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Easiest way for you to understand is to take apart the old rb30 motor and look at it. You will notice that there is a considerable wear mark on the crank drive and also on the gear itself on the pump. Because the drive surface area is so small it tends to bite into the gear and places all drive pressure onto that small surface. By using the JUN OR OTHER collar you are increasing the drive surface area of the crank to the same or a similiar size as the gear in the oilpump. This spreads an even load of drive force across the pump gear as to not direct it into a small point where it will eventually crack and break through the gear and damage if not destroy your beautiful new engine.

The various pumps you can use have different size gears. The collars are made to suit typically a gtr pump 33 or onwards, N1 pumps(most typical) or any other aftermarket oil pump eg. Tomei, JUN, blah blah blah. Part of the cracking is not purely because of the crank gear drive, the pumps small gear which varies in size in different engine model oil pumps can also be held accountable.

The rb30 pumps are capable of failing as is any rb pump, i would think that typically old age is a big thing, and the fact that they just seem undersized for a performance application...especially if you compare them to an aftermarket or n1 pump.

Geez i hope all that crap made sense...

Easiest way for you to understand is to take apart the old rb30 motor and look at it. You will notice that there is a considerable wear mark on the crank drive and also on the gear itself on the pump. Because the drive surface area is so small it tends to bite into the gear and places all drive pressure onto that small surface. By using the JUN OR OTHER collar you are increasing the drive surface area of the crank to the same or a similiar size as the gear in the oilpump. This spreads an even load of drive force across the pump gear as to not direct it into a small point where it will eventually crack and break through the gear and damage if not destroy your beautiful new engine.

The various pumps you can use have different size gears. The collars are made to suit typically a gtr pump 33 or onwards, N1 pumps(most typical) or any other aftermarket oil pump eg. Tomei, JUN, blah blah blah. Part of the cracking is not purely because of the crank gear drive, the pumps small gear which varies in size in different engine model oil pumps can also be held accountable.

The rb30 pumps are capable of failing as is any rb pump, i would think that typically old age is a big thing, and the fact that they just seem undersized for a performance application...especially if you compare them to an aftermarket or n1 pump.

Geez i hope all that crap made sense...

works for me

Man im glad someone understood it then.

I think with all this information and still uncertainty with certain areas regarding the build im sure more info could be added to the guide that could clarify certain things for people, because it seems everyone doesnt wanna read through all the pages anymore. Dunno why? I did it. Took me the better part of a week after work every night.

The RB30 pumps have a small engagement gear that is roughly the same size as the small crank drive, and interesting enough they tend not to have the issues we do.

I've attached a pic of the rb30 oil pump gears, AND the rb25det oil pump gears. Take note of the smaller inner gears lug that engages with the crank. RB30 small.. RB25 BIG and wide. :D

From what I've seen the rb20 pump is a bee's dick smaller in width to the rb25det pump. It was interesting to note the rb25det pump internal gears appeared the same as a standard r32 rb26det oil pump. Its likely the only difference between the rb25det pump and the rb26dett is the pressure.

I've updated the crank section of the guide a little so its easier to understand.

The R32 RB20/25/26 and series 1 R33 RB25DET crank to oil pump engagement does not engage the full length of the oil pumps internal gear. Think of it as placing pressure on your rib cage with a single finger then doing the same with your palm. With a greater surface area wear on the surface where the two gears engage is reduced.

It’s a well known issue, It is a very wise move to have a full length crank collar installed, the item costs approximately $100 or $350 installed from http://www.proengines.com.au.

A JUN crank collar can also be purchased from Japan.

Both crank collars are universal and suit ALL oil pumps. All RB twin cam oil pumps will benefit with the use of a full length oil pump drive collar.

post-382-1158061629.jpg

post-382-1158061636.jpg

my rb30 crank has the wear pattern like right hand crank in this pic

http://www.skylinesaustralia.com/forums/in...st&id=55657

so looks like the wear is the same with rb30 oil pump as well, regardless of the smaller gear

I originally slapped together (literally) the rb30det guide without too much detail as it was my intention not to provide everything on a silver platter.

I figured if one doesn't understand how (for example please don't be offended) the oil pump engages with a crank then really they simply don't need to know as their level of knowledge won't allow them to build up a motor anyway. All they really need to know is its best to use a full length crank collar and that’s it. Hand the guide to an engine builder and no doubt there will be very little if any questions.

Some times the best way to understand is to grab an engine manual and rip the rb30 engine apart yourself. Next thing you know you will be thinking.. bah I could have some one do the machining on the block and assemble the sucker myself.

I'm hoping Christian will get this SAU wiki sorted and I will drop the rb30det guide in to that.

At that time I will also include information on whats required for the rb30 GTR/GTS4 combo.

my rb30 crank has the wear pattern like right hand crank in this pic

http://www.skylinesaustralia.com/forums/in...st&id=55657

so looks like the wear is the same with rb30 oil pump as well, regardless of the smaller gear

erm... There is no wear there. :D

Thats the engagement lug that slides in and engages with the oil pumps internal gear.

http://www.skylinesaustralia.com/forums/in...st&id=55680

As you can see by the above pic there is a flat section in the inner section of the oil pumps inside gear, that engages with the flat section on the crank that provides drive to the oil pump so that it spins around and pumps oil.

erm... There is no wear there. :D

Thats the engagement lug.

you see the small square that is darker on the right hand side of the engagement surface ??

mine is about that size and is about 20 thou deep ...

Ahh yeh thats good. Yes i know where your coming from cubes with that point. I guess i was thinking it was more a way of educating people on here about it so they could give it ago themselves or else they wont learn at all but i understand that a certain percentage of people just dont have any mechanical feel at all and couldnt do it even if they half grasped the concept.

I think i just want to overpopulate every nissan with a rb30 hybrid, get more combinations out there, which will mean more information about setups and the like. So rather then just everyone using a gt35/40 they will try out different setups and see the results in comparison to their old 20/25/26.

The rb30 has the same wear as well if not worse. When i pulled down our rb30 the drive and gear had a massive bite mark where it was wearing from the drive pressure, there would have had to have been about 40thou of slop between the flat and then when the gear actually engaged on the wear mark. It was nasty to look at, and originally we were gonna use the rb25det pump and the std drive, im glad we didnt especially since its a race car.

Edited by r33_racer

I forgot to add....

I'm thinking of making the guide indepth and hopefully cover any questions as seeing the same questions time and time again is becoming a little tiring. ;)

Unfortnately my build up was done when the Jun collar was the only one that existed and it was at the time this thread was only starting.. So.. I'm running around without a crank collar. :P

Unfortnately my build up was done when the Jun collar was the only one that existed and it was at the time this thread was only starting.. So.. I'm running around without a crank collar. :)
Yep I've racked up 40,000km's in mine. :3some:

good to see that its not 'required' just a good idea.

Yep just like forged pistons arent required, or conrods or new bearings or new pumps or a steel headgasket or anything else that might improve the quality of the motor. You build to suit the application...you wouldnt build a bodgy motor and expect it to hold 400rwkws reliably would you or even 300rwkws? Build to suit is all i can say.

I would say the same also. Oil is important, especially in a performance application. But the problem is not everyone can afford to get it done, they want a budget motor which might blow up in the future. I dont understand why people do that...why not just build it right the first time....makes me remember the saying "Measure twice, cut once".

But the problem is not everyone can afford to get it done, they want a budget motor which might blow up in the future. I dont understand why people do that...why not just build it right the first time....makes me remember the saying "Measure twice, cut once".

Its not like its expensive though... $300 odd and its installed. If one cant stretch the budget $300 then wait another pay or two until u can then build it up. :3some:

One thing i have learnt during this whole process, is never count on anything been done in a set timeframe, as one "part" relies on another "part" of the build being finished/machined before you can continue.

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