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1978 gtv4 to 6 conversion

Posted: Mon Oct 16, 2006 7:14 am
by jazig.k
iv got the chance to pick up a cheap 90 2.5 v6, and i plan to use the engine and trans to drop into my 78 gtv.

so far iv been told it all bolts in fine, and that the engine mounts need to be moved forwards 10mm. anyone know which is correct from experience?

which tail shaft do i use? the 90's or the gtvs?

also, are the torsion bars the same length?

what problems should i expect?

Posted: Mon Oct 16, 2006 8:11 am
by sh0rtlife
once i have the 79 in my hands this weekend i could compare it to my 83...but untill then im useless :?

Posted: Mon Oct 16, 2006 12:52 pm
by MD
1 Buy a set of V6 engine mounts, cut off the old ones and weld in the new taking careful note of location or extend the original ones forward by the amount indicated by the engine mount (on the engine).
2 Use the 90 shaft with possibly the 2 litre rear donut coupling to clutch input shaft.
3 You wil need to intergrate the ECU with your existing wiring and install an eletric fuel pump and return line to the fuel tank.

What to watch out for?

More regular invites to the policemens ball. :D

Posted: Mon Oct 16, 2006 12:56 pm
by Daniel
Dead easy. :D
You retain your original mount and weld the front half of the 90 mount (cut from the 90 chassis) to it. I don't have a pic with me but I'll grab one tonight and post it so you can see. ** Actually, have a look at http://alfagtv6.com/bb/viewtopic.php?t= ... b599efb5f2 **
Use the front half of the 90 tail shaft and the rear half of the GTV one. The biggest issue here is the trans tunnel size in the GTV - small ! The 90 shaft is a little different to a GTV6 one and that makes fitting that big front donut up through the tunnel a little more difficult.
The V6 rear engine mount (bell housing one) is actually about 5mm narrower than the 4cyl but that's easy fixed by slotting the holes.
Beyond that, everything else pretty much bolts in.
I retained the standard GTV radiator and it was fine.
I also retained the standard GTV trans but it only lasted a few years before spitting a few teeth from the diff planetaries (go the 75 TS) but the 90 setup is good if a little tall in diff ratio (3.55:1) and a bit of a pain to set up a speedo on (can be done - same as 75 TS swap).
You will need a GTV6 bonnet to fit the intake under unless you get (and modify) a 164 setup.
The 2.5 swap is a worthwile conversion but lots of people will ask why you didn't just buy a GTV6 (been there :evil: )
** Damn, looks like MD beat me to the post **

Posted: Mon Oct 16, 2006 9:13 pm
by MD
"** Damn, looks like MD beat me to the post **"

Hey big guy, look for the same treatment on the track. haha :D

Posted: Mon Oct 16, 2006 9:53 pm
by Daniel
Hey Mike, just like me you have to finish the car and get it on the track before you can take any bragging rights but you're gunna have to push a lot of horseys outa that ol 4 banger to keep up :lol:

Posted: Mon Oct 23, 2006 1:13 pm
by hagen111
Go to http://www.alfetta.nl

In the Picture Book you can select Steve's Alfetta 3.5 V6, which includes pictures of the modified engine mounts. This is a 4 cyl. sedan converted to 3.5 V6 monster.

Image

Posted: Mon Oct 23, 2006 2:48 pm
by rz
hoi hagn!

Posted: Mon Oct 23, 2006 5:53 pm
by patzo_3l
are u in victoria. i have done this conversion a few times. if u need any parts or anything else pm me and ill see what i can do for you.

cheers

How about a TS?

Posted: Tue Oct 24, 2006 5:29 pm
by MatthewK
Hey Patzo, have you ever done a twin-spark drop-in for a GTV 2.0? I'm hoping to do it to my 1984 model sometime.

Posted: Wed Oct 25, 2006 2:34 am
by TS_turbo
TS is direct bolt on for 2.0 GTV :) only slight clearence problems with narower and taller TS head ..and especialy ign. cables and holder