RB head on L-Gata

[atomman]

I have pretty much finished all those little jobs around the house , redone my camper van , done the garden etc
So when an old thread came up on here the other day if twin cam RB head fit on L-gata engine's it got me thinking ,

Found one on eBay just up the road and made a cheeky offer and it was mine , turns out he was very fed up with time wasters and knew my car , so was happy for me to have it for pretty cheap,

I have a spare L24 with the head off in my workshop and looks like I'm not going back to work for another 3 weeks so can have a look at mocking it up and work out a plan,

Anyways here it is RB20DET head



Comes with cam's , rocker covers and even an old head gasket , put the L-series gasket up to it last night and head bolts line up and combustion chambers to , oil drain isn't far off but not sure about the head oil feed , gonna clean it up today and get the L24 block on the engine stand,


Here is the E88 with the RB head gasket on it,

Been doing some reading and found some YouTube videos featuring cars in Japan with RB heads , not sure how to overcome the cam drive problem yet , convert the head to chain or convert the L-series to belt ?

Either way its should give me something to do over the next few weeks and a bit on an engineering challenge to keep me busy,

Plan is run some DCOE's for now maybe ITB's later , I did find a adaptor plate that allows Mikuni's to bolt up to the inlet manifold,

So if anyone has links or anything that could help just post them up , all help appreciated ,

 

[jonbills]

got to be chain drive I think! you can probably plagiarise whatever Derek did with his twin cam head on hybridz.org

 

[richiep]

You need to look at the pics here:
http://spark88.blog.fc2.com/blog-category-50.html

Here’s your timing chain...

 

[uk66fastback]

Project of the Year 2020 so far, and only a day in ... !

 

[Rob Gaskin]

I was thinking about that sort of thing or a chain driving one cam and then another (or a belt) driving the second from the first.

Will a RB crank fit an L series?

 

[atomman]

You need to look at the pics here:
http://spark88.blog.fc2.com/blog-category-50.html

Here’s your timing chain...

thanks Rich , I need all the info i can get

 

[Alphabettispaghetti]

Would a belt setup be easier?

 

[Mark N]

You need to look at the pics here:
http://spark88.blog.fc2.com/blog-category-50.html

Here’s your timing chain...

Using the L series cam sprocket as the intermediate drive would keep the crank to cam timing correct.
Those three equal sized top sprockets look quite small and you would only be able to time the cams to the nearest link, which is quite a bit bigger than an RB belt tooth.
SR20 (or similar) adjustable sprockets might be an option if they can be made to bolt up to the cams.

 

[Mark N]

Would a belt setup be easier?

Running an electric water pump and belt driven oil pump wouldn't be too difficult.
However, sealing off the oil behind the belt would be harder as there is no oil seal behind the L series crank sprocket.

 

[richiep]

And here’s a video of that Japanese RBL in the Hakosuka running:

 

[richiep]

And a second one by the same guys in a Z:

 

[Mark N]

This would let you run RB26 ITBs if you want to in the future.

https://otakugarage.com.au/product/rb26-intake-manifold-adaptor-rb25-rb20/

RB26 ITBs and sandwich plate can be had for around £500 on eBay.

 

[jonbills]

And a second one by the same guys in a Z:

That's a lot of work.

 

[atomman]

Looks like it got to be chain drive , unless I try and put a seal on the crank behind the drive , or maybe go dry sump , but probably easier to chain and try and improve what others have done before, modify the fron of the RB head to seal up and have a front cover like the ones in the videos ,


Got the bottom end on the engine stand and cleaned up a bit , but forgot my socket to take the front pulley off , so could only do so much today,
I found some old cam sprockets to and they fit straight on the RB cams, and are the same size as the RB items but I need to work out the gearing ratio for cams and crank, teeth etc



looking at the RB head the back oil return channels are outside the L-series block but can hopefully sort that by welding them up and then tapping a hole and running external lines back to the sump,
front Oil feed looks to be out by only a few mm between RB and L-series , other needs some work, the water feeds that are between the RB inlet manifold need a workaround , the Hako in the video has them blanked off but the Z has a tube running along the top with the feed plumbed in , I could use the Rb26 lower inlet manifold and use the standard water ways , and then make adaptor plate to mount the DCOE's or design and machine up my own manifold design,

lots to overcome , plan , design and work out by I can only cut the grass so many times a week ,

thanks for the videos Rich

 

[atomman]

some more vids

 

[jonbills]

The middle oil feed is the important one - the front one is "only" the supply from the head back down to tensioner. Presumably for the middle one you can just have an external hose?

 

[atomman]

The middle oil feed is the important one - the front one is "only" the supply from the head back down to tensioner. Presumably for the middle one you can just have an external hose?

yes should be able to just drill and tap into the oil feed gallery , just need to check the feed on the head and where the oil way is

 

[atomman]

need one of theses i reckon but for ITB's or chop up this type

 

[uk66fastback]

Some clever people on this site, that's for sure!

 

[Alphabettispaghetti]

Have you finished it yet?