Oil cooler project for '81 750e

[Prescot]

Looking for project outlines or links to parts for installing an oil cooler on a '81 750E.

Can just tap the filter cap cover and with a ss line to cooler then make a custom fitting that replaces the oil cap for the out line.?

Trouble is finding the parts oil cooler and lines and fittings?

Thanks in advance.

 

[Steve]

How "stock" is the engine? :-k

If you have a stock engine and are not racing, there is probably no need for a cooler, especially in your area.

Why do you feel the 'need' for a cooler?

.

 

[Guest]

You mean like this ( he says cryptically) ....... This may be available soon along with lines and oil cooler.

Its on an 82 750E - ignore the large hole and conrod making a rare guest appearance though

 

[Prescot]

Stock other than the exhaust and jetted carbs. Thought it might have been a little hot and with all the newer bikes being liquid or oil cooled or both it would be an upgrade?
Also seen some other bikes like the one here https://youtu.be/VovsTR_-S2w

 

[Cipher]

A cooler is nice insurance if you do a lot of city stop and go driving.
I wonder of anyone has real metrics on how hot the oil gets in those conditions.

I do know that in the height of summer my legs are in pain at a traffic light.

 

[Nessism]

The 2nd generation 750's had real issues with their oiling system. Spun rod bearings and trashed heads/rockers are quite common. Only mod I'd perform is shimming the pressure relief spring to increase oil pressure. Adding an oil cooler will cause a pressure drop in the system and that's the last thing you should be doing.

 

[Prescot]

Pretty much. But was just going to route the return back around the side to be sure it circulates if had to cut a new filter cover?

 

[Rob S.]

Adding an 1150 cooler and filter cover made a huge difference in my oil temp.

 

[Nessism]

Let me see if I have this right...

Some guy posts a photo of his engine with a rod through the side of the case AND a tapped oil filter cover, and you want to use this same setup? On an engine with known oiling system issues?

Also, realize that where you pick up the oil makes a big difference in how oil flows through the system. You need to grab the oil after it runs through the filter, not before. And simply grabbing oil flow off the filter cover and dumping it in the crankcase will reduce pressure and flow in the system and is NOT recommended.

 

[Guest]

I guess my inner English irony didn't come through ...... I will say that every 1000/1100 I've owned has responded well to an oil cooler .

on the 750 I wouldn't comment either way , however , they do not have the same reputation for durability and while cooler running oil is a good thing - low pressure isn't .

this particular example was massively over revved (while static) by home mechanic who obviously thought this was the answer to fouled carbs

other than that it was in great shape -

 

[posplayr]

Adding an 1150 cooler and filter cover made a huge difference in my oil temp.

Rob,
Although both are 16V and look similar, the oiling systems are very different.

 

[john wiggs]

Only mod I'd perform is shimming the pressure relief spring to increase oil pressure.
could you point me in the right direction to do this upgrade since i've already got my 81 1000 torn down? or should i even bother?

 

[Griffin]

Only mod I'd perform is shimming the pressure relief spring to increase oil pressure.
could you point me in the right direction to do this upgrade since i've already got my 81 1000 torn down? or should i even bother?

You don't need to do that on an 8 valve GS engine. If you do proper maintenance, they will run forever as is.

 

[ptegsotic]

Adding an 1150 cooler and filter cover made a huge difference in my oil temp.

No it didn't. (the Suzuki engineers did well in this regard ... you're trying to BS the wrong group of folks)

Adding an oil cooler to this engine has about as much effect as removing the centerstand to reduce weight on 700lbs rolling down the road!

(geez, next you'll be trying to tell us you hit a bump in the road and got all Evel Kinevel flying 250 feet in the air!! )

 

[GSCafe]

Okay, I'm curious. I was interested in the oil cooler thing for a while and finally decided it just doesn't matter on the 8v engine. Where is the benchmark at which an oil cooler might be a good idea? I'm rocking a 1979 GS550. I use Kerker pipes, shortie pods, retrofit electronic ignition with slight advance, 10% ethanol in my fuel (thanks a lot CA), and I twist it up close to 5 digit rpm in 100-110 degree temps as well as sitting at some streetlights. I'm still in the zone without an oil cooler, imo. Or would it make a difference for me? I think knowledge of the point at which the cooler becomes worth having might be useful to the OP and me. "Never" is an acceptable answer.

 

[GregT]

Okay, I'm curious. I was interested in the oil cooler thing for a while and finally decided it just doesn't matter on the 8v engine. Where is the benchmark at which an oil cooler might be a good idea? I'm rocking a 1979 GS550. I use Kerker pipes, shortie pods, retrofit electronic ignition with slight advance, 10% ethanol in my fuel (thanks a lot CA), and I twist it up close to 5 digit rpm in 100-110 degree temps as well as sitting at some streetlights. I'm still in the zone without an oil cooler, imo. Or would it make a difference for me? I think knowledge of the point at which the cooler becomes worth having might be useful to the OP and me. "Never" is an acceptable answer.

In my experience, the 550 has a very good fins to capacity ratio - ie it's well cooled as stock. The low pressure moderately high volume oiling system on the roller motors works well too. The ethanol - if it's jetted correctly - should actually help cooling also. So a probable never...

The 16V plain bearing 750 is just plain awkward. It suffered from low pressure as introduced - which was fixed to a certain extent in later versions. But oil gallery size and design are against it. Fitting a cooler has drawbacks incl as has been noted, pressure drop. The GSXR's did it right with a separate pump for the cooling circuit. I've noted here before that i've seen them used in speedway TQ's with a 3 stage external pump and cooler - and even with MUCH higher pressure than stock they've still done rod bearings...
Use them gently and change the oil frequently and they last acceptably.

 

[GSCafe]

In my experience, the 550 has a very good fins to capacity ratio - ie it's well cooled as stock. The low pressure moderately high volume oiling system on the roller motors works well too. The ethanol - if it's jetted correctly - should actually help cooling also. So a probable never...

The 16V plain bearing 750 is just plain awkward. It suffered from low pressure as introduced - which was fixed to a certain extent in later versions. But oil gallery size and design are against it. Fitting a cooler has drawbacks incl as has been noted, pressure drop. The GSXR's did it right with a separate pump for the cooling circuit. I've noted here before that i've seen them used in speedway TQ's with a 3 stage external pump and cooler - and even with MUCH higher pressure than stock they've still done rod bearings...
Use them gently and change the oil frequently and they last acceptably.

Thanks Greg. I know how to calculate for ethanol. (fun with turbo, but that is another story) It is just that it is *up to 10%* so sometimes more ethanol, sometimes less. Never mind that ethanol is not good for my rubber parts. I think it runs me lean sometimes. I try to stick to specific gas stations. I'm tracking with you. Probably no need for oil cooler without internal mods.

 

[Prescot]

Not exactly came across a video on youtube on gs750 and it looked like Suzuki techs working on a prototype or experimenting but in was all in Japanese so couldnt be sure.

looked like it ran from the filter cover>oil cooler> back to crank case.

Think will pass on this even though the oil cap gets hot was riding in stop and go beach traffic without any problems, may just think about changing the oil more often.

 

[dorkburger]

NJ beach traffic can be a beast... Sound like your best bet is avoid the cooler..... and stay off of Rt 35 /36.....