GT6 lump in a MK1

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tr250
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GT6 lump in a MK1

#1 Post by tr250 » Thu Sep 27, 2012 2:05 pm

I know there's another thread on this, but my situation is a bit different.

I have a Mk1 GT6 engine that has a Mk2 or Mk3 head on it. The PO had the stud holes enlarged for the later head. It ran great and naturally breaths WAY better than the Mk1 engine currently in my 68.

So, I'm planning on dropping the GT6 engine in my 2000. Naturally, I'll need a different exhaust system and intake. My question is the intake. I have a couple later GT6 intakes which I'm assuming will work fine, but will a TR6(early) intake and carbs mount up AND clear the bonnet??

The GT6 that this engine came from...has a GT6 intake with adapters that allowed ZS-175 carbs. Unfortunately, the PO cut off water pipes so I'd rather not use that intake. I have lots of TR6/TR250 intakes that I can use and bolt up 175s to it directly. Will they clear the bonnet if I do? I've not seen any 2500 TC models, but it would make sense that I should be able to do it.

I know I'll have to change the front engine plate as well.

Regards,

Todd Bermudez
'68 MK1 Saloon/w Overdrive
United States

Dazzer
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Re: GT6 lump in a MK1

#2 Post by Dazzer » Sat Sep 29, 2012 4:10 pm

I don't think you'll have problems clearing the bonnet but you need to see that the front carb with some sort of air filter will clear the suspension turret. I've not done your TR6 mod but I've taken an original 'short' MK1 inlet manifold and mounted larger TR4 carbs on it with ram pipes and home made filters.

You can always pack the engine mounts and tilt the engine over to clear, whatever needs clearing as well. If you look on, I believe Chris Witors web site, there is the technical tip on how Triumph added packing shims and moved the engine mounts to accommodate different inlet manifold carb arrangements.

I just drilled and packed my engine mounts to suit.

Hope this helps.

Cheers
dazzer

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Re: GT6 lump in a MK1

#3 Post by Mike Stevens » Mon Oct 01, 2012 11:55 am

The carb saloons over here either use 'short' or 'long' inlet manifolds, the latter with HS6 carbs from SU. All of these fit in the space available, although the 'long' manifold uses an air collector with a flexible pipe to a front mounted single air filter rather than separate filters on each carb.

I guess the TR250 and TR6C used a very similar inlet manifold so, apart from the air collector business, I think it should all fit OK.

I had a Mk3 GT6 some years ago into which I planned to fit a 2.5 engine. I never got around to it (and sold to car when I bought my current Stag!) but I did look into it. The GT6 manifold actually 'drops' the carbs further down than on a saloon to clear the bonnet I guess. It is logical then that if it fits in a GT6, it should fit into a saloon OK.

Cheers,
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Re: GT6 lump in a MK1

#4 Post by Richard B » Tue Oct 09, 2012 2:53 pm

I would get a correct saloon manifold shipped over from the UK (or elsewhere). Keep the carbs you have for the engine.

The GT6 manifold will put the carbs at angle as the GT6 engine is vertical and the Saloon engine is sloped at 7 degrees and the carbs will be tilted upwards.

What carbs will you be fitting? As there are various different inlets for 2000 MkII's
1970 - 1973 Stromberg 150CD's
1974 SU HS4's
1975 - 1977 SU HS6's

nb if you have later carbs you may have to convert to cable throttle. You could do that by either fitting a MkII throttle pedal or a MKI PI throttle cable conversion which clamps onto the mechanical linkage by the bulkhead.
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Re: GT6 lump in a MK1

#5 Post by Richard B » Tue Oct 09, 2012 3:08 pm

Sorry just re-read your original post.

I fitted 175 Strombergs to an ex PI Estate years ago. I used the early MkII 2000 inlet which is designed for 150CD's and I fitted adapters that TriumphTune used to sell (1/4" steel plates with countersunk screws for the OE mounts and two studs for the 175's).

Hope that makes sense? :?
Richard
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Re: GT6 lump in a MK1

#6 Post by tr250 » Fri Oct 19, 2012 4:58 pm

Hi Richard,

Are you saying the manifold compensates for the 7 degree slant?

I have a boat load of TR manifolds that should mate up to the head. They don't compensate for any slant afaik.

Todd

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Re: GT6 lump in a MK1

#7 Post by Richard B » Fri Nov 16, 2012 11:52 am

Hi Todd, Yes the MkII Saloon manifold caters for the 7 degree slope. Some options spring to mind, either;

First: Have one of your TR6 (US) manifolds machined at 7 degrees on the head face. I know of people who have done the opposite (had 2500S manifolds machined so that the could fit in GT6/Vitesses). This may require TIG welding the flanges afterwards.

Second: Have a 2000 MkII manifold or 2.5S manifold (they're quite different so be sure of what you want). shipped over from the UK. I can recommed a couple of people who should'nt be too dear.

Third: An option that I've been think about for one of my cars is fit the engine vertically. This would require a TR6 sump, move the battery into the boot for better weight distribution, and modify the front plate and gearbox adapter to suit. This is quite a bit of work, but I think would be quite 'neat'! It would mean the gearstick would be in a more sensible position!
Richard
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Re: GT6 lump in a MK1

#8 Post by suman » Sat Aug 24, 2013 5:53 am

I noticed that they are a few who transfered they engine to EFI. I am transferring mine vitesse 2l to EFI.
With megasquirt 2. I would like to know what difference I can expect from this conversion. I have an standaard engine fitted with an phoenix manifold.
Also I am looking for an timing table. I only have 2 refences 13 degrees at idle and 24 degrees at 2000 rpm.
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Re: GT6 lump in a MK1

#9 Post by Richard B » Tue Jun 17, 2014 9:56 am

I think with efi you can be looking at 5-10mpg better than carbs, and a bit more power as well!
Richard
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Re: GT6 lump in a MK1

#10 Post by tr250 » Sun Aug 03, 2014 7:24 pm

Richard B wrote:I would get a correct saloon manifold shipped over from the UK (or elsewhere). Keep the carbs you have for the engine.

The GT6 manifold will put the carbs at angle as the GT6 engine is vertical and the Saloon engine is sloped at 7 degrees and the carbs will be tilted upwards.

What carbs will you be fitting? As there are various different inlets for 2000 MkII's
1970 - 1973 Stromberg 150CD's
1974 SU HS4's
1975 - 1977 SU HS6's

nb if you have later carbs you may have to convert to cable throttle. You could do that by either fitting a MkII throttle pedal or a MKI PI throttle cable conversion which clamps onto the mechanical linkage by the bulkhead.
Ok so I made the major purchase of a mk2 inlet suited for 150zs carbies. Mentioned above is my dilemma now...it's essentially set up for a cable. I have a late gt6 inlet manifold that set up for a cable so I believe I have the end for the carbs, but not the other end. So I have the mechanical linkage now. Where pray tell do I get a PI setup? Or if I go the pedal route, where/how does it install? Do I have to drill the bulkhead somewhere?

Btw, I have adapters to install the 175zs carbs. I guess I can do a tr6 linkage?

Cheers

Todd Bermudez
67 mk1 conifer/cactus gt6 engine
United States

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