Oil hoses under the gearbox

fiatfan · Apr 15, 2020

There was a thread about this a while ago, I liked the idéa and thought I´d check how it would work on my build. I don´t understand how you can make it work? When the box is as far forward as possible there´s maybe 3/8" space between the junction block and the box, with the pipes removed. And even with the box moved back as much as possible there´s still not much room. As far as I know there´s only one type of junction block, even though the pipes do look a little different. Have you custom made new junction blocks?

cliffa · Apr 15, 2020

Hi fiatfan, I think this was the thread you refer to..

https://www.accessnorton.com/NortonCommando/oil-pipe-junction-block-upside-down.29330/

it looks as though the block was modified to achieve it.

I have to admit I prefer the look of the lines under the gearbox too, but haven’t done it myself (yet).

Steve Maney used to make a junction block..

http://www.stevemaney.com/products/Oil junction block.jpg

maybe you could look for one of those?

hope that helps,

cliffa.

Joachim · Apr 15, 2020

I started the other thread. I had to bend the pipes a bit so they go past the gearbox. It does look a lot closer in your photo. Mine is 850 MkII but I cant imagine it makes a difference.

robs ss · Apr 15, 2020

This may help some...
I made a new junction block for my 500 single (very similar to heavy twins) because I wanted the return line to go under the gearbox to an Oberg (v low pressure) filter behind the gearbox.
I don't have flash tools (lathes, mills etc) so with a lump of alloy, a drill press, files and taps made a block that standard fittings would screw into - and it works.
Anyway.. a picture is worth a thousand words - hope it helps someone!

mdt-son · Apr 16, 2020

Matchless G15's (and M33's, N15's) all had junction blocks tailored for oil lines below the gearbox. Please note there are pre-66 and post-66 versions, for 3-start and 6-start oil pumps and oilways, respectively. P11*s had the lines above the gearbox and there was just one version for the larger pipes.

RGM sells various junction blocks, so might be worthwile to have a look.

Spare part numbers:
Small bore junction block and pipes: 030300
Large bore junction block and pipes: 032046

-Knut

fredful · Apr 16, 2020

Hi Fiatfan, I made a few of these for myself and a mate so I ended up with a couple of spares, steel block with copper plated steel tube silver soldered together, tidies up the hoses and no issues at all. pm me if you want one. Fred.

ludwig · Apr 16, 2020

mdt-son said:
Matchless G15's (and M33's, N15's) all had junction blocks tailored for oil lines below the gearbox. .

-Knut

Yes, but they have vertical engines, which makes a big difference:

fiatfan:
your engine cradle bolts are too short!
These are critical bolts.
If they ever come loose, they will wallow out your engine cases..

Fast Eddie · Apr 16, 2020

ludwig said:
fiatfan:
your engine cradle bolts are too short!
These are critical bolts.
If they ever come loose, they will wallow out your engine cases..

Especially likely to happen if your cradle has been powder coated !

acadian · Apr 16, 2020

Looks like 2 washers under the nuts, eliminating one might let the bolt protrude from the lock nut

EstuaryBoy · Apr 16, 2020

If you have to brake quickly you'll rue the day your nuts were too far out!
(Apologies... too much time on my hands..)

mdt-son · Apr 16, 2020

ludwig said:
Yes, but they have vertical engines, which makes a big difference:

In terms of tube clearance - true, and am not saying the use of these junction blocks is a mere bolt-on issue.
Going by the second picture of posting #7, a special oil junction body is required.

-Knut

fiatfan · Apr 16, 2020

mdt-son said:
Matchless G15's (and M33's, N15's) all had junction blocks tailored for oil lines below the gearbox. Please note there are pre-66 and post-66 versions, for 3-start and 6-start oil pumps and oilways, respectively. P11*s had the lines above the gearbox and there was just one version for the larger pipes.

RGM sells various junction blocks, so might be worthwile to have a look.

Spare part numbers:
Small bore junction block and pipes: 030300
Large bore junction block and pipes: 032046

-Knut

As far as I can see the blocks for twins are the same, it´s the pipes that differ.

fiatfan · Apr 16, 2020

fredful said:
Hi Fiatfan, I made a few of these for myself and a mate so I ended up with a couple of spares, steel block with copper plated steel tube silver soldered together, tidies up the hoses and no issues at all. pm me if you want one. Fred.

Ok, interesting, would you by any chance have a picture? I´ve been leaning more and more at making a new block from alu or brass. Have a friend who has the necessary machines, and knows how to use them.

fiatfan · Apr 16, 2020

ludwig said:
Yes, but they have vertical engines, which makes a big difference:

fiatfan:
your engine cradle bolts are too short!
These are critical bolts.
If they ever come loose, they will wallow out your engine cases..

No worries Ludwig, Fast Eddie and EstuaryBoy, the whole engine/box/cradle package is just temporarly put together for the build, I´ve put a few extra washers on the bolts so I don´t waste the new lock nuts.....as Acadian sharply noted! But thanks anyway, and it´s a big difference with the engine standing straight up, good image!

fredful · Apr 16, 2020

fiatfan said:
As far as I can see the blocks for twins are the same, it´s the pipes that differ.

I can't seem to post photos, if you PM me your email address I will forward photos to you. Fred.

Oil hoses under the gearbox

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