fr0st

You need a motorbike to go with the car. If at least one of them is one the road then I'm a happy man Well I had 3 options - Stock/N1 oil pump Nitto oil pump + extended sump Dry Sump The stock and N1 pump sucks. It's pot luck whether they live 10+ years or crack within 2 weeks, I didn't want to risk forged rods and pistons on a $400 oil pump. The dry sump has every advantage over the Nitto + extended sump. It costs less, it's a more stable oil supply, I can rev higher and I get to learn about designing and fabricating a dry sump. Seemed like an easy decision for me. I don't see how it could be a waste of time, once it's setup it's done. Just stick to regular belt and oil changes it should look after itself and the motor. In a decent 4 stage setup the sump pressure is a fair bit lower than slightly negative. It's enough to eliminate the head -> sump oil flow issues and the majority of the vapour trail behind the crank. General opinion (from what I've read) is that dry sumped cars rev easier and have better fuel economy due to the lower windage losses. I haven't experienced this first hand as this is my first dry sumped car but I'm looking forward to finding out how the engine feels.

There is only one line under pressure, the rest are in vaccuum. The one pressure line only needs to take 150 psi max which isn't really that high for 750psi rated -12 hose. I'm taking plenty of pics during my build so I should be able to write it all up in a few weeks. If the engine runs for a week and dies then I'm willing to learn from my mistakes and rebuild.

As much as I want to support local business, these fittings are available at less than half the price on eBay. Considering the local stuff is likely to be made in China/Taiwan anyway the quality is exactly the same. The -12 fittings and hose for my 4 stage come to around $300, I have to get a 2 meter -16 made locally which is going to break my wallet. Overall my dry sump will probably end up costing around $1500 inc. pump, tank, fittings and hose. The sump I'm fabricating myself. It's not bad when you consider a Nitto pump + collar is around $1500 and you still need a high capacity sump to be completely safe.

I was just talking RB's. Dry sumping a FWD just seems... sad

From what I've learnt lately (I'm building a dry sump setup now) - The pump is normally run at half crank speed. This is because normally can only turn up to 5000-6000 rpm. The gears in a usual pump are much larger than the stock pump, so flow is not really much of an issue. You will normally get excess flow (which causes increased pressure) and the pressure regulator in the pump will bleed it back into the scavenge stages. Stages depends on what you are trying to achieve. More stages means more even oil collection accross the entire engine and more vaccum, it also means more complexity. You can run a two stage pump if you want but you may not achieve the vaccuum or oil pickup evenness you want (because you can't scavenge the head) It doesn't matter which side of the engine the pump is mounted.... it will turn the same direction regardless (clockwise) So yeh, it depends a lot on your wallet and what you're trying to do.

From that thread - RIPS has a good point here... even the stock external drain is in now way in a position where the oil can pool. If the standard block drains work well enough the head scavenge will get no oil and will eventually wear out the pump. What's everyones opinion on having 3x sump scavenge instead of 2x sump and 1x head? R33_racer, do you run a head scavenge?

Just 98 octane, it's a regular street car with a touch of insanity Fairly sure there are no E-85 pumps in Perth... I might have to steal some off Simon once the engine is run in and do a dual map.

Ordered the T67 for my dry sumped RB25/30. My dry sump pump also arrived today so I'm getting a bit happy in the pants thinking about how nuts the car will be when its done. Spec's so far are - RB25DET head RB30 block CP Pistons (8.5:1) Spool rods Raceline 4 stage dry sump pump Shortened sump and head scavenge Greddy inlet Reinforced/modded china manifold 44mm ext gate All showhorned into a little R32 GTS-T... should be mental

I was considering doing something custom but there isn't a whole lot of room between sump and girdle to put a proper scraper. The stock windage tray is probably about as good as you can get unless you have a custom girdle with an inbuild windage tray (if anyone wants to give me a massive piece of billet I'll happily CAD one up in Solidworks). I'll have another look at my block tonight but I'm fairly sure it won't work well unless you angle it between the block and girdle somehow. Something like this would be awesome - http://www.crank-scrapers.com/BMW-M30-DUAL-TEFLON-B.jpg Who wants to bank roll my CNC machine build?

I think you would find the catch can will fill up very fast. There is a heap of oil vapour in a wet sumped engine and the vacuum pump would pretty much suck it all in. It may be good for a few laps around a track but I think it might fill the can too quickly to be viable. Happy to be proven wrong though, have you got a link to a wet sumped car running a vac pump?

I was actually under the impression that were used with dry sumps for the sole purpose of pulling more vacuum than a regular dry sump setup (without having a 6 stage pump). I'm not sure how it would work in a wet sump since you are extracting air/oil vapour from the engine then piping it back into the sump, the net effect would be zero.

I've just found this old thread - http://www.gtr.co.uk/forum/121558-dry-sump-13.html The conclusion they came to is that the oil draining system in an RB is sufficient once you remove the positive crank pressure and windage by running a dry sump. In a wet sump the crank is normally positivly pressured whilst the head is low so the direction of airflow is to the top of the engine, stopping the oil from coming down into the sump. The reverse is true on a dry sump due to the scavenge pumps, asumming there is some sort of leak/breather in the head, the oil will flow freely or even sucked down into the sump using the stock drains. I'll be putting the 3rd scavenge on the stock head drain for good measure. If you take into account the above the oil level will probably not get high enough to even hit the return so it will usually just suck oil vapour. In the event of high speed corning or sustained high revs it's there as an overflow/safety measure. ... now I just need to finish building the f#$%ing thing

So you are isolating the oil return from the head/turbo to the block... why? It doesn't seem like a bad idea, but it also doesn't seem like it accomplishes anything? If you went this direction, I assume you would have to drain from the rear of the head all of the oil out as opposed to some oil through the stock external drain?

Hey all, I'm putting together a dry sump for my RB25/30 build and had a few questions for the more experience builders. At the moment I have a 4 stage pump and the plan is cut the stock sump off below the windage tray and weld it up to make it look like this - http://www.hioctanedirect.com/index.php?main_page=product_info&cPath=67_74&products_id=1828 The only mods I was going to make was using 2 scavange instead of three and to move the oil catch further to the drivers side of the engine. Does anyone have any other suggestions for the sump? The third scavenge is going to the head, is it best to use the stock oil drain on the side or block the front, remove the big welsh plug and drain from the back? The head will have VVT, front restrictor blocked and 1.5mm rear restrictor. The tank will be ~6.5 liters (1.5 gallons). Should be plenty overkill. If anyone has done this before that can drop some wisdom it would be most appeciated. Thanks -Matt

My head and block is getting machined up at the moment. Apparently my pistons were missing there spec sheet so I did a search and came up with 3 thou piston to bore... thought I just read another thread that said 3.5 thou is the standard. Should 3 thou be fine for CP flat tops? Cheers -Matt