Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

RB30DET compression

88-SERIES200

New Member
Joined
Apr 28, 2010
Messages
81
Reaction score
2
Points
0
Location
Brisbane
Members Ride
rb30det VL wagon project, VL series 200
Hi i just need some proper advice on an engine im building. It is a genuine vl turbo bottom end with a rb25det head. could i run into any issues compression wise with using the standard turbo pistons with the twincam head and will this affect fuel enconomy?
 

Pub247

Well-Known Member
Joined
Apr 14, 2006
Messages
3,372
Reaction score
58
Points
48
Location
Melbourne S.E.
Members Ride
Ford Fairmont
um you cant use stock turbo pistons with twin cam head i believe

There's no valve reliefs in piston for 4 valves
 

88-SERIES200

New Member
Joined
Apr 28, 2010
Messages
81
Reaction score
2
Points
0
Location
Brisbane
Members Ride
rb30det VL wagon project, VL series 200
Thanks. Can anyone else validate this?? If using the stock turbo pistons is going to be an issue i might just use a single cam head until i can afford forgies with higher compression
 

88-SERIES200

New Member
Joined
Apr 28, 2010
Messages
81
Reaction score
2
Points
0
Location
Brisbane
Members Ride
rb30det VL wagon project, VL series 200
also does anyone know if the vl turbo head uses stiffer valve springs than a non turbo head? I am aware that the cam is different.
 

Pub247

Well-Known Member
Joined
Apr 14, 2006
Messages
3,372
Reaction score
58
Points
48
Location
Melbourne S.E.
Members Ride
Ford Fairmont
No springs are same but i suggest getting new ones theyre fairly cheap

Single cams make good power so not much point putting on twin cam unless your going all out
 

88-SERIES200

New Member
Joined
Apr 28, 2010
Messages
81
Reaction score
2
Points
0
Location
Brisbane
Members Ride
rb30det VL wagon project, VL series 200
i already have the head with cams and exhaust manifold and dump pipe all i need is a plenum,sensors,dizzy,injectors etc. No i dont want big power just a quick and reliable street car. and i really like the note of the rb25 too and i thought that combination would make the power i want easily. 220 - 280 kw
Surely that wont cost much more than a rb30 single cam build
 

nasty1

New Member
Joined
Feb 16, 2008
Messages
1,739
Reaction score
3
Points
0
Location
adelaide
Members Ride
vy2 clubsport
220-280 rwkw good $5000-10000
 

88-SERIES200

New Member
Joined
Apr 28, 2010
Messages
81
Reaction score
2
Points
0
Location
Brisbane
Members Ride
rb30det VL wagon project, VL series 200
I dont really see how.. maybe 5. I already have the block and head and other parts i need. I will be getting the block cleaned and honed and the head cleaned and checked but im keeping the stock rods just getting new pistons, rings, bearings. And that figure i gave is more a second stage of the build. I'd be happy with 170 - 200 straight up. what can the factory rb25 ecu and injectors handle?
 

Pub247

Well-Known Member
Joined
Apr 14, 2006
Messages
3,372
Reaction score
58
Points
48
Location
Melbourne S.E.
Members Ride
Ford Fairmont
Your going to have to go forgies for the pistons to clearance the head They're an off the shelf item these days as its a common mod.

I assumed that you didnt have all the gear already which is why i said go single Cam.

You could probably keep the bottom end to 2000 including piston which are going to be half that cost
 

cracker

New Member
Joined
Aug 21, 2004
Messages
959
Reaction score
7
Points
0
Age
33
um you cant use stock turbo pistons with twin cam head i believe

There's no valve reliefs in piston for 4 valves
actually... they do.

use n/a bottem end, gives around 8.5 comp ratio.

turbo bottem end would be quite low...
 
Top