using a used jun oil pump

[gtrjon]

So i dont wana get flammed for this even though i might. But what are your guys opinion on using a used jun oil pump? there is a guy on here selling his. I know its a cheap way out and i planned on going with a n1 oil pump (i ordered a r34 crank, weisco pistons, eagle rods....etc) but i have just read far too many horror stories about the n1 pump (felix) for example. so how sketch/bad is it to run a used oil pump? i mean it is a jun i know its not as good as tomei as some have said but it is still supposed to last. so anybody feel free to chime in.

[evilgtr]

You didn't order a used crank,rods,pistons for a reason.. So why cheap out now.
The old saying goes "we never have money to do it right,but we always find money to do it twice"

You won't have issues with the N1 pump, ultimately it's your car so the final decision is yours.

[cobrAA]

the thing is.... people never tell the whole stories and just blame the n1 pump lol. They're good pump.

[gtrjon]

yea i know.... i have just heard so many conflicting arguments on the n1 apparently there was a bad batch of them that made it out there such as the ones on ebay. i am spending about 10000 on my build and i dont want a bad oil pump to ruin it. and evilgtr your right cheaping out always bites you in the ass i just cant fit it in my budget spending 1500 on a oil pump!!!! i want my car done as soon as i can. I know in an ideal world i would wait and save and do it right but i am not that patient and i am not trying to cheap out on something i need. just trying to get some opinions. i might end up going with the n1. of all the bad stories i have heard about them i havent heard any problems when they had a new r34 crank. we will c.......

[NismoS-tune]

I'd do it. It's still a Jun pump. New used doesn't mean much if it's in good condition. Kinda like some people buying a car that's already modified. It's used.

Do it

[GodziRRa]

Well if you want to take the risk mate then go ahead. But if budget permits go for a new one. Nismo oil pump is just a bit cheaper compared to JUN, you might want to check it out also.

[evilgtr]

If you buy a genuine N1 pump and have the gears replaced with the reimax gears then re-seal the pump and and use some locktight on the srews then punch the heads to avoid seperation. Add a quality Crank damper and you should be fine. I am running the N1 pump but didnt opt for the reimax gears - instead I had my gears removed and machined to remove all the tiny burrs then re-assembled. So far so good.

We all know there are alot of horror stories regarding the N1 pump but CobrAA hit the nail on the head when he said people are quick to blame the pump. Everyone drives there car differently,if you intend on eventually running 7-900whp or taking it to the track and excercising the rev limiter on a daily basis then maybe a larger pump is what you need for your application. But if thats the case you will also need stronger rods,crank,mains,valve train ect ect. If you intend on running 700whp or less then I feel the N1 (properly set up and with supporting mods) will suit your application just fine.

The Aussies punished these pumps for years on the track and Iv yet to see video footage of a GTR pulling over or quitting the race due to pump failure,HI OCTANE used the the N1 pumps on all their time attack R32 GTR's.

If you do alot of homework on RB26 builds you will also find that Eagle rods fail actually more often then the N1 pumps if you put it into perspective. And look how many of us run eagle rods ?!

All parts have the potential to fail, the trick is trying to perfectly match parts that will fit the criteria for the intended purpose of your build.

[gtrjon]

yes evilgtr all of that is true. and i have done my research believe me. hence why i just revieved my bnib r34 crank. i also ordered pistons and rods. i am giong to be under 700whp cause i am going to be using my stock tranny so i will be around 650 and hope my tranny holds up. i am going to be at the track rather reguraly for 1/4 so i wont be on the limiter all day but will see some limiter. i will be locktiting my screws but as far as reimax gears by the time i do that i might as well spend the few extra hundred and buy a jun.... i still have to think about it more i guess. i know rips uses the n1 on some of their 1000whp gtrs with no complaints. so i guess the hating on the n1 pump might just be alot of heresay.

[NismoS-tune]

If you do alot of homework on RB26 builds you will also find that Eagle rods fail actually more often then the N1 pumps if you put it into perspective. And look how many of us run eagle rods ?!

Someone (shop owner) convinced me the Eagle rods would suffice under 800hp and be reliable... Soon after I realized that I could care less that they were half the price of the good rods so I tried going to Carrillo rods but it was too late as everything was already balanced. We'll see how they go. The weakest parts of my car are the rods, transmission, OEM fuel tank and driveshafts. Let's hope it stays together eh?

i am giong to be under 700whp cause i am going to be using my stock tranny so i will be around 650 and hope my tranny holds up.

I wish I could afford to make that kind of power

[archaeic_bloke]

keep in mind the N1 you can install it and not have to worry, it flows MORE PRESSURE than the oem oil pump, but not more volume.
The JUN on the other hand flows MORE PRESSURE ... and.. MORE VOLUME, so if you move to a JUN you're going to need to do some oil mods as well... you're going to need to:

- install an oil drain from the head to the pan
- drill out the oil returns in the block to allow more oil return
- install a tomei oil restrictor into the block to limit flow to the head
- fit a larger baffeled oil sump and pan

you need to do this because the JUN flows significantly more oil, in fact theres a guy named Toby (aka Kismetcaptain) on the UK boards who installed a JUN oil pump and didnt do those things I mentioned, he took his car out, the oil pump sucked the pan dry and he blew the motor.... you cannot run a larger capacity oil pump with out a large capacity of oil...you need to build your engine to the same spec all over~ remember that saying: "a chain is only as strong as its weakest link"... it matters for engines too!

on the other hand, if you want to keep the stock oil pan, and baffles, and not modify the head and return, then run an N1 oil pump. thats what I did, ran it for one season alrdy, no issues. of course the N1 pump should be brand new, and a late model crank will complete the solution. really, if you were looking for a good pump the N1 will do it.

[gtrjon]

[QUOTE=NismoS-tune;437549]Someone (shop owner) convinced me the Eagle rods would suffice under 800hp and be reliable... Soon after I realized that I could care less that they were half the price of the good rods so I tried going to Carrillo rods but it was too late as everything was already balanced. We'll see how they go. The weakest parts of my car are the rods, transmission, OEM fuel tank and driveshafts. Let's hope it stays together eh?

i am giong to be under 700whp cause i am going to be using my stock tranny so i will be around 650 and hope my tranny holds up.QUOTE]

I wish I could afford to make that kind of power

lol my budget for my build is 10000 out the door and i am coming pretty damn close. i am going big single with a bw 91-79 turbo so big power wont be hard to make with some meth a built bottom end and some tomei pon cams. i am just trying to take my time and do it right without sacrafising on things i need such as a oil pump lol.

[gtrjon]

yes i realize i will need to add the oil restrictor to the head it will be coming with my tomei head gasket and i am planning on having my return line modified as well. i think i am going to go with n1 and see how it goes with the new crank. still gonna check my clearances before i install it. archaeic bloke did you measure the clearence on your n1 pump and your r34 crank?

[amnash]

If you buy a genuine N1 pump and have the gears replaced with the reimax gears then re-seal the pump and and use some locktight on the srews then punch the heads to avoid seperation. Add a quality Crank damper and you should be fine. I am running the N1 pump but didnt opt for the reimax gears - instead I had my gears removed and machined to remove all the tiny burrs then re-assembled. So far so good.

We all know there are alot of horror stories regarding the N1 pump but CobrAA hit the nail on the head when he said people are quick to blame the pump. Everyone drives there car differently,if you intend on eventually running 7-900whp or taking it to the track and excercising the rev limiter on a daily basis then maybe a larger pump is what you need for your application. But if thats the case you will also need stronger rods,crank,mains,valve train ect ect. If you intend on running 700whp or less then I feel the N1 (properly set up and with supporting mods) will suit your application just fine.

The Aussies punished these pumps for years on the track and Iv yet to see video footage of a GTR pulling over or quitting the race due to pump failure,HI OCTANE used the the N1 pumps on all their time attack R32 GTR's.

If you do alot of homework on RB26 builds you will also find that Eagle rods fail actually more often then the N1 pumps if you put it into perspective. And look how many of us run eagle rods ?!

All parts have the potential to fail, the trick is trying to perfectly match parts that will fit the criteria for the intended purpose of your build.

is a crank damper the same thing as a crank collar?

[jdms13rhd]

n1 is good.
I have a friend running 800hp in his gtr on a n1 pump and collared crank no problems for several yrs.

I am poor and run N1 pumps and never busted one.

That jun pump could be a good opportunity to get in on a better pump but Id take it to a machinist and get it checked out before considering installing it on ANY engine. In fact, buddy thats selling it should do that to help his sale and he could possibly get a little more that way :S From my experience, even with a N1 pump, there are still modifications you should do to compensate.
Drag car with 700+hp, Id have an upgraded sump on my mind. 9 sec gtr is going to toss the oil back all the way down the 1/4 mile. That should be a priority as well as the drains.

[jdms13rhd]

is a crank damper the same thing as a crank collar?

no. The collar is just a machined part on the snout of the crank that drives the oil pump. The damper is a harmonic balancer. ATI or ross would be the most popular of them and should be one of the first things to do when considering a "serious" build imo. Its only an extra $500+ish anyways. And I always balance the flywheel with the rotation assembly. Dont balance the damper's tho. lol. They are perfect out of the box hence, thats what you pay for