Topic: Yet ANOTHER dyno result

[Sam Green Racing]

Not to derail this thread ........

You guys obviously dyno tested at the rear wheels..........

Dunlop recommends against using any tire on the street that has been used in dyno testing......

Qoute: Never put a tire in use that has been subjected to on-the-motorcycle dynamometer engine testing. This severe use of the tire may result in tread compound degradation and subsequent failure.

http://www.dunlopmotorcycle.com/infocenter_tiretips.asp?id=11#tip

Thoughts? Comments?

Tim, I have asked the question on a hyper sports bike forum.
It will be tomorrow night for answers as it's in the UK.

Sam.

OK guys, I asked on a UK forum, what bhp, last time on the dyno, do you still use the sam tyre, I got 12 replyes.

178 yes...439 yes...176 no...166 yes...179 yes...170 yes...157 yes...179 no...172 no...195 yes...225 no...240 yes.

From reading between the lines, it sounded like three of the no's was ready for a new tyre anyway.

The last no, the 225bhp one said, it was a heavy session and the tyre was trashed, but saying that I can wear a tyre out in a day on the strip he said.
He runs Shenkos.

I would think if the tyre was in reasonable condition at the time of the dyno runs, providing you don't do a big sesh with a very powerfull motor,
then you may get away with it.

Saying that, just look at the power from the second reply,...439bhp

Sam.

[HondaMan]

First thing: by a new oil pump. They wear pretty quickly into an 80% flow situation, like in 5k miles.

Mark,

Is this in reference to the stock oil pump? You mean it loses 20% flow rate in only 5K miles?

Yep, sure does. I think it's because of the metals used on the housing of the pump: they wear in real fast. Honda seemed to know this, leaving their bearing surface vs. "old" flow with reasonable numbers (heck, I got lots of miles out of mine!), but users need to consider 20w50 oil for longevity. Racing bikes often ran with 10w30 or 10w40 oil, so flow was critical and no one made hi-flow pumps that I know of, ever.

An easy check: get an extra cap for the oil journal (behind the cylinders, where the switch is) and tap in for an oil gauge (or stick one in where the switch goes). When the pump is fresh and new, it generates about 80 PSI cold or warmed up and running 3k RPM, dropping to about 50 PSI hot at idle (1100 RPM). After 5k-8k miles, they usually drop to about 35 PSI on hot idle, and the running PSI is down around 55-65. All these numbers refer to 10w40 Castrol oil, which I used as the "base reference" value for evaluations. Using 20w50 oil kicks everything up almost 10 PSI (80 is the bypass limit, so that seldom changes) across the ranges.

But, when going for many, many RPM, you need lots of oil.   

[MRieck]

Not to derail this thread ........

You guys obviously dyno tested at the rear wheels..........

Dunlop recommends against using any tire on the street that has been used in dyno testing......

Qoute: Never put a tire in use that has been subjected to on-the-motorcycle dynamometer engine testing. This severe use of the tire may result in tread compound degradation and subsequent failure.

http://www.dunlopmotorcycle.com/infocenter_tiretips.asp?id=11#tip

Thoughts? Comments?

Tim, I have asked the question on a hyper sports bike forum.
It will be tomorrow night for answers as it's in the UK.

Sam.

OK guys, I asked on a UK forum, what bhp, last time on the dyno, do you still use the sam tyre, I got 12 replyes.

178 yes...439 yes...176 no...166 yes...179 yes...170 yes...157 yes...179 no...172 no...195 yes...225 no...240 yes.

From reading between the lines, it sounded like three of the no's was ready for a new tyre anyway.

The last no, the 225bhp one said, it was a heavy session and the tyre was trashed, but saying that I can wear a tyre out in a day on the strip he said.
He runs Shenkos.

I would think if the tyre was in reasonable condition at the time of the dyno runs, providing you don't do a big sesh with a very powerfull motor,
then you may get away with it.

Saying that, just look at the power from the second reply,...439bhp

Sam.

A big # for sure Sam. I guess the only thing I'd add is let the tire cool down between monster pulls.

[Bob Wessner]

First thing: by a new oil pump. They wear pretty quickly into an 80% flow situation, like in 5k miles.

Mark,

Is this in reference to the stock oil pump? You mean it loses 20% flow rate in only 5K miles?

Yep, sure does. I think it's because of the metals used on the housing of the pump: they wear in real fast. Honda seemed to know this, leaving their bearing surface vs. "old" flow with reasonable numbers (heck, I got lots of miles out of mine!), but users need to consider 20w50 oil for longevity. Racing bikes often ran with 10w30 or 10w40 oil, so flow was critical and no one made hi-flow pumps that I know of, ever.

An easy check: get an extra cap for the oil journal (behind the cylinders, where the switch is) and tap in for an oil gauge (or stick one in where the switch goes). When the pump is fresh and new, it generates about 80 PSI cold or warmed up and running 3k RPM, dropping to about 50 PSI hot at idle (1100 RPM). After 5k-8k miles, they usually drop to about 35 PSI on hot idle, and the running PSI is down around 55-65. All these numbers refer to 10w40 Castrol oil, which I used as the "base reference" value for evaluations. Using 20w50 oil kicks everything up almost 10 PSI (80 is the bypass limit, so that seldom changes) across the ranges.

But, when going for many, many RPM, you need lots of oil.   

Jeez, now you have me nervous. My 750 Ko just rolled over 18K today. On a typical summer day, say low to mid 80's and the bike good and warm, if not hot, with 10w-40 Castrol, makes about 10 lbs. per 1000 rpm. You suggest 20w-50, but what about the affects of that during start-up during colder months?

[kghost]

Think I recall the bypass opening at 56 PSI

20W-50 acts thinner when Cold as its a multiviscosity.

[Jerry Rxman Griffin aka MuthaF'er]

I wonder if keeping it at 736cc, finding lighter pistons and such,increasing valve size, heavy duty rods, and good headwork could get you safely (and still be making power) at 12k rpm. Proper cam would be needed, and lots of low end would be gone, but you'd have more of a modern bike feel witht he engine (rev rev rev, basically).
Ah well, sounds expensive.

It was expensive circa 1974, and a little work.    

That's all it takes!   

I agree fully with Hondaman - That's all it takes !!!!

[Sam Green Racing]

 

Sam.

[Bob Wessner]

Think I recall the bypass opening at 56 PSI

20W-50 acts thinner when Cold as its a multiviscosity.

Yup, get the multiviscosity part (low number measured at 0^o, etc. I guess my question is, is 20W, which is obviously thicker than 10W at the low temp, thin enough for start-ups at say 35-40^o?

[kghost]

I should think so.

Beats straight 30 or 40 weight.

Give it enough time to warm up as always.

I always smoke a ciggarette while mine warms up....

[HondaMan]

Think I recall the bypass opening at 56 PSI

20W-50 acts thinner when Cold as its a multiviscosity.

Yup, get the multiviscosity part (low number measured at 0^o, etc. I guess my question is, is 20W, which is obviously thicker than 10W at the low temp, thin enough for start-ups at say 35-40^o?

(beginning of this thread...) You'd think I could spell "buy" buy now...   

The 10-40 and 20-50 numbers are really quite misunderstood: I was fortunate enough to have to undergo special training in the oilfield under Conoco's rein in the local refinery. I learned one particularly memorable item from their oil engineers: the lower number refers to the "remaining viscosity at rated operating temperature" and also "is the body weight of the oil". For example, the 10 in 10w40 means it is a 10 weight oil that has viscosity enhancers added that make it act like 40w oil at 220 degrees F. (for type SE oils at the time), which happens to correspond to the 10w viscosity at 32 degrees F. This is similar for all multi-viscosity oils.

I run 20w50 in mine until November, then run 10w50 until March or so. It is cold-blooded in cool weather, but the 750 is kind enough to let you know when it has oiled the top end: holding the engine at about 1500 RPM after starting, it will suddenly jump past 2000 RPM when the top end is oiled. It always has to run about 2 minutes if I am trying to run too heavy (20w50) in too cold weather, stumbling and sputtering if I'm pressing my luck (because I slept too late, now I'm running behind to join the mad highway rush....).

[Bob Wessner]

Thanks Mark. After reading this, I guess I have to ask, why not run 10-50 year round? Is the difference between 10 and 20 that critical during start-ups in the summer months?

[dusterdude]

bob,in the automotive world,10 psi per 1000 rpm`s is a damn good number.

[Bob Wessner]

That makes me feel better.

[HondaMan]

I prefer to run the 20-50 in the hotter weather because the oil has more body to it, and because sometimes I run a full fairing in hot weather: gotta help the poor engine out a little.

Plus, the 10-50 has been getting more difficult to find, lately.   

[Bob Wessner]

Plus, the 10-50 has been getting more difficult to find, lately.   

That was going to be my next question.  Can't say if I ever saw it around here.