Triumph Spitfire/GT6 weight list

[BiTurbo228]

As a part of my Spit6 conversion/restoration, I've put a good deal of effort into trying to offset the weight of the big 6-cylinder hanging out over the front axle.

So, I've been weighing a lot of the bits that need to be changed, and researching the various weight saving bits and pieces you can get for these cars.

I thought a list of these might be quite useful posted here

Whole car weights are the kerb weights advertised by the factory and engine weights are 'fully dressed' . Anything in italics is something I've weighed myself and anything in normal text is garnered from the internet. Feel free to add anything you know about in the comments. It's far from comprehensive at the moment

Cars
Spitfire 4 - 712kg
Spitfire MkII - 711kg
Spitfire MkIII - 711kg
Spitfire MkIV - 734kg
Spitfire 1500 - 790kg

GT6 MkI - 864kg
GT6 MkII -
GT6 MkIII - 863kg

Engines
1100 OHC -
1300 OHC I4 early -
1300 OHC I4 late - 125kg
1500 OHC I4 -

2.0l OHC I6 -
2.5l TC OHC I6 -
2.5l PI OHC I6 - 183kg

1850 Slant 4 - 132kg
2.0l Sprint I4 - 140kg

3.0l Stag V8 - 202kg

Engine Parts
Stock rocker cover (6-cyl) - 1.046kg
Alloy rocker cover (6-cyl, Rimmerbros) - 1.419kg

Steel backplate (TR6) - 5kg
Alloy backplate (TR6, Canley Classics) - 2.4kg

Steel frontplate (GT6) -
Alloy frontplate (GT6) - 1.25kg less

Cast iron alternator bracket (6cyl) - 1.05kg
Alloy alternator bracket (6cyl, Canley Classics) - 0.32kg

Cast iron alternator adjuster - 0.59kg
Stainless alternator adjuster (Canley Classics) - 0.29kg

Cast iron distributor pedestal -
Alloy distributor pedestal (Canley Classics) -

Spitfire MkIV flywheel - 7.6kg
2500PI flywheel - 12.3kg
Lightened steel flywheel (Chris Witor) - 6.3kg

Stock alternator (TR6) -
Lightweight alternator - 1.95kg less

Stock starter (Spitfire MkIV) -
Stock starter (TR6) -
High-torque starter (TR6) - 2.4kg less

Cast iron water pump (6cyl) -
Alloy water pump (6cyl, Canley Classics) - 1.5kg less

Cast iron water pump housing (6cyl) -
Alloy water pump housing (6cyl) - 1.4kg less

Exhausts
2500PI manifold - 5.6kg
Centre section (Spitfire MkIV) - 0.9kg
Backbox (Spitfire MkIV) - 5.6kg

Gearboxes
Spitfire 3-rail non-overdrive gearbox - 34.5
TR6 overdrive gearbox - 41.1kg

Radiators
Spitfire radiator (full length) -
Spitfire radiator (reduced length) - 5.528kg
GT6 radiator -
Alloy GT6 radiator - 3.317kg

Body Panels
Steel Spitfire bonnet (MkIV) - 28kg
Fibreglass bonnet (GT6) - 12kg

Steel hardtop -
Fibreglass hardtop - 10.2kg
Soft top - 8.5kg

Steel valences (2) - 4kg
Fibreglass valences (2) - 2kg

Suspension, Diff & Hubs
Swing axle rear (per side) - 11.5kg
Rotoflex rear (per side) - 19.5kg
Canley Classics CV conversion rear (per side) -

Cast iron vertical link (each) - 4kg
Alloy vertical link (each, Canley Classics) - 1.5kg

Cast iron rotoflex wishbone (each) -
Alloy rotoflex wishbone (Canley Classics) -

Steel upper front wishbones -
Tubular upper front wishbones - 0.5kg less

Cast iron front hub (Spitfire) -
Alloy front hub (Canley Classics) - 0.8kg

Cast iron diff casing - 6kg
Alloy diff casing - 2kg

Chassis
Cast iron steering rack mounts (2) - 0.566kg
Alloy steering rack mounts (2) - 0.288kg

Brakes
GT6 caliper (each) - 4.5kg
Billet alloy caliper (each, Canley Classics) - 1.8kg

Cast iron caliper brackets -
Alloy caliper brackets (Canley Classics) -

Cast iron rear drum (Spitfire) -
Cast iron rear drum (GT6) -
Alfin drum (Spitfire, Canley Classics/Rimmerbros) - 1.36kg less

Wheels
Spitfire MkIV steel wheels (5J x 13, each) - 6.35kg
Spitfire MkIV steel wheels + 155/80 tyres (each) - 12.2kg

GT6 steel wheels (5.5J x 13, each) -

Cosmic Mk2 alloys (5.5J x 13 each) - 6.8kg
Cosmic Mk2 alloys + 165/75 tyres (each) - 13.3kg

Dunlop racing magnesium alloys (each) - 4kg

[Martins Stag]

Realy useful and interestign post I have a 2.5 rotolex/Cv 1500 spitfire so it all usefull stuff.

Martin

[BiTurbo228]

Quoted from Martins Spitfire

Realy useful and interestign post I have a 2.5 rotolex/Cv 1500 spitfire so it all usefull stuff.

Martin

Thanks I'm doing the same with my little MkIV. I'll be updating it as I go along and weigh more things.

[JohnD]

Very interesting!  Thanks for all that hard work!

Now, lets do a little adding up.
Replace all those engine parts with alloy, except for the rocker cover, which is HEAVIER!   And for the flywheel, which is a special case.  Total 10.4kgs   You could save that by taking out the spare wheel and having an aerosol wheel inflator/sealer with you!  In fact you could afford two cans, and still have a wallet load of money left over , instead of buying all those fancy alloy bits.
The flywheel is a special case as it rotates, and that uses more power, because it accelerates and decellerates far more than the whole car.  BUt they cost a BOMB, and the advantage is so small that you should only do it when you have used every other posisble means of improving perfomance.

Now lets look at the GRP body panels:
That's more difficult, because you haven't been able to weigh a steel hard-top.  Anyone know? And a fibreglass one weighs a whopping 10.2kgs!  I can tell you that the original steel roof of the car that became Silverback (an estate) weighed 30kgs, and the GRP roof I made for it was only 9kgs.   And a lot stiffer! Then doors at 5kgs each, excluding the glass but including the door furniture, that are at least 30kgs each in steel.
And the glass!   Very heavy, in relation to the alternative, unshatterable Polycarbonate, which is almost exactly half the weight of the same pane in glass.

Finally, that big engine hanging over the front axle.  Have you measured the front/rear axle weight ratio?   Can't speak of a GT6, which is a little bit shorter, but a Vitesse has a F/R ratio of 55/45%, near ideal.

One of the few ways in which to make a real difference to this, without exotic and difficult mods, like moving the engine back nine inches, is to put the battery in the boot.   The nine inches is achieved by fitting a Spitfire front engine plate and mounting the engine on that - but that is the easy bit!  Bulkhead, gearbox tunnel, all need major mods to make room.

John

[BiTurbo228]

Quoted from JohnD

Very interesting!  Thanks for all that hard work!

Now, lets do a little adding up.
Replace all those engine parts with alloy, except for the rocker cover, which is HEAVIER!   And for the flywheel, which is a special case.  Total 10.4kgs   You could save that by taking out the spare wheel and having an aerosol wheel inflator/sealer with you!  In fact you could afford two cans, and still have a wallet load of money left over , instead of buying all those fancy alloy bits.
The flywheel is a special case as it rotates, and that uses more power, because it accelerates and decellerates far more than the whole car.  BUt they cost a BOMB, and the advantage is so small that you should only do it when you have used every other posisble means of improving perfomance.

Now lets look at the GRP body panels:
That's more difficult, because you haven't been able to weigh a steel hard-top.  Anyone know? And a fibreglass one weighs a whopping 10.2kgs!  I can tell you that the original steel roof of the car that became Silverback (an estate) weighed 30kgs, and the GRP roof I made for it was only 9kgs.   And a lot stiffer! Then doors at 5kgs each, excluding the glass but including the door furniture, that are at least 30kgs each in steel.
And the glass!   Very heavy, in relation to the alternative, unshatterable Polycarbonate, which is almost exactly half the weight of the same pane in glass.

Finally, that big engine hanging over the front axle.  Have you measured the front/rear axle weight ratio?   Can't speak of a GT6, which is a little bit shorter, but a Vitesse has a F/R ratio of 55/45%, near ideal.

One of the few ways in which to make a real difference to this, without exotic and difficult mods, like moving the engine back nine inches, is to put the battery in the boot.   The nine inches is achieved by fitting a Spitfire front engine plate and mounting the engine on that - but that is the easy bit!  Bulkhead, gearbox tunnel, all need major mods to make room.

John

Thanks yeah I've done a lot of maths vis-a-vis weight distribution. The battery I have is 18.6kg, so swapping that to the rear does a lot to offset the weight of the 6. I'd rather not mount it further backwards myself. It's an elegant solution, but I wanted to see if it could be done without it.

The point behind the alloy bits is they take weight off the front of the car where it's needed. Taking out the spare wheel reduces the weight, but does so in the wrong place and you end up with an even more nose-heavy car. I'm not planning to get most of the little alloy bits that only save a couple of grams, but the front and back engine plates I'll get, same with the water pump and housing (partially because the alloy pumps are a better design).

With all the various little bits I'm getting, and weight I'm shifting around, I should have a 54/46 weight distribution (compared to a 56/44 for the stock Spitfire). That's some very loose maths there, for instance I haven't taken into account how far away from the various axles the lightweight bits are, but with a 2% margin for what I was aiming for (stock Spitfire distribution) I think I should be ok.

[ferny]

Very useful info! I'm surprised the Herald is over 100kg heavier than a Spitfire though, but it does explain why they always feel nippier. The weight saved from all the alloy parts seems a little pointless as well, except perhaps with the hubs, brakes and wheels.

The engine weight came up in discussion last night when someone said they must weigh around 180kg, my response was "nah, remember I lifted that 1500 engine into the boot on my own and it still had the exhaust and everything on it so they can't be more than 80kg". I won't be doing that again then! And it explains the dent in the boot of the Acclaim.  

[uksnatcher]

Brill, thanks for the info....(ok)

[drofgum]

Quoted from BiTurbo228

With all the various little bits I'm getting, and weight I'm shifting around, I should have a 54/46 weight distribution (compared to a 56/44 for the stock Spitfire). That's some very loose maths there, for instance I haven't taken into account how far away from the various axles the lightweight bits are, but with a 2% margin for what I was aiming for (stock Spitfire distribution) I think I should be ok.

This seems very front biased for the stock Spitfire. I would think the stock GT6 is close to this.
                                                                     Cheers,
                                                                     Paul

[BiTurbo228]

Quoted from ferny

Very useful info! I'm surprised the Herald is over 100kg heavier than a Spitfire though, but it does explain why they always feel nippier. The weight saved from all the alloy parts seems a little pointless as well, except perhaps with the hubs, brakes and wheels.

The engine weight came up in discussion last night when someone said they must weigh around 180kg, my response was "nah, remember I lifted that 1500 engine into the boot on my own and it still had the exhaust and everything on it so they can't be more than 80kg". I won't be doing that again then! And it explains the dent in the boot of the Acclaim.  

I think the added weight in the herald comes from the chassis rails that run between the outriggers on the Herald chassis, but were chopped off for the Spitfire. Maybe the body weighs a bit more as well, not sure.

The little alloy bits do seem a little dear for the weight they save, but they're probably worth it if you've got deep enough pockets and want to make the absolute lightest 6-cyl car you can. I haven't got weights for all of them, but they probably add up to something near a kilo. The alloy engine plates and water pump assembly are good chunks of weight saved though the alloy bits for the rotoflex suspension are fairly hefty chunks of unsprung weight too.

Bloody hell ~125kg on your own is no mean feat. When I sold the 4-cylinder from my Spit I remember it being bloody heavy for two of us :S

Quoted from uksnatcher

Brill, thanks for the info....(ok)

No worries I should have lots more info by the time I'm finished

Quoted from drofgum

This seems very front biased for the stock Spitfire. I would think the stock GT6 is close to this.
                                                                     Cheers,
                                                                     Paul

I thought so too actually. I think the wisdom was that the added weight of the bodywork out back on the GT6 offset the weight of the I6 (which should be a fraction lighter than the 2.5l as the crank's smaller). I could be wrong though, so if you know the distribution of a Spitfire I'd love to know it

[Sheepy]

Can I add to the list! 🙂

Just been out to the garage to weigh the hard top (totally original, never welded) for mk3 spitfire
Complete with glass etc

21kg

Was going to weigh the bonnet, but it's tucked away in the corner of the garage! So next time I can get it out I will do!

[BiTurbo228]

Quoted from Sheepy

Can I add to the list! 🙂

Just been out to the garage to weigh the hard top (totally original, never welded) for mk3 spitfire
Complete with glass etc

21kg

Was going to weigh the bonnet, but it's tucked away in the corner of the garage! So next time I can get it out I will do!

Excellent, thanks shall have a go at adding it to the list

Edit: it would seem that I can't edit the OP any more. Anyone know if there's a way?

[Saltddirk]

Shaun,
go round to my place, then you can lift and weigh anything you want, without paint and glass, Doors, bonnet, hardtop, chassis....
But for the sake of accuracy in this highly scientific threat (thanks BiTurbo) please remove the dust with a soft rag and mild soap first if you would 😀

[BiTurbo228]

Quoted from Saltddirk

Shaun,
go round to my place, then you can lift and weigh anything you want, without paint and glass, Doors, bonnet, hardtop, chassis....
But for the sake of accuracy in this highly scientific threat (thanks BiTurbo) please remove the dust with a soft rag and mild soap first if you would 😀

Hah Does that mean I should remove the gaffa tape patching up a hole as well?

Also, four more weights from the Canley Classics website:

Steel frontplate (Spitfire) - 2.25kg
Alloy frontplate (Spitfire) - 0.8kg
Steel frontplate (GT6/TR6) - 1.75kg
Allot frontplate (GT6/TR6) - 0.5kg

[Sheepy]

I weighed my bonnet for you.

Mk3 spit, metal bonnet, complete with bonnet support/hinge tubes
No lights fitted (some rust) 🙂

33.2kg

So I don't know how that compares to a fibreglass one?

[Sheepy]

Quoted from Saltddirk

Shaun,
go round to my place, then you can lift and weigh anything you want, without paint and glass, Doors, bonnet, hardtop, chassis....
But for the sake of accuracy in this highly scientific threat (thanks BiTurbo) please remove the dust with a soft rag and mild soap first if you would 😀

[BiTurbo228]

Quoted from Sheepy

I weighed my bonnet for you.

Mk3 spit, metal bonnet, complete with bonnet support/hinge tubes
No lights fitted (some rust) 🙂

33.2kg

So I don't know how that compares to a fibreglass one?

Tricky to tell as the Mk3 and MkIV/1500 bonnets were slightly different. My GT6 one is 12kg without the supports or hinge tubes.

I've found the weight for my MkIV bonnet though. It's 28kg without the hinge tubes but with the bonnet supports.

[npanne]

I could weigh my spare GT6 bonnet for you, but I suspect that it's significantly lighter than when it left the factory - I must have swept up a kilo of it over the years.

[BiTurbo228]

A couple of new weights

Spitfire front coilover - 3.591kg
GAZ front coilover - 3.352kg

Spitfire rear shock - 0.82kg
GAZ rear shock - 1.501kg

Oil cooler assembly - 1.928kg

Kenlowe fan - 1.69kg

Spitfire starter - 4.739kg
Hi-torque starter - 4.237kg

TR6 alternator - 3.874kg
Lightweight alternator (Canley Classics) - 1.9kg

Spitfire steering wheel - 1.301kg
Moto Lita steering wheel (padded) - 1.046kg

Cast iron rotoflex wishbone - 2.258kg
Alloy rotoflex wishbone (Canley Classics) - 0.75kg

Rotoflex rear assembly (complete) - 19.5kg
Swing axle rear assembply (complete) - 10.5kg

[BiTurbo228]

Two new weights:

Front bumper (Spit MkIV) - 3kg
Rear bumper (Spit MkIV) - 3.9kg

Hopefully I'll be making a fibreglass front bumper at some point, so I'll weigh that for comparison too

[HMaze]

Hi BiTurbo228,

this is a very interresting weight list!

I weighed some parts in my shed, but my scale does only 0.5kg, so not the accuracy you weighed your parts.

petrol tank spitfire mk3 empty: 5.5kg
you could add 0.72-0.78 kg per litre petrol.

radiator " screen" with cards and irons (spitfire): 1.5kg

(water in the radiator should be also accounted for if you move the radiator to a different position)
washer bottle full:?
Overflow bottle half full:?

front bumper with overriders spitfire mk3: 4kg
cast iron manifold with hose pipe 1500: 6.5kg
door shell bare mkiv: 9.5kg
boot lid bare mkiv: 9kg
gearbox casing 3-rail: 7kg
bell housing spitfire: 9kg
2 headlight covers mkiv: 2kg
heater assembly: 4kg

I put some of those weights in an excel spread sheet to calculate some rough weight shifts.

Thanks for your effort,
Harry

[booley]

Quoted from BiTurbo228

Hopefully I'll be making a fibreglass front bumper at some point, so I'll weigh that for comparison too

PRI used to sell a fibreglass front bumper a few years back, but they were discontinued. I believe they had trouble with the mounting points not being strong enough.

Very interesting list...

[Richard B]

The Herald chassis is also 9" longer in the main rails.

Totally agree that its a nose weight problem with 6 pot Spitfires.


I'd be a bit wary re aluminium water pumps, unless you can rebuild them?

[BiTurbo228]

Quoted from HMaze

Hi BiTurbo228,

this is a very interresting weight list!

I weighed some parts in my shed, but my scale does only 0.5kg, so not the accuracy you weighed your parts.

petrol tank spitfire mk3 empty: 5.5kg
you could add 0.72-0.78 kg per litre petrol.

radiator " screen" with cards and irons (spitfire): 1.5kg

(water in the radiator should be also accounted for if you move the radiator to a different position)
washer bottle full:?
Overflow bottle half full:?

front bumper with overriders spitfire mk3: 4kg
cast iron manifold with hose pipe 1500: 6.5kg
door shell bare mkiv: 9.5kg
boot lid bare mkiv: 9kg
gearbox casing 3-rail: 7kg
bell housing spitfire: 9kg
2 headlight covers mkiv: 2kg
heater assembly: 4kg

I put some of those weights in an excel spread sheet to calculate some rough weight shifts.

Thanks for your effort,
Harry

Thanks and no worries

I'd forgotten about the headlight shrouds. The might be alloy but they're fairly hefty castings. I wonder if there's some weight to be saved there.

Good point about the water weight as well. I haven't accounted for the weight of the oil in the oil cooler either come to think of it.

Quoted from booley

PRI used to sell a fibreglass front bumper a few years back, but they were discontinued. I believe they had trouble with the mounting points not being strong enough.

Very interesting list...

Thanks hum, shall see if I can make the mountings fairly beefy. Maybe I could bond some metal brackets into it. It could just be that they didn't want to sell a flimsy product that would impact on their brad-perception. Fine by me though

Quoted from Richard B

The Herald chassis is also 9" longer in the main rails.

Totally agree that its a nose weight problem with 6 pot Spitfires.


I'd be a bit wary re aluminium water pumps, unless you can rebuild them?

Yeah, I'm trying to get the weight distribution to a decent level without moving the engine backwards. Not simple, but it's looking like it's possible.

I've been looking at the alloy water pumps from Canley Classics (alongside the alloy housing). Supposedly they're of a more modern, better design but I haven't actually got any experience with them.

[HMaze]

Hi BiTurbo228,

one interresting thing my excel spead sheet showed, was playing around with the petrol tank.
Using the GT6 petrol tank in the boot instead of the spitfire petrol tank on the rear axle, adds more weight on the rear and subtracts weight from the front. It also puts the CG lower and should be a nice counterbalance for the driver in a RHD car.
On the negative side, it puts the fuelcell in the crash zone, and spreads the weight of the car too far from the center.
Just a thought..

Cheers,
Harry

[BiTurbo228]

Quoted from HMaze

Hi BiTurbo228,

one interresting thing my excel spead sheet showed, was playing around with the petrol tank.
Using the GT6 petrol tank in the boot instead of the spitfire petrol tank on the rear axle, adds more weight on the rear and subtracts weight from the front. It also puts the CG lower and should be a nice counterbalance for the driver in a RHD car.
On the negative side, it puts the fuelcell in the crash zone, and spreads the weight of the car too far from the center.
Just a thought..

Cheers,
Harry

Very interesting. I didn't know the GT6 had a different tank than the Spitfire. That's pretty much where I was planning the battery to go, but if I make a bolt-on battery tray rather than a welded one, I could see what the distribution's like and if it's still off I could swap to a GT6 tank. It's marginally bigger as well, which would be useful with a thirsty 6-cylinder.

Also, my alloy frontplate arrived today and weighs a featherlight 528g. Compared to the 2.25kg iron one and that's sod all