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hey guys,

im starting to think of doing a 2.0 NA motor up just to be different now im going out to the wreckers on the weekend to get a magna head now i have read the i should look for a M6-M7 head as these flow best, now questions

will any of this change when i shave the head 3mm?

What magnas are these heads off?

How to i make a fwd head into a rwd head?

Thanks in advance

Nick

mate, all these questions have been answered heaps of times before. I usually don't care when a question is re-asked over again, but we've had a heap of global announcements and other stuff about these kind of FAQs.

You don't change the head from fwd to rwd (as in the head stays the same) it's the intake manifold that gets modded (the ends get chopped and welded to opposite sides).

The head shave will just bump up the compression (not sure how much by with 3mm though) and therefore in theory up the power a bit or at least improve the throttle response.

M6-M7 heads are off TR-TS magnas from memory, but I'm sure someone will either confirm or correct this.

Btw, when you say 2.0 NA are you talking 4g52 or 4g63? Cos neither were in the magnas and I'm pretty sure the heads aren't interchangable (again, sure someone will either confirm or correct this).

Cheers

FWD to RWD heads are exactally the same, just bolt on (just check ur inlet because the Astron 1 heads the bolts for the inlet manifold are directly above/below each other (for carby) where as the Astron 2 (M6 or M7) the inlet bolts are on a diagonal (for fuel injection). Also the water inlet is different I think, but cant remember how.........

The easiest way to tell what type the head is (ie M6 or M7 etc) is on the exhaust side it will be cast into the head.

Hope this helps.


Cheers Matt

RWD and FWD Astron ll heads have different rear water ports, for obvious reasons.

If you are going to use a front thermostat housing , you can use any Astron ll head
If you are going to use a rear thermostat housing, you have to use a Magna head for the large rear water port.

yeah no mate i was wondering about the cam and so on or does that come out of the right place? for some reason i was under the impression that it came out the wrong end

yea mate the 4G52 ive been told all astron heads are interchangeable but need slight modification eg, head shaving to get compression right so 81GL tells me and hes doing the same conversion so ill take his word ;)

Nick

Shaving 3mm may lead to chain slackness.
The only thing to remember when using a magna head in RWD config is the rear coolant port. When using a RWD inlet manifold you either need to weld the head or manifold

Cam is the same as the rwd set up mate, just on the fwd engines the cam protrudes out the 'back' of the engine a small amount to run the water pump.

yes, shaving that much off the head does leave a bit of chain slack, & should be able to deal with easy enough with a half link (havn't done this as yet... one day when i have some spare time... )

Shouldn't require any welding of the head, use the correct manifold & gasket & seals up okay.
-Was using a GN carby manifold my self, good luck finding one which isn't corroded

Nick.

Also all Magna heads (except the TM M1 head) have no lobe on the cam to operate the mechanical fuel pump, as they were EFI with electric fuel pumps. ;)

what you want to do is keep the rocker gear of
your 2.0 and install it onto the astron 2 head then
install a plug (that i will suppy with your manifold)
into the back of head/rocker cover
this way you will have a mechanical cam not hyd
that way you can cam up
as hyd are shit
cheers stealth

so keep my astron 1 rockers?

Will they just bolt in?

lol coincidence really... today at my automotive course i had to take apart and reassemble a head

stealth, when i get ur manifold do i need to worry about the water gallerys??
and mate can u do me a favor? when i get the manifold can u please make me up a fuel pump cut off thingy out of some metal, just the cover thing that would be great ;)

Last thing can anyone confirm what psshhhht said about the heads comming off TR - TS magnas?

Nick

This is a Magna cam on a Sigma head. Not enough sticking out the back to worry about.



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Posted this on another topic, but this is an Astron ll head with adjustable rockers from an early Astron.

You have to use an early cam, but you can use the Astron ll rocker shafts .

hang on lol im a bit confused so i just take the rockers off but use the shafts off the magna? which springs do i use??

Nick

When you get your new head, use the valve caps which come with it and use the rest of the valve train from the astron 1 head.

Nick

i get it now so the holes will bolt up? so dont need to touch valve springs what about if i get a upgraded cam? then do i need to change them?

Nick

exactly as sigma project showed you. I left the magna cam and head as it was, bolted it on and left the rear shafty bit out back. Its so clear of the firewall you could put a fist in there almost and the seals all stay standard. No customisation

So far it hasnt leaked a drop. Though ive had some issues in other areas nearby not related.

yeah no worries i can supply a fuel pump cover (polished stainless too)
and no probs for water gallerys my manifold will work on both
and yes you need to change valve springs to suit your fat as man cam!
cheers stealth