CB PERFORMANCE DRY SUMP PUMP.

[Piledriver]

Looking at the CB750 oil tank, I really love the idea and may pick one up to play with for the ~$10 bucks, but I would have to install a capacitive oil level sensor in the tank to make sure it had enough oil in it to allow starting the rig up. (possibly interlocked to the starter via a relay, with a warning light as well) another 3 quarts would be a good plan, looks like making it wider would be relatively easy given a welder.

Note motorcycles bank in turns, so while its inarguably "race proven", that's not with the same side loads/sloshing as in a car. It almost certainly need some baffling added, and probably best modded to be a take apart..

Thought: The previously mentioned electric scavenge pump could also be plumbed to pump out the case in the event of a full case/no oil in tank on startup issue. Could prove handy. They have also been used as manual transmission and rear end oil cooler pumps.

[RHough]

Looking at the CB750 oil tank, I really love the idea and may pick one up to play with for the ~$10 bucks, but I would have to install a capacitive oil level sensor in the tank to make sure it had enough oil in it to allow starting the rig up. (possibly interlocked to the starter via a relay, with a warning light as well) another 3 quarts would be a good plan, looks like making it wider would be relatively easy given a welder.

Note motorcycles bank in turns, so while its inarguably "race proven", that's not with the same side loads/sloshing as in a car. It almost certainly need some baffling added, and probably best modded to be a take apart..

Thought: The previously mentioned electric scavenge pump could also be plumbed to pump out the case in the event of a full case/no oil in tank on startup issue. Could prove handy. They have also been used as manual transmission and rear end oil cooler pumps.

Experience was a road racing sidecar, they don't lean. Never needed any baffles. Yes this is me as passenger. This rig was Kawasaki powered but I've added notes as to placement of the Honda powered rig's oil tank. First in the nose of the sidecar by the cooler, then above and behind the engine as on the stock bike. The first tank was internally baffled and, cut apart and re-baffled etc and it kept eating cranks. After the change to the smaller stock tank high above the pump there were no oil related failures. A one g load can be simulated by tilting the tank 45° from upright. The feed tube never uncovers. The only question I have is the relative flow requirements for the VW vs Honda. VW flows 4.2 gal/min over 3000 RPM I can't find a test of the Honda pump that made 50 psi OP and ran to 7,000. I know we never had symptoms of oil emulsion returning to the pump from the tank, but the Honda pump might be pumping much less than 4 gal/min.

We found a weak link we couldn't fix then switched to Kawasaki Z1 based engines. I can tell you that a 736cc Honda engine with a 1080cc Powerall kit will yank the front wheel of the ground into 2nd and also lift the cylinders off the case after less than two laps at Laguna ... we sold that one to a drag racer. 836cc was the sweet spot for displacement as long as the engine never saw 11,000 RPM for even a second. One side of the cam chain was a straight run from the cam sprocket to the crank. Somewhere between 10,500 and 11,000 there was a harmonic that started to weld the chain links together and I had to re-cam the engine to make power under 10,000 to keep the chain alive. Replacing the chain required a full split the cases tear down after any RPM excursion close to 11,000.

The Kawasaki 900 bored to 1015cc with a the stock sump and full roller bearing crank was bulletproof by comparison. I liked the SOHC Honda engine better but the Kawi was stupid reliable and made enough more power to overcome being much heavier.

Sidecar.jpg

[Piledriver]

"Passenger".... Cool, you're certifiable too!

Even the stock VW pumps are huge compared to most 1600ish cc engines.
width of the oil pump pressure stage gear/s would allow a comparison.
...
after quick Googling, looks like gerotor 12mm wide for pressure, 18 for scavenge. so probably about half the flow, maybe more as IIRC gerotors have a more swept area for a given width, I'd love to have a dual gerotor pump for a VW same size as the CB pump. Gerotor sucks better. Hmmm...

...looks like most Subarus use 10-12mm width gerotor pump in wet sump, don't know about diameter.
They run much tighter bearing clearances, sometimes very much to their detriment.

I'm leaning toward "keep the tank high and use a ball valve with an interlock" and use the largest possible suction tube/pickup in the engine for scavenge.

On a DD you could instead choose the "emergency scavenge pump" and level sensor interlock combo.
You could even tie in the interlock to fire up the scavenge pump at key on if low, would be automagic.

I suspect you cannot err making the tank to pump feed run too large, too short, or too straight.
That location is ~perfect even if the tank might be too small.
For what they cost, run two of them stacked

[FJCamper]

Hi Marc,

Your mentioning of what size AN oil lines to use triggered an important, practical point I would have left out.

We run 10-AN to and from our tanks. No problems so far. We find ourselves obliged to remove our stinger headers to loosen or tighten the AN hardware on the CB pump. No idea what trouble other exhaust or mufflers cause.

The SCAT headers, with an extended 4-into-1 collector, give us the most room to work. We might get enough wrench clearance with the SCAT headers to tighten a leaky fitting during a race.

FJC

[RHough]

The overpressure valve at the flywheel end is only open when pressure is >65psi, so there's no direct drainback to the sump with the engine off but the cooler is never isolated, nothing shuts off the "hot" passage from oil pump to cooler or the "cold" passage from cooler to main galleries, ever. You'd be surprised how long oil can stay in the cooler, too, with no "vacuum break" to admit air in...it will drain eventually, but that small amount of oil isn't going to be enough to cause hydraulic-locking of the bottom end. I wouldn't lose any sleep over that. It's that full dry-sump tank that could potentially drain through the pump and/or siphon through the cooler which makes an isolation valve wise. I once saw a team use a truck to attempt to push-start a car that had so much oil in the sump that the starter couldn't rotate the crank...the result was grenaded pistons and bent connecting rods, all because they couldn't be bothered to take a few minutes to drain the crankcase down by a couple of quarts.

I doubt that the flow rate to or from the AccuSump warrants 10AN plumbing, 8AN should be more than adequate - but if you've got the room for it, the larger hose/fittings can't hurt....except that generally, a larger-diameter line is going to be more prone to kinking than a smaller one at the same radius, so if space is tight and the hose needs to have some tight bends in it that's a liability of using bigger hose than needed.

I'm not worried about the amount of oil in the cooler being a problem. The eventual drain is what I think would break the siphon from the tank into the sump as long as the oil level in the tank is lower than the top of the cooler.

As I understand it the total oil volume of the system only effects time to get the oil up to temperature. So a smaller capacity system should allow the engine to warm up to operating temperature sooner. With about 3.5 quarts total in the old deep sump system I had no sign of overheating the oil, so I don't see a reason to increase the oil capacity when I dry sump it. 3 quarts in the tank + the filter, lines, and 2 quarts in the Accusump is more total oil than I have now. With only 3 quarts in the tank it is not enough to be a problem even if it does drain back into the engine. 3 quarts in the sump at cold start would be high enough to keep the pressure pump primed and the Accusump should provide backup starting oil until the scavenge pump refills the tank. Since the oil does not flow through the Accusump the engine only has to bring 3-4 quarts up to temp not the entire 6 quarts in the system.

Bottom line is that as long as the tank volume is not enough to hydro lock the lower end at startup I don't need to lose sleep over drain back except for the pressure pump sucking air from an empty tank and the Accusump should cover that.

At least that is my working theory at the moment.

Only question now is how much time it takes to get the air out of the oil. With a 3 quart tank and 4 gal/min flow the tank only has about 12 seconds to de-aerate the oil. A 6 quart tank would allow 24 seconds.

I'm thinking about a way to build a test rig on the bench to pump through the system an evaluate the tank's ability to remove air from the oil. I'm not real clear on the effect of feeding the pressure pump an emulsion. If it would show as a drop in oil pressure the accusump valve would open and that would be an indicator that there was still air in the oil coming out of the tank. Another option would be to rig a clear sections of hose in the system so I could see the difference between oil/air in and oil/air out. Once warm the flow could be observed in the lines to verify proper air removal. My recollection from using the Honda tank was the oil returning to the tank was not a milkshake type emulsion, but more of a wet fart mixture of oil and air bubbles. Oil stuck to the side of the tank and stayed there, air/oil mist got handled by the separator in the tank and I don't remember oil ever getting pumped out the vent. If the tank vent was tied to a case vacuum system it should speed the air extraction (I think). We never had a concern with it on the sidecar outfit.

[RHough]

"Passenger".... Cool, you're certifiable too!

...
I suspect you cannot err making the tank to pump feed run too large, too short, or too straight.
That location is ~perfect even if the tank might be too small.
For what they cost, run two of them stacked

I'm glad you agree. It looked like a natural to me. Added benefit is no oil lines outside the engine compartment unless there is a need to add a larger cooler someday.

I'm primarily an engine builder. I got tired of standing in the pits watching and listening to my babies on the track so I rode passenger for a few seasons. Right up until I was limiting lap times by being to big and too slow. We ran 141 MPH at Ontario Motor Speedway and the end of my career as passenger was a 100+ MPH walk down the track at Sears Point after just missing my handholds in the esses (turn 9). We raced a few more years until we ran out of money then went to Sports 2000 in SCCA. BTW that car had a dry sump system with a proper 3 stage pump that scavenged the sump and valve cover. Smallish tank mounted high above the pump inlet and never a problem. I did get known as the only builder to have a S2000 (Ford 2.0L) engine hand grenade ... I missed the fine print about only torquing rod bolts once ... you could see all the way through the block. After that our engines were only down 3-4 HP from the pro-builds. Car was 10 sec a lap faster at Sears than the Sidecar. The benefits of a working suspension, 4 tires, and good brakes made up for a much lower power/weight ratio,

Back to tanks ... and my parts list ... nice thing about short, simple, minimum fitting designs is they are cheaper too!

[Marc]

...as long as the tank volume is not enough to hydro lock the lower end at startup I don't need to lose sleep over drain back except for the pressure pump sucking air from an empty tank and the Accusump should cover that...

I would think that the 2 quarts in the Accusump should last long enough for some oil to make it to the tank. If it turns out that it doesn't, adding the electric scavenge pump would make it easy to recover. If you have a "universal" case with the blockoff flange for Type III oil-fill applications, that'd be a natural place to connect the suction line. If not, that location could be tapped for a ⅜NPT fitting and capped off so there'd be a spot to connect to if it was ever needed.

[RHough]

...as long as the tank volume is not enough to hydro lock the lower end at startup I don't need to lose sleep over drain back except for the pressure pump sucking air from an empty tank and the Accusump should cover that...

I would think that the 2 quarts in the Accusump should last long enough for some oil to make it to the tank. If it turns out that it doesn't, adding the electric scavenge pump would make it easy to recover. If you have a "universal" case with the blockoff flange for Type III oil-fill applications, that'd be a natural place to connect the suction line. If not, that location could be tapped for a ⅜NPT fitting and capped off so there'd be a spot to connect to if it was ever needed.

That's my plan. Plan B is to use a $29.95 12v fluid change pump from the dipstick tube to the tank. The dipstick tube is large enough and close enough to the bottom of the sump so that little pump would time the tank in seconds.

These are often on sale for cheap and pump about 3 quarts a min. http://www.northerntool.com/shop/tools/ ... _200596412

I think you can find just the motor and pump if you hunt around and not have to buy fittings and packaging you don't need.

The plate in the case is probably going to be my overfill return from the tank location. Honda wanted to keep the level in the tank below the oil separator so if you dump 4 quarts into the tank it drains back into the sump before it gets pumped out the vent.

[RHough]

Crank pulley round 2.

The CB 6" pulley #1953 uses a no machine work required sand seal and a spacer to fit an unmodified case.

The problem is my case is already at 2.250" for a sand seal. Does that mean I have to run one of the 5.25" pulleys? Like #1854 with the dry sump?

http://www.cbperformance.com/product-p/1854.htm

This does not appear to use a sand seal ...

I want to make this choice now so I can get a pulley from Mario that has a hidden crank trigger.

Help!?!

[Piledriver]

IIRC the BMD serp belt setup, crank pulley bolts onto a steel hub.
You can space that out. won't need much.
The only problem is serp belts dont slip.

[Marc]

Not all "machine-in" sand seals have the same O.D. ....2.250" and 2.260" are common. 1.770" is probably the most common nominal diameter for the pulley hub (accommodates ~1.750-1.780").
Armed with the O.D. & I.D. dimensions, odds are you could find a seal the correct width that'd fit nearly any combination but it might take some hunting. I'd look for one with a rubber periphery that's a snug fit in the case, but a steel-jacketed type can be glued in with RTV if that's all you can find.
If you start with a stock-style grooved hub it can be turned down to fit the seal, but raw aluminum doesn't have the greatest wear resistance. Many seal manufacturers offer "Speedi-Sleeves" (thin SS sleeves that can be pressed over worn hubs), it'd be better to have the hub cut to fit one of those which has the correct O.D. for a readily-available seal that fits your case.
http://www.oit.edu/docs/default-source/ ... f?sfvrsn=2

[RHough]

Not all "machine-in" sand seals have the same O.D. ....2.250" and 2.260" are common. 1.770" is probably the most common nominal diameter for the pulley hub (accommodates ~1.750-1.780").
Armed with the O.D. & I.D. dimensions, odds are you could find a seal the correct width that'd fit nearly any combination but it might take some hunting. I'd look for one with a rubber periphery that's a snug fit in the case, but a steel-jacketed type can be glued in with RTV if that's all you can find.
If you start with a stock-style grooved hub it can be turned down to fit the seal, but raw aluminum doesn't have the greatest wear resistance. Many seal manufacturers offer "Speedi-Sleeves" (thin SS sleeves that can be pressed over worn hubs), it'd be better to have the hub cut to fit one of those which has the correct O.D. for a readily-available seal that fits your case.
http://www.oit.edu/docs/default-source/ ... f?sfvrsn=2

I ordered the CB pump and the 6" pulley. I'll mock it up while I'm fussing with hose sizes to find a seal that will work. If I can't figure that my fall back is to use a smaller pulley. JayCee makes one that will work.

[RHough]

The electric scavenge pump has been discussed in the past, and has been used for awkward turbo installations...but simply not venting the 3/4 valve cover, (ex valve guide bleed by provides postitive pressure) or feeding it purge air with a check valve and pulling some case vacuum keeps the 3/4 rocker box clear of oil.

You can buy excellent quality low popoff pressure check valves from Swagelok or Parker in naval brass or SS down to 1/3 PSI, with viton seals.

However...I suspect the slow to-sump leakage path to be through the pump itself, the shaft bore between stages is not sealed, just a relatively tight tolerance hole><shaft clearance.

Wow Swagelok valves are pretty pricey! $75 each for brass 1/3 psig valves in brass. I though they might be a less expensive option to the Krankvent ... the Big Twin kit from ET is only $130 and includes two valves.

Great thread on case venting is here: http://www.shoptalkforums.com/viewtopic ... ase+vacuum

[Piledriver]

The electric scavenge pump for use in case of a full case is a much better plan, the in-line check valve won't help anyway.

[RHough]

The electric scavenge pump for use in case of a full case is a much better plan, the in-line check valve won't help anyway.

LOL ... I was thinking of using the check valves in a case vent system ... until I saw the cost.

Using a cheap 12v pump to clear the case after a drainback incident is the way to go. I think I've seen the guts for cheap ... making a tool run now.