Topic: original honda sohc oil cooler set up?

[turboguzzi]

was a bit surprised to find this,

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310146542065&ssPageName=STRK:MEWAX:IT

anybody's got an idea if it'll work on a sohc?

seems to be from the CBX dohc 650/750 series motors, i.e. like those of mid eighties 650/750 nighthawk

diameter seems like that of a sohc

TG

[voxonda]

TG,

Can't see why it should not work, it is the same simple setup as I, and others produce.

Cheers, Rob

[turboguzzi]

rob

do you have any idea if the CBX type motors used the same oil filter cover as the sohc's?

[voxonda]

Looking at the adaptorplate I think they do, it even has casted piece to center the oilfilterhousing on top. Sorry, do not know how to describe it, hope you understand. Just googled a bit and yes they do have the same setup.

Cheers,

Rob

[wrenchmuch]

You'll need the longer filter housing bolt to use it on a sohc . Later F's had a cooler plate in between the case and filter cover (no lines or external cooler ) and used the longer bolt .

[voxonda]

+1

[turboguzzi]

You'll need the longer filter housing bolt to use it on a sohc . Later F's had a cooler plate in between the case and filter cover (no lines or external cooler ) and used the longer bolt .

kewl, will look it up on the parts list, the seller already told me he doesnt have the center bolt

[RRRToolSolutions]

That is the exact cooler I use on mine - I bought the 1983 650 version and had new, custom cloth-covered lines and fittings made for $25 to fit Terry's 750 adapter. Mine works like a charm.

Gordon

[Terry in Australia]

I've got a feeling that these adapters (which were used on several Honda's including late model SOHC 650's, apparently) have been tried by some folk here before, but there was a problem that they wouldn't work without some additional machining/fabrication?

Also, as Rob will attest, the purpose of the adapter is to block flow and redirect oil from the engine, up the hose to the cooler radiator, and back down into the engine via the filter. Because of this, the longer oil filter bolt from a CB750 F2/F3 on it's own won't do much, as it will allow oil to flow past straight into the filter, and not up the oil hose, into the cooler radiator. So while it might look like you've got an oil cooler on your bike, in truth, it's just a non-working replica of an oil cooler.

The radiators are good though, I've used a few over the years. Cheers, Terry.

[turboguzzi]

I've got a feeling that these adapters (which were used on several Honda's including late model SOHC 650's, apparently) have been tried by some folk here before, but there was a problem that they wouldn't work without some additional machining/fabrication?

Also, as Rob will attest, the purpose of the adapter is to block flow and redirect oil from the engine, up the hose to the cooler radiator, and back down into the engine via the filter. Because of this, the longer oil filter bolt from a CB750 F2/F3 on it's own won't do much, as it will allow oil to flow past straight into the filter, and not up the oil hose, into the cooler radiator. So while it might look like you've got an oil cooler on your bike, in truth, it's just a non-working replica of an oil cooler.

The radiators are good though, I've used a few over the years. Cheers, Terry.

good explanation as why this stock dohc 650 setup wont work with just a longer bolt, but then, how does it work on those nighthawks? what are we missing?

TG

[bryanj]

Some, and i cant remember which(750 twin cam maybe), had a short steel adaptor piece that held the sandwich plate(for want of a better description) to the crankcase then the filter bolt screwed into that.

Didnt the longer F2 bolt have a loose alloy "sleeve" on it?

[Terry in Australia]

good explanation as why this stock dohc 650 setup wont work with just a longer bolt, but then, how does it work on those nighthawks? what are we missing?

TG

It could be like Bryan suggests TG, there might be an adapter bolt that secures the adapter to the engine? Cheers, Terry.

Some, and i cant remember which(750 twin cam maybe), had a short steel adaptor piece that held the sandwich plate(for want of a better description) to the crankcase then the filter bolt screwed into that.

Didnt the longer F2 bolt have a loose alloy "sleeve" on it?

G'Day Bryan, no need for a sleeve mate, the (useless) F2 heatsink thingy didn't redirect oil anywhere, so it was just a loose fit between the engine case and the oil fiter housing. Cheers, Terry.

[City Boy]

Hi gang.An alloy sleeve was used in 350/400F filter housings to bridge the gap between the 750 type filter and the crankcase in the longer housing of the little 4's.I use the longer housing on my 750 and 1100F.It holds 140 ml.[4.5 oz.]extra of the nectar.Clearance may be an issue depending on the exhaust pipes used.      Rock On

[coyotecowboy]

That is the exact cooler I use on mine - I bought the 1983 650 version and had new, custom cloth-covered lines and fittings made for $25 to fit Terry's 750 adapter. Mine works like a charm.

Gordon

Ok, I gotta know, what is that filter housing off of?  I'm running into a problem with my cooler plate putting my filter housing out too far to clear my 4 into 1 header.  The fins hit, and I could chuck it up in the lathe and turn them down but it would be better yet to just buy one without the fins in the first place...

[cb650]

I dont think they are off a sohc 650.   Most of the nitehawk dohcs had them  550 650 700 ect.

[Ross Davis]

It is like the one off the 650 Nighthawk DOHC with HVAs.  The SOHC F2 750 had a spacer for a cooling fin it had and a longer oil filter bolt.  You can machine the lower housing it to fit and use the lines that are there.

[RRRToolSolutions]

That is a customm adapter Terry in Australia made for me. Give him a PM and see if he'll hook you up.

Best Regards,
Gordon

[Terry in Australia]

Ok, I gotta know, what is that filter housing off of?  I'm running into a problem with my cooler plate putting my filter housing out too far to clear my 4 into 1 header.  The fins hit, and I could chuck it up in the lathe and turn them down but it would be better yet to just buy one without the fins in the first place...

That is a custom adapter Terry in Australia made for me. Give him a PM and see if he'll hook you up.

Best Regards,
Gordon

Thanks Gordon, that's one of my adapters with a spin on filter. Cheers, Terry.

[coyotecowboy]

I see now.  I've already got the adapter plate and cooler, it just has a hollow bolt that threads into the block, then the oil filter housing fits onto that with the stock bolt.  It came off a K6 that hadn't run since about 78.  I should probably check the passages and make sure that the oil flow is directed through the plate then the cooler, and not just directly into the filter.

[RRRToolSolutions]

Terry sent me a special fitting that threads through the adapter and into the crankcase at 30 lbs. The exposed end fits the K&N chrome filter perfectly. I buy the filters through discount parts retailers for about $12 each. This set-up makes oil and filter changes a breeze and with the oil filter and cooler - almost a quart more Motul synthetic can circulate inside - a win-win for me and a bunch of expensive pieces inside.

Regards,
Gordon

[mick7504]

Here's an adaptor plate and bolt from the 70's.
Simple and efficient.
Easy enough to turn up in a lathe.

[turboguzzi]

hei mick

seen those plates, since the central wall has to be thick enough to take the pipe threads, it looks like it weights a ton. can you weight it?

I am trying to add as little weight as possible to my racer and since that honda adapter plate is cast, it has material only where needed = much lighter.

manged to find that the stock honda plate has a similar short fitting to hold the plate.

cheers

TG

[mick7504]

TG
The adaptor plate weighs 400gms and the bolt 80gms.
A friend uses a lot of Bronze Alloy and I think it should be lighter than than a cast plate while still maintaining strength.
Or maybe turn an adaptor plate from aluminium stock.
The plate could be trimmed a little shed some weight.
Mick
 

[Terry in Australia]

TG
The adaptor plate weighs 400gms and the bolt 80gms.
A friend uses a lot of Bronze Alloy and I think it should be lighter than than a cast plate while still maintaining strength.
Or maybe turn an adaptor plate from aluminium stock.
The plate could be trimmed a little shed some weight.
Mick
 

That adapter is the same as one type that I make, it is heavy compared to the lightweight cast potmetal "Lockhart" and "Derale" adapters of the era, but it could be lightened considerably as most of the 20mm (+/-) wall thickness could be milled out, either side of the oil passages.

I did it a few times on adapters that I made, but it's time consuming, and most of the 200-odd that I've sold on EBay and to members here have gone on road bikes, where weight wasn't an issue.

CB750 racers use a cooler with pipes coming from and returning to the engine and oil tank, the advantage being that the long hoses carry a fair bit of extra oil, so when you add a big cooler radiator as well, you're increasing the oil capacity by a litre or so. The racing coolers aren't all that practical on road bikes, where space for running the long hoses over the engine and under the tank is limited when shared with wiring looms, cables and other hardware. Cheers, Terry.

[turboguzzi]

hei terry

thanks for the info, in my case it would go on a 500, so no hose volume added.

question still remains, is that SC series adapter a bolt on on a 500?

Cheers

TG