how to tell an rb20 fropm an rb25?

[TunaFish]

I was wondering if there were any dead give aways from the 2 motors just from looking at one when its swapped into a 240. i am looking to buy an s14 with an Rb in it, and the guy says its an rb25 however it does not say rb 20 on the cam gear cover and the coil pack cover doesnt say the normal 2500 on it, it only says nissan motorsports. were would the block code be on this motor? any other ways to tell the 2 motors apart other than the cam gear cover and the coil pack cover?

[Joe]

I was wondering if there were any dead give aways from the 2 motors just from looking at one when its swapped into a 240. i am looking to buy an s14 with an Rb in it, and the guy says its an rb25 however it does not say rb 20 on the cam gear cover and the coil pack cover doesnt say the normal 2500 on it, it only says nissan motorsports. were would the block code be on this motor? any other ways to tell the 2 motors apart other than the cam gear cover and the coil pack cover?

RB25's have a hump on the camgear cover where it says 'rb20' on the rb20 engines.

the intake manifold on the RB20 says ECCS on top of it

those are 2 dead giveaways. pictures for refrencemy RB25, see the huge hump on the cam gear cover?RB20

[TunaFish]

sweet thanks for the help

[AmoebAssassin]

For the most part, the firewall side of both valve covers is raised on RB25s, the RB20s have are more or less flat along their length

[hannibal]

Arent the intake manifold bolt patterns different too?

[intrexin]

it looks like the intake mani, tps, bov, the whole area by the upper rad hose too

[hannibal]

Actually, I think it was the exhaust mani bolt pattern thats different. As intrexin reminded me, the intake manifolds are shaped differently too. The last two runners (cyl 5 and 6) on the RB20 are a different shape than cylinders 1-4. On a RB25, all six runners are shaped the same.

[themadscientist]

uh, casting mark on the american driver's side, above the pan rail, at the back "RB20" or "RB25", just a thought

[intrexin]

so is the rb25 a "better intake manifold than the 20

[gt3037s]

Hey Block and ECU ..... U can also know from the block /ECU .

RB 25 timing belt cover can be modifeid to use from RB20.Coil cover Rb25 can also use on RB20 So it mean u can not look by the cover......

GT3037S = GTRS

[themadscientist]

My RB25 timing cover looks lik an RB20 but it says " ", explain that, hmmmm?

[JonPowell]

R32 RB25DE?

[intrexin]

didn't the later rb20's not say rb20 on the timing cover?

[themadscientist]

R32 RB25DE?

maybe that was too easy. Ok I am think of a number between one and 246865435,,,,,,

[JonPowell]

Not too easy, just some paid attention in Skyline class.