4g52 + 4g54 II head

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Jailjubic
Posts: 47
Joined: Sat Jul 04, 2015 8:56 pm

4g52 + 4g54 II head

Post by Jailjubic »

I've read that putting on 4g54 heads onto the 4g52 can change the compression. Does anyone have personal experience with applying a head from a 4g54 II to a 4g52? I'm still trying to find a donor magna atm.

Secondly, are the ports and values on the 4g54 heads bigger than the 4g52? I was under the impression they were. Which was why i wanted to do this, save me having to pay for them to be opened up. Supposedly the 4g52 heads don't have much room for opening up either.

Any guidance on this would be much appreciated thanks.
C_Fernance
Posts: 728
Joined: Tue Mar 17, 2009 1:19 am
Location: Central Coast

Re: 4g52 + 4g54 II head

Post by C_Fernance »

I believe all Astron 1 heads are the same, with slightly different cams. Astron 2 have a larger combustion chamber to suit the flat top pistons. Putting an Astron 2 head onto a 4g52 will result in a lower compression ratio.

The later heads do have bigger valves, ports and so on. The preferred heads being the M7 castings from the TR Magna which also have roller rockers, though I have heard of people liking the TS heads however these require different pistons.
C_Fernance
Posts: 728
Joined: Tue Mar 17, 2009 1:19 am
Location: Central Coast

Re: 4g52 + 4g54 II head

Post by C_Fernance »

All you need to know should be in this thread.

http://www.sigma-galant.com/viewtopic.php?f=30&t=3970
Taz
Posts: 517
Joined: Sun Apr 26, 2015 7:16 pm

Re: 4g52 + 4g54 II head

Post by Taz »

I have a TP magna 2.6 astron 2 full injection conversion kit at work (brisbane) if you are interested
Jailjubic
Posts: 47
Joined: Sat Jul 04, 2015 8:56 pm

Re: 4g52 + 4g54 II head

Post by Jailjubic »

Cheers mate, I'm sticking with carby though. Thanks for the info guys.
webby
Posts: 1644
Joined: Thu Apr 02, 2009 10:38 am
Location: Parkes, NSW

Re: 4g52 + 4g54 II head

Post by webby »

C_Fernance wrote:I believe all Astron 1 heads are the same, with slightly different cams. Astron 2 have a larger combustion chamber to suit the flat top pistons. Putting an Astron 2 head onto a 4g52 will result in a lower compression ratio.

The later heads do have bigger valves, ports and so on. The preferred heads being the M7 castings from the TR Magna which also have roller rockers, though I have heard of people liking the TS heads however these require different pistons.
4G52's all have flat-tops anyway, don't they? I'd have thought it shouldn't make too much of a difference if that's the case, depending on whether or not the A2 heads have a 2.6 bore chamber diameter?
-Josh.
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