Topic: Oil Cooler for CB750

[H2Eric]

After last years oil problem (i.e. lack of it) and destroying the cam, right cam tower and rockers, K9 is back on the streets. Thanks to Mike and Bill for the supply of replacement parts. So far all seems well.
The side panels have now been painted to match the tank. The rear wheel is due for replacement with a flanged alloy rim to match the front, but the next job is to fit an oil cooler, so if anybody has any advice I'm all ears. Some pics of your set up would be great. I have an oil cooler from off a CBR1000, which I have attempted to fit, but has no oil lines to it as I'm just playing around with various ideas. Anybody recommend a particular size of oil line -6 or -8 ?

Cheers
Eric

[NalleyRacing]

Yeah +1 on the oil lines..

I'm building a k2 with an oil cooler, and I have been wondering what to do for oil lines as well!

[bwaller]

I have felt like the poster boy for destroying oil coolers. I first used one from a CB650 Nighthawk, it sprung a leak and coated the rear tire. The second was an Earl's which started leaking on the dyno. (MikeR. claims these are now manufactured offshore??) I then bought a Setrab which in my opinion is the best yet. I ruined the first one in a crash but bought another exactly the same.


They have lots of models to choose from, this is a 13 row and -8 hose. I would think you shouldn't go with anything less than -8 on your engine.

[Jayhawk]

I strongly advise staying away from the Earl's brand coolers; "junk" would be a kind description:

http://forums.sohc4.net/index.php?topic=74547.msg1450486#msg1450486

It also took several months and a threatening letter before Earl's would warranty the part and reimburse me.

So far, the Setrab has been oil-tight.  I also suggest -08 lines and fittings:

http://forums.sohc4.net/index.php?topic=74547.msg1375113#msg1375113

[Retro Rocket]

Yeah +1 on the oil lines..

I'm building a k2 with an oil cooler, and I have been wondering what to do for oil lines as well!

Trey, have a close look at Erics engine mate, it's got one of Mike Riecks billet blocks...

[Jim F]

plus one of the Setrab
I have this for my turbo build

J

[Bill/BentON Racing]

K, -8 on hoses for sure. Glad the parts worked out. Yeh on Earls damn thing leaked from day one I think, and almost cost me running the semis or finals! Got an old Lockhart on there now!  Bill

[Sam Green Racing]

Same on mine, don't think it did 50 miles. 

[Tintop]

Think I'll hold onto the Lockhart that's on the shelf.

[PeWe]

My old oil cooler look like this. Typical for CB750?
Photos in my thread about running 230F on oil dipstick gauge
http://forums.sohc4.net/index.php?topic=136968.msg1543865#msg1543865

[Retro Rocket]

Think I'll hold onto the Lockhart that's on the shelf.

Yes, i have an NOS Lockhart as well....

[H2Eric]

Thanks for the response guys, that's a great help especially with the oil line size. It's -8 for me.
The oil take off plates I have are -6 though, but can be opened up. One of the plates has a pressure relief valve in it whilst the other just has a hole between the chambers, hmm.

Cheers
Eric

PS
Couldn't resist another pic of the engine. Droooooooooooool

[mrbreeze]

I'm running one of Terry's coolers and I'm going to start a thread about oil filter options. I need a more common filter, I'm running a 1390 Napa gold. This comes off of an early 70's Honda Civic 1.2 liter. They have to order them in at most of the auto parts stores like O'reilly's or Autozone. Question for you Eric. Why are your hoses coming out of the top of you cooler away from the filter instead of out the bottom towards the filter like mine, Seems like you would have to have some long cooler lines. I'm going to look into getting some chrome hard lines that come out of the cooler and 90 down to filter. Then I can run 2 short straight braided lines between filter and cooler.

[NalleyRacing]

So about the adapter for the filter housing.. What are the options for starting from scratch? If you only had the cooler but no lines or adapter?

Has anyone made, or converted one? Have any extras laying around perhaps?

+1 that block looks epic! I noticed it earlier when I first saw the pictures but didn't put 2&2 together.. What size is the motor?

[Terry in Australia]

This is a Lockhart "Upside Down" cooler on my bike, with one of my adapters on the engine. Cheers, Terry.

[H2Eric]

Question for you Eric. Why are your hoses coming out of the top of you cooler away from the filter instead of out the bottom towards the filter like mine, Seems like you would have to have some long cooler lines. I'm going to look into getting some chrome hard lines that come out of the cooler and 90 down to filter. Then I can run 2 short straight braided lines between filter and cooler.

Just using what I have lying around and trying to find the best option. The CBR1000 cooler you've seen on the bike was a cast off from my CR750 project, hence the modified inlet / outlet. I also have a similar if not identical cooler to the one that you have, which came off a Honda CB900 and I was considering using that instead with Goodridge lines going down between cylinders 2 and 3 to the take off plate behind the filter. Another option is to use the CBR1000 cooler with 180 degree fittings which would then take the oil lines down between cylinders 1 & 2 and 3 & 4 making the lines fairly short. Other coolers lying around include another CBR1000 with and extra row and a Mead Speed one. Decisions, decisions. I need a beer.

Eric

[mrbreeze]

Yeah.first 2 pics look like mine.

[Dion]

Hi Chaps, where do i find an adapter like the one in this pic? What oil filter is used?  Thanks

[Tintop]

Hi Chaps, where do i find an adapter like the one in this pic? What oil filter is used?  Thanks

Contact Terry in Oz ( http://forums.sohc4.net/index.php?action=profile;u=25 ) he can make you one.

[Terry in Australia]

Thanks Brian, but I'm out of the oil cooler business nowadays, I got tired of arguing their benefits with Lloyd, (Twotired) so now I only make them for myself. Cheers, Terry.

[H2Eric]

Hi Chaps, where do i find an adapter like the one in this pic? What oil filter is used?  Thanks

D and M Engineering here in the UK do one. You will find it in the CB750 section of their web site.
www.d-mengineering.co.uk

Eric

[PeWe]

CycleX sell an oil cooler kit.
http://www.cyclexchange.net/index%20pics/cafe%20oil%20cooler%20combo%201.JPG
http://www.cyclexchange.net/index%20pics/cafe%20oil%20cooler%20combo%202.JPG
http://www.cyclexchange.net/index%20pics/cafe%20oil%20cooler%20combo%203.JPG

[PeWe]

This is a Lockhart "Upside Down" cooler on my bike, with one of my adapters on the engine. Cheers, Terry.

Upside dow in Austraila, yes. Correct for me living on other side of the equator, your bike however, is upside down

A serious question regarding an oil cooler.
Which size is recommended? I have a 836 kit and got back the compression compared with my old pistons.
My engine reach up to 230F (105-110C) after 10km, ambient temp 60F (15C).  Heat back as well! I painted my cylinder and head with engine paint and that can add heat too. Before glass beaded surfaces.

I think that the small coolers that was standard on later bikes are not enough for my engine. They might do the same job as the external oil tank does on our SOHC CB750's.

I measured on my bike, the size that would fit fine is 235x100mm, 13 rows right over my exhaust, under the horns. 235mm is between the connecting pipes, total width >300mm. Too big.
115mm model is better in my view, total 210mm 13 or 16 rows
Setrab has one model 163mm cooling width, total 122mm, 13 or 16 rows

Other from here
http://www.demon-tweeks.co.uk/performance/oil-coolers-fittings/mocal-oil-coolers

http://www.rallynuts.com/oil-coolers/mocal-standard-aluminium-oil-coolers.html

Setrab might look better when it's black. Alu will blend in with the engine.....
Always money to spend on the bike
Setrab has a slim version too. http://www.demon-tweeks.co.uk/motorsport/oil-coolers-accessories/setrab-proline-engine-transmission-oil-coolers

[wiskey]

Here is an Earls Oil cooler on my 836, used the cycle x adapters.

[PeWe]

- Do you use a thermostat?
Or did you get high temperature direct due to the 836 High CR kit and less need for thermostat?  Like me..

I have searched more about this and found that a Setrab cooler with 7 rows Type 107 (210mm wide in total) is a common choice.
I have thoughts about a 10 row version Type 110, no thermostat. Thermostat should be in the adapter to avoid something hitting into the engine case, cylinder.