Why is this engine unknown?

[maniac57]

Gosh I can see you are excited about these engines!
Good for you!
I really do feel almost anyone can have more fun with these tiny little MAB motors than a fire-breathing rice rocket!

You might want to re-consider one of your improvements...
"I replaced them with high quality sealed bearings from the aftermarket."

Can't say I've come across any sealed bearings that will hold up to the heat and power / rpm that an open bearing, lubricated by the fuel/oil mix will.

But we're all looking for something better!
Please post the part number and a source if they prove to be reliable in this application.

Tnx
rc

I ALWAYS remove the inner seals on crank bearings to allow lubrication.
But good thinking!


Davezilla
Re: Why is this engine unknown?
there are some good metal sealed bearings that would work realy well in these, just remove the inner seal so it can get lube from the fuel/oil mix instead of the grease that's packed in there at the factory. the outer seal can be retained to boost the efforts of the crank seals. I'll have to look up the part numbers I got and post the links, but there are a few good ones in the 6202 and 6203 sizes. The SKF bearings are also excellent and will hold up.



I think these are in fact SKF bearings Davezilla....MUCH better quality that the Chinese stockers.

 

[Davezilla]

For all that matters, most the American, Japanese, and European made bearings are far better than the Chinese ones, but I've really been happy with the SKF brand, they just seem to be a bit better made than the other big brands like Federal Mogul and Timken... both which are really good brands as well.

Here's an ebay like to the VXB 6203 bearings with the metal seals, these are also excellent quality and there's all kinds of selection for ball bearings, sealed and un sealed, ceramic bearings, roller bearings, one way clutch bearings, pretty much you name it... But this is the metal seal type I was talking about earlier.... http://www.ebay.com/itm/6203ZZ-Bear...905?pt=LH_DefaultDomain_0&hash=item5d43ff8999

You can also get these and MANY other type bearings like that wrist pin bearing that's about 2mm wider for a better fit etc, etc.... http://www.vxb.com/

Another nice thing about the VXB website is that they do list specs and rpm limits for most their bearings as well as torque limits for their one way clutch bearings... just in case anyone wants to make their own freewheel hub or freewheeling front sprocket without that ratcheting noise...

 

[mapbike]

i have got the upper bearings from vxb.com in the past but last i checked they dont have any in 10x14x15mm that dont have the outer race, all they seem to have is the hk type bearings now in that size, i used to get them from motionindustries.com also but i cant find them there now either so the last three i ordered from a bearing company in the UK.

 

[Davezilla]

Same here... I had to really shop around for the right sized wrist pin bearing and to find one that's also good quality. I think I got mine from vxb last summer but I think it was either 15 or 16mm wide, its definitely wider than stock but I cant remember where I got it from.

 

[mapbike]

Same here... I had to really shop around for the right sized wrist pin bearing and to find one that's also good quality. I think I got mine from vxb last summer but I think it was either 15 or 16mm wide, its definitely wider than stock but I cant remember where I got it from.

bearingsdirect.com is the best source I've found here in the states so far lately, but there has to be another place to get them without having to order from overseas, there are a couple of places in Europe to order them but it takes a while to get them here even though shipping is very reasonable.

I have several high quality 10x14x13 bearings which actually work fine, but I kinda like to have the 15mm wide ones if possible.

There is a thread on here somewhere in which a member had made some thin spacers out of a fuel and oil resistant plastic bmaterial designed for making industrial bushings, I cant think of the actual name of the material right now, but he made theze so he could keep the more common 13mm wide needle bearings from having all that room to float side to side on the wristpin.

Im sure with a couple quick searches the posts an be found, it been 3or 4 years ago I think.

 

[Davezilla]

I was thinking about making a set of aluminum spacers to do the same thing but I think I know what type of plastic you're talking about... it's kinda like Teflon and these are used in hydraulic systems as seals for internal components. I can see the benefit here because it would shave off a little weight in the piston assembly, not a lot but every little bit counts at high rpm.
I'll search it and see if I can find it to be sure it's the same type of plastic I'm thinking about.

 

[maniac57]

I remember that post but not the specific material used... maybe Delrin?
I know Delrin is some TOUGH plastic! We used it for wear plates in industrial clay shredders back when I could work and it held up to abrasion MUCH better than even AR (abrasion resistant) steel!
Only thing I'd be worried about is it's temperature limits which should be fairly easy to check.

Personally, I'd rather use a wider bearing and avoid the extra weight of spacer.
Even a tiny amount of weight becomes a HUGE issue at high rpms...

 

[mapbike]

i tink you hit the nail on the head here maniac, I. thinking thats it Delrin

Its white colored and it will outlast steel inareas that have another flat surface rubbing aganst it.

i may be able toget a few scrap pieces of it here where i work.

two very thin Delrin spacersare gonna weigh less that 2mm of extra steel i would think

 

[Rudz]

Delrin is very light and tough, I've been told it machines nice too.

 

[mapbike]

here's a good size to chuck up in the lathe and turn down to about 15-16mm in dia. after a 10mm hole has been bored in it.

it seems that on ebay you can get delrin rods in white or black, I assume its all the same, Im not sure but Im familiar with the white and I know how well it resist wear.

Im gonna order me a stick of it and see what I can get done with it when I have the time, I've planned to do this for a long time but just never done it, I have several quality 10x14x13 needle bearings and even though I think they work fine without a spacer I do think its better to keep them from floating back and forth on the rod end.

www.ebay.com/itm/Delrin-Acetal-Rod-...6&pid=100005&rk=1&rkt=6&sd=191505434341&rt=nc

 

[Skyking]

Any update on finding this motor in stock?

 

[Davezilla]

I hadn't really persued it lately due to lack of time, but I may look for one later on this fall when business slows down... That's when I have the most time for my projects, right now I'm lucky if I can get an hour a day in on the bike projects.