Careless Posted September 6, 2006 Share Posted September 6, 2006 after reading the entire RB30 thread on SAU, i've come to the conclusion that the crank colar is somewhat tapered on R32 GTR and VL C rb blocks. they taper ever so slightly, and allow only about 1/8th of an inch seating area on the pump drive or whatever it is you would call that circular provision with the flat spots on it. the drive ends up getting cut away as the smaller surface area tends to not hold up to the excessive harmonics at 6500+ rpm, due to the fact that it's not making full contact, and that there is room for vibration. also, if you change your oil pump, you will have to install some restrictors which you can make out solid brass rod that is a smidgen over 6mm in diameter. u just need to drill a hole at the proper size, directly in the center.... toss it in the freezer, and wait a couple of hours. then when you're ready to install it, you just hammer it in over top the factory restrictor. you may also need to make some restrictors that block off the two further holes completely, depending on your engine application. there are sizes from 1.5, 1.25, and 1.00 mm which you would drill into the restrictors holes that would allow only the required amount of oil to enter the head, and cause it to not overflow with the added pumping of the N1 or JUN/HKS larger blades. again, that's what i've read.... you can buy the JUN crank collar to rid the issue completely, but i hear it's an expensive part and i dont think it's made any more. Quote Link to comment Share on other sites More sharing options...
Stealth-Z Posted September 6, 2006 Share Posted September 6, 2006 after reading the entire RB30 thread on SAU' date=' i've come to the conclusion that the crank colar is somewhat tapered on R32 GTR and VL C rb blocks. they taper ever so slightly, and allow only about 1/8th of an inch seating area on the pump drive or whatever it is you would call that circular provision with the flat spots on it. the drive ends up getting cut away as the smaller surface area tends to not hold up to the excessive harmonics at 6500+ rpm, due to the fact that it's not making full contact, and that there is room for vibration. also, if you change your oil pump, you will have to install some restrictors which you can make out solid brass rod that is a smidgen over 6mm in diameter. u just need to drill a hole at the proper size, directly in the center.... toss it in the freezer, and wait a couple of hours. then when you're ready to install it, you just hammer it in over top the factory restrictor. you may also need to make some restrictors that block off the two further holes completely, depending on your engine application. there are sizes from 1.5, 1.25, and 1.00 mm which you would drill into the restrictors holes that would allow only the required amount of oil to enter the head, and cause it to not overflow with the added pumping of the N1 or JUN/HKS larger blades. again, that's what i've read.... you can buy the JUN crank collar to rid the issue completely, but i hear it's an expensive part and i dont think it's made any more.[/quote'] Attached is the oil restrictor modifications I think you are talking about. Also the JUN crank collar is still available. Bought mine from RHDJapan for $139.00 a few months ago. Also as a note, the RB20 cranks have the same amount of contact area as the early R32 RB26's. I am not sure if they ever fixed these or not. Last night I took apart a R32 RB20 and it looks like the early RB26. Looks like someone had changed the pump because it had the later model with more internal surface area. Will post more photos of the pump differences if anyone is interested. RB_oil_gallery_mods.pdf Quote Link to comment Share on other sites More sharing options...
cheftrd Posted September 11, 2006 Share Posted September 11, 2006 When I called the Nismo pump a bandaid, I meant with the short drive crank. That crank will break any pump. The Nismo pump is the same volume/pressure as the stock pump, but it has a hardened rotor and scroll. This is straight out of the 2006 Nismo catalog, which is the same as the one before it, and the same that Nismo sends me every year, so please don't argue because you read on a forum somewhere that the Nismo pump is higher volume/pressure. THE VOLUME OF THE STOCK/NISMO/N1 PUMP IS FINE FOR ALL BUT SUPER DRAG MOTORS. 90% of the RB26's I have built are 9,000rpm engines and have zero oil pressure drop at the gauge due to not enough pump volume using these pumps. The HKS and JUN pumps are for serious power motors turning serious rpm's. Oil flow is what keeps the bearings cool. High power creates lots of pressure on the oil/bearing, creating lots of heat which will kill the bearings. In this type of motor, you combat this by opening the oil clearances, which in turn flows more oil over the bearings, keeping them cool. This requires......drumroll please.........a higher volume pump. If you don't have a higher volume pump, oil pressure will drop in the upper R's and the bearings will die a horrible death. I am thinking about writing something up about all the ABC's of the RB26 I have observed and posting it here. Any interest? Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 11, 2006 Share Posted September 11, 2006 Hi Matt I'd really like to read some of your collected wisdom on the RB series motors. I'm looking at building either a 26 or a 30 with a 26 head, single GT35R. I'm interested in what you feel is required for camsheadwork for a 550 hp 9k motor Doug Quote Link to comment Share on other sites More sharing options...
Careless Posted September 11, 2006 Share Posted September 11, 2006 I am thinking about writing something up about all the ABC's of the RB26 I have observed and posting it here. Any interest? anything pertaining to any RB engines that you could provide would be awesome. and no one is arguing with you on anything, i don't think... Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted September 11, 2006 Share Posted September 11, 2006 Matt, Thanks for the "band aid" clarification. Quote Link to comment Share on other sites More sharing options...
hotimport Posted September 11, 2006 Share Posted September 11, 2006 Thanks Matt for the good info. I think of you as a King of RB's, so if you wana write some up for us that would be awesome. Quote Link to comment Share on other sites More sharing options...
Bob_H Posted September 11, 2006 Share Posted September 11, 2006 Matt, A comprehensive thread would be great - just start a sepearate one from this thread so it is easy to search for. (Likely will remain a sticky to prevent repeat questions). -Bob Quote Link to comment Share on other sites More sharing options...
Cal Poly Zmanaustin Posted September 12, 2006 Share Posted September 12, 2006 I am thinking about writing something up about all the ABC's of the RB26 I have observed and posting it here. Any interest? Yes, would really appreciate your wisdom. Thanks, Quote Link to comment Share on other sites More sharing options...
Careless Posted September 12, 2006 Share Posted September 12, 2006 with the added pumping of the N1 or JUN/HKS larger blades. I just realized i got the water pump and oil pump mixed up. It's the N1 water pump that has 6 blades instead of 8 from the stock pump. sorry for the miscommunication. Quote Link to comment Share on other sites More sharing options...
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