using a used jun oil pump

[gtrjon]

Allen could you explain to me a little more how the harmonic balancer or damper works? and why it is important? havent seen alot of info on them.

[archaeic_bloke]

did you measure the clearence on your n1 pump and your r34 crank?

for inner diameter of the oil pump gear and outer diameter of the crank drive, they were equal to the hundredth, which means a difference in the thousandths... which means they were almost press-fit together, which means they fit VERY snugly, perfectly together.

as for a harmonic balancer, ATI or ROSS makes good ones, don't bother with anything else... you need one to rev high reliably, like 8k and above,... they are filled with something (im not sure what exactly) and it helps to reduce any "run-out" in the crank, and helps to keep everything rotating smoothly. thats a pretty basic response, someone else might be able to give a better one tho

[gtrjon]

great i hope mine is the same you and the skyline life were kinda my inspiration for the r34 crank lol.

[jdms13rhd]

Allen could you explain to me a little more how the harmonic balancer or damper works? and why it is important? havent seen alot of info on them.

I might not be the best person to explain this. Im not a engine builder or machinist or engineer. Just using my "common sense". :P

Every engine needs to have a zero balance. When you balance an engine they take every rod and weight them exactly the same. Usually taking the lightest one and then they remove the material on the wrist pin and the bottom cap balancing it top to bottom. Then they do the same with the crank on every counter weight and then the same with the flywheel and pistons of course. Those drilled holes in the crank and flywheels are the factory balancing those items. The damper absorbs any other vibrations. If an engine was not balanced or done properly i would suppose you could feel it and your engine wont last long. The higher the rpm and the more power you turn out the more crucial the balancing must be in order to keep everything together.

The crank sits in the block and forward towards the balancer, its roughly 4 inches of un-supported crank. If the engine were off balance in any way the crank could see micro movement and damage the pump and or bearings or more. The aftermarket dampers are just a more precise piece that is engineered to handle more power and higher rpm where as the stock damper is engineered to take roughly 300hp at 8000rpm and most of ours are 15 years old and could be in better condition:P

So, you spend $4500 on a engine build with new pieces, it only makes sense that you spend the extra $500 on a new damper as the balance is what keeps the engine together.

I think I got the concept right anyways.

[NismoS-tune]

[QUOTE=gtrjon;437558]

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?



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.

Power to you if 10k is enough for 650whp (I hope that's just the engine getting the 10k), then again, I guess people can make lots of power without having many supportive mods. My engine alone was much more than that and I'm getting 5-550 but with smaller turbos and response/torque, much like the Mine's car and not like a laggy single turbo supra . The thing is, it's built for durability and reliability.

As for dampers, ATI and Ross are great but I remember seeing the HKS is slightly better than the ATI race (Still made by ATI though I think) as it had more ribs on one of the belts or something?

Most people can't afford HKS is the usual issue. It's around $1000 compared to the cheap $600 ATI ones.

[gtrjon]

yea 10000 is just in my motor. with supporting fuel and oiling mods. you can have your twin set up and have no lag for time attack or whatever you plan on doing with your gtr but i like to race in a straight line and a big single is easier to make big power for 1/4 yes its laggy but once it spools it hits hard sounds better and the engine bay looks better imo. but thats all just my opinion. to each his own i guess. Allen thanks for the simple break down for newbs like me

[BenC]

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

I agree. If theres is no wear to the drive surface, solid clearance and there is no damage to the pump itself a Jun is a good choice even when it is used

[Dragon Humper]

I agree. If theres is no wear to the drive surface, solid clearance and there is no damage to the pump itself a Jun is a good choice even when it is used

+1

BUT, I only have a stock pump (maybe an N1, don't know for sure) and it's working just fine, I have rev-ed to 9000 on occasion too.

You don't need high volume unless you need it, there has been alot of myths dispelled in the last 5 years or so in motorsport around oiling. The old rule of thumb that you should have 10psi per 1000rpm is now bunk, as long as you have 60psi and your clearances are good you can go as far as your parts will take you. Volume is also a result of clearances, if they are good and you don't have other things gobbling up volume (like 4 turbos in a Veyron) then hi-volume is not needed. What could be of value though is to have ALL the volume go through your oil cooler then by-pass the un-needed oil back to the pan, that way you oil will circulate through the cooler more often.



Jon.

[gtrjon]

yea i think i am going to go with n1 thanks for all the help guys!!!!!!!