Triumph Sports Cars

engine swaps and other performance upgrades, plus "factory" V8s (Stag and TR8)

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nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


GT6 2.3l turbo engine swap
Posted by: nmanville
Date: April 15, 2008 12:21AM

I need some help. I am currently looking for a 2.3l turbo to go into my GT6 MK3. I was just wanting to gather some info on the work that is required. Do I have to modify engine mounts, transmission mounts? Is it imparative that I switch out the dif. What kind of fuel pumps are good and what kind of wiring is needed? What about gauges? Any help would be nice. Thanks for any replys.


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: V6 Midget
Date: April 15, 2008 12:11PM

Nick, I'm no expert on the GT6 but am fairly familair with the chassis. You'll probably have to fabricate new engine mountings. Would you be using the existing Triumph transmission or planning on using a matching 5 speed from the same car as the 2.3? I'd recommend using the 5 speed and making a mount for that transmission. As far as the rear differential goes, it's a real problem as it's not easy to replace with any other unit and has limited strength and ratio availability. I've heard that there is a swap for the Datsun/Nissan 240z diff that's been worked out, but I don't have any details on this. There is one GT6 being built that has been covered in the newsletter a bit that has some information on the differential mods [forum.britishv8.org] You might contact Jon and see what he's done in that area.
For the turbo engine you'll probably run electronic fuel injection, so you'd need a high pressure high flow pump. The easiest pump to adapt is the Bosch pump used on some BMWs and VWs. Mounts outside the tank and can handle most fuel injection requirements. Since the GT6 has a wooden dash insert, changing gauges isn't a big job, just make up a new panel to fit the gauges you want. I don't have any particular brand to recommend, what ever you like.


turbospitfire
Max Brewster

(49 posts)

Registered:
04/25/2008 01:05PM

Main British Car:
1979 Triumph Spitfire Ford 2.3 Liter Turbo

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: turbospitfire
Date: April 25, 2008 03:10PM

Hi Nick, been there done that. See my writeup under the Spitfire section, Max Brewster. Not every detail is included but you will get an idea of the work needed. I'm assuming you mean a Ford 2.3 turbo. If not, then never mind.

Some notable modifications:
Even with the center hump in the bonnet, you will have to raise the height about an inch. You will have to cut down the intake or about 4 inches will have to be added to the bonnet. That could be ugly. I cut the upper intake down, rotated it 90 degrees, and had it welded to the lower. I also removed the runners from the upper intake and knife edged the lower intake runners where the upper and lower meet. Alternatively, there is an after market intake that has this done. Some of the Merkur guys use it.

If you use the T5, you will have to narrow the top of the frame in the area where the starter mounts to the bell housing for clearance. I cut a sliver out to the top, moved the side outward and re-welded it.

You should use the T5 and this will involve moving the emergency brake mounting bracket back 3 inches for shifter clearance. The T5 from a 4 cylinder mustang will work or if you use a 5.0 mustang the pilot on the input shaft will need to be machined smaller to match the pilot bearing. You will need a stronger differential. I have a four cylinder T5 and the gear ratios are to low because of my rear end ratio. I can't use 1st gear, its usless and the over drive of .79 is not quite enough for cruising at highway speeds, 3500 rpm at 75 mph. I have to start in 2nd gear. I plan on upgrading to the after market ratios mentioned in my writeup.

Depending on the differential you use, pay attention to the ratios. I used an RX7 with 3.9:1. If I had to do it again I think I would use a early 90's T-bird differential, they had IRS. There are more gear sets available and you can get a limited slip. A salvage yard should have these.

Due to speedometer cable clearance issues, I used a Smiths electric speedometer, cobra style, that fit into the original dash.

Another issue will be rear bearing housings, axles, brakes. Again look at my writeup.

Upgrade the brakes. My Spitfire is scary fast and you need to more brake. Be safe!

You will need to modify the firewall, floor around the transmission, transmission cover, etc. Depending on you differential and suspension modifications, you may have to modify the rear body where it goes over the differnetial and rear suspension.

With fuel injection, you will need to modify the fuel tank with a baffle and add a return line. If you don't the pump will starve when the tank is half empty from fuel sloshing around while cornering. I would use a drop in unit to avoid having to weld a fitting into the bottom of the tank which I had to do since I used a frame mounted fuel pump.

Wiring took me two full weekends.

I had to make motor mount brackets I modified and existing on on the passenger side and fabricated a complete new onefor the driver side. On the driver side, I had to weld a plate to the shock tower to strengthen it before clearancing the pinch weld for the oil pan. I was able to the GT6 rubber mounts. They are fine since the ford motor weighs 20 lb less than the GT6 motor.

I'm sure I am missing something, but this may give you something to think about and maybe save you some time.

This project was a lot of work, but it was worth it.
Cheers,
Max Brewster
1979 Spitfire


nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: nmanville
Date: April 25, 2008 10:10PM

I was wanderig what rear end gears would be best? I saw that there were 4.11 to1 gears in some later Spitfires and Vittese models. Would that work or would I need something altogether stronger? The car still needs a lot of work but with some help it can be a lot of fun.Thanks for all of your help.


turbospitfire
Max Brewster

(49 posts)

Registered:
04/25/2008 01:05PM

Main British Car:
1979 Triumph Spitfire Ford 2.3 Liter Turbo

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: turbospitfire
Date: April 25, 2008 10:49PM

Any Spitfire or Vitesse differentials are basically the same and the old Herald has an even smallet pinion shaft. These are all to weak for the motor since it has a lot of torque. Have you considered something with good hourspower but less torque? In the Spitfire photo section like Larry Breitkreitz's car? There was a lot less fabrication and the motor has 124 HP but not a lot of torque. With the torque lower you could probably use the stock differential, but I would not be doing any burn outs! Otherwise, if you want a lot of power, you will need to get a beefier rear end. The T-bird is strong enough and not expensive. You will still have to deal with stronger rear hubs and brakes. You may be able to install the entire T-bird subframe. You will of course have to narrow it. That a big issue with these cars, they are so darn narrow. When I was planning my project, I considered a Corvette rear end, but it was overkill for what I was going to do. Also, they are expensive, even used.

Cheers,
Max Brewster
1979 Spitfire


turbospitfire
Max Brewster

(49 posts)

Registered:
04/25/2008 01:05PM

Main British Car:
1979 Triumph Spitfire Ford 2.3 Liter Turbo

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: turbospitfire
Date: April 25, 2008 11:00PM

Nick, One more thing. If you use the 2.3 turbo and t5 from a 4 cylinder Mustang or Turbo T-bird (They are the same), you should be looking at rear end ratios of 3.5:1 or maybe even 3.3:1. It will increase drivability. These ratios are not available for the RX 7 diff. Like I said before, My 1st gear is worthless since it is 3.97:1 ratio. If I use it I have to shift in about 1 second. It wouldn't even help in a drag race!

--Max


nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: nmanville
Date: May 11, 2008 08:51PM

I was wandering if you could send me a picture of your engine mounts?



turbospitfire
Max Brewster

(49 posts)

Registered:
04/25/2008 01:05PM

Main British Car:
1979 Triumph Spitfire Ford 2.3 Liter Turbo

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: turbospitfire
Date: May 13, 2008 12:56AM

Nick, I took a few photos but I don't have any from before the engine was installed. They aren't very good, lots of stuff in the way. Top to bottom:

Front driver side - I used the existing mount. I made a plate to mount to the engine and cut down the mount so I could weld the plate to it.

Next 2 photos, Rear driver side motor mount.

Rear driver side shock tower - You can see the plate I welded in and the steering shaft going through it.

DSCF0782.JPG
DSCF0783.JPG
DSCF0784.JPG
DSCF0785.JPG

More to come......


turbospitfire
Max Brewster

(49 posts)

Registered:
04/25/2008 01:05PM

Main British Car:
1979 Triumph Spitfire Ford 2.3 Liter Turbo

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: turbospitfire
Date: May 13, 2008 01:12AM

The next three photos:
A view of the top of the shock tower - You can see where I had to grind off the pint welds where it goes by the engine pan rail. That is why I welded in 1/8th inch plate on either side of the shock tower.

Motor mount, passenger side top view - its built like the original in design but longer and made to mount to a few threaded holes in the block. This is the only photo I can get. I can't get my camera in to get a front or rear view.

One more of the driver side rear view of the shock tower.

I think I mentioned before that I used the stock GT6 rubber mounts. They work just fine.

DSCF0786.JPG
DSCF0790.JPG
DSCF0793.JPG

Hope this helps,
Cheers,
Max


nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: nmanville
Date: May 13, 2008 01:43AM

Thanks for the photos, they helped a lot. I was just wandering if you had any cooling issues? I didn't see a cooling fan on you radiator. I like your design for the front air dam but I was thinking about mounting the intercooler in front of the radator and putting a cooling fan on the back. Would this block too much air? I noticed that some of the TR6 guys had done that, but I don't know if I could get it to work in the little space the GT6 provides. Thanks for any imput.


turbospitfire
Max Brewster

(49 posts)

Registered:
04/25/2008 01:05PM

Main British Car:
1979 Triumph Spitfire Ford 2.3 Liter Turbo

authors avatar
Re: GT6 2.3l turbo engine swap
Posted by: turbospitfire
Date: May 13, 2008 11:20AM

Nick, the fan is in the front, its a pusher. The radiator is a Scirroco style I bought from Jegs. Griffin makes it. Its all aluminum, no plastic tanks. It cools just fine as long as I'm moving. In the summer, it does get pretty hot at stop lights. My fan flows around 850 CFM, I am going to replace it with one that flows 1200 CFM. Since it cools just fine when driving (190 degrees), I think the increased air flow will solve my problem. The factory fan temp sensor doesn't kick in until 210 degrees. I am going to replace it with one that kicks in at 200 degrees, if I can find one. I added the air dam to get more air into the radiator. The secondary effect was to prevent front end lift at speed. It actually made a difference. The stock 79 Spitfire had a spoiler and ducting to the radiator so the air dam does the same thing. Your configuration idea should work. You can play with the angle of the radiator. There are several ways to do this. You will just have to try it and see what happens. You can always rearrange things later.

Cheers,
Max


dtindell
david tindell

(19 posts)

Registered:
05/23/2008 09:45PM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: dtindell
Date: May 24, 2008 09:19AM

Hello I have a 70 gt6 with the inline 6. I would like to change the car over to a V8 350 with automatic transmission. Can you guys help with some questions I have?
Do you have to change the yoke on the gt6 drive shaft to match the chevy transmission?
Do you need to change the rear end? I would liek to keep the one in it.
The inline 6 runs well, but I would like automatic?
Thanks


nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: nmanville
Date: May 25, 2008 04:28PM

Like it said in the above section, the GT6 diff is just to weak. I am putting a 4 cylender turbo into mine and I have to change out the rearend. I don't think it would be vary relaible to hook a 350 to the standard rearend.


nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: nmanville
Date: May 25, 2008 04:30PM

I saw a Jaguar in the junkyard the other day and saw the rearend. I am looking up the gear ratios but I like the double coil spring idea on an IRS. I don't know if it would work but it is supposed to have a very good ride in the Jaguar.


tycorace
mark thompson

(45 posts)

Registered:
05/31/2008 02:00AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: tycorace
Date: June 01, 2008 04:20PM

The trans for either the spitfire or gt 6 are strenth wise junk for the 4 cylinder with the 6 cylinder the break all the time. For racing we changed the rear end to a 240 z rear end and axles , but now days I would suggest either the toyota supra rear end and axles , conquest willl also work but the supra come with a limited slip with 411 ratio stock. The triumph trans is garbage The sycros would last one race week end some times. If you are going to run any thing over 250- hp I would recomend a totaly reworked or redesiged frame.
Mark



nmanville
Nick Manville

(8 posts)

Registered:
04/15/2008 12:12AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: nmanville
Date: June 05, 2008 12:47AM

I am a little behind. I just got my engine this saturday. I put it in for a test fit. Coud you use both of the existing motor mounts? I saw that you only used one and then fabricated the other. Could I just cut down the mounts I have and weld a plate to them to make them work? Would this be too weak or would it work? I can use the stock mounting holes on the engine too right?


tycorace
mark thompson

(45 posts)

Registered:
05/31/2008 02:00AM

Main British Car:


Re: GT6 2.3l turbo engine swap
Posted by: tycorace
Date: June 05, 2008 09:21PM

We never had any problem with the stock engine mounts and they are easy to use when puttinh in a 4 or 6 cylinder engine.
mark


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