all thd little tricks to get them faster. Snowmobiles where raced just after 1926, 2- strokes. This is a 1966 Panther with a high compression 8 hp Kohler engine 4-st. It was very hard to start. Engine was made in Kohler Wisconsin . I delivered a container from Chicago there, very old building.
The improvements are not as much as you expect, blue is steel bearing, red is ceramic bearing...
https://www.hambini.com/ceramic-bearings-vs-steel-bearings-an-engineering-analysis/
Frictional losses from the bearings are insignificant compared to other losses from the crank to the rear wheel.
Spur gears typically lose 1-2% (so total loss of 2-4% from primary drive gear to clutch outer, and mainshaft to countershaft), clutches loses 0-5% depending on load, clamping force and friction area, the chain drive loses 9-10%, depending on type of chain and condition.
If your looking to reduce frictional losses start with a well maintained, well lubricated conventional chain, o-rings in chains increase friction
Soooo.... Since you're an Engineer nonpareil--- explain to me how you were able to determine all of your detractors financial portfolios from just a few posts contained in this thread ?? I rescind all of my earlier statements--- you ARE the smartest man alive !!!!! Bravo 👏
And my bearing guy told me that wheels would be the last place he would put ceramics on a dirt bike, he said ceramics are a lot more susceptible to failure when exposed to dirt, mud, water etc.
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PTShox....when you tested this "polished engine theory" how do you know that all variables were exactly the same?
Was the moisture content in the dirt exactly the same?
Was the track prepped the exact same to ensure the same exact traction?
Outside temperature exactly the same?
Brand new tires on the bike each time?
Same fuel from the same batch each time?
LB-- all of what you asked is inconsequential when you have data like this . Exhibit A-----"People would come up to him at various races and say "what the heck did you do to those motors? Those things bark". I rest my case......
These (generic picture of the bearing) have gone into lots of very high end motors including factory. Only thing to watch for is OD clearance some of them might be on tight side so its very important to check fit as in rare cases with some top 15 guys have cracked the cases on a SX. I've never heard of anyone outside of them having an issue. If need be you can spin the bearing on a buff wheel with some cutting compound a quick spin and I was told that will fix it. But again it a very rare issue.
You guys are so smart! Brillant. Just an amazing amount of talent and foresight.
Let me ask you... how many computers have you seen riding a dirt bike? How many? What did the computer tell you about how the suspension worked or how the motor performed?
The guy that taught me this trick... His name is Arnold Plant. He was a MX Pro back in the day from Sacramento. Arnold wrench on the US National Moto/Supercross circuit for several years. He built motors for folks that won National motos and supercross, He also worked for Bob Fox @ Fox shocks. Tell Arnold it can't and doesn't work because of whatever reason you want to come up with. LOL... Armchair quarter backs.
I never said a god damn thing about computers.
Can you answer the very, very simple questions that I asked or not?
You definitely have the typical arrogant asshole engineer attitude that's for sure.
All this time spent arguing on vital while you could be revalving suspension and making millions with all that knowledge!
Isn't that your line of business?
I wouldn't bother with that as a business personally. But for you... maybe a great fit.
You win man, I'm polishing my engine cases right now!
Don't judge all engineers by him.
There are arrogant, incompetent people in every profession.
And the porn industry has fluffers. You could be... IMO, a fluffer in the dyno industry.
You ever worked with Bob Wirth? Run stuff on the dyno he built?
I know.. you know all.. you know more than Bob.. But Shell Oil hires Bob to do dyno work for them when they were developing race gas formulas. Also Yamaha Japan hires him. And KHI ( you may struggle with the initials). As do various F1 teams. Star racing Yamaha as well. If you have run race gas in the last 10 years.. very good chance it was developed on Bob’s dyno. That he custom built.
You don’t even know who he is… you fluffer! LMAO. Clown.
BINGO
No.. you won. You are clearly brilliant! Amazing. Super smart. 200+ IQ. Solving cancer issues in your spare time. Of course.....
I bow down to you. Clearly you are a brilliant mind. And from your profile photo... Of course Geoff Fox must have invited you to the 50th anniversary party in Cambell Ca last month? Where were you sitting?
Did you bring a computer? A dyno?
Mitch hired Ryan Cox, that’s what he did. Ryan is a genius when it comes to building usable power.
Pit Row
Is Bob's dyno a "Butt dyno"?
Asking for a friend.
Really?? My past experience they were junk. This was 5 or so years ago.
Bump.
PT, Yeah not alot of people know that. It was a pretty well kept secret. I know ive talked about him in the past. His work is kind of like ron hamp. Not many people know hamps head, pistons and cams were in tomacs mx title bikes over khi, pc and in house. He started working with Star around 07-08 if i remeber ccorrectly which was around the same time they started workin with Dasa. He was heavily iinvolved in the newer generation motor (14+) develpoment as well. Didnt he work with VP when they were updating their motorcycle race fuels and new ones.
See me first: He's a Motor building engineering genuis who had his hands on multiple championship or factory bikes for fun. Nothing pt said is an exaggeration about the guy. Hes done testing for more then just shell oil, othere big corps and many oems in cars, truck and motorcycles. If you know him or are able to get him to help you with anything count yourself lucky.
Pt is also a lot more knowledgeable then hes getting credit for. I wouldnt doubt to much of what he says when it comes to shit like this.
Just some observations from a guy whos seen some shit.
Yeah, I wasn't trying to dispairage Bob's accomplishments.
It was just funny to me how PT went from discounting computers to praising them.
A little confused is all
Idk man. You’re the one that told me to build a KYB A-Kit shock for my KTM when all I had asked about was a $120 bladder kit. You seem to know more than all of us combined. Let me know what address to ship my stuff to so you can back up your claims.
1) What are you drinking? Is it even sold over the counter in stores?
2) Which Fox family member are you dating?
If they spent more time polishing their cases and less time polishing their shaft they would know if it worked…l
Don't do it... Don't do any of it. It's too hard. Won't work for you.
Thanks. I have talked to Bob W. He's from the same town I am from. I know a few of his very good friends. Bob told me some of this information I shared directly. There is some I didn't share..And I talked to Bob about polishing cases in the intake track . I asked him what he thought was going on.... Because it goes against conventional wisdom. He told me his take on what he thinks is happing - which I'll keep to myself. I don't want to burst the dyno guys and the theory's guys all knowing knowledge (LOL) ) And I used to talk talk to Ron Hamp all the time. I ran his heads and coated valves on a CRF250 bigbore in 2005-2008. He was just awesome to work with and talk to. Hands on guy that was real.. and used real world data. It's a real shame he never got the attention he deserved. I miss that guy a lot! Very few realize how much knowledge he had (although some industry folks did). He used to have a guy Rouch racing used weld up intake port floors so he could reshape them and get the angle of the air flow down onto the valve at the angle he wanted. I have a Yamaha 250F I m about to do some work to and if Ron was around it would be headed to him.
One guy has a clue here.. those are not good numbers....
Thats the thing some things work but don't make perfect sense. Ive seen things that are identical perform ccompletely different from each other and both different one better, one worse then the data model predicted. Nothing on specs or in the data measured different. Same same but not the same. Kinda like dimples you always hear they dont work but i know a few motors that had them in there. No they don't work for every aapplication but I'v seen them work when they said they shouldn't.
Man I miss Santa Claus. The best thing about him is if you were genuinely intreste in learning he was happy to show you and explain the whys and hows as he understood them.
Brian Truesdale is another guy whos really and under the radar guy who does amazing work. He was gonna teach me the ins and outs but at that time i had to double down on my business. Might have to see if i can revistit that with him one day.
Theres alot of guys that have a clue they just dont post as much as they use to to avoide some of vitals bs. Look at williams, and harris they use to post all the time and barley do now. Im waiting for the day billy at luxon gives up to lol.
"Thats the thing some things work but don't make perfect sense. Ive seen things that are identical perform ccompletely different from each other and both different one better, one worse then the data model predicted. Nothing on specs or in the data measured different. Same same but not the same. Kinda like dimples you always hear they dont work but i know a few motors that had them in there. No they don't work for every aapplication but I'v seen them work when they said they shouldn't."
Totally 100% agree. That's why when I see/hear someone say "the computer model says xyz"... or the data says,, bgf... or the theory says wxf...
Does it work? That's what matters. Does it work? From there you can reverse engineer it and try to figure out the why. You won't always get there. There are still lots of unknowns as to the "why" stuff works.
How do you know about Bob? Not a lot know just how good he is and what he does. Certainly not the general public. I talked to guys that went to grade school with him and he was doing wild stuff to mini bikes as a very young kid. Jim Regar was the same.
Shell spent a LOT of $ to build a sister to Bob's self built dyno though.
Post a reply to: Engine Builders or Moto Dads who do the work their own, what bearings do you use?!