ShaunW Posted June 28, 2018 Report Share Posted June 28, 2018 Now correct me if I'm wrong but something doesn't look right here. The clue, the 'Demist' telltale on the tacho ... on a Spitfire? And a bonus indicator light which is a bit surplus to requirements. I don't think the GT6 had a rear demister did it? They do look like a pair though. Has anyone got a photo of what should be in there? Link to comment Share on other sites More sharing options...
ShaunW Posted June 28, 2018 Author Report Share Posted June 28, 2018 Why would a tacho have a diff ratio on it? 3.55:1. On a speedo yes, but on the tacho? Link to comment Share on other sites More sharing options...
Mat Posted June 28, 2018 Report Share Posted June 28, 2018 They are early GT6 MK3 Dials (mk2 and mk3 gt6's had rear demist) Link to comment Share on other sites More sharing options...
ShaunW Posted June 28, 2018 Author Report Share Posted June 28, 2018 Thanks Mat. 140 on the speedo was a bit optimistic. ? Link to comment Share on other sites More sharing options...
Mat Posted June 28, 2018 Report Share Posted June 28, 2018 1 minute ago, ShaunW said: Thanks Mat. 140 on the speedo was a bit optimistic. ? Yes, But I think it was the in thing, back then? Link to comment Share on other sites More sharing options...
ShaunW Posted June 28, 2018 Author Report Share Posted June 28, 2018 I remember those days well Mat, first thing a lad looked at when he got in a car. Why the diff ratio printed on the tacho though? Suppose there's no room on the speedo. And if they came as a pair, why not I suppose. Just seems odd coming from the days cars were made from bits out of the parts bin. Link to comment Share on other sites More sharing options...
Mat Posted June 28, 2018 Report Share Posted June 28, 2018 Yes, probably the only speedo that would match the rev counter was that speedo ratio Link to comment Share on other sites More sharing options...
ShaunW Posted June 28, 2018 Author Report Share Posted June 28, 2018 The speedo is only a decorative feature, it just waves at me to say it's there rather than performing any useful function. Swings between about right and about +10. Link to comment Share on other sites More sharing options...
Clive Posted June 29, 2018 Report Share Posted June 29, 2018 looks like it should be late spit 1500 (later type switchgear by the glimpse of the binnacle) The issue may be of which gearbox and diff you use. If a 3.89 you could use mkIV spitfire gauges, the rev counter is cable driven and the speedo should be the correct "ratio" Not sure what will happen if you use a 1500 speedo, they relied on the gearbox speedo drive to get teh ratios right. 1500 rev counter is electronic, but 4 cylinder so no good (possible to convert? with some electronics nouse) But the rev counter out of a 2.5 saloon should match 1500 speedo... Ultimately choose what you like the look of...but accuracy of both is useful. (and you haven't said what the fuel/temp gauge are like......) Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 29, 2018 Report Share Posted June 29, 2018 The 3.55:1 on the revcounter is nothing to do with a diff ratio ts the ratio of cable input rev to the needle reading and is based on the dizzy drive cable gearing Sorry but To think its anything to do with the drive line is a mis assumption. All the cable drives were 3.55:1 Pete Link to comment Share on other sites More sharing options...
Clive Posted June 29, 2018 Report Share Posted June 29, 2018 Indeed, the cable drive rev counters are all interchangeable.... I guess I turn of the engine is just that. (speedos different matter, and I think the only one I have ever had that is accurate is the one in my current spitfire, fitted with subaru diff and type 9 gearbox! accurate with 1% compared with gps) Link to comment Share on other sites More sharing options...
NonMember Posted June 29, 2018 Report Share Posted June 29, 2018 12 hours ago, ShaunW said: Why the diff ratio printed on the tacho though? Suppose there's no room on the speedo. As Pete said, the 3.55 has nothing to do with the diff, it's the gearing of the distributor take-off. And there is plenty of room for the gearing figure on the speedo; it's the 1152 printed just below the decimal place of the trip counter. Link to comment Share on other sites More sharing options...
dave.vitesse Posted June 29, 2018 Report Share Posted June 29, 2018 1152 turn per mile with 140MPH is used in a GT6 with 3.89 diff and three rail gearbox. If you have a Mk4 1300 Spit then this did have 3 .89 diff and three rail gearbox so no problems with speedo cal. If it's a 1500 with a 3.63 diff and a single rail gearbox then the speedo will read very slow. So no chance of hitting the 140MPH! Dave Link to comment Share on other sites More sharing options...
ShaunW Posted June 29, 2018 Author Report Share Posted June 29, 2018 When I thought it's meaningless having the diff ratio on the rev counter I should have believed myself. Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 29, 2018 Report Share Posted June 29, 2018 Its the old one, if you look in the mirror you can see the problem Ha You learn from questions or .....mistakes we have all been there Keep em coming if we have an answer something will appear from someone theres a lot of Tee shirts out there Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted June 29, 2018 Report Share Posted June 29, 2018 When I look in the mirror I see my dad staring back at me. db Link to comment Share on other sites More sharing options...
Colin Lindsay Posted June 29, 2018 Report Share Posted June 29, 2018 At least you know who it is, I see a grey haired old man that I don't recognise at all! Where did that young guy go that used to be there? Link to comment Share on other sites More sharing options...
Badwolf Posted June 29, 2018 Report Share Posted June 29, 2018 Forget the mirror... try putting your picture in the atic (Dorian Gray)! 1 Link to comment Share on other sites More sharing options...
dougbgt6 Posted June 29, 2018 Report Share Posted June 29, 2018 BW, That did not end well! At least my dad now wears hip cloths and drives a cool car. db 1 Link to comment Share on other sites More sharing options...
Badwolf Posted June 29, 2018 Report Share Posted June 29, 2018 True. Not a happy tale. Glad to hear about your 'Dad' though. Hope springs eternal for all of us. Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 30, 2018 Report Share Posted June 30, 2018 Doug , you need a 2nd bathroom shave on your own Colin , same problem used to blow dry me quiff now its just a polish,,,,, where do they go?? Pete Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now