I DESPERATELY NEED HELP! (4g52 rebuild)

[Jailjubic]

I am so utterly confused.

I bought a reconditioned 4g52 block a while back, just the block with pistons, rods and shaft. I have come to the rude awakening that the parts I salvaged from another 4g52 from a GE or GH 79 Scorpion (auto) do not fit! The sump is about an inch too wide, subsequently, timing cover I also got is also slightly too wide where it meets the sump. This has led me to the conclusion that I have a narrow block. However, I am having extreme trouble FINDING narrow block parts. I went to a fella with many many astrons and grabbed supposedly narrow block timing covers and sumps from him, but they are the same size. The only timing cover I could find which would fit was from a wreckers. It appeared to be from a magna or something, since the water pump location was deleted on that version. I'm so confused. Aren't auto 2.0l scorpions meant to be narrow block? Nothing makes sense. I just need a sump and timing cover to fit my engine. My rebuild is at a stand still until I can find replacement parts. Any help is really appreciated!

[Superscan811]

Aren't auto 2.0l scorpions meant to be narrow block?

First and foremost, NARROW BLOCK and WIDE BLOCK only applies to the BELLHOUSING bolt pattern, and has nothing to do with the sump and timing cover.

Most Astron engines have the wide sump and timing cover, irrespective of whether it's a 2.0L, 2.6L, Auto or manual.

The one that breaks that rule is the GN Sigma.

These are the transition blocks with the blanked off water port that sticking out of the back drivers side of the block, where Magna's run their water pump pickup.

There are some other ones but they are hard to accurately predict which make and model they came from.

Hope this helps.



Cheers.

[Taz]

Hmmmmmmmm that might mean i have the GN sigma 4g54 block then. Has the magna style blanked off hump at the rear, but has that weird sized sump on it. Year stamp on the block adds up too. Interesting...

[Jailjubic]

Amazingly, I just managed to discover this myself 10 minutes ago after more research. After talking with my friend with a wideblock, I realized indeed, wide and narrow blocks do not affect the sump at all. I assumed it did since my sump wouldn't fit. SO, I DO have a GN block. I hope there aren't many differences, all the parts I've bought have been for GE/GH. So this means I either have to use a magna water pump (if I wanna use a magna timing cover, since it blocks off the front water passage). Or find GN timing cover (if I wish to use the GE/GH water pump I've already bought.)... Wow. TBH the magna timing cover would be better, cus them I wouldn't have the rusting bolt problem.. But... Gosh. Let's see if I can find any GN sigmas! Thanks so much for your speedy reply. What a rollercoaster this has been.

[Sigmaproject]

Just to elaborate on the sump and timing case width issue.. All of the sumps and timing covers fitted to Sigma 4g52/4g54 are the same size EXCEPT for the Sigma GN 2.6 Astron 2, which is around 30mm narrower across it's width.
Also the Magna timing cover has no provision for the water pump..totally different. Easy way to tell which Astron motor you have. Under the inlet manifold ,the Astron 1 has a removable balance shaft cover. The GN Astron 2 does not have the removable cover.

[Superscan811]

Under the inlet manifold ,the Astron 1 has a removable balance shaft cover. The GN Astron 2 does not have the removable cover.

True to a point, From the GJ onwards, the silent shaft housing on the passenger side of the block DON'T have the removable cover.

I hope there aren't many differences, all the parts I've bought have been for GE/GH.

Almost all the Astron parts are interchangeable. Pistons are the only obvious exception (82mm for the 2L and 91.1mm for the 2.6L) and the crank throw is obviously different (98mm for the 2.6L and 90mm for the 2.0L). The TS Magna oil pump is worth getting but it requires a bit of grinding to the front timing case to fit properly, as it hits on some of the webbing.

Hope this helps.


Cheers.

[Jailjubic]

Just to elaborate on the sump and timing case width issue.. All of the sumps and timing covers fitted to Sigma 4g52/4g54 are the same size EXCEPT for the Sigma GN 2.6 Astron 2, which is around 30mm narrower across it's width.

Not just the GN 2.6, but the GN 2.0, as we've just established. I have a 2.0l GN.. and the regular sumps don't fit. Indeed, my 2l has no removable balance shaft cover and is about 2-3cm narrower across its width at the bottom. I will try to stick with the sigma timing cover, i don't wanna buy another new water pump. If I do decide to go for magna parts, will the sump fit too? Furthermore, this engine is actually going into a LB Lancer. I hope the sumps didn't get larger or anything in the GN.

Speaking of which.. Anyone got a GN sump and timing cover?