Oil Sample Analysis ANyone?

[Kyler]

Update. When I tore down the top end to check the valves, I found out the motor was a high-time motor and the cams had wear from the followers - that explains the high lead content.

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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.

Thoughts?

 

[Nessism]

That model engine has oiling system issues. Lots of engines died from spun crank/rod bearings and/or wiped out cams/rockers/head. Fix is reputed to be shimming the oil pressure relief spring by .060" to increase oil pressure. Might be a good idea, particularly since the oil analysis shows some bearing wear. I'd use a better oil too. The zinc and phosphorus count shows pretty low levels. Some high zinc Brad Penn or Valvoline Racing oil wouldn't hurt. I think those formulas have in the range of 1400 PPM of zinc and phosphorus.

 

[Kyler]

I've searched for info on how to "shimming the oil pressure relief spring by .060". Haven't found anything. Where is this and how do I shim it?

 

[Nessism]

Sorry, but I don't have much info. There was a thread a few years ago where a former dealer mechanic guy from AZ or NZ (can't remember) told us about the shimming trick. The relief spring is under the engine, in the sump. Maybe attached to the sump cover? I'm not an expert, just been here for a while and remember this. A number of guys have had their 2nd generation 750 engines blow up around here so I know it can happen. Personally, I'd shim that spring for sure.

 

[zuzu]

This thread might help.

http://www.thegsresources.com/_forum/showthread.php?t=181353

 

[Nessism]

This thread might help.

http://www.thegsresources.com/_forum/showthread.php?t=181353

Nice work!

 

[Kyler]

This thread might help.

http://www.thegsresources.com/_forum/showthread.php?t=181353

your Search Fu is STRONG!

 

[Kyler]

My last race is this weekend. After more research, my post-racing season to-do list includes shimming the oil pressure relief spring and adding a Canton Racing Accusump Oil Accumulator. Sounds like the perfect solution to the potential of oil loss in turns.

Canton Racing Accusumps are oil reservoirs that connect to the engine's oiling system. They are designed to collect pressurized oil from your engine and store it so that it may be discharged when oil pressure is low. Canton Racing Accusump oil accumulators deliver oil before starting to eliminate dry start scuffing (pre-oiling). They also discharge oil during low oil pressure surges to protect against engine damage during demanding racing conditions.

 

[GregT]

Ah,sidecar oiling....currently building a drysump setup for a yamaha FZR1000 motor in a chair....The owner of this one has three spare motors, all with big holes in them.

I've heard of the Accusump but never seen one used. Any feedback gratefully accepted.

Oil analysis - I can tell you, somewhat regretfully, OE Suzuki bearing shells are lead/bronze...

I wish you the very best of luck. Finish your season without a blowup and you should go buy Lotto tickets.

 

[Kyler]

Ah,sidecar oiling....currently building a drysump setup for a yamaha FZR1000 motor in a chair....The owner of this one has three spare motors, all with big holes in them.

I've heard of the Accusump but never seen one used. Any feedback gratefully accepted.

Oil analysis - I can tell you, somewhat regretfully, OE Suzuki bearing shells are lead/bronze...

I wish you the very best of luck. Finish your season without a blowup and you should go buy Lotto tickets.

I figured it was the bearings and I have a subscription to the Maryland lottery :-\\\... just in case

I have one more race this weekend. If it makes it through that, I'm a happy man. I added Liqui-Moly before the previous race. Am anxious to see what that oil sample looks like. I'm sampling after every race weekend.

And I'd like to see how you make a dry sump - might try that myself - post a thread please.

 

[GregT]

I'll put it in Other projects when i have a couple of pics.

Frankly, you'd be better off grafting in a roller bearing motor - either a 1000 or an 1100. They have oil pickup probs too in a chair but nowhere near as bad - and a roller bottom end will survive a momentary drop in pressure.

And the power....!!!

 

[Kyler]

I'll put it in Other projects when i have a couple of pics.

Frankly, you'd be better off grafting in a roller bearing motor - either a 1000 or an 1100. They have oil pickup probs too in a chair but nowhere near as bad - and a roller bottom end will survive a momentary drop in pressure.

And the power....!!!

an 1100 is in my near future. Right now I need to keep this baby alive until I have the cash to replace the whole motor. Grafting the motor in is likely to result in a lot of frame work. Which means even more $$$!

 

[Kyler]

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.

 

[Kyler]

Here's the last sample for this season. I'll change the oil and start over next year.

 

[subid]

Looks like Liqui Moly works, I think I'll try it

 

[Kyler]

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 too thoroughly.

Anyway, this is NOT a low time motor! The valve adjusters are worn at a slight angle and the cam has noticeable (but light) 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.

I've always been told these motors are rock solid and now I'm a believer!