Crank Collar Pics

[GTR Shop]

Someone has hit the nail on the head in a prior post.

Other than FAILURE of the oil pump due to the drive (I'll post some pics up this arvo) you are tugging yourself with a big pump.RBs don't have oil supply problems to bearings etc PERIOD.. they have supply problems to pickup... ie toomuch oil everywhere BUT at the pickup.Once you have a collar, you still are not fixing supply to pickup orbs.. restrictors help.There is areason Rb25 turbo engines have a head drain...

Th biggest problem you have is wheelspin.An oil pump pumps Xml per revolution of the crank.. if you accelerate from 2000-8000rpm over 20 seconds you have moved the same amoutn of oil that if you have popped the clutch and hit 8krpm in 0.5 of a sec... the issue you now have is that over 20sec oil can drain back sufficiently.. over 0.5sec, it can't.The fix is to add volume out the side of the sump (I'll also post pics later)Therefore if you pump 2l of oil out of it in a split second, you don't have 2l left of your total 4, you have say 4l left of total 6, thus giving and oil lvl thats not 1/2 full, but 2/3 full.

[Yellow4g63]

nope, wrong again. i was responding to what Darius posted about bearings.

you talk as if a true oil pump solution isn't going to cost 3-4k, when in actuality you are too cheap to even buy forged pistons.

the reason other pumps are offered is because they have bigger gears and flow more. you will probably be worse off if you buy a nismo/jun/greddy/hks pump and throw it in with a good collar. it will flow a ton more and you'll probably end up sucking your pan dry or starving it. with your nismo pump, do you plan on putting in a head restrictor? adding external drains to the back of your head to the pan? enlarging your block oil drains? adding baffling to your pan? adding a swinging oil pickup? to most people, the answer to those is NO. maybe to you with the money saved on pistons the answer to all of those is yes.

most people want to have a realistic fix, and that is getting a new pump which is FINE (oem or n1) for sustained 8.5k rpms. its a good replacement because it is cost effective, it works, and it replaces a pump where the drive gear is probably already dented from years of driving on the short snout. the oem pumps just dont "blow up" for no reason. high mileage and unecessary wear from a bad drive causes it.

you talk as if you will have head work/cams to flow beyond 8.5k rpm too. but then again i forgot you'll have 700+ whp

Modified by RB_Dreamin at 1:49 PM 2/2/2007

Ok ok now tell him how you really feel lol.

[TriniGT]

Someone has hit the nail on the head in a prior post.

Other than FAILURE of the oil pump due to the drive (I'll post some pics up this arvo) you are tugging yourself with a big pump.RBs don't have oil supply problems to bearings etc PERIOD.. they have supply problems to pickup... ie toomuch oil everywhere BUT at the pickup.Once you have a collar, you still are not fixing supply to pickup orbs.. restrictors help.There is areason Rb25 turbo engines have a head drain...

Th biggest problem you have is wheelspin.An oil pump pumps Xml per revolution of the crank.. if you accelerate from 2000-8000rpm over 20 seconds you have moved the same amoutn of oil that if you have popped the clutch and hit 8krpm in 0.5 of a sec... the issue you now have is that over 20sec oil can drain back sufficiently.. over 0.5sec, it can't.The fix is to add volume out the side of the sump (I'll also post pics later)Therefore if you pump 2l of oil out of it in a split second, you don't have 2l left of your total 4, you have say 4l left of total 6, thus giving and oil lvl thats not 1/2 full, but 2/3 full.

Read on the Nissan Silvia Aussie site that there are things that need to be done to ensure that the oil does not drain from the sump:1. Install restrictors in the head, the RB26 already has one of the oil supplies blocked which is fine and all that needs to be done is to reduce the size of the other to restrict the flow to the head without starving the head. This is all dependent on the oil pump flow rate and whatever application you are using.2. Next up is to ensure that you are using an external oil cooler setup3. Another thing that helps is to have the head drilled and tapped by removing the upper welsh plug form the back of the head and tapping it and running a braided line directly to the sump, thus eliminating the return issues from the head4. Also what helps the oil return quickly form the head to the sump is to work the oil gallery areas with a die grinder so that the oil will flow quicker5. Lastly, the oil gallery can be widened slightly to allow more oil to return from the head to the sump.

This is not my findings but from someone that rebuilds engines for different applications and does this as a standard thing and never had a problem with oil starvation. Hope this helps and also some of this work is an engine out affair.

Also invest in an Accusump setup to keep the pressure at start up.
Modified by TriniGT at 4:19 AM 3/13/2007

[Darius]

I agree with most of this info except for the external oil cooler setup. I don't see how that is going to help oil drain back into the sump from your head better?

Your best setup is to do the oil passage restrictor and plug. Then, drill and tap the head for the external return line. I am assuming you run a stainless line under the exhaust manifold to the existing head oil return line? Where else have people run their external return line to? Tap the oil pan? Carl didn't you do this?

[Carl H]

adding in an external cooler isnt to help in draining the head but rather adding capacity to the system, a large cooler and associated plumbing can add as much as a quart to the system if not more...i added twin -6 return lines to the back of the head, i would have gone larger but space said no.its also easier to bring them back around the intake side of things instead of the exh mani where they will be subject to loads of heat, and hot oil is never good; after all what good is an oil cooler if all its doing is bringing temps back down to where it was before it flew by the exhaust mani?becareful with restrictors, afterall most people are still on hydro lifters and without enough oil they will starve and collapse.

[s14kouki]

http://www.racebread.com/files.htm

dl the GTR crank comparison, that should help you

[l0nestar]

When should you consider an oil cooler? (HP wise) or is it something that helps regardless of your HP levels / goals? Or possibly higher output has a higher yield / return?

[l0nestar]

Thanks for the link, but I got my crank done around Valentines day... I guess I should have posted that.. my bad.

[s14kouki]

well i guess its there for reference for others then. How much did it end up costing you?

[GTR Shop]

adding in an external cooler isnt to help in draining the head but rather adding capacity to the system, a large cooler and associated plumbing can add as much as a quart to the system if not more....

Which does NOTHING to help oiling issues other than temperature control.There is always that xtra oil in the cooler. If it end up in the sump as a help, you have a cooler full of air!

[l0nestar]

$100 for machine work AND collar AND installation AND micro-polish.
Modified by l0nestar at 1:40 PM 5/29/2008

[KlanjacOFF]

Could somone please upload a picture of the side profile (for thickness reference) of a crank-collar for me? Or just tell me how thick it is. Or conversely, how much material should I remove from the crank-shaft?

Thanks!

bumpin this old beast back up. Does anyone know, like he asked, how much material to remove from the crank? The machine shop I took mine to asked me this and I told them I didn't really know, maybe its in the directions, and that I would contact them with more info when I found out. Can't be that hard for them to screw it up, but I thought I would double check.

[DriftX]

I doubt 90% of the people on here even need a collared crank..

If the whole purpose of the crank fix and high volume pump is to make your bearings survive at 8k rpm +, why are people with stock pattern camshafts, stock cyl heads shifting that high? total nonsense.

Now for your guys running cammed motors with head work and a turbo that can actually flow air in the 8k rpm range, then oiling is an issue. why do you think people run dry sump setups? To allow the oil to move where it needs to go and prevent oil poolage in the head.. ect ect.

Now, if you need enough oil for your high rpm motor, then invest in a high volume pump, but make sure that oil gets back to the pan so it doesn't starve the pickup.

It would be safe to say that most people on this board that want <350whp don't even need the crank collar fix... just a new oem pump and run good oil in it to prevent damage. And of course learn to shift so you don't hit 9k rpm every now and then.

[KlanjacOFF]

Clearly you can't read, The collar will skip teeth for other reasons besides going past redline and having > 350hp

[Phat_Optimo]

Sucking the sump dry is pretty damn hard to do even with a oversize pump. To suck the pan dry we are taking about making a landspeed record passe. WOT for extended periods of time. I am sure many of you know of JUN's RB26 that held a landspeed record. These were their problems when hitting over 200 mph. lol

[240z4u]

Not fixing a known design DEFECT after spending thousands on a swap seems like false economy to me.

Evan

BTW, my drive was showing wear when I took it apart.