Basic weight of an A7 rolling chassis + engine etc

[AllAlloyCup]

I’ve just weighed an entire set of woodwork recently made 
For a GE Cup  which came to 40kg
Adding in the screen, alloy body skin, wings bonnet etc
I reckon the coachwork total will be about 50kg all up, or 112lbs or 1 cwt perhaps a few lbs more?

My ash timber is 1” rather than the 3/4” of an original body.

Has anyone weighed their completed GE Cup or a bare
running chassis?

Interested to know what my final all up weight of a finished GE Cup will likely be
and how much lighter than say a Chummy of the same era
1926 to 1928?

Hoping I can get to 60mph on the flat!

Regards
Bill G
(AllAlloyCup)

[Mark R]

I built a cup body from eBay plans(I think pictures come up on Pinterest if you Google it, not sure how they got there) which had no floor and the boot lid off and I could quite easily pick it up, I'd guess it weighed 25-30kg approx with the ply skin.

[AllAlloyCup]

Hi Mark
30kgseems about right for the tub
Floors , seat and trim might add another 5kg?

I see from Bryan Purves book that the all up
unladen weight of a Cup is 6.5cwt=728 lbs
Weight of an early Chummy of the same era
Is also quoted as 11 lbs per 10cc = 823 lbs

So a Cup is roughly 1cwt lighter than a Chummy
and 2 1/2 cwt lighter than an early Saloon.

So at least 10mph faster....?

Regards
Bill G

[Ian Williams]

Put a decent engine in it with an appropriate set of gear ratios and you will see 70mph+ it takes very little to make some reasonable power gains with no real outward signs, ask any of the trials boys!

[Tony Press]

Put a decent engine in it with an appropriate set of gear ratios and you will see 70mph+ it takes very little to make some reasonable power gains with no real outward signs, ask any of the trials boys!

The weight might affect how fast you get there but as Ian notes a good engine will get you there-
I have had the Austin Standard Sports with an SU on a mildly tuned engine up to 100 kph on a nice flat road !

The Fabric Saloon with updraught Zenith on a completely standard engine will only reach 70 kph - scary enough.

Cheers, Tony.

[AllAlloyCup]

Hi Ian

Planning to have lightweight pistons,
a 1 1/8” steel crank and an 1” SU on a Ruby
Manifold with a Cherry Bomb exhaust.
Perhaps with just 3 lbs off the flywheel.
Not decided about the cam shaft yet.

100kph sounds more than enough!

Regards

Bill G

[Ian Williams]

Hi Ian

Planning to have lightweight pistons,
a 1 1/8” steel crank and an 1” SU on a Ruby
Manifold with a Cherry Bomb exhaust.
Perhaps with just 3 lbs off the flywheel.
Not decided about the cam shaft yet.

100kph sounds more than enough!

Regards

Bill G

Speed is addictive Bill, but 100k should be achievable, thats only about 4000rpm or so depending on your ratios........ so plenty of scope as the cravings bite, your car is light enough to benefit from a better cam, but look for mid range torque not top end.
And before anyone starts to get excited about 1 1/8" cranks at that rpm, you said Steel crank so I am assuming Phoenix or JB in which case the rods will probably be the limiting factor in any case.

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I might add Bill that on a car that light std 1st gear will be completely pointless, you will make it a much nicer car to drive if you put a set of CR gears in the box....much nicer!

[AustinWood]

My RK fabric saloon will cruise at 50mph and see 60mph downhill.
Since fitting the Accuspark ignition I've had the needle 'off the clock', probably 63ish.
My speedo agrees with my sat-nav.
Not sure why it goes so well as the engine mods are minor.