Page 1 of 2

v6 conversion

Posted: Wed Jan 19, 2011 1:50 am
by BradGTV
hi guys :D
i looking to put all the running gear from my gtv6 into a 4cyl gtv as the gtv is a great body and car and the gtv6 is rusty and needs a re-spray and alot of work.

just wondering what is required to put a v6 12v and transaxle into a 4cyl gtv coupe?
cheers, Brad

Re: v6 conversion

Posted: Thu Jan 20, 2011 6:14 am
by xrad
engine, electronics,driveshaft,rear engine mount (depending on alfetta year is different) driveshaft bearing carrier (depending on alfetta year is different) all the guibos, shifter could be different (depending on year), transaxle (v6's are better made)

Maybe you want to swap 4 for 5 bolt axles?

Hood from GTV6

Different speedo drive and converter

Different radiator, twin fans

update electronics to include more relays (especially starter)

adjust front torsion rods to carry more weight.

bigger tires

bigger brakes

etc....

Re: v6 conversion

Posted: Thu Jan 20, 2011 1:09 pm
by BradGTV
hi xrad, thanks for the info,
from my local froum i have lernt that:

using 2.0 nord mounts on the v6 it will bolt into engine bay,
tunnel needs to be streched to clear v6 dount,
gtv6 shaft will then bolt in,
gtv6 dedion and transaxle will bolt in,
i will use non-isotlaic shifter on gtv6 gearbox,
radiator will be JE camira,

car already has volvo 4pots but i might change them out for the gtv6 brakes,
torsion bars are alreday bigger than standard, suspension has all new bushes, and wheels will be 17x7 from 156. hood will also be swapped over,

i hope to also instal a MS - 2 to simplifiy the conversion, and get rid of the l-jet!!

the things i need to know are:

will the speed work with the gtv6 gearbox?

can i use a isotalic gear stick and housing with the non-isotlaic shift rod??

cheers, Brad

Re: v6 conversion

Posted: Sun Jan 23, 2011 7:10 am
by xrad
speedo on alfetta is mechanical...and on gtv6 is electronic..so you will need to convert speedo. different years of GTV6 gearboxes have different style of speedo output on gearbox. Milano all electronic sensor type.


if you have an nice isostatic milano box, and you do not want the iso mechanism, change out shift rod for non isostatic

I am sure you can use the non-iso gear stick mount...it is the back end of the shift rod that causes issues. Of course, throw length varies with lever length ratio.

the rear portion of shift link rod is different (for isostatic hook up).. . the non -iso shift rod for alfetta may fit the non iso input shaft for gtv6 directly..i don;t know. probably close or the same. you need to check the alfetta transmission selector arm vs the gtv6.

Milano shift rods all iso type and too long

alfa may have changed the front bushing of the shift rod for different years..not a big deal if you can fabricate something. or use what you have.

Re: v6 conversion

Posted: Sun Jan 23, 2011 4:04 pm
by la_strega_nera
BradGTV wrote: using 2.0 nord mounts on the v6 it will bolt into engine bay,
You sure about that?

Re: v6 conversion

Posted: Sun Jan 23, 2011 6:36 pm
by MR2 Zig
you might have a faster car if you go with the twinspark and a turbo...or at least lighter in the front.

Re: v6 conversion

Posted: Sun Jan 23, 2011 7:28 pm
by BradGTV
well im not sure, but ive been told by two people from the aroca forum that they will, do you know any differernt?

as per my thread in track preperation i was originally building a turbo nord engine,i have since droppped that idea and are now putting the 164 3.0 in and later on a turbo for that, much quicker than a TS turbo will ever be :mrgreen:

Re: v6 conversion

Posted: Mon Jan 24, 2011 10:38 am
by Giuliettaevo2
4 cil engine mounts don't fit the v6...

v6 turbo and TS turbo? my bet is the TS turbo is faster around track. weight distribution is way better.

straight line performance can be quite comparable since the gearbox is the limiting factor here... 300 bhp with the v6-T(T) or with the TS-T is not a problem for the engine but the gearbox won't like it very much.

If you have a rotten GTV6 and a mint 4 cil just put the two next to each other and start pulling stuff off one car and putting it on the other. :wink:

Re: v6 conversion

Posted: Mon Jan 24, 2011 2:47 pm
by la_strega_nera
BradGTV wrote:well im not sure, but ive been told by two people from the aroca forum that they will, do you know any differernt?
Every 4cyl to v6 conversion i've ever encountered involved cutting the chassis mounts off a rotten 90 to weld into a 4cyl GTV - Dan's done 2 from memory, Julians was a cut and weld... the v6 block is much wider at the mounts than the 4cyl just from eyeballing the engine in my 164 and my 105's motor on a stand - the bolt pattern looks similar but I think it's different?
The quality of info on alfaclubvic is a bit variable.

Re: v6 conversion

Posted: Mon Jan 24, 2011 3:18 pm
by xrad
Here are a few pics on the mounts. I know you will use gtv6 mounts, but kinda cool how close they are..

pics of New alfetta mounts against 164 block.

alfetta mount holes line up perfectly( neat since 20yr difference), length is different. So you will obviously need the shorter v6 mounts and rubber blocks. V6 Rubber block pin holes look like they line up to Alfetta body (mine is a 78)


I do not know if V6 dimensions between engine mounts is different than the Alfetta

I might have the mounts backwards, but holes line up either way

Re: v6 conversion

Posted: Mon Feb 21, 2011 8:44 pm
by BradGTV
thanks for the info,
im still going to put a 164 3.0 in my daily gtv, but will keep the gtv6 together and not wreck it.
ive got a 75 2.5 engine that gives me the flywheel, sump, oil pump, bellhousing, studs ect..
im woried about the driveshat, without getting a gtv6 driveshaft (to expensive and hard to find) is there anyother option?
like using the front half of the shaft from a 75 with the rear half of a gtv driveshaft?

or getting a gtv driveshaft, cutting the flanges of, getting a 75 shaft and also cutting the flanges off, then welding (done by driveshaft specialist) the 75 flanges on a gtv driveshaft so the gtv driveshaft has the v6 donuts on it then have it re-balanced?

Re: v6 conversion

Posted: Tue Feb 22, 2011 2:37 pm
by la_strega_nera
BradGTV wrote:thanks for the info,
im still going to put a 164 3.0 in my daily gtv, but will keep the gtv6 together and not wreck it.
ive got a 75 2.5 engine that gives me the flywheel, sump, oil pump, bellhousing, studs ect..
im woried about the driveshat, without getting a gtv6 driveshaft (to expensive and hard to find) is there anyother option?
like using the front half of the shaft from a 75 with the rear half of a gtv driveshaft?

or getting a gtv driveshaft, cutting the flanges of, getting a 75 shaft and also cutting the flanges off, then welding (done by driveshaft specialist) the 75 flanges on a gtv driveshaft so the gtv driveshaft has the v6 donuts on it then have it re-balanced?
Even simpler than that - take the 2 driveshafts to the shop, and ask them to shorten the back half of the 75 shaft - they'll set it up in a lathe, cut the weld off the flange, cut the tube down, slot it back together and weld away. should only cost a couple hundred tops.

Re: v6 conversion

Posted: Wed Feb 23, 2011 1:21 am
by MD
..using the front half of the shaft from a 75 (V6)with the rear half of a gtv driveshaft?

That's all you have to do.

Fit a V6 donut in the front and 2 litre donuts for the middle and rear.
It will work fine. However, it will need to be rebalanced as a new unit.

If you are using an existing 2 litre transaxle, the clutch input spider will be ok, if it is a V6 box, change the spider to a 2 litre one and fit the shaft.

Just remember this.
All the shafts are the same length at the front.
The rear sections are short if they are from a coupe and long if they are from any sedan

BTW If you are going expand on this, perhaps it should go in the transmission topic set?

Re: v6 conversion

Posted: Wed Feb 23, 2011 2:13 am
by BradGTV
thanks MD and lasteganera :D
good to hear its a easy fix, ive found a 75 2.5 driveshaft for cheap today aswell!

cheers, Brad

Re: v6 conversion

Posted: Sun Mar 06, 2011 3:04 pm
by la_strega_nera
Spoke with Dan about v6ing a 4cyl at some length on the weekend - the front stud on the 4cyl mounting is in the same position as the rear stud on the 6cyl mounts - the trick is you fab up (or chop out of a balled up 75 or 90) a half mount and weld it to the front of the 4cyl chassis mount. I should have taken a photo, but it basically means you can swap from 4banger to 6banger and back at will.