ESE's works engine tuner

[Flettner]

In view of the above rule of thumb, most pumps are, Neil.

I'll have to upgrade the size pump I've got lined up for the FOS. Have not had much spare time recently to work on FOS cylinder but yesterday I had a fair crack at it. I don't think cooling will be an issue on this cylinder as I've got water cavities everywhere.
The FOS will run on the same cases as the sleeve cylinder and I expect that to need careful cooling control ( lots of cold water ).

[wobbly]

I was incredulous ( big word for the day ) when told by the Yamaha head of engine design at the time that I would need 1L / Min / hp to keep the 500 cool.
We had to get into deep discussion with the washing machine engineers at F&P to gain some insight into what was actually required to achieve that number.
In the end I finally got it right with a combination of impeller/scroll shape and speed, but it took near 5 Hp ( worked out from the test electric motor power consumption )
to squirt 160L/min across the BSL carpark.

Re the crank fits, for solid pins that dont crush then 0.035mm to 0.045mm, the hollow pins need a little more at 0.05 to 0.06 or even more with a big thru hole.
The bigger the pin the less is needed,but both should end up with around 5T press fit, if its not then you run the risk of the wheels moving out of true.
Much more than that with hollow pins and they will barrel where they enter the hole.

Re the deto in the sim.
I havnt seen a sim that was super sensitive to duct length - except I must say I often lengthen the C port duct to the same as the rest ,as this makes the sim run time much quicker.
It also looses power, so yes that would help to reduce deto as it also reduces the peak cylinder pressure.
As I have stated before reeds dont like big cases, and 1.3 to 1.35 seems to work on most - but the crappyer the duct geometry the 1.35 + area will make more power.
The RZ ducts are not too bad except in anything over 64mm bore.

[jasonu]

I know of the Lincon heads, we had to machine a few for Garth Hogan a year or so ago, Hogan race heads. You know, alloy with small fins and Hogan cast into them. Race, yer right.

Really????? Talk about cheesy.

[jasonu]

Frits would be horrified to know what Mike and I are currently using for water pumps on our MBs.

Surely you guys are still not using thermosyphon???

[F5 Dave]

No a tiny 12V Galley pump (think boat hand-basin taps) with small hose inlets. I've tried a larger brushless design but the vibration cracked it & I need to machine a lid for it. But either way it can maintain 60 degrees so its better than air cooling by a much larger margin than further improvements to cooling desirable as they may be. other priorities atm.

[Grumph]

Re the crank fits, for solid pins that dont crush then 0.035mm to 0.045mm, the hollow pins need a little more at 0.05 to 0.06 or even more with a big thru hole.
The bigger the pin the less is needed,but both should end up with around 5T press fit, if its not then you run the risk of the wheels moving out of true.
Much more than that with hollow pins and they will barrel where they enter the hole

If your hollow pin is not going to be as good a fit as you'd like, you can always use a very old trick - well Villiers used it...and press expander plugs into the open pin ends. After it's fitted up of course...

[wobbly]

Yamaha still do it on KT100 cranks as they are rebuilt continuously and pushing out the plugs helps to keep the fit in the wheels.
Makes assembly and truing easy as.

[peewee]

Re the crank fits, for solid pins that dont crush then 0.035mm to 0.045mm, the hollow pins need a little more at 0.05 to 0.06 or even more with a big thru hole.
The bigger the pin the less is needed,but both should end up with around 5T press fit, if its not then you run the risk of the wheels moving out of true.
Much more than that with hollow pins and they will barrel where they enter the hole.

.

seems like alot of people weld the pins to keep anything from moving. is it not a good idea ?

[Frits Overmars]

I was incredulous ( big word for the day ) when told by the Yamaha head of engine design at the time that I would need 1L / Min / hp to keep the 500 cool... In the end I finally got it right with a combination of impeller/scroll shape and speed, but it took near 5 Hp to squirt 160L/min across the BSL carpark.

Did you notice that the cooling water already heats up just from being pumped around, even when the engine is not firing?
With your 500cc you will have had the added challenge of fitting a cooler big enough to get rid of the engine heat without using ridiculously high water temperatures.
I remember that Cagiva deliberately sacrified engine power in exchange for less air resistance by reducing their radiator size.

[wobbly]

Its butchery really to weld crank pins, but it does exacerbate a multitude of problems.
In the RZ the press fit of the centre axle is suspect due to there being another big end press fitted into the same wheel.
So its all but impossible to keep an RZ straight if is seizes without welding the centre.

When I did the pump tests thats exactly what I found Frits, when ramming 160L/min thru a 22mm exit pipe from the pump
the water was already warm to the touch.

[jasonu]

seems like alot of people weld the pins to keep anything from moving. is it not a good idea ?

Not if you plan on rebuilding the crank in the future.

[adegnes]

No a tiny 12V Galley pump (think boat hand-basin taps) with small hose inlets. I've tried a larger brushless design but the vibration cracked it & I need to machine a lid for it. But either way it can maintain 60 degrees so its better than air cooling by a much larger margin than further improvements to cooling desirable as they may be. other priorities atm.

I use a aux coolant pump from a mercedes, works good. You find it on a lot of different cars.

[Flettner]

Here we go again, beginnings of the 100cc FOS.

[ken seeber]

When I did the pump tests thats exactly what I found Frits, when ramming 160L/min thru a 22mm exit pipe from the pump
the water was already warm to the touch.

Couldn't help myself. 5 hp = 4 kw @ 160 lit/min gives a temp rise of 0.36 deg C Wouldn't notice it over here cos it is now sitting on 39 deg, but for Frits 0.35 deg would be a pleasurable increase over the 5 deg daytime temps in the good (c)old Netherlands.

[41juergen]

Thanks' Wob, I use a 66mm bore and playing with the CC comp it shows a bit more power when going up to 1.4 (still with YAM1 as the next set of barrels then will get the A port over the B port setup). Is the 1.35 with the volume of the transfer ducts included?