BenB
|
| posted on 5/12/06 at 04:27 PM |
|
|
Oil pump design
Is there a standard design for the flow of oil in an engine. My st1100 has two parts to the oil pump (main and scavange). Only one goes to the filter,
the other goes ? up to feed the crank and cams?? I'm assuming the oil from the filter comes back to the pump for the second pumping stage??!?!
I ask this because I'm planning a chopped sump and it may mean a DIY oil pump outer housing (I can probably keep the internals / pressure
release valve etc) just modify the position of a few things...
Cheers,
Ben
|
|
|
|
|
Nick Skidmore
|
| posted on 5/12/06 at 04:52 PM |
|
|
I'll think you'll find the oil pump may have two pressure stages, one for the engine components and another usually smaller to the oil
cooler and back.
This was how it was on a Yamaha Genesis I had.
It may be possible with a bit of blanking off and piercing of the plate between the two rotors to make a high capacity oil pump if you loose the oil
cooler.
scavange pumps are not usually found on bikes theyare usually wet sumped with oil sucked from the bottom of the sump by the pressure stages but some
bikes, apprillia and buell etc are dry sumped so I could be talking bull.
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
jack trolley
|
 posted on 5/12/06 at 04:57 PM |
|
|
Big Kawasakis have two pumps - one for the oil cooler.
|
|
|
BenB
|
| posted on 5/12/06 at 05:00 PM |
|
|
Aha! That could make sense in terms of the ST1100 has a water / oil cooler thingy next to the filter....
It's definately got two parts to the pump... I'm thinking about taking the oil lines externally through the side of the engine and using
an external pump. Almost like a dry sump setup 
|
|
|
NS Dev
|
| posted on 5/12/06 at 05:04 PM |
|
|
The Aprilia RSV (Rotax) engines I am using are similar but actually fully dry sumped with an external tank
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
|
|
|
BenB
|
| posted on 5/12/06 at 05:16 PM |
|
|
The advantage of using an external Pacet style pump is mainly that it would be relatively easy to change the pulley if I was over / under pressure
(I've got to have a pulley belt for the blower and VX alternator anyway)....
If I go for a Pacet pump internally but keep the standard drive pulley off the st1100 I'd be pretty buggered if I found the pump wasn't
developing the same amount of ooomph... I'm going to look at fabricating a new oil pump though- there's a bloke on Ebay selling half the
innerds of a ST1100. I don't want the rest of the stuff, but the oil pump could be handy for checking out how complicated the passageways are.
There's loads of spare room in the ST sump for alternative oil pipe routes etc so making a new one out of billet wouldn't be impossible as
I've got access to a mill, lathe, pillar drill etc... I'd then also be able to keep the st1100 rotors, pressure release valve etc, just
point the necessary bits in different directions... Essentially I should get the same oil pressure...
Some of the design features of the ST pump seem a little bit strange. Like outlet pipe comes out the bottom of the pump and then immediately does a
180 degree turn into the filter. Why not come out at the side (centrifugal pump after all so pressure equal all way round) and then just have one 90
degree turn).... Perhaps they're just strange design features, perhaps I'm missing something!!
|
|
|
