Rb26 Build Details

[GTR1993]

I have a R32 GTR that i bought with a rebuilt engine, unknown spec high flowed turbos etc. As always the oil modifications were not done to the motor. Im going to pull the motor and do these mods along with (possibly) a few other modifications. A few friends of mine race some 1600s out at malalla and i want to give it a bit of a go my self.

Motor as it stands now:

forged pistons

Tomei cams

Tomei cam gears

some type of porting job according to receipt

std rods

N1 oil and water pumps

Tomei metal head gasket

Proposed rebuild option:

enlarge oil drains at back of head

add extra oil drain at back of head to sump

fit oil restrictor

ARP studs mains and head

Some forged rods

new bearings

new head gasket (or gasket set)

The reason for studs is that they are pretty cheap and if later on i want to run some more power through it they are there, also the rods, buying some arp bolts is what like 250, for 650 i can get some forged rods with arp bolts in them, cheap upgrade. Parts such as pistons will be reused with the block getting a line hone (because of arp mains) and bores re hones, the pistons in it seem to have dropped static compression of the motor so i will CC the head and the dish of the pistons and work out a suitable head gasket or machining to get compression back up to standard.

I have been doing alot of reading on this forum over the past few months along with fresh alloy and the more i read the more N1 oil pump failures i seen to find. Is the pump failure really this common? Is it related to harmonics? If it would help i was thinking of also fitting a Ross tuffbond balancer. Is it worth the 1000 to upgrade to a JUN pump, even with this i have read about some failures. I don't want the cost to blow out substantially considering my friend running under 1:20s at malalla with stock internal sr20!

The next question i have is about the sump, SK seems to say that the performance metal craft sump for the 4wd 26s is very good, and costs around $1400, i want to run on R compound tyres so is this a wise investment?

Power is around 290 rwkw at 16 psi as it stands now.

Thanks for any help

[R31Nismoid]

Pump failure is due to people smashing the limiter for extended periods, if you dont do this i reckon it'll be fine.

I've had two, and countless 100's of other people use them without issue.

Sump isnt needed if your just poking around the 300rwkw.

Nice to have, but not a requirement if the oil mods are done (and you overfill by 1ltr before race time)

[Grunter]

Hi mate if the motor has already been run in I think there is no need to replace bearings

or hone out block that is something that should of been done before rebuild.Me I would

have a very close look at everything and just fit your new rods and arp bolts oil restricter

and oil mods and put it back together.Another thing is you may need baffles for the

rocker covers.Happy motoring

[Blitz]

If the motor is coming apart, replace the bearings - They are too cheap to consider reusing them.

[Adriano]

Sounds like you have a good plan ahead, i would ensure you add a crank collar to suit the N1 oil pump if it doesnt already have one

[GTR1993]

The mains will need a hone because of the arp main bolts, generally these will clamp up a bit tighter.

The car is a 1994 so i didn't put crank collar in as i "think" the crank should be like the R33 variant, so i should be ok, if not that is definite mod.

Thanks for input, so you think the new balancer is not needed?

[GTR1993]

Just following up this topic for anyone that is interested....I was talking to peter hall who used to work for willall and now works at a shop i frequent to buy parts. Anyway he recommended the ATI balancer over the Ross, and said that the 26 std balancers are usually shagged by now.

Also recommends the performance metalcraft sumps. Im going std rods as well now with just some arp bolts (only 100 bucks), main and head studs, acl gasket kit, acl race series bearings, ATI balancer, performance metalcraft sump, reusing my pistons and N1 oil pump etc.

Another thing he said that most people over look was a front LSD, he says if u have to not spend money somewhere else on the car to get this its well worth the money and really transforms the car, im going to look into it. He recommended ATS over OS giken as ats is direct kit, OS you need to machine the sump for it to fit in.