[blackpopracing]

But if they are not exactly 2:1 you will get drift. If they are 2.01:1 then after 1000 turns they will be .1 of a turn further round. I know you like old school but would it not be easier to use a crank trigger and electonic ignition?

 

[steve1275]

Er, toothed belts are used to drive camshafts, any 'drift ' would be catastrophic so LL will be just fine with this setup.

 

[mygasser]

agreed, that's like saying my 4.11 gears will be 4.56 if i drive long enough. a certain number of teeth will always be that number of teeth :lol:

 

[blackpopracing]

I disagree Neil, I'm saying your 4.11 gears might be 4.1125.
I hope it's fine but for timing it add's an unnecessary potential for error.

 

[Itchy]

:yeahthat: Thats what I was thinking!

 

[thisYup]

sorry Blackpop, you're wrong on this one! 4:11 gears will always be 4:11, wear will cause backlash, but won't change the ratio

my boss' hart 420 r race engine has a cogged belt driving the cam train like many, many other engines, and another cogged belt from cam to dizzy.. it's a 9000rpm engine, so cam timing is pretty critical considering the valves overlap in the head!

the cogged belts are otherwise known as timing belts in industry

20 teeth on one to a 10 tooth one via a tooth belt will always be 2:1 until the cogs rot or the belts snap!...

there's probably more backlash in a conventional dizzy gear drive off the cam, than there is with a toothed belt drive off the crank!

 

[mygasser]

I disagree Neil, I'm saying your 4.11 gears might be 4.1125.
I hope it's fine but for timing it add's an unnecessary potential for error.

it might be 4.1125, but it will always be 4.1125. the number of teeth on each gear can't change (unless they break).

 

[legendlives]

Blimey, I didn't mean to start WW3!

Blackpopracing you're right, I could just use a crank trigger with the associated electrical gubbins, but it wouldn't be half as cool!
There is a budget issue as well. I'm trying to make everything I can to keep the price down. So far I've only spent $4000NZ (about 2K GBP) on the entire build including purchase of the car. New crank trigger etc would probably add 50% to that number.

Oh, and as far as the belt drive is concerned its 2:1. It came (as I may have mentioned) from driving a balance shaft on a Mitsubishi engine. I'm sure most Mitsi drivers would be sorely pissed if their engines went progressively out of balance......

 

[69 ford]

Belt drive/cogged belt it is then!

 

[legendlives]

Carb tried in place:

Hmm. May have to rethink the bonnet bulge!

Also took out these annoying panels that were originally there for the bonnet catches. I'm not using bonnet catches......

I also ended up with hairy hands. Either I've been fingering a sasquatch or it's fibreglass time!

Aah. Must be fibreglass time. New sexy front-end brackets glassed in place. I'll take out the screws and fill the holes once it's fully set:

 

[MYTHING]

Now about this toothed belt and drift

 

[legendlives]

Disi Part 2

The distributor itself started life as a standard Chevy points distributor. I chose the Chevy one as the rotation is clockwise - essential for the belt drive (allowing for the anti-clockwise drift :rofl: )

Stripped down:

And 'slightly' modified:

(It was cut down more after the photos were taken)

About that time I found these on our local auction site, and bought them for $40NZ (about 20 quid):

So I now had top & bottom, I just needed a body to connect them.

To make the body I used the neck from an expired fire extinguisher bottle (3mm thick) with 5mm top & bottom plates welded to it.
These were shaped, tapped and slotted to suit the cap and mounts:

Between the top of the body and the cap I turned this up from 10mm Lexan. Hopefully it will act as a nice isolator/insulator. I was going to paint it but then figured it would look cool at night with the sparks etc going on inside!

The rotor arm (surprisingly enough) fitted exactly to the Chevy shaft. Even the mount bolts are the right thread:

Made up these stands which line up with the adjustment slots:

Painted the body to look MSD-like, and bolted the whole assembly together:

Currently it still has points, but I will probably put electronic ignition in it.

Easy!

 

[blackpopracing]

Impressive! you make it look so easy too. I assume you faced it off after welding to keep it all level?

 

[legendlives]

Impressive! you make it look so easy too. I assume you faced it off after welding to keep it all level?

Yes, all trued up after welding. Quite happy with it myself, just hope it works......

 

[mylesdw]

The distributor itself started life as a standard Chevy points distributor. I chose the Chevy one as the rotation is clockwise - essential for the belt drive (allowing for the anti-clockwise drift :rofl: )

Remember it's clockwise drift for our northern hemisphere readers. :rofl:

 

[ivanhoew]

brilliant.

 

[Ian34]

Superb !! :rule:

 

[legendlives]

Late night and an early morning to get the car ready for the CRC Speedshow in Aucklands ASB Showground. Entered in the 'unfinished custom car' category.

 

[SpencerMoparFan]

So.... not entering "best paint & interior category" yet then ??:lol:
Looking great so far though , have a good show !

 

[legendlives]

I don't know, the paint is better than some of the rat-rods!
Maybe next year for the paint and interior!

Clip from the show preview. My little monster at about 1:15 on: