metric or imperial??

[kestral]

A question for those of you out there who are lucky enough to be able to build your owen dragsters. When building do you use imperial(inches) or metric(centimetres)? Are the Americans starting to use metric yet?

[cougarracing]

i always use imperial, its far more accurate, for instance
you never get reocuring numbers with imperial measurments

[Tet]

cougarracing said:

i always use imperial, its far more accurate

That's one of the more bizarre claims I've heard! Accuracy might possibly come from the use of fractional rather than decimal mathematics, but not inherently from imperial over metric measurements. After all, when you're talking about thousandths of an inch, you're no longer using fractions anyway -- at least, not with a denominator with convenient factors, which is where the percieved advantage of fractions is to be found.

Disclaimer: I'm a professional gambler, and I deal with rounding errors from conversions between fractional and decimal odds on a daily basis :-)

As for building a car, that surely depends on the parts you're using. If your engine has a 4" bore, then you'll get funny looks asking for parts to fit a 101.6mm bore. Personally, I like things to be metric (my weather station confuses most people because my readings are all metric, for example), but you have to be pragmatic, and if the available parts are all imperial, then that's what you use.

[kissmyrs]

I think most car builders use a combination of both.
My car has US (imperial) engine and running gear, but the majority of body, chassis and ancillary fixings are metric because I find them easier (and cheaper) to source.
From a security and longevity point of view I don't find any difference between them.

[cougarracing]

Tet said:

cougarracing said:

i always use imperial, its far more accurate

That's one of the more bizarre claims I've heard! Accuracy might possibly come from the use of fractional rather than decimal mathematics, but not inherently from imperial over metric measurements. After all, when you're talking about thousandths of an inch, you're no longer using fractions anyway -- at least, not with a denominator with convenient factors, which is where the percieved advantage of fractions is to be found.

Disclaimer: I'm a professional gambler, and I deal with rounding errors from conversions between fractional and decimal odds on a daily basis :-)

As for building a car, that surely depends on the parts you're using. If your engine has a 4" bore, then you'll get funny looks asking for parts to fit a 101.6mm bore. Personally, I like things to be metric (my weather station confuses most people because my readings are all metric, for example), but you have to be pragmatic, and if the available parts are all imperial, then that's what you use.

Tet its not that a bizare a statement...for example how about i wanted to Measure a rod a third of the length of 1X....X meaning either a cm or an inch....if you measure the rod in metric because metric is to the base 10 then you get 0.33333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333cm....and so on, however because imperial is to the base 12 if you measure it in inches, you get a definate answer, no reocuring numbers. so therefore imperial is more accurate beacause you have a wider range of units to choose from within the inch and when you break the inch down into thirds, it splits directly into 3, unlike the cm, ok this may not make a lot of difference when building chassis but it sure makes a hell of a lot of difference when designing an engine. however accuracy and precision are 2 different things, especially in this day and age where less people can read imperial and use metric because its easier, people tend to get more precise measurements by using metric, simply because they can understand it properly.

i uppose the simple answer to the origional question is it depends on what your measuring or building...!

Edited by cougarracing on Friday 7th March 07:28

Edited by cougarracing on Friday 7th March 07:41

[BB-Q]

I've just bought the rod ends for my 4 link and have bought imperial, purely because they're easier to source in the sizes I want. I would much rather do metric throughout but have a car that came from the factory with a mixture of metric and imperial sizes on it (crazy Swedes), so one more thing really won't matter.
As long as the bolts you're using are the right type for the use you intend to put them to then I can't see that it matters as long as you have the right sized spanners. Don't forget to have metric and imperial spares too (separate boxes is always a good idea)!

Slightly off topic but along those lines- those of you with 3/4" rod ends on your four links- what grade and material bolts have you used?

[Dnac]

BB-Q said:

Slightly off topic but along those lines- those of you with 3/4" rod ends on your four links- what grade and material bolts have you used?

Mate, what you need to do is join either SPRC or APIRA Racers club and get the rule book, its all in there!!

[Jon C]

cougarracing said:

Tet said:

cougarracing said:

i always use imperial, its far more accurate

That's one of the more bizarre claims I've heard! Accuracy might possibly come from the use of fractional rather than decimal mathematics, but not inherently from imperial over metric measurements. After all, when you're talking about thousandths of an inch, you're no longer using fractions anyway -- at least, not with a denominator with convenient factors, which is where the percieved advantage of fractions is to be found.

Disclaimer: I'm a professional gambler, and I deal with rounding errors from conversions between fractional and decimal odds on a daily basis :-)

As for building a car, that surely depends on the parts you're using. If your engine has a 4" bore, then you'll get funny looks asking for parts to fit a 101.6mm bore. Personally, I like things to be metric (my weather station confuses most people because my readings are all metric, for example), but you have to be pragmatic, and if the available parts are all imperial, then that's what you use.

Tet its not that a bizare a statement...for example how about i wanted to Measure a rod a third of the length of 1X....X meaning either a cm or an inch....if you measure the rod in metric because metric is to the base 10 then you get 0.33333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333cm....and so on, however because imperial is to the base 12 if you measure it in inches, you get a definate answer, no reocuring numbers. so therefore imperial is more accurate beacause you have a wider range of units to choose from within the inch and when you break the inch down into thirds, it splits directly into 3, unlike the cm, ok this may not make a lot of difference when building chassis but it sure makes a hell of a lot of difference when designing an engine. however accuracy and precision are 2 different things, especially in this day and age where less people can read imperial and use metric because its easier, people tend to get more precise measurements by using metric, simply because they can understand it properly.

i uppose the simple answer to the origional question is it depends on what your measuring or building...!

Edited by cougarracing on Friday 7th March 07:28

Edited by cougarracing on Friday 7th March 07:41

The issue here is not so much one of accuracy, but tolerance. Tolerancing costs, big time.




is a cheaper soultion

[cougarracing]

ROFL...is that hammer an imperial one or a metric one?

[Jon C]

cougarracing said:

ROFL...is that hammer an imperial one or a metric one?

I think its Whitworth.

[cougarracing]

LOL....dont get me started on witworth!

[Jon C]

cougarracing said:

LOL....dont get me started on witworth!

Want to get started with Whitworths?



HTH

[cougarracing]

LOL>...im going to refrain from making jokes about punes....it will get me in trouble!

[MotorPsycho]

kestral said:

A question for those of you out there who are lucky enough to be able to build your owen dragsters. When building do you use imperial(inches) or metric(centimetres)? Are the Americans starting to use metric yet?

To actually answer your question, I would imagine measurements at least will all still be in inches, as all the rule book have chassis dimensions, tube sizes etc etc given in inches

When designing/making brackets or anything for our car we use inches but an increasing number of nuts and bolts are metric* purely because they're easier to source, that said most of the engine related fixings are imperial because thats how they're designed.

edited for typo*

Edited by MotorPsycho on Friday 7th March 13:16

[anonymous-user]

Everything on our car is imperial and that's all I ever work in where drag racing's concerned. Mainly due to the fact I've grown up with my Dad referring to metric stuff as "French" lol

[DWphil]

cougarracing said:

i always use imperial, its far more accurate, for instance
you never get reocuring numbers with imperial measurments

No wonder all our jobs at work are wrong we need to switch to imperial and throw away all the metric inspection equipment.

[kestral]

MotorPsycho said:

kestral said:

A question for those of you out there who are lucky enough to be able to build your owen dragsters. When building do you use imperial(inches) or metric(centimetres)? Are the Americans starting to use metric yet?

To actually answer your question, I would imagine measurements at least will all still be in inches, as all the rule book have chassis dimensions, tube sizes etc etc given in inches

When designing/making brackets or anything for our car we use inches but an increasing number of nuts and bolts are imperial purely because they're easier to source, that said most of the engine related fixings are imperial because thats how they're designed.

Have you got that right "an increasing number of nuts and bolts are IMPERIAL purely because they are easier to source"? I thought things were moving more towardes metric.

[Time Machine]

kestral said:

Have you got that right "an increasing number of nuts and bolts are IMPERIAL purely because they are easier to source"? I thought things were moving more towardes metric.

I would guess so, yes.

However I did once discover that Peter Crisp department store in Rushden have a really good ironmongery department who stock imperial threads (and an 'old boy' who can tell whitworth from UNC at a glance)

[MotorPsycho]

kestral said:

MotorPsycho said:

kestral said:

A question for those of you out there who are lucky enough to be able to build your owen dragsters. When building do you use imperial(inches) or metric(centimetres)? Are the Americans starting to use metric yet?

To actually answer your question, I would imagine measurements at least will all still be in inches, as all the rule book have chassis dimensions, tube sizes etc etc given in inches

When designing/making brackets or anything for our car we use inches but an increasing number of nuts and bolts are imperial purely because they're easier to source, that said most of the engine related fixings are imperial because thats how they're designed.

Have you got that right "an increasing number of nuts and bolts are IMPERIAL purely because they are easier to source"? I thought things were moving more towardes metric.

sorry t'was a typo, it was early

[cougarracing]

MotorPsycho said:

kestral said:

MotorPsycho said:

kestral said:

A question for those of you out there who are lucky enough to be able to build your owen dragsters. When building do you use imperial(inches) or metric(centimetres)? Are the Americans starting to use metric yet?

To actually answer your question, I would imagine measurements at least will all still be in inches, as all the rule book have chassis dimensions, tube sizes etc etc given in inches

When designing/making brackets or anything for our car we use inches but an increasing number of nuts and bolts are imperial purely because they're easier to source, that said most of the engine related fixings are imperial because thats how they're designed.

Have you got that right "an increasing number of nuts and bolts are IMPERIAL purely because they are easier to source"? I thought things were moving more towardes metric.

sorry t'was a typo, it was early

ROFL... todays lesson is to read what weve written bfore we post it ;-)