Ej20 V Rb20

[TTT]

without being biased on engines, and without bringing the actual CHASSIS in to the arguement, I want to have a discussion about which engine is better in certain conditions.

as a starting point.

89 - 93 rb20det silver top (160kw etc)

89 - 93 ej20t - from RS liberty (147kw etc)

now these engines are of the same vintage.

rb has more power.

don't have the torque figures handy.

lets say for street, drag or circuit.

both engines like to rev.

both are fairly low in compression.

now I know for a fact that there are a few liberty RS's around (if not MOST rs's) that have over 220,000kms on the standard engine, carting around a 1400kg car for 15 years.

highway driving maybe when new, but as they got cheaper all the hoodlums got to them (generalisation yes...)

the rb's are known for their oil control problem as SK recently posted in a thread on here.

ej's of this vintage are usually compared to the "calm before the storm" when driving below 3000rpm, which I guess could be said for the rb20 as well.

apart from hydrolic lifter issues on the ej's, I don't know of any obvious problems.

so the questions..

for street, drag or circuit, which engine is actually better from a power, reliability and bang for buck point of view.

both engines can be had complete for about $700 from wreckers.

both engines can have bolt ons to make power.

you can compare stock for stock or modded if you like.

remember, keep the chassis out of this arguement.

no "understeer this and that" bullshit.

also, I know for a fact that the RS Liberty EJ (and probably all of them really) is a shit load lighter than the RB.

my brother and I were able to pick one up off the floor and put on back of ute together where as the RB we couldn't even lift one side together.

the EJ's are alloy..

anyway.. let the conversation begin.

SK - I know how you feel about subawho in general, but taking the chassis/4wd out of it, you might find something you like about them...

maybe..

[lordsnipe]

i thought the EJ motors had trouble with one of the cylinders failing.. something like cylinder 1 always runs lean and is the cause for 80% of EJs going pop? im no export but, so dont' quote me.

disregarding chassis and speaking purely about the motor, I think the EJ would be better.. as you said, lighter for a start. You can make decent power with both...

[dangerous_daveo]

So whats it going in to? Physical size might be an issue too, or just the whole direction of piston thing.

Either way, Id say the rb20, i've been up against a few rs libs, and always been on top, and they have always had more mods. Weight and kms on the motor would be about even. Diff is mine is still going, theirs have both blow up... Thats my perspective anyway.

[TTT]

the piston failure is due to the fuel rail design and the fact that it's closer to turbo I believe.

MRT fuel rail fixes that issue.

daveo - good point on what it goes in to..

lets say some sort of kit car...??

[skylinecouple]

If it was a kit car the suby would easily be better, lighter weight, already front wheel drive.

[TTT]

bump

[RCEBNR]

my old flat mate used to own a fairly powerful (abt 180kw at the wheels) rs liberty, he lost his license so it became my daily drive for a while.. i now own an r32 with the same power, and have driven both on a daily basis... the rs seems to have a little more down low (but again this is because of turbo choice on the rs)... drivetrain is an issue with gbox strenght being a downside of the rs, but again it can be overcome. the ej's top mount cooler suffers a bit with heatsoak, esp with the hotter days, but again can be overcome...

they both seem to have a fairly high lifespan

[Sydneykid]

Being a cast iron block, the RB20DET will ultimately handle more combustion pressure, that means more power.

Being a 6 cylinder versus a 4 cylinder it will ultimately be easier to achieve a rotating balance for higher rpm, plus each up and down component is individually lighter (that means more horsepower)

The 24 valve versus 16 valve configuration = more valve area per cc. That means more power

Being a straight 6 versus a boxer 4, a street legal, turbo exhaust is more efficient in design

Circuit race quality oil control in a FJ is not easy to achieve, it’s a boxer, that means the oil rushes to the cylinder heads due to cornering G forces. Take a look at a Porsche oil control system for an example.

Don’t ignore gearboxes, a high power RB gearbox is much easier/cheaper to obtain than a high power FJ gearbox. A standard R33GTST box will handle more torque and RPM than the most modified FJ gearbox.

But lets face it if you were building a car you wouldn’t use either engine. If you want turbo power you would go for an R30DET. If you want light weight, an SR20 or a K20 would be a better proposition. If you want N/A grunt, then an LS7 is hard to go past.

cheers

[dangerous_daveo]

the piston failure is due to the fuel rail design and the fact that it's closer to turbo I believe.

MRT fuel rail fixes that issue.

daveo - good point on what it goes in to..

lets say some sort of kit car...??

Wellll, kit car, it would seem many are VW beatle based, so ej20 rear mounted. But if you want a strong gearbox you would be looking at say a porka box... They make the rb25 box look REALLY cheap.

[edit]

You should also look at the 1GGTE (6cyl twin turbo) from toyota. Quite a few aftermarket parts about for them as well (not as many but still a few). I know of one that was reliably making 350rwhp on a fully standard bottom end that was out of an ex-race car that had been sitting for 2 years without being started. So really, doing all the wrong things it still worked. You could also get the supercharged bottom end that has higher compression (which the above motor actually was). I think price would be equal or better, and gearboxes should be as cheap and def stronger than the two combined. That and its toyota so its more reliable to start with.