2.6 Magna engine block cracked.

[BrianO]

Hi all,over the last few months i have built up a 2.6 early Magna engine to fit into my L-200 ute.Naturally i had to change front timeing cover,intake manifold and other parts needed to fit RWD ,no problem there and fitted the engine about a week ago.All went great for the first couple of days ,lots more power,torque etc,then things started to go bad.Couple of the welch plugs behind the exaust manifold looked to be leaking[or so i thought].Bit later i noticed a hair line crack running between the Welch plugs and coolant seep out when the engine heats up.I.m wondering if this is common for Magna engines to crack or was i just plain unlucky with this block.I bought the engine from a wrecked car which looked to have big Ks on it.Any one else had this happen?Cheers.

[C_Fernance]

Seems to be fairly common on the Magna 2.6's. I've sent a few blocks to Sims that have cracked in that exact same spot.

[DragonCypher]

Perhaps due to the layout of the FWD water jackets/pump location etc?

Tis all I can think of really, never heard of any other 2.6's doing that, even the narrowblock RWD autos


-
Chris

[amgis_obrut]

Hi all,over the last few months i have built up a 2.6 early Magna engine to fit into my L-200 ute.Naturally i had to change front timeing cover,intake manifold and other parts needed to fit RWD ,no problem there and fitted the engine about a week ago.All went great for the first couple of days ,lots more power,torque etc,then things started to go bad.Couple of the welch plugs behind the exaust manifold looked to be leaking[or so i thought].Bit later i noticed a hair line crack running between the Welch plugs and coolant seep out when the engine heats up.I.m wondering if this is common for Magna engines to crack or was i just plain unlucky with this block.I bought the engine from a wrecked car which looked to have big Ks on it.Any one else had this happen?Cheers.

its not just a magna thing its an astron thing

chemiweld works a treat

[cheaterparts]

Bit later i noticed a hair line crack running between the Welch plugs and coolant seep out when the engine heats up.I.m wondering if this is common for Magna engines to crack or was i just plain unlucky with this block.I bought the engine from a wrecked car which looked to have big Ks on it.Any one else had this happen?Cheers.

its not that uncommon even rwd astrons can have this happen
I have welded blocks before between the welsh plugs but would only do it at a pinch

what I did was knock out the welsh plugs and grind out the crack ( vee groove ) including the welsh plug sides where it is cracked
heat around the side of the block and weld with NiFe cast rods and pean the weld between runs after welding the welsh plug hole are die ground to form a new surface on the welded side

it dose work but I only did it to keep an engine running I would prefur to reblock

hope this is some help

[BrianO]

Thanks Cheater & all others who replied to my post.I also had other issues besides the cracked block,namely the hydraulic lifters became noisy after couple days running,BAD rattle noise which i suspect was oil pressure or timeing chain related.Engine also started running rough etc.Basically when i noticed the cracked block that was the last straw so i have pulled out the 2.6 and fitted my old motor back in which runs perfectly[2 lt Sirius 4G-63].I may look around for another block later next year but in no hurry.Thanks all.

[Jamie]

...... namely the hydraulic lifters became noisy after couple days running,BAD rattle noise which i suspect was oil pressure

Bad luck on the cracked block.

Fortunately I have never suffered a problem like yours.
I rebuilt a new engine for my L200 ute using a GK sigma block.

The guys at the local engine shop recommended using the GK block as they had never seen one crack.
I'm sure someone will prove me wrong, but one of them did his apprenticeship at a Mitsubishi dealership so he had seen his far share of Astrons.

Apparently GK and GN blocks were a bit of an exception.

As for the Hydraulic lifters being noisy, I cleaned, inspected and tested 32 of them just to find enough to use in my new engine. But even after a afternoon's worth of work doing this, I still had a noisy one!

I priced a new set from the local Bursons. When they quoted $50 for a set I nearly died thinking about how much time I had wasted.

Just remember when you are fitting new lifters to bleed them first.
This is easily done by fitting the new lifter into an old rocker in a dish of diesel, a Chinese take-away container works well.
There will be a hole in the top of the rocker, push a pin into the hole and pump the rocker up and down.
When the air bubbles disappear, it is ready to install.
I have found that the easiest method is to do this on your work bench and put each lifter into a jar of diesel.
When you have bleed the lot, then take the jar of lifters to your car.
Loosen the rocker assembly just enough so you can get the lifters in and out of the rockers, (this saves them falling out which can be really frustrating!)

All the best,

Jamie

[Billsy]

i ve got a GK with a cracked block. they definitely areny exempt from cracking.

[81GL]

Apparently GK and GN blocks were a bit of an exception

Correct me if I'm wrong, but aren't the scorps less likely to crack welsh plug to welsh plug and also porous?
-Being full imported rather than "Aussie made" (no offense to us... but we really weren't too with it in the early days )

Cheers,
Nick.

[stealth]

just an opinion here
but the only ones ive seen crack have factory exhuast
manifolds on them and are exposed the localised heat
and one block the was lightened and hyd locked at full noise
the answer would be to keep the pipes away from the area
and use a heat shield between block and exhaust like the
factory ones that everyone removes
cheers stealth

[amgis_obrut]

Apparently GK and GN blocks were a bit of an exception

Correct me if I'm wrong, but aren't the scorps less likely to crack welsh plug to welsh plug and also porous?
-Being full imported rather than "Aussie made" (no offense to us... but we really weren't too with it in the early days )

Cheers,
Nick.

some of the import blocks have a ridge between the plugs right in the place where the aussie ones crack

[Billsy]

just an opinion here
but the only ones ive seen crack have factory exhuast
manifolds on them and are exposed the localised heat

i think thats it aswell
ive got a shield between the turbo manifold and the block, having red hot 850 degrees radiant heat on one side and 70 degree convected coolant on the other cant be a good combination for crappy cast metal.

[amgis_obrut]

just an opinion here
but the only ones ive seen crack have factory exhuast
manifolds on them and are exposed the localised heat

i think thats it aswell
ive got a shield between the turbo manifold and the block, having red hot 850 degrees radiant heat on one side and 70 degree convected coolant on the other cant be a good combination for crappy cast metal.

i have a non turbo engine here thats cracked

[stealth]

doesnt have to be a turbo manifold to be to hot and close to the block
like the gay as cat manifold that came on unleaded astron two
take the heat shield off that and use it and it will more than likely crack
mate im happy to be wrong ,but this is my opinion!
cheers stealth