Uprating Rb Bottom Ends

[carl h]

well since ive melted a hole in my rb20's no. 5 piston its obvious i need to rebuild it.

ive got a nice set of cp pistons to rebuild the motor with but im wondering what else i should do to the bottom end while i have it apart.

i plan on using arp head studs and an oringed block with stock hg to keep it from blowing out under high boost but what other things should i do while the engine is apart.

i was gonna have the rods resized as well as shotpeened, but got to thinking do i need to change out the rod bolts and the main studs?

the motor should be capable of nearly 500whp, and i want it to last a while so what are your guy's thoughts on making it do so.

i was also gonna toss on an n1 oil pump to help the oiling system as well as a proper oil cooler.

ideas?

[Al]

If you are going to stick with factory rev limiter, shotpeened rods are adiquate, but if you plan to rev the engine harder thin get a new set of rods. Replacing rods bolts is a must, get ARP rod bolts.

N1 oil pump and oil cooler is also highly recommended.

It goes without saying that you are getting the block x-rayed and crack tested, internals checked, ballanced and blue-printed.

[carl h]

yeah, block is going to be inspected and cleaned along with the crank and what not, going to have the crank's oil gallerys grubscrewed for proper cleaning......

as for revlimiter im proly going to keep it near the stock 7.8k rpm, perhaps raise it just to add a bit of head room but nothing more past 8.5 for sure.

the head will be cleaned and checked as well as well as uprated valve springs to cope with sustained high rpm operation.

what arp bolts can i use on the rods will z32 vg30 bolts work?

[Bl4cK32]

How about sussing out why you burnt a hole in the piston, or you may end up doing it again with a fresh motor...?

Id hate to think what the power band will be like on the 2Lt with just more up top....

Why not go for a 2.4Lt bottom end (rb26 crank and rods, and them toyota factory forged pistons) ?

Edited January 2, 2006 by Bl4cK32

[Cubes]

More cubes via RB26 rods and crank is the only way you are going to make it possibly reliable.. It will need too many rev's and boost to make ~600hp at the fly with only 2ltrs and 7.8rpm.

Do the airflow calcs you will see what I mean.

500whp is 373rwkw... Good luck reaching and maintaining it if you stick with the 2ltr.

Edited January 2, 2006 by Cubes

[RB20DET_Silvia]

RB30 bottem end is all thats needed.

- Luke

[fEkuaR]

rb30 bottom end with alot of work .... 500hp reliably is alot of money in any terms

[Cubes]

Carl wants 500rwhp... Thats around 600hp at the fly.

For any motor its going to need rods and pistons.

The larger motor will always last longer than the smaller and be more reliable as it won't need to spin as hard to make the same power.

[Downforce]

bit off topic - but who in vic sells N1 oil pumps? other alternatives for oil pump upgrades?

[carl h]

hrmmm, you are right on a few fronts but i didnt say it was going to MAKE 500whp, i just wanted to beable to make one dyno pull and get a number like that......

the reason the piston went was due to a dodgy romtuned ecu, however decided that for high power needed to step it up so i invested in a pfc.

i do believe its possible to make 450whp as it was making nearly 400whp (387 to be exact) untuned and at moderate boost (17psi) made peak power at about 6.5k rpm iirc.

but back to the original question what arp bolts can i use on the bottom end?

[carl h]

awww come on i know some one on this foum has put arp bits in their bottom end....

[qik32]

i put sr 20 arp rod bolts in my rb20

[carl h]

the answer i wanted to know!

[boostn32]

My machine shop used L20 arp rod bolds.

[Roy]

RB30 bottem end is all thats needed.

- Luke

<{POST_SNAPBACK}>

Maybe...but an RB30 is a bigger engine that sits higher in the engine bay...not major problems but problems all the same. Some may have problems with engine numbers/registration etc.

Plus, i love revs, and screaming out of 2nd gear corners with the thing just screaming its head off up to 8,200-8,400rpm. A std RB30 bottom end wont do that. Some will say wont need to, and thats fine, but i like how it does.

RB24 again would be good...but im more inclined to spend the money saved with using std RB20 crank and rods on headwork, valve springs, perhaps bigger valves and cams etc. Things that will actually help the engine make power.

Whilst i am always impressed with how Rb25s with bigger engine RB cars always get up and boogie so quickly, im a lazy street driver and i now like how my car isnt spooling up everywhere with lots of induction noise etc.

If my RB20 let go, id be curious to do fresh bearings, oil/water pumps etc. Crack test, balance...the usual. Then just throw in a set of 81/82mm pistons with 8.6-8.8:1 compression...and then spend the rest of my budget on headwork, cams etc.

And im still trying to get my head around how everyone says the torque makes the car easier to drive, when all i ever see is the engine with better low rpm/torque just frying tyres. With a little less response, and higher rpm power band it seems the tyres/suspension handle the power better at higher road speeds?!?!?!?!

With something like a HKS 3037 or some other nice 550-600hp turbo, i think i would quite enjoy the power band from 4,750rpm to 8,500rpm. I would hope it makes 320-330rwkws on about 1.4-1.5bar.

[Sydneykid]

N1 oil pump ......... is also highly recommended.

I read this a lot, and personaly I think it's a big mistake to use a wide drive flange oil pump on a narrow drive flange crank. This is made even worse by the higher oil pressure relief spring the N1 pump has, because it means more torque loading on the narrow drive flanges. With the crank driving on less than half of flange on the oil pump, the tendancy to crack the rotor is exacerbated.

I see no reason to run an N1 oil pump anyway, they flow no more than a standard RB26 oil pump. All they do is relieve at a higher pressure.

cheers

[carl h]

I read this a lot, and personaly I think it's a big mistake to use a wide drive flange oil pump on a narrow drive flange crank.  This is made even worse by the higher oil pressure relief spring the N1 pump has, because it means more torque loading on the narrow drive flanges.  With the crank driving on less than half of flange on the oil pump, the tendancy to crack the rotor is exacerbated.

I see no reason to run an N1 oil pump anyway, they flow no more than a standard RB26 oil pump.  All they do is relieve at a higher pressure.

cheers

<{POST_SNAPBACK}>

fair enough SK, but i had planned on fitting a oil pump drive collar to the crank while it was out, it couldnt hurt any........

another reason for the n1 pump is for the slightly higher pressure, since the poor rb20 got stuffed with no oil cooler an external one is to be fitted to this new motor for longevity's sake.

roy - my gt30r is the same as a hks 3037, and belive me when she gets going it is an insane blast to drive, im anxious to see what she will do once i rebuild it with proper compression......

boostn32 - the l20 rod bolts were a proper fit? hrmmm i may have to look deeper into this.

Edited January 4, 2006 by carl h

[Bl4cK32]

RB24 again would be good...but im more inclined to spend the money saved with using std RB20 crank and rods on headwork, valve springs, perhaps bigger valves and cams etc. Things that will actually help the engine make power.

Increasing cubes does increase power. I know going from the 3.0Lt std bore to the ~3.1Lt i have in my car roughly equals about 10 more Hp across the rev range....or so a reliable source tells me

I would have stuck with modding my rb20 had it not blown, and i know what you mean about revs there Roy. Having ridden a RZ250r for the last 6 years i love revs, and that thing is built for it (redlines at 12,000rpm )

But i like not having to downchange (as you noticed when i drove your car) when goin up a slight gradient. I like the fact i can leave it in 5th and cruise up a hill.....tyre frying just means you havent sorted suspension or tyres properly

[Roy]

Increasing cubes does increase power. I know going from the 3.0Lt std bore to the ~3.1Lt i have in my car roughly equals about 10 more Hp across the rev range....or so a reliable source tells me

I would have stuck with modding my rb20 had it not blown, and i know what you mean about revs there Roy. Having ridden a RZ250r for the last 6 years i love revs, and that thing is built for it (redlines at 12,000rpm )

But i like not having to downchange (as you noticed when i drove your car) when goin up a slight gradient. I like the fact i can leave it in 5th and cruise up a hill.....tyre frying just means you havent sorted suspension or tyres properly

<{POST_SNAPBACK}>

You are a lazy man. I estimate 42 gearchanges in my car per 1000mtrs whereby burning approx 72 calories. That is extra sauce on my meat pie, and an extra beer with dinner base don the average number of kms travelled in a day.

As for 3.0L vs 2.0L no doubt, but as for 2,4L with the same head? Your 3.0l is also using a different head.

I have no idea what the answer is, but would be interesting to take your RB30 build budget, and spend all that money on headwork and cams. It will be interesting the performance difference of the two engines usign the same high flow turbo , even allowing for the differend head etc?????

[Roy]

...and for what its worth, the car doesnt have that nasty tune anymore, or the 10cm housing. When the 8cm housing went on with the new tune it transformed the car...LOL, that means it still sucks and is laggy, but at least i dont have to use 1st gear and a carrot on a stick and string to get the thing up a hill in 1st gear