Gibbon’s 1971 GT6 bothering - comment here

[VitesseEFI]

Couldn’t find a place to comment so I made one…..

Nice looking little car in the first pic…. Like the wheels (14”?) been looking for a set for years!

My GT6 build thread is here

https://sideways-technologies.co.uk/forums/index.php?/topic/7535-nick-chriss-gt6-mk-3/#comments

might have something useful.

Also my MX5 gearbox conversion here

https://sideways-technologies.co.uk/forums/index.php?/topic/8925-mazda-gearboxes-some-bstard-told-me-it-was-impossible-so-i-had-to-do-it/
 

Obviously you’re not trying to fit it to the Triumph six but chopping the box tail housing down, mountings, speedo drive and moving the gearshift position are also covered. I wouldn’t recommend repeating my gearshift mods, although it works ok it was a lot of effort and I think it would have been smarter to accept the position of the shortest of the “easy” mods (look for the links in my thread), mod the tunnel cover and perhaps move the handbrake back 60 - 80mm which is alleged to be easy….

Keep up the good work 🙂

[Lord Gruntfuttock]

They are a pretty car...

[VitesseEFI]

1 minute ago, Lord Gruntfuttock said:

They are a pretty car...

They are, from most angles. And really small. I spent the 2 plus years of my restoration wondering whether I’d be able to drive it (I’m 6’3” and son’s Spitfire was a very tight fit). But it’s fine. Though getting out with dignity is a challenge. Key is to use the Triumph seats. MX5 seats only work for shortarses…..

It’s a nice drive too; completely different from the near-mechanically-identical Vitesse and also the Spitfire.

[gibbon]

1 hour ago, Lord Gruntfuttock said:

They are a pretty car...

I'm firmly of the opinion that they blew the entire budget on the styling and made up the shortfall by parts-binning the rest of the project 

[gibbon]

1 hour ago, VitesseEFI said:

Couldn’t find a place to comment so I made one…..

Nice looking little car in the first pic…. Like the wheels (14”?) been looking for a set for years!

My GT6 build thread is here

https://sideways-technologies.co.uk/forums/index.php?/topic/7535-nick-chriss-gt6-mk-3/#comments

might have something useful.

Also my MX5 gearbox conversion here

https://sideways-technologies.co.uk/forums/index.php?/topic/8925-mazda-gearboxes-some-bstard-told-me-it-was-impossible-so-i-had-to-do-it/
 

Obviously you’re not trying to fit it to the Triumph six but chopping the box tail housing down, mountings, speedo drive and moving the gearshift position are also covered. I wouldn’t recommend repeating my gearshift mods, although it works ok it was a lot of effort and I think it would have been smarter to accept the position of the shortest of the “easy” mods (look for the links in my thread), mod the tunnel cover and perhaps move the handbrake back 60 - 80mm which is alleged to be easy….

Keep up the good work 🙂

ah, I actually read through that thread while researching, didn't realize it was you! suffice to say I doubt you'll be learning anything from my thread but hopefully you'll get a laugh and might lend some advice, which you already have

my modified shifter sits just behind where yours is, and yes I absolutely regret it haha. Did you have a bastard of a time keeping the rod aligned? 

 

[VitesseEFI]

2 hours ago, gibbon said:

Did you have a bastard of a time keeping the rod aligned? 

The whole project was a howling bastard. Took months. By about half way through I was just being stubborn. I don’t remember the rod being especially awkward, but it had plenty of serious competition.

The final kick in the nuts was that the howlingest bastard of the lot was the gearbox I fitted, which whines vigorously in all indirect gears. Louder than the Triumph box that came out in fact. 1 -3 I don’t mind that much. It sounds “authentic”. 5th though - that’s just annoying. I do have another box and all the special parts will swap over, though interestingly enough the Mazda box in my sons Spitfire (mated to a Ford Sigma 1.6) is noisy in exactly the same way so maybe we just need to develop a better sound proofing approach.

I shall follow this with great interest as my GT6 engine isn’t the healthiest. Not sure I can stand loosing the 6 cylinder noise though.

[VitesseEFI]

2 hours ago, gibbon said:

I'm firmly of the opinion that they blew the entire budget on the styling and made up the shortfall by parts-binning the rest of the project 

Well yeah…. It’s based on and developed from the late 50s Herald. Only somewhat developed mind! The main surprise is that they are as good as they are.

this is a rather more extreme development (just in case you’ve not already come across it (random episode I’m afraid)

)

[Alfashark]

36 minutes ago, VitesseEFI said:

I shall follow this with great interest as my GT6 engine isn’t the healthiest. Not sure I can stand loosing the 6 cylinder noise though.

@yoeddynz Still got the little Mazda V6 dimensions handy?

[dmulally]

1 hour ago, VitesseEFI said:

The whole project was a howling bastard. Took months. By about half way through I was just being stubborn. I don’t remember the rod being especially awkward, but it had plenty of serious competition.

The final kick in the nuts was that the howlingest bastard of the lot was the gearbox I fitted, which whines vigorously in all indirect gears. Louder than the Triumph box that came out in fact. 1 -3 I don’t mind that much. It sounds “authentic”. 5th though - that’s just annoying. I do have another box and all the special parts will swap over, though interestingly enough the Mazda box in my sons Spitfire (mated to a Ford Sigma 1.6) is noisy in exactly the same way so maybe we just need to develop a better sound proofing approach.

I shall follow this with great interest as my GT6 engine isn’t the healthiest. Not sure I can stand loosing the 6 cylinder noise though.

My old standard 10 had a whine in the diff so I swapped it for a herald one and it was worse but better gearing. 

I'm convinced that with old triumphs if you don't hear some sort of whine you might as well keep driving to the audiologist as they have some bad news to hand signal to you. 

[gibbon]

2 hours ago, VitesseEFI said:

The whole project was a howling bastard. Took months. By about half way through I was just being stubborn. I don’t remember the rod being especially awkward, but it had plenty of serious competition.

The final kick in the nuts was that the howlingest bastard of the lot was the gearbox I fitted, which whines vigorously in all indirect gears. Louder than the Triumph box that came out in fact. 1 -3 I don’t mind that much. It sounds “authentic”. 5th though - that’s just annoying. I do have another box and all the special parts will swap over, though interestingly enough the Mazda box in my sons Spitfire (mated to a Ford Sigma 1.6) is noisy in exactly the same way so maybe we just need to develop a better sound proofing approach.

I shall follow this with great interest as my GT6 engine isn’t the healthiest. Not sure I can stand loosing the 6 cylinder noise though.

the 6 does sound incredible, especially with the wheelbarrow exhaust

My final plans actually include a supercharger, with which I will mask all other drivetrain whining

[gibbon]

12 hours ago, VitesseEFI said:

Nice looking little car in the first pic…. Like the wheels (14”?) been looking for a set for years!🙂

 forgot to answer this, yes 14", they were on the car when I bought it and I've never actually seen another gt6 with different wheels that made me think "wow I wish I had a set of those instead". I actually think the body design is so nice that wheels will always play second fiddle (unless they're grabbing attention by virtue of being horrible!) 

[VitesseEFI]

8 hours ago, Alfashark said:

@yoeddynz Still got the little Mazda V6 dimensions handy?

Yeah….. have given this some thought. Was always a great admirer of Alex’s Viva. These engines were never plentiful here though. Ford Probe was maybe the most common and they are mostly gone. No natural-fit RWD gearbox and needing to make the inlet and 2x exhaust manifolds makes this a serious effort!

[Alfashark]

VR6 it is then!  Probably far too tall for the space available...

[Bearded Baldy]

V4 capri/transhit motor. All the lols in one package!

[VitesseEFI]

2 hours ago, Bearded Baldy said:

V4 capri/transhit motor. All the lols in one package!

Original S6 rather nicer in all respects and only a bit heavier!

On 19/06/2025 at 08:31, Alfashark said:

VR6 it is then! 

Height would be a problem. Not light either and no obvious RWD gearbox solution.

Suspect the Jag V6 and RWD box as occasionally fitted to MX5s will be just too big. Although I have seen a couple with RV8s squeezed in.

[gibbon]

12a would be a pretty serious goer given that the gearbox fits, just the exhaust would come out directly inline with the steering shaft. Plus I've already got one other rotary to worry about 

Also it looks like that "heater outlet" on the back of the head should be anything but blanked, mx5 people have kits to INCREASE the flow out of it because apparently cylinder 4 overheats under enough load otherwise. So I guess I'll weld a hard pipe to it, and maybe look at adding a second outlet on the other side. Or I could notch the firewall for clearance but that's kinda going against my principles 

[gibbon]

hey @VitesseEFI, what's the best bet for a custom propshaft, just a MX5 front and GT6 rear somehow mated together?

[VitesseEFI]

For both of ours we had new propshafts made from new parts.

The mainly because the factory MX5 units have staked joints making re-using the yoke problematic.

[gibbon]

I had heard that they were "non-replaceable" - didn't know if that meant you couldn't just cut behind them and join the tubes, but then again i appreciate not having to have a new driveshaft made if a u-joint wore out 

That gearbox and it's variants got used in a few other cars, I wonder if any other models were lucky enough to get replaceable u-joints, did Ford use them as well?

anyway the long story short - so there's no reason for me to buy an mx5 shaft? 

[bigfoot]

I m just going to leave this here

https://www.hpacademy.com/blog/ryans-1973-triumph-spitfire-with-a-twist-featured-build/?utm_source=facebook&utm_medium=social&utm_term=&utm_content=&utm_campaign=scheduled-post&fbclid=IwY2xjawLQZB9leHRuA2FlbQIxMQABHq8k0ZI_yiNDEQkIZjcwFnZOdaxkeYGKIXDCQXkpfgJwBPKYjKyn6I6hXtwC_aem_EPNTwerkO3unV2ROUDGLnA