R33 Rb30 Conversion

[Alf]

87mm bore is safe providing you don't go silly with the horsepower and the bores have been crack tested. i.e 600+hp

 

Over that you would also want to make sure you are running a set of forged rods.

Thanks for the info Joel.

I'll start with getting the block pressure tested and cleaned, it's no loss if it's no good it was free after all. :cooldance

What over size pistons and rings did you guys use?. I'm looking at the arias RB30E forged pistons to suit the twin cam conversion, but they only come in 20 thou as I know of.

I'd rather have the bores bored out to a minimum to keep the cylinder walls as thick as possible just for peace of mind.

Does anyone know what the size of a virgin bore is? and can it be measured easily? :Pimp2:

[Skyrine-Dave]

bore is 86mm

[Cubes]

86mm.

The stroke is 85mm. :cooldance

I used Wiseco forged pistons.

If I were to do it again I would go custom and get the quench/squish setup exactly. But you learn as you go along.

This has been my first engine build so at the start of it I didn't even know of quench/squish.

[Bl4cK32]

Sounds like another build is in the pipeline there eh Joel

Neverending search for the perfect combustion engine continues...lol

[Cubes]

R1.

:upurs:

[Bl4cK32]

Ducati 999r

:devfu:

[Cubes]

The Ducati is the nicer choice. :freak:

[Trust33]

Hi has therre been any updates made to the rb30/25 how to page?

The one with pics and specs and all that.

[NickR33]

hey guys has anyone got a quote from High Octane on their RB25/30 kits?

going to call them anyway just wanted to know if anyone has had any experiences with them or their kits?

[MonstaS4]

The Ducati is the nicer choice. :freak:

Damm right!! Maybe i'm biased though.

[GTR-Ben]

Thought this might help some of you. Shows the clearance of RB30 sump to RB crossmember.

[Cubes]

The only difference that i've noticed between the 20t and the 30 sump is at the very front where the sway bar slips in underneath.

The RB30 sump has less clearance as it has a slope to one side where as the 20 sump is horizontal.. in otherwords.. straight.

If you are having sway bar issues Ben I would definately go the rb20 sump.

I can't say if the 25 sumps are the same as the 20 sumps.

[GTR-Ben]

A Slope at the front or back?

I don't have a swaybar issue due to using a cefiro bar.. and getting a custom one made

[Cubes]

At the very front of the sump.. The sway bar resides underneath.

On the RB30 there is a slope that runs from the passenger side down to the drivers side.

The RB20's section at the front does not slope, it stays at the same level.

Hope that makes sense.

I'll post a pic if you need.

[GTR-Ben]

Oh i'm more worried about the slope at the back.

I think I may move the engine forward a little then down a whole lot. Just have to put a kink in the gearstick

[Cubes]

A slope at the back... I see what you mean.

I didn't actually take notice of that.

[GTR-Ben]

See if the engine was forward a little more, it could be dropped 50mm or so! I just wonder what other problems this may cause..

[Cubes]

That I do..

Darren used the RB20 sump and has lowered his motor to the point where the sump base is sitting ever so slightly lower (either that or its perfectly level) than the x-member.

Just have to be carefull not to loose the arse end out and mount a gutter.

[GTR-Ben]

Well yeah.. but we install trust sump extensions onto quite a few GTR's.. which drops the sump a lot!! and never had one rip off yet..

I was thinking more about the problems with the gearbox/driveshaft with having the engine 30-50mm lower..

[Cubes]

Well yeah.. but we install trust sump extensions onto quite a few GTR's.. which drops the sump a lot!! and never had one rip off yet..

I was thinking more about the problems with the gearbox/driveshaft with having the engine 30-50mm lower..

Thats exactly why I was umm and arrring about dropping the motor.

The last thing I want is for it to have the driveline alignment issues of a VN Commodore.. lol

BA V8 Ford bonnet here I come.. lol