Hey all

im wondering if a sigma astron 2 head can bolt onto a magna astron 2, and will it have the horizontal inlet manifold water jacket?

if i remember correctly the sigma heads a tad wider but will bolt up but isnt there the issue with the water pump cos there isnt a cut out for it i dunno dont know a full lot on this

Hey all

im wondering if a sigma astron 2 head can bolt onto a magna astron 2, and will it have the horizontal inlet manifold water jacket?

i was sure that the sigmas astron 2 head will bolt up. wen i bought my new head for the new engine, the engineer had it in stock as a "sigma 2.6L head".

i thought the astron I heads had the vertical water jackets?

the only diff i think is the sigma head has a hole on the rear side of the head, something for the oil. anyway, the magna head u have should have a plate bolted across this hole with 2 bolts and some gasket goo or a gasket of some kind. i had to rip this plate off my old head and put it on the new one. thats the only differenence i found.

ok on my current head there are two water thinngys in the inlet manifold both higher than they are wide

on a sigma im pretty sure that one of them is smaller and wider than it is tall

i have a linx manifold for my new carby suited to a 2.6 and 2l sigma

it fits up to the head yet that water hole in my head is to big and comes ova the top were on a sigma im pretty sure it doesnt ill take some pics to show u

as u can see in the bottom pic there is a gap that would prove to be a problem with my cooling system

although as a side note, on the manifold the hole has been clamped shut, i can un screw the clamps, yet any guess to why someone would plug this?

that manifold even looks too big to fit in the engine bay anyway man... looks like it'll hit the chassis.

but yeah, i probs wouldn't use that manifold. the water jackets are different. number 1, the coolant won't flow properly and number 2, how will u gasket it? u wouldn't even be able to gasket goo it properly.

it fits in, with filter on it i have very little clearence (yes i have included engine movment in this)

i have a sigma engine with ****ted rings that i pulled apart, the guy i bought it off for 20 bux put a reco'd magna head on a few years back which is decked, its an astron 2, i'd go have a look but its night time and shed doesnt have lights.

It's hard to say. Some of the times, the head will be entirely serviceable on the motor, others it's rather fussy. I was running a Sigma head for a short while on my second motor, but blew the head gasket (not entirely related. I went through 4 head gaskets, and 3 heads, before the block cracked, and stripped the bearings.)

It's hard to say. Some of the times, the head will be entirely serviceable on the motor, others it's rather fussy. I was running a Sigma head for a short while on my second motor, but blew the head gasket (not entirely related. I went through 4 head gaskets, and 3 heads, before the block cracked, and stripped the bearings.)


:bowrofl: :bowrofl: lol

sorry

I have compared magna and sigma heads in the past, the sigma head and block deck is wider, sigmas have a coolant groove/passage running the length of the underside of the head beneath the exhaust ports, it is fed through the timing case. I have used sigma head gaskets on magnas and found that the extra width under the exhaust and the coolant port in the timing case are the only differences.
A Sigma head might leak coolant from the head gasket on the exhaust side if it was fitted to a Magna block, especially if the narrower magna headgasket was used.