Road Racing Sidecar - GS750

[HackNutz]

Background: this motor had 14,000 miles on it before I put it in my racing sidecar. At the time of this sample, it had 6.1 hours of race time. Sample was taken cold.

Motor is a 1980 GS750 (16-valve).

No engine work had been done other than making and installing an external oil cooler and filter. I run 87 octane pump gas.

 

[CATERHAM]

Do you have an oil pressure gauge installed?
Just wondering if you're getting any oil starvation during high G cornering?

 

[HackNutz]

Originally Posted By: CATERHAM
Do you have an oil pressure gauge installed?
Just wondering if you're getting any oil starvation during high G cornering?


Yes I do and I've not seen any low pressure. Pressure is normally at 70#. Honestly I'm looking forward and not at the gauge. I'll ask my passenger to check it this weekend at the next race.

 

[SlipperyPete]

What oil did you use?

 

[rrounds]

Originally Posted By: HackNutz
Originally Posted By: CATERHAM
Do you have an oil pressure gauge installed?
Just wondering if you're getting any oil starvation during high G cornering?


Yes I do and I've not seen any low pressure. Pressure is normally at 70#. Honestly I'm looking forward and not at the gauge. I'll ask my passenger to check it this weekend at the next race.

Put a low oil pressure light on your bike. Get a adjustable oil pressure sender so you can have the light come on at a higher pressure, like 45 lbs that way you know to cut back on the power if the light comes on. And I would/use a bright LED light that you can see even if your not looking right at it. I had one on my dragster, set at 50 lbs just so I could maybe save my engine if I ever did get low oil pressure(it never light up going down the track).

 

[HackNutz]

Originally Posted By: rrounds
Put a low oil pressure light on your bike. Get a adjustable oil pressure sender so you can have the light come on at a higher pressure, like 45 lbs that way you know to cut back on the power if the light comes on. And I would/use a bright LED light that you can see even if your not looking right at it. I had one on my dragster, set at 50 lbs just so I could maybe save my engine if I ever did get low oil pressure(it never light up going down the track).


I've been looking at a new set of gauges and one has a low pressure warning where the gauge all flashes. This is an appealing idea - thanks!

 

[HackNutz]

Oil sample #2

I'm running pump gas 87 octane with some Stabil and MMO added to the gas.

This is the sample where I added LiquiMoly before the race.

 

[HackNutz]

Here's the last sample of this race season.

 

[Clevy]

So if I'm reading this right all wear metals were lower after adding moly to the sump?
How much did you add and did you notice any effect in clutch behaviour.

 

[HackNutz]

I added moly as directed -- for motorcycles it is 20ml per liter of oil.

There was absolutely no change in clutch behavior.

Can't wait to see what the next sample reads. Unfortunately my racing season is over and that won't be until next spring.

 

[Clevy]

Originally Posted By: HackNutz
I added moly as directed -- for motorcycles it is 20ml per liter of oil.

There was absolutely no change in clutch behavior.

Can't wait to see what the next sample reads. Unfortunately my racing season is over and that won't be until next spring.

Was it MOS2. If so,and you couldn't make the clutch slip in a racing situation with mos2 in the sump then you've just taught me to concern myself far less with the whole moly/shared sump condition.
And it seems even at a low enough dose that clutch was unaffected the addition seemed to lessen wear metals,although not a staggering amount it seems to have still contributed to less wear.
Chalk another one up for liqui-moly. In an industry dominated with the term snake oil these guys show that it is possible to have integrity,and achieve what they claim.

 

[HackNutz]

Originally Posted By: Clevy
Was it MOS2. If so,and you couldn't make the clutch slip in a racing situation with mos2 in the sump then you've just taught me to concern myself far less with the whole moly/shared sump condition.
And it seems even at a low enough dose that clutch was unaffected the addition seemed to lessen wear metals,although not a staggering amount it seems to have still contributed to less wear.
Chalk another one up for liqui-moly. In an industry dominated with the term snake oil these guys show that it is possible to have integrity,and achieve what they claim.


I bought "Liqui Moly Racing Bike-Oil Additiv" and I wasn't gentle on the clutch. Keep in mind there are two (2) people on-board a racing sidecar. That clutch gets a workout starting with the all-out drag race at the start and then the usual plethora of up/down shifts throughout the race. The oil gets danged hot too even with my extra-large external oil cooler.

got it here

http://www.oilchangekits.com/additives/liqui-moly-racing-bike-additive.html

 

[sunruh]

does your crank sit in plain saddle bearings?

nice report.

wow a 10w40 that stayed in grade twice now.

so, what really changed from sample 1 where it wasnt in grade?
taking it easy on the motor i bet! HA HA HA!

i dont know if i would change anything, but now that the season is over....any plans for work on it? (new rings, cams, piston.....)

steve

 

[HackNutz]

Originally Posted By: sunruh
does your crank sit in plain saddle bearings?

nice report.

wow a 10w40 that stayed in grade twice now.

so, what really changed from sample 1 where it wasnt in grade?
taking it easy on the motor i bet! HA HA HA!

i dont know if i would change anything, but now that the season is over....any plans for work on it? (new rings, cams, piston.....)

steve


yup - this is a plain bearing bike. I changed oil after sample #1 and went to Suzuki Racing 10W-40 pure synthetic and added the Moly then.

For next year, I'm debating adding an oil pan baffle or an engine oil accumulator. This last sample report has me reconsidering. Other than that, I'll just check the valves, etc.

 

[HackNutz]

I finally got around to checking the valves. This motor was supposed to be a low-time motor when I installed it and I was in a hurry so I didn't check it out to thoroughly.

Anyway, this is NOT a low time motor! The valve adjusters are worn at a slight angle and the cam has noticeable grooves where the cam followers ride. That explains the metal in the oil analysis!

The good thing is the figgin' thing still runs like a scalded dog. So, we left everything as it was (the valves were close enough) and closed it back up. I'll run it as-is another season and start buying parts for my spare motor.