Joined: Sep 2017 Posts: 17 Threads: 8
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Hi all,
I own an austin seven blown with cozette loader. I bought it two years ago.
I have two problems.
my 4-speed Gearbox is very noisy 1-3 speed the 4th is ok. What is the cause, it must be repaired quickly?
the second Problem ist the Ignition timing. What is the correct Timing? I drive a coilconversion and i think
the timing is wrong
The Engine only rotates a maximum of 4200 rpm.
can someone help me with information?
Thanks and Regards from Switzerland
Thomas
(excuse my English)
Joined: Aug 2017 Posts: 725 Threads: 38
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Location: Herefordshire
If you have an early "crash"-type 4-speed gearbox, it will be quite noisy at higher speeds in 1st, 2nd and 3rd as the gears are straight-cut. A synchromesh 'box should be much quieter in lower gears and if yours is of this type you may have a problem.
Joined: Aug 2017 Posts: 1,713 Threads: 47
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
Sounds to me like you have a set of straight cut close ratio gears, these are commonly fitted to specials intended for racing or hillclimbing, Don Rawson used to make them but I do not know if they are still produced. They are quite noisy until you get into top and for spirited a road car I would prefer a Nippy or Super Accessory type CR set such as Andrew Bird now makes, being blown you can probably get away with wider ratios than a natural aspirated car.
Black Art Enthusiast
Joined: Sep 2017 Posts: 25 Threads: 3
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Hi Thomas
I also live in Switzerland (Fribourg) and I'd be glad to help in any way I can.
My Nippy has a modified 4-speed gearbox to raise the ratios to Nippy specifications (supposedly). It is also noisy on the first three speeds due to straight cut gears. But it's a noisy car anyway :-), I wear now ear protectors (Pamir) to drive it.
Joined: Mar 2015 Posts: 5,442 Threads: 231
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Location: Scotchland
To add weight to the comments already made, my Pearl has a Nippy c/r box and has a (purposeful) whine on 1st, 2nd and 3rd. I quite like it however.
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29-09-2017, 01:20 PM
(This post was last modified: 29-09-2017, 01:22 PM by Austin in the Shed.
Edit Reason: Add content
)
Any older/vintage/classic car will be much more noisy with little or no sound insulation compared to a "modern" car,especially gearbox.Many conversions use corrected tooth form gears to achieve the different ratio.
You say you have a coil conversion,Is it one using a bosch 009 type distributor?.If it hasn't been modified to reduce its advance and bob weight springs its likely to have too much advance and too early.
As we all know its hard to diagnose something like this via computer but it should rev to 6,000 or so subject how much boost the cozette gives and carb and ignition settings being right.The car should start easily and be very lively!
Are you sure the rev counter is reading correctly ?
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Timing
Adjust the distributor to the highest/smoothest possible idle speed and back it off a touch. I use an inductive meter with a rev counter to check the speed.
Joined: Aug 2017 Posts: 261 Threads: 1
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Thomas, how is the Cozette driven? Your description of the performance sounds almost as if there is no drive to the supercharger. Is it driven by chain from a sprocket on the back of the flywheel, in which case I remember the car - probably!
Regards,
Stuart
Joined: Aug 2017 Posts: 637 Threads: 29
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I wonder if your supercharger is giving any boost,There are some poor superchargers out there.Has your car always run this badly?
Do you have any photo's of the engine bay?
I've never tried this but if the blow off valve is accessable you could try taking it out and either hold your hand over the hole or a suitable plug and start the car,under throttle the supercharger pressure should want to blow your hand/or plug out if you dare to try it!
Unless you have a boost gauge that is.
Don Rawson knew how to build a good seven engine so originally it would have performed well.