Engine Gurus Please Check My Shopping List

[NickR33]

Hi guys,

I recently spun a big end bearing in my RB25 at a track day... this is the second time I have had to rebuild so it was a relatively fresh engine (25,000km)... I have already been over most of this but wanted to throw it open to the whole forum, see thread here for more info http://www.skylinesaustralia.com/forums/in...howtopic=173225

I don't know whether the problem is oil starvation, oil contamination or misassembly from the previous build... so I'm going to try and cover all 3 with this build... I don't have any pics of the bearings but #2 took most of the punishment ... my mechanic and myself will be doing everything excluding machining so I need all the info I can get

engine will be used on the street as well as frequently at circuits and motorkhanas... will only be pushing 200rwkw for the time being but when my bank balance recovers we will be going for no more than 300rwkw... reliability is the number 1 thing I want to achive, I want to be able to thrash the living hell out of it and not have to take the engine out again any time soon (ever if possible! pain in the butt to take an RB out!)

parts list:

New RB26 crank

ACL race bearings (no more aluminium!)

Eagle rods with ARP bolts

Arias pistons and rings (already in there from last build)

N1 oil pump

N1 water pump

ACL gaskets

Nismo engine mounts (current ones are shagged)

Oil cooler (yes I should have already had one!)

oil control:

block off front oil feed to head, 1.25mm restrictor in other oil feed, leave VCT feed alone

external oil drain from back of head to sump

clean up of oil galleries for improved flow

That's about it but I have a couple of questions:

is the JUN oil pump worth $450 more than the N1? I am happy to pay the extra as long as its not just for the brand name...

If I were to go a stroker crank would the extra .3 of a litre be worth an extra $2000? been thinking of RB30 but that would be a similar additional cost as I would have to buy new pistons

in the other thread there was some argument about a baffled sump, do I need one?

Cheers,

Nick

[CEF11E]

I am sure you have already thought of it but RB30DET then no need for rb26 crank

the cost of the build would be nearly the same. you would loose VCT but the extra capacity is a big bonus

[GTS-t VSPEC]

I used Nismo bearings in mine, an HKS Oil Pump, and a larger capacity sump. Other than that the parts look ok.

[BAMR33]

  NickR33 said:

Hi guys,

I recently spun a big end bearing in my RB25 at a track day... this is the second time I have had to rebuild so it was a relatively fresh engine (25,000km)... I have already been over most of this but wanted to throw it open to the whole forum, see thread here for more info http://www.skylinesaustralia.com/forums/in...howtopic=173225

I don't know whether the problem is oil starvation, oil contamination or misassembly from the previous build... so I'm going to try and cover all 3 with this build... I don't have any pics of the bearings but #2 took most of the punishment ... my mechanic and myself will be doing everything excluding machining so I need all the info I can get

engine will be used on the street as well as frequently at circuits and motorkhanas... will only be pushing 200rwkw for the time being but when my bank balance recovers we will be going for no more than 300rwkw... reliability is the number 1 thing I want to achive, I want to be able to thrash the living hell out of it and not have to take the engine out again any time soon (ever if possible! pain in the butt to take an RB out!)

parts list:

New RB26 crank

ACL race bearings (no more aluminium!)

Eagle rods with ARP bolts

Arias pistons and rings (already in there from last build)

N1 oil pump

N1 water pump

ACL gaskets

Nismo engine mounts (current ones are shagged)

Oil cooler (yes I should have already had one!)

oil control:

block off front oil feed to head, 1.25mm restrictor in other oil feed, leave VCT feed alone

external oil drain from back of head to sump

clean up of oil galleries for improved flow

That's about it but I have a couple of questions:

is the JUN oil pump worth $450 more than the N1? I am happy to pay the extra as long as its not just for the brand name...

If I were to go a stroker crank would the extra .3 of a litre be worth an extra $2000? been thinking of RB30 but that would be a similar additional cost as I would have to buy new pistons

in the other thread there was some argument about a baffled sump, do I need one?

Cheers,

Nick

I think a baffled sump would help when doing track work. Also slightly over filling the sump helps too.

RB30 you don't need new pistons for 200-300rwkW if you get a good rb30, you just need the pistons ceramic coated.

Was there much oil in the catch can when the motor let go? I think the rb25 pump will be fine and if you follow all SK's oil control modifications you should have reliable motor.

[sweetr33]

i like the rb26 crank upgrade as ive done the same hehe but this was 3 years ago and the rb30/twin cam thing wasnt as well advertised then as it is now so in away im spewin i didnt go that way, but at same time am happy with results so far with 2.6 crank... i would prob recommend going for rb30/twincam setup. roughly same costs and benifits from wat ive heard are well worth it....

[R31Nismoid]

You dont need $$$ rods.

GTR rods for $150 are more than upto the task with decent bolts.

They will hold another 100rwkw over what you will ever want.

Personally, i'd have Racepace built it, and thus... contact em for their thoughts

[NickR33]

thanks for the input guys:)

GTSt-Vspec - I will look into the Nismo bearings, just don't want to go with aluminium again as it isn't as resiliant as the lead/copper

RB30 will definately be more expensive than this build, just due to the little fiddly extras (like plenum and rerouting the cooler pipes etc), I don't really want to go back to cast pistons and I don't want to use high km second hand parts if I can avoid it... GTR rods would be okay I guess and would save me enough to get a baffled sump or the JUN/HKS oil pump... I will be blueprinting/balancing everything I can lay my hands on anyway

yep Ben would do a better job than me but where is the fun in that;)

[R31Nismoid]

Well doing things maybe yet another time might not be so fun if it was right the first time

[Adriano]

If you use an rb26 crank, you will need to get different pistons wiht a different pin height. RB30 FTW

[foznice]

Hey nick, whats the difference between the nismo engine mounts and the OEM replacements?

[NickR33]

no idea what the difference is between the OEM - Nismo mounts are... but Nismo FTW;)

Thanks Adriano I wasn't sure if I could use the 26 crank and rods with the Arias pistons already in there... but when I bought the pistons they were 26 spec anyway as arias don't make 25 spec???

very true ash, it gets a little less fun every time hehe

[GTRNUR]

Definatly go the JUN/HKS or Tomei pump depending on your available dollars. Ive heard rumour that the new N1 pumps are failing due to problems with the quality of the metal in the pump rotor. With the gtr crank make sure it has the oil pump drive extension fitted if its an R32 GTR crank. Especially considering how your circuit race it. Last of all if you can afford to, put in a set of H-beams. Cheap insurance.

Same oil pump mods should be done if your going down the RB30DET path and still will race the car as well.

Sump baffel definatly or oil surging can still cause bearing failure like you already have. The other possability is a sump extension to add a few more litres of oil to the sump. Extra oil in the oil lines from the cooler and remote filter doesnt help if the pickup is sucking air.

Have fun with it!