cjernigan

iTrader: (13)

Even if the fuel pump could handle the viscosity i'm not so sure it could handle the heat considering our oil gets upward of 230* easily for people with no oil cooler. There are oil pumps on the market, looks like they're around $2-300 for a high flow one.

MX5-4me

Not sure that the cams or cam journals are designed to have that sort of side load.

patsmx5

iTrader: (16)

??? There would be no additional load put on the camshafts. The load would be on the cam gear, belt, crank pulley for timing belt, etc.

brgracer

iTrader: (14)

I can completely understand your desire to keep costs down, but as already said, you are adding a lot of complexity that has a lot of unknowns.

Also, the crank flex/vibration is harmful to more than just the OP, granted oil pump failure is dramatic, but there is also potential damage from hammering on bearings, loss of power, etc... So, while it is expensive, doesn't it make more sense to address the crank flex directly?

Again, since most failures happen at higher HP/rpm, I'm going to assume a built engine so why not address crank flex/vibration with things like balancing the entire rotating assembly, 01+ mbsp, ATI dampener, etc.. as there is benefit beyond just the OP. Yes, those things are pricey, but at this point (aka >300hp) you're pretty deep into it no?

MX5-4me

What is the Cam gear conencted to?

If you are driving a pulley off the cam gear you are also putting extra side load on the cam.

hackerchris

iTrader: (13)

This route would give me another reason to relocate my oil filter. If you develop it further I am definitely interested.

TurboTim

iTrader: (9)

What is this?

MX5-4me

http://members.aol.com/solomiata/MBSP.html

brgracer

iTrader: (14)

01 and up miatas had a stiffer main bearing support plate. Or you could buy the stiffer caps and plate from miataroadster for lots of ka-ching.

patsmx5

iTrader: (16)

I'm no ME, yet, but how it it going to put a side load on the cam? Sure, if I added a pulley the front of the camshaft, put a belt on it, and tightened the **** out of the belt, it would pull on the camshaft. However, I'm not going to do that.

Oh, oh, you said pulley. Yea, I never mentioned adding a pulley to the camshaft sprocket. Reread my post. I want to add a different bolt to the cam sprocket that has a drive shaft coming out of it to spin the OP.

My point was that crank flex is going to happen, no matter what. You can try to suppress it with the main bearing support girdle (How much is that?) or billet caps. Of course, 4 bolt caps would be a better solution but that would be really expensive if it's even possible.

Had our oil pump been given a drive shaft from the get go, nobody would ever talk about crank flex. IMO, trying to build a super strong oil pump that can deal with all the harmonics and side loads placed on it from the crankshaft is a band aid approach. An expensive harmonic balancer will help with the harmonics, but not with crank flex. Spending a lot of money on forged main bearing caps, a girdle, etc, is just a band aid approach again. The flex itself is not directly going to harm the engine. You can argue it's not good, yea, but how many engines die from crank flex? They die from crank flex breaking the susceptible oil pump gears. The best solution would be to move the OP gears away from the crankshaft.

If my setup worked out, it would require no machining, no OP gears (literally, none at all), no balancer or girdle or forged main bearing caps or anything like that. It would require the 19 dollar OP, the drive shaft to spin it, the brackets to fasten it to the front of the camshaft, an oil filter relocation kit, and a 1 way check valve going from the sump to the inlet of the oil pump. I dunno what the oil filter relocation kit cost, but it would be more than the stuff to adapt the oil pump to the engine.

Zabac

iTrader: (39)

I understand what you are saying, it still makes no sense to me though. If you added a bolt to the cam gear, you realize this bolt spins at 3.5-4K rpm? How balanced will it have to be, plus you have to mount the damn oil pump very firmly in place, it cannot move, i do not want to be at 18psi and 8K rpm when your bolt decides to snap in half due to torsional tension applied due to motor vibration and god knows what else. If anything, you have to drive the OP with the TB and your best bet would be to replace the tensioner pully with a pully to drive the OP.
But you still have crank flex, it will not brake the OP gears this time, but it still robs power and creates extra friction and creates extra heat, you still have not touched this problem. If you are running higher RPMs and boost, making tons of power, i certainly hope you pulled your motor and replaced your spagetthi rods and rings at the least, well and your valvetrain, why in the world would you not balance your rotating assembly as Tom mentions, why would you not eliminate the porblem at the source. Relocating your OP seems more of the bandaid solution here. We know what the problem is, why not fix it.
There is a reason GM reliablity has gone down, they are cutting cost, relocating an OP was cheaper than building a more balanced motor i guess.

patsmx5

iTrader: (16)

Ok, the bolt in the cam gear scenario is a bit oversimplified (as I stated earlier). It would obviously have to be a robust piece. The bolt would not have to be balanced. Why would it? Are you one of those people that thinks everything on earth has to be balanced? It will be fine. People bolt pulleys to their crankshafts to drive SC's, add hubs to add a toothed wheel for ignition input, change crank pulleys, harmonic balancers, etc, and they don't have the assembly balanced. It's close enough. You ever make a part on a lathe? **** turns out round when it's done. Would you take your motor to a shop and have the cams balanced with the cam gear pulleys attached? What if you swapped cam pulleys or cam pulley bolts, would you take it to the shop to have it rebalanced?

My opinion is crank flex is NOT A PROBLEM! It's not. It's only a problem if it breaks your susceptible oil pump gears. You can not eliminate crank flex. That's impossible. You can reduce it with the items I listed earlier, but you will never "eliminate" it.

When auto manufacturers made their drive shaft driven oil pumps for their new OHV V8's back in the early 50's (53 I think for chevy) they did it because it was simple and effective. It is isolated from crank flex, rod flex, and every other stress, strain, and torque the motor experiences. That way it will never be broken from crank flex causing the middle gear to twist inside where there's .002 clearance. Basically they were smart. Their solution was cheap, simple, and has proven reliable.

Think of it this way, what if they did want to build a more reliable oil pump then their drive shaft driven ones. Would they have put the gear on the crankshaft? What do you think? Would they have started building all their engines with 4 bolt mains, forged cranks, forged rods, and a crank driven oil pump? Would that really be any better (more reliable, use less power, cheaper, easier to service, etc)?

The tensioners are idler pulleys. They are smooth, not toothed. They would be insufficient to drive the pump. It will need to be driven with a toothed belt and gear. That's my idea.

Arkmage

iTrader: (3)

dodge common rail = bosch. bosch common rail = lift pump built into the high pressure pump. That link common rail. Given the year I think it is a P-pump.

That point aside, a diesel lift pump can handle the temperature, but not the flow or pressure. Their job is to eliminate vacuum on the input side of the high pressure pump. Vacuum on the inlet causes cavitation and significantly reduces pump life. They are only designed to supply 5-10 psi in MOST applications, and I don't recall any of them being designed for greater than 30 psi.

patsmx5

iTrader: (16)

Perhaps a high quality 12V electric motor could drive a chevy oil pump. That way the pump could stay low for instant priming. The big if is finding a good high quality reliable damn good 12V electric motor. Also, I'm unsure what HP motor I would need. I think something like this would work fine, but not 100% sure.

http://cgi.ebay.com/1-4-HP-12V-DC-MO...713.m153.l1262

Granted that's from eBay. I'm not finding any great motors online. However, we have a shop that builds electric motors at my home town so I may consult them and find out if they can order something or build me something that would suffice. Not sure how many HP your standard electric drill is but they will spin the fire out of a chevy 350 high volume oil pump.

Electric oil pump has it's appeal for sure. That removes all the other complications of mounting the pump high. Anyone that can find some good links to 12V DC motors post them up!

patsmx5

iTrader: (16)

Yea, I think the electric motor driving a chevy oil pump is going to be the winning combination. Just need a high quality 12V electric motor. I found the above motor for 70 through Harbor Freight ( I know, that says quality....). I want to find a nice one and go pickup a cheap chevy oil pump and do some testing. If the electric motor could turn the OP 1500 RPMs, that's the equivalent of the engine turning 3K. I think that would be plenty of oil. (dosn't the OP just bypass a lot of oil at higher RPMs anyway?) As mentioned earlier a simple pressure switch wired up to cut fuel or something would be the safety device in case of a motor failure. If it were cheap, I could put two motors and one pump or something like that so that if one motor fails, the other comes on. Would have to have a sprocket and belt to tie the two motor shafts together or something, but that wouldn't be too hard to do. Space could be a constraint. Dunno.

Anyone want to guess at what HP electric motor it would need? Most corded drills are 1/4 to 3/4 hp. I think a 1/2 hp would be plenty, but I'm not finding any 1/2 hp 12V motors. Still, if a 1/4 would do the job, then I'll go with that. Need to get a motor and start doing some testing.

Zabac

iTrader: (39)

If you are gonna drive the OP by an electric motor, you would need to figure out how to make it spin at variable speeds. Reason being is that you need lower pressure at low RPM and high pressure up at high RPM. You will have to be very careful to not "over-oil" the motor. I could be speaking way out my *** here, but if your pressure is too high in lower RPM would that not cause issues in the motor, maybe not since I do have pretty high pressure on cold starts. But I don't see how a constant oil pressure would be much good. This could easily be solved, you just nee to d some very complex math.
1. Figure out at what pressure the OEM pump puts out at what RPM
2. Figure out what pressure the chevy pump puts out at what RPM
3. then figure the RPMs the electric motor will put out at various currents
4. Figure out how to make the motor spin the chevy pump to produce desired pressure across various RPM of the Engine.
etc.
Im sure there is more to it, just ran out of steps as my bed is calling my name

Joe Perez

iTrader: (8)

Too complicated. There's no reason to artificially lower pressure when RPMs are low. At most, I might engineer it such that the pressure when cold does not exceed, say, 100 PSI. And even that might not be necessary- depends on whether the pump can out-flow the relief valve, I suppose. But 60 PSI at warm idle is not going to cause any problems.

Some vehicles use electric hydraulic pumps. Hybrids are one example- for the P/S system. Also, I think Fiat uses electric hydraulic pumps for the suspension system on some of their cars. You might be able to find a complete automotive-grade system that can simply be transplanted.

patsmx5

iTrader: (16)

Pretty sure it running at a constant PRESSURE is key. It's not going to over oil the engine. It will maintain a certain pressure via the relief valve. If pressure gets too high, the valve opens. I'll probably use a standard volume, standard pressure chevy pump. Also I don't see why the engine would need more oil at higher RPMs. I suppose it can squish out more oil from the bearings at higher loads or something, so maybe a bit more volume is needed to replenish it. Still, I think if that OP will turn 1500 RPMs, my motor will be happy no matter what.

Zabac

iTrader: (39)

So the Chevy OP has a relief valve to prevent it from haveing too high of a pressure?
Now it makes sense, I assumed that too much oil pressure at low engine speeds was a problem, but if it's not then you are ok i guess.

patsmx5

iTrader: (16)

Well, a search at Mcmasters shows a super high quality 1/4 hp 12V DC motor is 300 bucks. 1/2 HP is like 360 I think. Hopefully I can find a good one for much less. If I can find a high quality continuous duty motor for 100 or so, that would be great.

EDIT: Yea, all oil pumps have bypass valves to regulate oil pressure. I'm pretty sure that valve goes wide open at higher RPMs, but it can't bypass enough oil so pressure builds up.