1986 VW Golf is now in my possession.

[Christ]

What's left after disassembling the booster and attempting to make some kind of adapter. The piece with the 4 holes in the lower left is part of the adapter I made and probably won't use. Its the back of the booster. The goldish metal thing is what the vacuum acts on. The spring stops the vacuum from activating the brakes alone.

Once an adapter is made, I'll have to shorten the force rod to make up the difference from removing the booster. Mount everything up, and it'll be ready to go....erm...STOP!





Before starting work on the booster, just to reference how dirty and cluttered the engine bay looks.

[roflwaffle]

Originally Posted by Christ

The oil pump is driven by the vacuum pump via the intermediate shaft, so my next goal is an electric drive for the oil pump, so I can delete both the balance shaft and oil pump drive altogether. Between the two, they can rob a significant chunk of energy.

Are you planning on going mild hybrid in the future? I would think going from the engine to the alt to the motor to the oil pump would use more energy than direct drive.

[Christ]

The idea is that the balance shaft uses up a bunch of power on its own, and THEN it drives the oil pump as well. Removing the balance shaft, which has no real use in this engine other than the oil pump/vacuum pump, means that there is no way to drive the oil pump.

The balance shaft has journal bearings as well, which will have to have their oil galleys tapped and plugged.

So the benefits are:

• Less bearing drag
• Less accessory load
• Less rotating mass
• Less timing belt stress (major plus)
  

Also, the electric oil pump setup gives specific control over oil pressure by increasing pump speed, and plugging those galleys means additional volume for the other bearings, and the turbo (coming soon).

I do plan on deleting the alt and running 2-4 batteries @24vdc with a DC/DC converter running 13.6vdc output.

That's the plan so far, anyway.

[roflwaffle]

If you're deleting the alt it may be worthwhile, trading ~35+c/kWh of useful diesel energy for ~15+c/kWh of useful electricity from the grid is a winning proposition if you can get storage costs at or below ~15c/kWh, but I don't think you'll be able to see the difference in bearing drag or rotating mass in terms of FE. I also think you should also wire it up to the IP solenoid, so if the electric pump/controller fail the fuel stop solenoid cuts off fuel to the engine.

[Christ]

In the 140hp 2.2 ecotec engine, the balance shaft is suspected to rob up to 12hp at 5krpm. Extrapolating downward, and assuming the drag increase is square to increase in speed, that would be about 3hp (2.2kw) at 2500rpm, no? I think I did that wrong anyway... Never was good with that stuff. However, when you've only got 52hp, each one, IMO, is worth fighting over.

12hp to a 140hp ecotec is only ~10 percent of the total package... To a 52hp motor, it's ~20 percent.. Def more substantial.

That means that at 5krpm, not that the engine can get there yet, I could be using 20% of the engine's potential _just to spin a shaft, which doesn't serve a valid function anyway!_

[roflwaffle]

According to who? I'm a bit wary of claims that seem to be a bit high. For instance in this thread Robert posted that at 1500rpm engine friction accounts for about 4hp in a baseline 1.8L Honda engine. That's everything moving, valvetrain/cams, pistons, the crank, plus the balance/intermediate shafts. It seems unlikely that removing one shaft would cut friction losses by three quarters. According to this the friction losses from the entire valvetrain are only about a quarter of the total losses. Realistically I figure a a balance shaft would be equivalent to a third of the valvetrain since the rockers are where most of the losses appear to be. That's what, about a sixteenth of the total engine friction, so a max of .25hp and probably a lot less?

Road load for a VW at 50mph is about 10hp, so you may go from 52mpg to 53.3mpg, if you're lucky. I think the oil pump otoh will net a more noticeable increase. What about getting some data with the oil pump out and the balance shaft still in, and then pull the balance shaft to see if you see anything? It's no A-B-A, but it's better than nothing.

[Christ]

I wasn't saying those were the figures to stand by. I was just trying to get an idea for what kind of loses are there.

The only test I can think of is to remove the timing belt and soon the intermediate shaft with the engine on a stand, using an electric motor and an ammeter to determine wattage required with and without the oil pump attached. Once I get the other motor on the stand to rebuild, that might be an option.

3600 rpm is a decent speedfor a test, because it would be in excess of 70mph road speed, and is likely the highest speed the engine will regularly see.

A motor that spins 3600 @ xVDC with an ammeter to read current draw should give enough basic data to form a conclusion, yes?

Test 1: Intermediate shaft and oil pump installed, sae30 oil.
Test 2: remove oil pump pickup, leave pump installed (bearings well be oiled fromm previous test.
Test 3: pre oil bearings, remove pump and spin balance shaft alone.

[Christ]

Estimating lower on the scale from my figures earlier, the sqrt of 3 is 1.72, at 2500/2=1250rpm.

So based on the information I read:
~12hp @ 5000
~3hp @ 2500
~1.72hp @1250
~1.31hp @ 625

My engine idles at 900.

Anyway, based on what you posted from Robert, (4hp @1500), its more like 50% than 75% of total friction. However, we're gleaning data from 3 different engines,.as well. No good way to tell for sure without actually testing.

I believe the balance shaft actually spins at twice the crank speed on some engines, as well, further skewering the possibility of getting usable data from guesses.

[jtbo]

Originally Posted by roflwaffle

Road load for a VW at 50mph is about 10hp, so you may go from 52mpg to 53.3mpg, if you're lucky. I think the oil pump otoh will net a more noticeable increase. What about getting some data with the oil pump out and the balance shaft still in, and then pull the balance shaft to see if you see anything? It's no A-B-A, but it's better than nothing.

That 10hp should be bit less with aeromods and tires inflated to higher pressures etc. I don't know how much it is possible to get off, but if it is possible to take 20% off, then there is again higher benefit when removing other losses.

Still rolling resistance and aero are perhaps those where most benefits can be sourced from. E-fan will help, but only tiny bit, still it is very good mod to do for vehicles which don't have E-fan already, it is around similar hp which was posted for balance shaft, every tiny bit counts of course, but is balance shaft needed because of reliability issues? I think that some engines have it because otherwise vibrations would cause some issues other than uncomfort.

[Christ]

E fan? How about "no fan"? Haven't had a coolant fan since I put the car on the road.