JPN 750 Daytona Question

I'm doing a mockup before a teardown and refresh but have hit a snag on finding pics, prints or drawings for the oil cooler arrangement in the tail section of the 750 Daytona. Matt Spencer covered it pretty well in 2012 but alot of the photos were taken down
( photobucket?). So I was wondering if anyone has any knowledge of this cooler arrangement or could point me in the right direction?
I don't possess Pete Williams book "Designed to Race" and this is probably where I should start.
Any light shedding on this will be greatly appreciated !!

I attached a section from Matts post that mentions the cooler in the last sentence.

My tail section has the front air intakes along with the opening in the tail, but I'm not sure if there's supposed to be ducting under the seat for ram air or just free fllow.

Thanks in advance,

RatedSpeed said:

I'm doing a mockup before a teardown and refresh but have hit a snag on finding pics, prints or drawings for the oil cooler arrangement in the tail section of the 750 Daytona. Matt Spencer covered it pretty well in 2012 but alot of the photos were taken down
( photobucket?). So I was wondering if anyone has any knowledge of this cooler arrangement or could point me in the right direction?
I don't possess Pete Williams book "Designed to Race" and this is probably where I should start.
Any light shedding on this will be greatly appreciated !!

I attached a section from Matts post that mentions the cooler in the last sentence.

My tail section has the front air intakes along with the opening in the tail, but I'm not sure if there's supposed to be ducting under the seat for ram air or just free fllow.

Thanks in advance,View attachment 83094View attachment 83095View attachment 83096View attachment 83097View attachment 83098

Click to expand...

I suggest contacting Norman White in UK.

jan nelder said:

I suggest contacting Norman White in UK.

Click to expand...

Will do, Thanks !!
I was just reading up on the F750. Little confused here, The model bike that's mentioned as the 750 Daytona is actually the F750? And was Norman the design engineer or was it Pete Williams? I've read that Norman designed some replicas.
Just want to get my footing before I make contact with him and make a real ass of myself.
Thanks,
Mike

Can you please clarify what it is you’re trying to achieve? Are you trying to replicate the factory race bikes? Or are you building a special and are just interested in the oil cooler mounting?

I don’t think your yellow seat is off of a Norton is it? I don’t think those are air scoops in the front, they're just gaps. And those gaps will be largely obstructed when the rider is tucked in.

The blue and white bike in your picture isn’t a Commando frame at all, so anything done under the seat for a cooler etc isn’t likely to be of much use on a Commando frame.

I’m not being pernickety, I’m just trying to understand. And I think it would be wise to do a bit of research and have clarity before calling Norman, as it will be the best way of helping him to help you.

Norman was a race shop development engineer.

Fast Eddie said:

Can you please clarify what it is you’re trying to achieve? Are you trying to replicate the factory race bikes? Or are you building a special and are just interested in the oil cooler mounting?

I don’t think your yellow seat is off of a Norton is it? I don’t think those are air scoops in the front, they're just gaps. And those gaps will be largely obstructed when the rider is tucked in.

The blue and white bike in your picture isn’t a Commando frame at all, so anything done under the seat for a cooler etc isn’t likely to be of much use on a Commando frame.

I’m not being pernickety, I’m just trying to understand. And I think it would be wise to do a bit of research and have clarity before calling Norman, as it will be the best way of helping him to help you.

Norman was a race shop development engineer.

Norman White Norton Home Page

www.normanwhite.co.uk

Click to expand...

No, I'm not trying to replicate at all. I would like to install an oil cooler in the tail section and was hoping to see a sketch of an original .
Correct, I know the seat isn't from a commando and was just showing that the arrangement will have airflow and was looking to see if someone knew how the F750? Had the cooler arranged.
Coolers on the front don't work well without a thermostat and thought this was a great alternative.

RatedSpeed said:

No, I'm not trying to replicate at all. I would like to install an oil cooler in the tail section and was hoping to see a sketch of an original .
Correct, I know the seat isn't from a commando and was just showing that the arrangement will have airflow and was looking to see if someone knew how the F750? Had the cooler arranged.
Coolers on the front don't work well without a thermostat and thought this was a great alternative.

Click to expand...

If you aren't a member, you should join the JPN group on fecebook.


You will see LOTS of really nice stuff having to do with not just the factory JPN, but many race bikes from the factory effort as well as privateers and replica builders. Norman is a member there, as is Steven Croxford (Dave's son) and a couple of the P.Williams family.

TONS of great info and detail photos on many of the original race bikes from back in the heyday.

RatedSpeed said:

No, I'm not trying to replicate at all. I would like to install an oil cooler in the tail section and was hoping to see a sketch of an original .
Correct, I know the seat isn't from a commando and was just showing that the arrangement will have airflow and was looking to see if someone knew how the F750? Had the cooler arranged.
Coolers on the front don't work well without a thermostat and thought this was a great alternative.

Click to expand...

grandpaul said:

If you aren't a member, you should join the JPN group on fecebook.

Log into Facebook

Log into Facebook to start sharing and connecting with your friends, family, and people you know.

www.facebook.com

You will see LOTS of really nice stuff having to do with not just the factory JPN, but many race bikes from the factory effort as well as privateers and replica builders. Norman is a member there, as is Steven Croxford (Dave's son) and a couple of the P.Williams family.

TONS of great info and detail photos on many of the original race bikes from back in the heyday.

Click to expand...

Thanks grandpaul, that's exactly some of the leads I was hoping for.
Much appreciated !!

Mike

RatedSpeed said:

No, I'm not trying to replicate at all. I would like to install an oil cooler in the tail section and was hoping to see a sketch of an original .
Correct, I know the seat isn't from a commando and was just showing that the arrangement will have airflow and was looking to see if someone knew how the F750? Had the cooler arranged.
Coolers on the front don't work well without a thermostat and thought this was a great alternative.

Click to expand...

Gotcha!

In that case, especially given the generous size of your seat, you’ll have plenty of options mounting a cooler.

I‘d mount it vertically. To maximise its chance of catching any air flow. You can probably rig up a mount to clamp to the rear frame loop. Mount the cooler using exhaust bobins. If using the after market Mocal type, mount bobbins on the bottom and use some tube to clamp the top to the bottom.

But as I mentioned prior, you‘re not going to get much air flow under that seat, there will be air, so the cooler will still cool to an extent, but there’ll be very little meaningful air flow IMHO.

Also bear in mind that you still gotta plumb it in. I presume you’ll plumb into the return. The oil contained high up will all drain back when not running, some into the sump and some into the tank. Therefore I’d mount the cooler with the unions facing up, that way at least the cooler will stay full.

Its not a 5 minute job though. Have you satisfied yourself that you actually need one?

From what I remember reading in Motorcycle sport the cooler was an improvised impromptu thing fitted because of hot running at Daytona .

Fast Eddie said:

Gotcha!

In that case, especially given the generous size of your seat, you’ll have plenty of options mounting a cooler.

I‘d mount it vertically. To maximise its chance of catching any air flow. You can probably rig up a mount to clamp to the rear frame loop. Mount the cooler using exhaust bobins. If using the after market Mocal type, mount bobbins on the bottom and use some tube to clamp the top to the bottom.

But as I mentioned prior, you‘re not going to get much air flow under that seat, there will be air, so the cooler will still cool to an extent, but there’ll be very little meaningful air flow IMHO.

Also bear in mind that you still gotta plumb it in. I presume you’ll plumb into the return. The oil contained high up will all drain back when not running, some into the sump and some into the tank. Therefore I’d mount the cooler with the unions facing up, that way at least the cooler will stay full.

Its not a 5 minute job though. Have you satisfied yourself that you actually need one?

Click to expand...

Thanks for the heads up about drain back and yes I was planning on plumbing the return side ( pump return to cooler to filter to tank )
That's why I'm looking for a photo or prints of the original setup, to see how they got around any drainback issues.
I saw that Ken posted a photo out of Peter Williams book a while back that showed the bare frame and there wasn't any visible brackets or hangers for a cooler.

Mike

oldmikew said:

From what I remember reading in Motorcycle sport the cooler was an improvised impromptu thing fitted because of hot running at Daytona .

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From the limited research I've done it appears that only a few F750 have what looks to be the cooler in the tail, unless they relocated it, or was it not successful and eliminated, or did they just move on to the space frame design?

Mike

As was suggested already by oldmike, it may be that only a few bikes got coolers and that they weren’t exactly a ‘race shop’ fit or product.

The factory racers wouldn’t have worried about any drain back, after the race all oils would have been drained and binned anyway.

Plumbing wise, it was a different frame, and certainly had no air filter plate etc in the way, so their plumbing solution is unlikely to help you much IMHO.

Nigel i think it was an adhoc thing done at Daytona in the pits using an available cooler. What was subsequently done back at base and with a different frame would be surely better engineered and different.


Mike, personally I see nothing wrong with plumbing a cooler on the front frame rails. At least if a line blows off or leaks you will get some warning before the oil is pumped over the back wheel. it need not be huge, and if the cooleris higherthan the oiltank return outlet all that is needed is a junction and one tap for manual operation.When tap is open .oil will go straight to tank, when closed it will circulate through the cooler.

Thank you both for your input, it's much appreciated !!

Mike

Well, I had to give it a go and mock up a cooler.
Excuse the welds, my mig is sputtering on all setting below 11 and 11 is a bit hot.

Gee Willikers . Now that night be described as overkill .

Glassing in a flange / diaphram with cut out ( Easiest maybe cut apartical board , plastic , or waxed steel profiled sheet to position flat and true )
so finished theres a F'glass cooler mount or duct / mount . Thats LIGHT . Connect the cooler when fitting the seat . The nasty Falcon Ute has
plug on Q Disconect - you depress the fuel injection pressure & return lines plastic flange with a C spanner ends flank & the line pulls free , easy .
When you know how . ( A hacksaw almost spoilt it ) .

The kwikertsakis found the seat hump wasnt the ideal place for a few extra gallons , on the most efficent way to tyrn fuel into noise , the H2 / K2R .
High & behind the axle is destabiliseing. like a drunk wriggly pillion .

Just as well the tubes are only tacked !

A over center catch / clip or two & a few pins or grommets'd locate SECURELY .
Is the seat nose notched / Veed to sit down Ea Side of the 2 1/4 top toob .

The JPN has the top tube flat , under the brace at the front . Think thats the C'do's archilles heel , in some respects .
Front cutaway center in the F Glass base , use cardboard exact template , would give excellent lateral location .
Flanged Pins thru a new corner gusset with a C Clip or split pin'd have it all Q. D. .



Wot ee was supposed to do is press the left black & right white plastic flange inward , where they goon the tank tubes there . Instant pronto . after a squirt of C R C .



you liberate these of a Falcon too . ( ford ) ditch the rubber .
Theres a flat 3 mm flange in it . Bolts 5/16 .
One Ea Side downward thru base 'd nail it down to a small flat gusset .
Or Suchlike .

Hope youve chucked a humongous oil tank in there ?
3 Imp. Qt.s One Imp. OIL .One Gal. volume to de aerate .
Would keep it cool .
Commandos near boil the oil . The First Fastback scaled Aussie Legs .
Hence the revision & cover .
Or fit a first series tank & asbestos legs !

Soory About That . Supose it weighs bugger all if its 20 G tube .
------------------------------------------------------------------------------------
Front of seat should be inline to sub frame though .
Like sitting on the sub frame . Cut a V outof say a 10 in wide 1/8 ply plank & sit on that . Knees n all 'll get lower .

Your supposed to be aerodynamically Thus .

seated . These guys save a lot of money deleteing the motorcycle and using hills . The problem there is getting back up again . If you wanna go 155 your gunna have to get used to it .
All the little pices of percentages are cumulative . Disadvantage or advantageous . Elbows on knees ( Aerodynamics & control leverage ) Hands on bars , all tucked in . Chin on tank .
back a way . See the Olde Chin Pad Positions ! 2/3 aft . So locates rearend stop . Yours . The seat hump .
Williams whole ethos was low & flat . Minimise Frontal area . C D is % of frontal area so automatically total minimalised , having nothing sticking out / protruding .
Of course , if your eyes are transplated to the top of your head you then have better forward vission ! .

Like Father Like Son .


Of course if you go to fast and the wind blows your feet off the pegs , and the seat falls off , you might slide back and roll the throttle fully on , the next thing the wind whips your leathers off ,
if you cant afford good ones as all the moneys gone on the bike - your liable to go quite a way before you manadge to pull it all up . So useing a folded up plastic storm jacket as a seat on a
Commando has its drawbacks .

RatedSpeed said:

Well, I had to give it a go and mock up a cooler.
Excuse the welds, my mig is sputtering on all setting below 11 and 11 is a bit hot.View attachment 83683

Click to expand...

Maybe it’s just the photo, but to be honest I can’t figure out what all that steelwork is actually doing…?

I'm confused by your thinking. And you may be over thinking.

You don't want to mount the cooler at the front because you are concerned about airflow.

But so far you have it placed where there is pretty much no airflow in at all. I don't think you have factored in where you sit.

(Not trying to be a smart arse, because I think I have the same issue with one of my bikes)

You have also placed oil system plumbing right over the rear tyre!

I have two race bikes with oil tanks over the rear wheel, and honestly I don't like that location on either of them, but they don't offer much in the way of options due to the placement of other components.

Non-trivial stuff like carburettors, shock mounts, additional frame tubes etc.

One of them actually has the oil cooler mounted on the front frame tubes, and by the time the oil gets up to the cooler and then all the way back to the rear of the bike, the cooler has done it's job!

SteveA said:

I'm confused by your thinking. And you may be over thinking.

You don't want to mount the cooler at the front because you are concerned about airflow.

But so far you have it placed where there is pretty much no airflow in at all. I don't think you have factored in where you sit.

(Not trying to be a smart arse, because I think I have the same issue with one of my bikes)

You have also placed oil system plumbing right over the rear tyre!

I have two race bikes with oil tanks over the rear wheel, and honestly I don't like that location on either of them, but they don't offer much in the way of options due to the placement of other components.

Non-trivial stuff like carburettors, shock mounts, additional frame tubes etc.

One of them actually has the oil cooler mounted on the front frame tubes, and by the time the oil gets up to the cooler and then all the way back to the rear of the bike, the cooler has done it's job!

Click to expand...

Thanks for this info.
My thinking for this setup is from reading that commando engines don't appear to need alot of extra cooling, but some cannot hurt in traffic congested areas. I know from my other bikes that a front mounted cooler can definitely over cool in certain conditions, so moving the cooler under the seat should transfer heat through convection alone if no airflow is available, but I do think there should be some flow. But I could be way off base, wouldn't be the first time, but experimentation is what it's all about.
The plumbing is above the rear fender so that shouldn't be a issue.

Mike

Just when you think its all over . . .