45" Flattie Oil Bag

Do any of ya'll know of anyone who makes and/or sales oil bags to fit 45s ?

I would like to mount one next to the seat post and use a small 12 volt battery.

Any help will be appreciated.

Thanks!

Oil bags?? In my day they were called oil tanks? Do they make them out of rubber now?

do you intend to fit it in the "British" position and use the stock battery box? If so then have a trawl about for repro or original British ones http://www.btinternet.com/~hawkshaw.mot ... kpics.html

Tiger Cub or C15 ones are widely available and will fit most places. If you want a bit mnore capacity then M20 ones are being remade http://cgi.ebay.co.uk/BSA-NEW-M20-OIL-T ... 8452725396 but I'd suggest you are probably better off with one from a plunger frame.

go for tanks made for rigid frames if you intend to use a BSA or Matchless one ( Matchless/AJS ones look good )

do you intend to fit it in the "British" position and use the stock battery box? If so then have a trawl about for repro or original British ones http://www.btinternet.com/~hawkshaw.mot ... kpics.html

Tiger Cub or C15 ones are widely available and will fit most places. If you want a bit mnore capacity then M20 ones are being remade http://cgi.ebay.co.uk/BSA-NEW-M20-OIL-T ... 8452725396 but I'd suggest you are probably better off with one from a plunger frame.

go for tanks made for rigid frames if you intend to use a BSA or Matchless one ( Matchless/AJS ones look good )

Thanks, 45Brit.

you will need to look closely at what you are buying. Quite a few British tanks have a shape incoporating a 'return' in front of the seat post, to give extra capacity. This isn't a problem for bikes with a single-cylinder engine but there may be problems with clearance behind the rear cylinder on a 45.

The small, squarish tanks fitted to some Velocettes or Nortons are worth a look http://cgi.ebay.co.uk/1969-VELOCETTE-35 ... 519971fde0 http://cgi.ebay.co.uk/OIL-TANK-CAP-Nort ... 336659b338 although you may end up cutting off the filter sleeve protruding from the upper rear.

remember also that 45s have a right-side chain drive, so check the clearance around the banjo and spigots underneath.

I am also looking at ideas for making an oil tank behind the seat post for a 45 flathead engine in a British frame. Any advice if it is advisable to incorporate internal baffles and/or a design to reduce air bubbles from the return line entering back into the supply line?

I don't think the air entrapment is a real big issue. Harley just lets it "plop" onto the surface of the oil in the tank. In the BSA tanks, they shoot it on a side and let the bubbles pop in that manner. Or the M20 percolates it through the filter fitted in the tank.
DD

I don't see why you would have problems with identifying a suitable oil-tank for a 45 motor in a British frame. Assuming you are using a British transmission then just look for the oil-tank for that frame. The various angles and curves tend to specific to specific frames and it's easy to end up with one that doesn't look as though it belongs there, because it doesn't.

You will need to pay attention to the various clearances around the oil-lines and fittings, but that's just attention to detail.

One significant difference is that 45 motors are notably hotter-running than British ohv singles or twins. The 45-style twin tank has a very large surface area relative to volume and this aids cooling. It's probably desirable to add a separate filter to add volume, improve cooling and improve filtration. On a bike using a British-type oil-tank and battery-carrier there is probably room for this in the space behind the seat-post and in front of the rear mudguard, or you could hang it below the oil-tank and behind the gearbox.

I don't believe air entrainment is an issue.

The frame is a Triumph which has been hard tailed, and the gearbox is also Triumph. However I plan to build the oil tank from scratch and place it behind the seatpost, in front of rear mudguard and above gearbox. Thanks for all your help and advice

ok, if you have a frame like that ( which isn't really a "British" frame in any proper sense, since the rear section is an after-market part for the chopper enthusiast ) then your starting question about putting the oil tank "beside the seat post" is the wrong question.

An oil tank in the "British" position on a frame like that will just leave a big void behind it and look as though it came from a completely unrelated bike, which of course it does.

There are oil tanks for the behind-the-seat-post position, of various descriptions, in any after-market parts catalogue, mostly cylindrical ones, with and without battery trays. I had one kicking about my shed for a long while which was sort-of styled on the Big Twin horse-shoe type, with a crease in the front to accomodate the seat post... never looked right in my eyes and in the end I swapped it for something or other.

A WR Cast aluminum oil tank mounts under the seat like a Big Twin does.

since you have now decided to build from scratch , the answer is "whatever you think looks right and fits in the available space"

Sorry about the confusion 45Brit. The original poster was looking for a ready made one, but I hijacked his thread since it was about oil tanks for a 45 engine and I am thinking of making my own. I will follow your advice: whatever looks right and fits in the available space

Heres one I built from a scrap piece of 5" chrome plated truck exhaust some 5" round X 1" long alluminum and a ebay filler neck from a Enfield. The whole mess was about a hundred dollars. the 5" o-rings were damed expensive.
Dusty

[Pa]

That oil tank is a beauty Dusty ! Pa

I'd be interested to see more pics of that bike?

45Brit,
The whole build is at http://www.thechopperunderground.com in this years BBO under Dusty-Dave. I'm having some high resolution pictures taken next week for The Horse Backstreet Choppers.
Dusty