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4G54 2.6 Heads...

Posted: Fri May 27, 2005 9:09 am
by mr_sikma
Hey,

I am looking at putting an Astron 2 magna head onto my astron 1 sigma block. I have been told its pretty easy but i may occur some problems.

Any got any info, tips, help etc?

Anything will be great :D

Cheers

Posted: Fri May 27, 2005 9:26 am
by WidebodyWoody
From memory, I heard that the only difference is the lack of Jet Valves. Thats it. But I haven't done it so I am not sure.

Posted: Fri May 27, 2005 3:28 pm
by mr_sikma
Jet Valves???

what are they on?

the magna head has bigger ports, valves than sigmas and some have roller rockers!

Posted: Sat May 28, 2005 10:12 am
by Chryzla
from my experience the studs are on the opposite corners and the waterjacket is slightly different

Posted: Mon May 30, 2005 7:30 am
by MrBishi
WidebodyWoody wrote:From memory, I heard that the only difference is the lack of Jet Valves. Thats it. But I haven't done it so I am not sure.
Jet valves are only on import Astron motors. All Aussie delivered stuff do not have jetvalves.

-Astron II head will bolt onto Astron I block.
-Exhaust manifold is the same.
-Inlet manifolds are different.
-Cams are not easily interchangable.
-Combustion chamber is larger on astron II.
-Rocker cover not interchangeable.

There are also minor differences between RWD & FWD astron 11 heads.

Posted: Mon May 30, 2005 12:06 pm
by Chryzla
I thought id be nice and share my research.


Astron 2's:
GN sigma head: small valves
GJ Scorpion head: largest valves on the market for Astron heads out of the factory (best head IF rollerrockers will go onto it)
TM-TS Magna: RollerRockers, dont know about Valvesize yet.

Posted: Wed Jun 08, 2005 7:54 am
by mr_sikma
so GJ scorp head is the easiest way to go? Is that the last of the scorps?

If it has roller rockers does that mean you cant run aftermarket cams?

Is magna head only better because of the roller rockers?