Non OEM rod kit for the 644cc?

Dr_C · Jun 20, 2011

bushmechanic said:
Dr-C what temperature do you think the rod gets to ?

I'm thinking Cromoly tube vertically, tack welded to a hardened steel big end and little end race, then run CF tow through the middle of the Cromoly tube and around each steel end, there are resins that can handle 250 deg C but I'm not sure of what "handle" means in practice

According to the "intelligentia" around here, the rod should not be able to get much higher temperature than the oil being continously sprayed on it. We agreed on the little end, that is closest to the heat source, might go up to max 150degC. If more accurate readings are required, a temperature measuring tape will be needed, fx (http://www.omega.de/produkt/t2/label-0.html).

bushmechanic · Jun 20, 2011

ah that's excellent! thanks for the tips Dr_C, I believe in the CF/steel rod and a stupidly lightweight crank with the funny mains, might take a few years to get into though

the "heavy" 105mm setup is working sensationally for what I do.

the katoom rfs builders are going for 1-2 thou preload at operating temp

I got my 35mm roller bearings from Max at alpha bearings, proper machined steel cage no silver plating over crappy sintered powdery junk, the oem silver plating is nice but not the powder construction roller cage

a possible source for liners is westwood in the UK, very nice quality

the Mrs's

yes with the introduction of currency and toys human paring becomes a very interesting symbiotic setup, but can't complain about mine I have a set of RXF forks on the way :cheers: :cheers:

bushmechanic · Jun 20, 2011

Dr-C I just saw your crank press pic

that's the "nice" 82mm crank? should be easy to lighten, get out the widow-maker

Dr_C · Jun 21, 2011

bushmechanic said:
I got my 35mm roller bearings from Max at alpha bearings, proper machined steel cage no silver plating over crappy sintered powdery junk, the oem silver plating is nice but not the powder construction roller cage

Sounds like serious work! I'll keep that in mind.

bushmechanic said:
a possible source for liners is westwood in the UK, very nice quality

We'll see. That will be after the season.

bushmechanic said:
the Mrs's yes with the introduction of currency and toys human paring becomes a very interesting symbiotic setup, but can't complain about mine I have a set of RXF forks on the way :cheers: :cheers:

Good on ya, mate!

bushmechanic said:
that's the "nice" 82mm crank? should be easy to lighten, get out the widow-maker

Oh, yes! Just push it through the crank til the lights in the ceiling starts blinking.

I have too much negative experience around balancing to make me want to open that door again. There are other things that I rather focus on a the moment.

The hydraulic press BTW: I built it based on the cylinder pushing out the nose wheel on the old Swedish fighter air craft "Viggen"... I'm not known for cutting corners, but NO, our son was NOT made standing in a canoe! :wink:

bushmechanic · Jun 22, 2011

:lol: :lol: :lol: :lol:

standing in a canoe sounds better than crouching in a bath

the press is very nice, and important to have some patriotic heritage in the workshop I have a rusty old harvester hand built in Mannum South Aust that I need to chop up and make a "knee" frame, the sides of the standard presses are annoying

balance factors gone wrong? was it the berg or the air cooled yamaha? I think about 0.6 to 0.62 is a nice one to aim for, mine is 0.58, a lighter crank should be nicer to the mains.. less spreading as rpm increases. what if you could keep the same balance factor but still manage to lighten the crank.....

bushmechanic · Jun 30, 2011

Take a look at the 106 mm pistons "Pistal" is making for the 1198 Ducati! Very nice work!

is this them Dr_C ? near 400gm do you think there is scope to mill it to near 330gm?

more pics here http://www.peakgarage.net/node/23

spanner · Jun 30, 2011

Hi bushie,

How much for one of those! Have given up hope of receiving my parts ( paid for) :angry:

cheers spanner

bushmechanic · Jun 30, 2011

Hi Spanner

no idea of the cost, My 105mm took 3 months out of the united kingdom, lucky i didn't need it in a hurry :lol:

I have been told CP is the company to contact if you want a high quality one off piston (i think min order is 2) although as Dr-C hints Wossner seem also do that kind of stuff as well

ElSnorro · Jun 30, 2011

bushmechanic said:
Hi Spanner

no idea of the cost, My 105mm took 3 months out of the united kingdom, lucky i didn't need it in a hurry :lol:

I have been told CP is the company to contact if you want a high quality one off piston (i think min order is 2) although as Dr-C hints Wossner seem also do that kind of stuff as well

Yes in his youtube video he says wossner made him a special piston on his order.

Dr_C · Jul 1, 2011

ElSnorro said:
Yes in his youtube video he says wossner made him a special piston on his order.

Yes he does, doesn't he? Wössner makes one-offs for a decent price <300€. Most vendors can offer custom pistons (Wahl, Mahle, Venolia, Omega, Arias and so on), but unfortunately Pistal has a minimum custom order quantity of 10 pieces...

I do not think you can mill off so much from an already skinny Pistal. You could end up with the same life length as an ELKO. :twisted:

The_Force · Jul 1, 2011

ELKO are they bad?

Dr_C · Jul 1, 2011

The versions (2004-) I know is very light weight, which will cost something in the other end. Maybe I'm unfair, but for Supermono use they will have to be replaced every 10-15 hours (take a peek in my gallery). I don't know their durability under normal conditions, but UHE is smacked with that experience.

bushmechanic · Jul 1, 2011

Yes he does, doesn't he?

I guess so, its a bit hard to follow sometimes for a slow widowmaker bearing bushmechanic :lol: the plasticene bits I understood after my kids explained it to me, im a bit slow,

elko about 220hrs no problems for me in stock 628 form 11.8:1 compression and 8500rpm max but it is good to know the limits of such a lightweight piston from your racing experiments Dr_C

FWIW force etal the STD berg wossner 100mm is about 282gm but low deck height and my elko weighed 272

the more I look at it it gets very difficult to keep lightweight parts with a long rod 35mm BE and stroke over 80mm together with a bore over 100mm. then if you go to a twin the total engine mass also goes up and becomes expensive and is no use for the nordic supermono cup :cry:

ElSnorro · Jul 3, 2011

Dr_C said:
The versions (2004-) I know is very light weight, which will cost something in the other end. Maybe I'm unfair, but for Supermono use they will have to be replaced every 10-15 hours (take a peek in my gallery). I don't know their durability under normal conditions, but UHE is smacked with that experience.

I am running fine at 25 hours Machined down (bit lower squish band) ELKO piston in my supermoto 550.

bushmechanic · Feb 21, 2014

bushmechanic said:
ah that's excellent! thanks for the tips Dr_C, I believe in the CF/steel rod and a stupidly lightweight crank with the funny mains, might take a few years to get into though the "heavy" 105mm setup is working sensationally for what I do.

the katoom rfs builders are going for 1-2 thou preload at operating temp

I got my 35mm roller bearings from Max at alpha bearings, proper machined steel cage no silver plating over crappy sintered powdery junk, the oem silver plating is nice but not the powder construction roller cage

a possible source for liners is westwood in the UK, very nice quality

the Mrs's yes with the introduction of currency and toys human paring becomes a very interesting symbiotic setup, but can't complain about mine I have a set of RXF forks on the way :cheers: :cheers:

just want to update what hapened with these steel caged big end bearings that I have written are "proper"

while the cage is indeed more robust it is heavier rougher and has twice the radial play of the OEM

the steel cage bored out the big end of my rod unevenly resulting in a roller failure at 50 hrs, I went back to the stock bearings.

you can see the lip from the uneven wear, measures 0.08mm deep so the rollers got overloaded in the centre

regarding the angular contact ball bearings I think the result will be a broken drive side crank case unless a steel sleeve is used to better distribute the axial load.

better explained here viewtopic.php?f=5&t=18085

Dr_C · Feb 23, 2014

I'm getting closer to ordering custom Carillio I-beam rods with c-c of 145mm and fitting a 35mm big end. So I will need good bearings and big end pins of a mtrl with as high e-modulus as possible. Any new thoughts on this?

bushmechanic · Feb 23, 2014

Dr_C said:
I'm getting closer to ordering custom Carillio I-beam rods with c-c of 145mm and fitting a 35mm big end. So I will need good bearings and big end pins of a mtrl with as high e-modulus as possible. Any new thoughts on this?

Spanner has a really good idea about the pin, ill let him explain it though

regarding the modulus and hardness.. I don't know if it helps but last time I used a PROX big end pin from the ktm530 which is a bit too long and has a smaller ID so it should be marginally stiffer ... it is also heavier

when I was trying to find out who could make me a good big end pin the only real info i got was "trick titanium will make you whatever you want ...for a price"

I know the jawa engines have 35mm big ends and you can buy various oversize "grinds" with bigger diameter ends to accommodate different press fit requirements in the crank halves

Taffy · Feb 23, 2014

Dr_C said:
I'm getting closer to ordering custom Carillio I-beam rods with c-c of 145mm and fitting a 35mm big end. So I will need good bearings and big end pins of a mtrl with as high e-modulus as possible. Any new thoughts on this?

well I think your settling for too short a rod but you know that Mats...

the 4 Jawa pins available are all smaller than the KTM pins from the off. even the 4th pin is like maybe at best 'the same'.

Taffy

spanner · Mar 14, 2014

Bushie wrote,

just want to update what hapened with these steel caged big end bearings that I have written are "proper"

while the cage is indeed more robust it is heavier rougher and has twice the radial play of the OEM

the steel cage bored out the big end of my rod unevenly resulting in a roller failure at 50 hrs, I went back to the stock bearings.

you can see the lip from the uneven wear, measures 0.08mm deep so the rollers got overloaded in the centre

Opened up a std 628 crank (10,000km 200h) today to find that the pin looks good, but the rod has grooves from where the cage has been rubbing.

It seems that the cage is the first thing to cause trouble.
Looks as if this OEM cage had no silver plating.
It is different to the the cage that came with OEM replacement rod/bearing/pin which has silver plating.
Might be an idea to change the cage and rollers earlier to get longer life from rod and pin.
prox sell a cage and rollers on there own, for the ktm but their rollers measure slightly bigger but that might be
handy if the pin and rod end are a little worn.

Cheers spanner

bushmechanic · Mar 15, 2014

also the oem cage contacts the id of the rod right across its surface so is less likely to make grooves.

the silver plating was introduced to our lineage of engines long ago by a husky engineer to extend the service life of the big end. the idea borrowed of course from 2 strokes

from Dave Hopkins

............... working on and as dealer for Huskys in the early 70s rod bearings seamed to run x number of hours, then fail, abt 1974 they came out with a new bearing and problems almost stopped, summer of 75 I was staying at the home of Ruben Hemin, their cheif of engineering and we got to talking about the bearing change, he explained two things that enlightened me;

1: THe magnets in the flywheel suck the rod to that side (left on the RFS, Right on the Husky) and the friction of rod against the crank is a part of the issue (note this has proven very tru more recently on the RFS quads which have bigger magnets and they have more rod issues of blueing on the magneto side, on quads I fix this by adding a copper washer and grinding 1mm off the magneto side of the crank), and

2: The centrifical force of the crank smining pushes the cage of the rod bearing out against the inside of the rod. So the cage rubbing the rod is wear much of the heat is made that ultimatly cooks the oil out that leads to failure.

So the change he made/added in '74 was to silver plate the cage. Silver being a dissimilar material cuases much less friction when it rubs the steel of the rod. So he said "when the silver wears off you have a 1973 bearing" (read a somewhat limited remaining life).

At that time I tlkded him and he talked the head of parts into making the bearing available, since I have talked to Travis and he has convinced one of the rod builders into making the bearings avaialbel (may have been before that??) Anyway I buy them from him and install in any crank I have apart, cheap extender of rod life!

i wonder if you could somehow inject oil through the rods ID so the cage could float like a plain bearing

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Non OEM rod kit for the 644cc?

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