Oil cooler restrictor

[Jackzx10]

Hi all … anyone have dimensions for the oil cooler restrictor I  need to use behind the filter cover (fitting an oil cooler.. 1983 GS1100E).. want to make one

Thanks 
 

 

 

 

Edited December 12, 2025 by Jackzx10
Left out

[inazumarob]

People change the filter cover plate for a plate off the 1135 cc 84 on efe shape engine. The oil cooler line feeds are plugged with blanking bolts on the engine.

[jameskat]

This may help http://www.theflyingbanana.com/oil-cooler.htm

 

[HUM]

17 hours ago, jameskat said:

This may help http://www.theflyingbanana.com/oil-cooler.htm

 

Hello...

I also want to install the solution with the EFE oil cap...

But if you look at Flying Banana's setup, it seems that with the EFE cap, most of the oil goes through the oil cooler, and only a very small portion goes directly from the oil pump via the filter to the engine...

What happens if you have a thermostat installed in front of the oil cooler that closes when the oil is cold? Wouldn't the engine then get too little oil? Especially if the oil is thick...

Not much, or enough, can pass through the thin slot in the EFE cap?...

Or am I missing something?

 

 

With the EFE cap/cover... 

 

[Gixer1460]

The sump also has auto filter bypasses if oil is too thick / cold, so if the stat is closed, oil will still circulate via filter bypass - not ideal but designed. Not a fan of thermostats - something else to go wrong IMO. I think oversize coolers that require a thermostat just shows that the cooler is too big! Look at cooler size designed by Suzuki for the EFE which was adequate for everything below racing levels of heat . Big cooler = style over function springs to mind?

[Arttu]

There is no any bypass for the oil cooler, except that small hole/notch on the filter cover. If we are still talking about an EFE engine, or older GSX1100 with an EFE filter cover. So if you add a thermostat on the system it must have a bypass channel. 

Actually you could use a thermostat that just opens the bypass when the oil is too cold. The cooler circuit can stay open all the time. I have done it that way on my GSX and it seems to work pretty well.

[Duckndive]

if you want an EFE filter cover i should have one some ware 

[coombehouse]

I still use the original cover, I just blanked the hole in the crankcase completely with a machined plug & o ring so 100% of oil runs through the cooler. Never been a problem in 15 years. I only use a 7 row cooler as anything larger overcooled (in the UK though)

[Dezza]

I think Nick Pepper at SPS supplies 'EFE-style' filter plates for non-efe gsx1100s.

[HUM]

Hi everyone...

It's a GSX 1100E engine, only slightly modified.

Okay, if I understand correctly, then an oil cooler without a thermostat but with an EFE cover? ...

Longer warm-up time, sure.

By the way, the bike will only be ridden on public roads in good weather, 20°C and above.

I don't think an oil cooler is absolutely necessary to keep the engine healthy, but it does look cool.  

Question:

What hose diameters are appropriate to avoid reducing oil pressure or other problems? AN10? AN8? Or even thinner...?

Cheers,

Uli

[slayer61]

I think I put AN6 on mine 

[Jackzx10]

On 12/15/2025 at 12:11 PM, Duckndive said:

if you want an EFE filter cover i should have one some ware 

Let me know. Ta

[rodneya]

If you want a thermostat I would recommend using a takeoff from the oil pressure switch location below the cam chain tensioner. EFE filter covers are stupidly overpriced or you have to buy a billet one.

[Duckndive]

On 12/21/2025 at 11:34 PM, Jackzx10 said:

Let me know. Ta

Sorry for the delay found one

Hows £35...tracked post to a UK address 

Edited December 30, 2025 by Duckndive

[Suzukian]

Those bikes were very cold blooded from the factory.  It was recommended (I was working for a Suzuki dealership in those years) to take off with the Choke "On", and then turn to "Off' when the bike got warmer.  It was easy to feel in the throttle.  My '83 GS750ES is cold blooded but when up to temperature, even one 100 degree days, not a hint of overheating.