k1100 build with external oil pump
Turbo Mini Forums

Hi,
so has any one tried to do a k1100 build with an external oil pump so you can loose the original cam/jack shaft?

stuart

Not meaning to dismiss it but Why? It's pretty easy to take a feed out of the sump plug and put it back in the blanking plate on the back of the box.. Or somthing simlar.. Then make a dummy oil pump.

The reason is I want to get rid of the jack/camshaft to reduce the rotational mass, it also means I can get rid of another pulley and oil seal on the engine.

The inertia of the shaft is bugger all. I there was zero friction in the bearings, imagine trying to spin the shaft be hand just be itself and also with the crank and flywheel attached. I asked a very similar question some months back and a big problem is the power needed to drive the pump. You need to find another way to drive the pump and that's electrically you'll still be loading the engine through the alternator, with hefty inefficiencies on top.

I thought about it, there are electric pumps what can do the job, but if that fails, your simply fucked!

Team Racing

I quite like having the extra pulley, as it helps shorten the run of the belt between the cam and crank pulleys, and helps keep the tension on it.

I have also thought about it in the past, but with the standard mini oil pump being so reliable, I didn't think the risk of an auxiliary pump worth while.

Edited by matty on 29th Sep, 2015.

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1/4mile in 13.2sec @ 111 terminal on 15psi

one reson i can think of is dry sump? but ether way i really dont think electric is the way if the factory pump was taken out id go with a gear style belt drive like on drag cars in witch case still have a pully and be just as much hp drain if not more

imo its best to use the tried and true way
once the factory cam is turned down the rotating mass is stuff all its the mass furthest out thats effecting rpm change not the inside mass thats a crummy way to explain it but it might get the idea across

I think you would be better doing some more development on a roller bearing supported jackshaft. That's my next project on mine.

What's wrong with oil film plain bearings on something that carries little load compared to what they use to? To justify the complexity of roller bearings or, doing away with it all together?

Is the extra effort and cost going T yield any worthwhile benefit?

Journal bearings cause much more drag especially considering the cam sized journals are now overkill for the jackshaft. If you can turn the lobes off then you could just as well turn the journals down to fit a bearing and also make sleeves to fit the bearings into the block.

I don't think the gains would be massive, but I don't think it would take much more effort either.

Why not just machine the jack cam stupidly think and do the jounerals on the bearings make them skinnier

For me it's 25% for drag reduction 25% weight loss and 50% somthing new to play with..

if you have the tools to turn the cam down and put roller bearings in then its simply a case of why not? whats to lose as Slater says
however if you had to pay someone to do it id put that money some place else