Jump to content
SAU Community

Recommended Posts

the coin needed to get the RB20 head to slow that of a RB25 (is you stroke to 2.4) doesn't justify the cost IMO.

But ye, 26/20... lol

Do any of the mods we do justify the cost?

Not really.

If you wanna build a tough 20, then you're going to build one. And you wouldn't bother putting a 26 head on top...way too much work reducing the combustion chambers. The only downside to a 20 in the cylinder head department is the valve sizes. Fix that and put decent cams in and away you go. 20's are stronger, rev higher more safely etc, etc.

It's like the CA18, everyone says they are a piece of shit 'go for the SR', but they are wrong. A fresh CA will outdo a fresh SR with similar dollars spent

Here was me initially thinking this was a topical pisstake thread relating to the RB26 vs 30 one hahaha.

Seeing as there was a question asked about trying to make an RB20 breathe I may as well try an answer - doesn't one of the R34 offerings have a Neo RB20 head? Are they any better than the R32 one? Maybe that could be something worth looking at?

Heres a picture of the intake port job we did on my rb20head to flow for the rb24 build

post-23119-1236223233_thumb.jpg

I can't get one of the exhaust because the manifold is urrently attached too it.

so why did you open up the port entry to slow down the air? did you touch anywhere near the valve seat?

so why did you open up the port entry to slow down the air? did you touch anywhere near the valve seat?

Of course... rite down to the valve seat. intake is port matched also.. no problems with air speed at 30psi :banana:

Toque x Revs = horsepower.

So, RB20 doesn't have mcuh torque, so rev the poor little thing as hard as you dare!

In order to rev really stinking hard, it will really want to breathe..

This thread doesn't seem that silly when you boil it down. Sure, there may be a better way of getting the airflow your after, but I cant see the issue with starting with a head that already is known for lots of air and has a massive amount of parts you can buy off the shelf to help you.

Issues doing any kind of build will always bugg you,

but i bet everybodies jaw would hit the floor if they got past by an RB20 revvvvving @11 000rpm.. or higher! The sound would be like an R1 on roids.

Say good bye to any spare time and all your cash! but you sure have proved one thing, nobody is going to beat you to it!

I say Go for it..

How are you going to address the fact that the bore sizes are seriously huge mismatches? 78mm bore into a chamber designed for something with a 86mm bore? Its not going to be nice in there at all.

How are you going to address the fact that the bore sizes are seriously huge mismatches? 78mm bore into a chamber designed for something with a 86mm bore? Its not going to be nice in there at all.

+20

It's not a stupid idea but it's stupid if you try it. People are always trying to re-invent the wheel. You don't need a 26 head on a 20 block to make power. Just because it's a 26 head doesn't mean you are automatically going to be able to rev it to 11k and make 1000hp. Thats a crock of shit. And as far as revving an engine to 11k, It's not just the cylinder head that limits rpm. Crankshaft, rod length, stroke etc all play a role. With a cast crank you are not going to safely rev a 20 past 9500rpm.

It's like putting a 20 head onto a 30 block. Stupid. Increasing compression ratio in a forced inducted engine is as simple as increasing boost. Plus chamber sizes are far too different to make it work. Going that way is more practical than 26 head on 20 block though. The valves will hit the edges of the block on the way down and you won't get the head gasket to seal.

But if you have unlimited funds and want to make something that no one else has, then go for it. You will have an engine that people will say 'wow, that's impressive' but then will wonder why their mum's corolla can nearly keep up with it.

TUF120

http://www.boostcruising.com/forums/index....=317565&hl=

AFAIK was running a 26 head on his 20...

He is on this site but cant remember his user id?

edit here he is! http://www.skylinesaustralia.com/forums/RB120WHY-m24062.html

Edited by dano4127

I have a 26 bottom end and head. What would b easiest is that i throw the RB20 crank in the 26 block with 26 head. Running the 86mm bore will give me a bit more diplacement but also increased weight of the pistons. But the shorter throw crank would make the thing a crazy rev happy engine. Dont understand why you would do it though, other then for shits and giggles or a class of motorsport that dictates your cc

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Thanks for doing that Duncan! Makes you a good person in my books. We don't get kangaroos or wombats here. But we have bats and it's similar. AFAIK it's often the mums with a baby attached that get hit because they drop lower when starting from a tree. If you hit an animal, check on it. https://www.ifaw.org/au/resources/wildlife-rescue-app An app to get the closest wildlife rescue contact.
    • My dream is also to have a proper hoist, but I don't think it will ever happen. My quickjack is probably as close as I'll ever get, it really is very good though. 
    • Yeah we keep on in the dailies, it is pretty poor how many animals get hit and the driver leaves without checking....have saved a couple of little ones over the years. Bit of a gruesome job though, pouches generally need to be cut open because they are so tight and often the joey doesn't realise mum is gone so they are still locked onto the teat. I checked the modules in front of the DS wheel where an oil cooler should go.... There is the radar unit - that can go for race use) One of the 2 HX water pumps, the silver cylinder. That needs to be kept but might be able to be relocated But the bad news, the big computer mounted vertically in front of the wheel (blocking any potential air exit) is the electric steering computer. That is required until/unless i do a hydraulic steering conversion, and in CAD based modern car design it is not like I can just pop a big unit like that somewhere else (plus the loom would be too short anywhere else too). So, the passenger side is OK to clear out (just use a smaller washer reservoir, potentially elsewhere), but the DS no beuno
    • Well, all the best with the new camry It was interesting to hear about the UK process, it is generally a lot more streamlined here with a shipping agent looking after all the import side (noting the exact final price can still be a surprise.....) and I've used a few different brokers on the japan (or US) side, and never had any trouble with any of them....luck of the draw I guess. You mentioned you didn't get the auction sheet (understandable since you bought it from a dealer, not auction), but I always try and get hold of that because they are pretty thorough. I've imported 2x R grade vehicles over the years and both were fine, repairs in Japan are pretty thorough compared to here in Oz.
    • BTW I measured the jack I have, it is 70mm at the saddle but you only have about 700 until it returns to 150mm high at the cylinder so it is good but no magic bullet.
×
×
  • Create New...