Rb Head L Block

[kenkelZ]

is it possible to put an rb20 head on a L20 bottom end if so how hard

[Duncan]

l20a or l20b? anyway - there are lots of differences and won't happen. You can however get a z series head (eg z18et) onto an l20.

[kenkelZ]

L20et would the z18 affect performance

[Duncan]

sorry mate I'm confused. are you talking about the 2l 4cylinder out of the bluebird and 200b? no turbo or injection on it, engine was called l20b. l20a was the 6 cylinder used in earlier models (skyline maybe?). Anyway, as I said the z18et head is about the best thing you can bolt onto it, single overhead cam with turbo - they are pretty rare these days though I think.

[kenkelZ]

r30 skyline 6 cylinder been told would be a lot of work to put complete rb in coz of L and RB different engine mounts so was just thinking about heads

Edited May 17, 2008 by kenkelZ

[Duncan]

in that case there are bigger l series motors you can put in, from patrol I think? goes right up to l28

[kenkelZ]

yes truewas just wondering about rb heads, no anything about doing an engine swap from L to RB?

[Boof]

yes truewas just wondering about rb heads, no anything about doing an engine swap from L to RB?

Mate if you want to put an Rb into an R30, go and have a look in the classic skylines section and do a search for this subject, its been discussed before...

And no, as far as i know you can't fit an RB series head onto an L series block, just much easier to do whole engine swap...

[Marco-R34GTT]

in that case there are bigger l series motors you can put in, from patrol I think? goes right up to l28

In which case the L28 can have it's displacement increased to 3100cc..

http://www.thezstore.com/page/TZS/CTGY/PEM05

[bryyy]

best thing you can bolt to an L series is an OS Giken twincam head.... good luck finding one though haha.

[B0oStEr]

best thing you can bolt to an L series is an OS Giken twincam head.... good luck finding one though haha.

Years ago I borrowed a book on the 'L' series and it mentioned the OS Giken twincam head.

Apparently it cost US$20,000 and was ultra rare more than 25 years ago.

[Nismo_Boy]

Years ago I borrowed a book on the 'L' series and it mentioned the OS Giken twincam head.

Apparently it cost US$20,000 and was ultra rare more than 25 years ago.

If not more, there were only a hand full (about 5) OS twin cam heads made for the 4 cylinder and roughly 20 or so twin cam OS heads made for the 6 cylinder.

OS has been approached a lot of times by very wealthy influential people and American business’s wanting more castings made and they just simply wont, nor sell the casting mould.

[B0oStEr]

is it possible to put an rb20 head on a L20 bottom end if so how hard

I thought about doing this to a L28 with an rb25 head for about 5 minutes.

Anything can be done but not worth the effort in this case.

I think the best option for an rb engine in the r30 is to use an r31 engine crossmember and also adapting the rack and pinion steering.

[Sweetleaf]

RBs are an easy fit into L powerd cars,Much easyer than converting an old chain driven cam engine to a belt driven twincam head.

L and RB have the same bore centers but thats about it.

[Marco-R34GTT]

OS has been approached a lot of times by very wealthy influential people and American business's wanting more castings made and they just simply wont, nor sell the casting mould.

I don't get that, if they aren't going to make any more... Then why keep the fcking mould?!?!?!??!!?

The L series motors with twin cams and 4vpc would rock my socks!!

[Nismo_Boy]

I don't get that, if they aren't going to make any more... Then why keep the fcking mould?!?!?!??!!?

Couldn’t tell you to be honest.

[r30kansai]

r30 skyline 6 cylinder been told would be a lot of work to put complete rb in coz of L and RB different engine mounts so was just thinking about heads

An RB20DET bolts straight onto a L20ET crossmember same as the gearbox mounts straight onto the gerbox mounts, you will however have to cut the tailshaft and also cut a bigger whole where the gearstick comes up into the cabin as the RB gearbox is longer than the standard L20 affair.

I have done this conversion twice now and suits the R30 chassis well.

All in all putting the RB20 is a sh#tload easier than getting an engineering degree which is what your going to need to fit an RBhead onto a L20 bottom as they are completely different.

As boof mentioned there is heaps of stuff in the forums about so give it a search.

another thing you can do if you want to retain the L series is get a L28 bottom end and bolt the L20 head and turbo on and away you go, alternatively you can put a L24 (much more common) but the L28 would be better

sorry mate I'm confused. are you talking about the 2l 4cylinder out of the bluebird and 200b? no turbo or injection on it, engine was called l20b. l20a was the 6 cylinder used in earlier models (skyline maybe?). Anyway, as I said the z18et head is about the best thing you can bolt onto it, single overhead cam with turbo - they are pretty rare these days though I think.

He was talking about a L20ET, Straight 6 2L Turbo SOHC, standard in a HR30 Skyline, Made from 1981 to 1984? maybe 85.

[race_snooze]

I really hope your not talking about the L16, L18, L20 series might be a bit hard to fit a 6cyl head to a 4 cyl block...

[r30kansai]

I really hope your not talking about the L16, L18, L20 series might be a bit hard to fit a 6cyl head to a 4 cyl block...

The L20ET was a six cylinder mate.

Still would be hard to fit a RB head to though.

[Fitzpatrick Speed Works]

A ka24 head will fit a l18 with a fair bit of work, we are about to attempt just waiting for the head to arrive from the states.

There is a guy in the states that cut 3 ka24 heads in to 2 cylinders then joined them together and put it on his z, with twin turbos the cars makes in excess of 500whp, very involved engineering project though not for the faint hearted.