How it works.


I cannot promise this will always be the latest information , but when things are slack in the garage Ill post up what I can.

Monday, 28 April 2008

Andy goes to the dyno....

Well the day finally came to go to the dyno.

With the engine strapped firmly to my home made stand I hoisted it into the trailer and fitted my carefully engineered bits of pallet to jam it in place. A couple more ratchet straps to hold it down and with a bit of luck it wont go bouncing off down the road!

I loaded all the other bits like starter, flywheel, ignition system and ari cleaner into the boot, strapped dad in the front seat and off we went.

After a fairly uneventfull 57 mph 2 hour trip up to Market Drayton we arrived and were met by Tim Adams.

During this build I have visited 4 key places, Henwick garage to buy the engine, John Gordons to buy the running gear, GD to buy the kit and now Tim to dyno the engine. The one thing that's common to all of them was the feeling you get when you walk in, they all felt right as if you could tell that they all knew what they were talking about before they said a word.

Anyway after a bit of a chat about business and what Tim does we unloaded the engine and headed for the dyno, and there it was like some macabre instrument of engine torture!

Tim set to work and after about an hours fiddling we were ready to go.


As you can see in the video I was astounded when it fired up on the third turn of the crank, Tim took it straight to 2,500 rpm and it sat there for 30 minutes breaking the cam in.

video

So we had water in the oil, not so good.

Mayonnaise with your lunch anyone?

We cleaned the worst of it out at this stage thinking t could be condensation and pressed on to jet the carb, heres what one looks like without a lid!


With it jetted correctly Tim was happy with the figures he was seeing. We decided not to play with the timing anymore so I could run on regular unleaded.

Still 331 BHP and 324 torque isnt going to slouch along!

Thanks goes to Tim for a great day out and all his help in trying to figure out what went wrong, taking the leak aside I am really happy with the way it fired up so easily and it idles nicely at 920 rpm. Tim says this is mostly due to Bassets Down's balancing work as its so smooth.

Now all I have to do is fix that leak!

Friday, 25 April 2008

Handbrake fixed.

After receiving a replacement cable from GD I modified and fitted this one with much greater success. So I now have working handbrake which will be useful when moving the chassis outside as the driveway slopes away from the garage!

Monday, 21 April 2008

Electrickery.

In the past I have seriously considered looking at the whole harness and wiring issue a little differently to what most people opt for.

The standard, and some might say tried and tested way, is to use relays to switch high current loads thus avoiding the need for high current capacity switches on the dashboard. In addition you will also find standard loom design requiring heavy capacity wires running from the relays to the front and rear of the vehicle to power the loads.

In the mass pro sector we use CAN bus, this system uses a messaging system from system ECU's to communicate with the central power distribution point so you no longer need a switch on the dash board that is capable of handling high currents. For example the heater control tells the heater fan to turn on using a message instead of actually switching the motor current in and out itself.

Anyway finally this type of technology has made it into the kit car world and the first unit which caught my eye was the Isquared 1+1 system on offer from www.isqe.com it does not appear to be what I would call a CAN system as it uses a single control module to a remote power distribution or smart fuse box. No relays here all switching via MOSFET's.


These images have been copied from another build site I found on the net:

http://home.comcast.net/~289fia_cobra/index.htm

After emailing Chris at ISquared I am now informed of a newer system called ISIS manufactured by Littlefuse which works more along the true CAN idea of a master controller connected to multiple sub power modules.

Each power module can control up to 10 loads. With this system the harness going from the front to the back of the car could consist of just +12V, Ground, the CAN lines (usually 2 wires in a twisted pair format) and any sender lines you may have. This instead of the normal tree trunk harness.

So for a Cobra you would most likely need 1 master module in the front and one power module at the back. No relays again.


So that's got me thinking again. Obviously I need to understand prices of both systems but I am warming to the idea, certainly with the 1+1 system fault finding will be so much easier as you can tell if the switch is working by checking the function LED on the power module.

Again watch this space, I may well change my mind totally and stick with the old ways or maybe not.....

Handbrake.

Having rebuilt the handbrake mechanism the final part of that particular jigsaw was getting the cable to fit. So first up a slot was requires in the handbrake itself, this was allows the cable to pass through.

Next up the shoulders of the cable ring end need to removed to allow the ring to pass through the handbrake lever.

A job easily accomplished with a Dremel, I was surprised at just how good my wife's cordless Dremel is, Ill be borrowing that a bit more I think!

With those mods made the cable could be assembled to the handbrake lever, and the other end assembled into the handbrake levers at the diff.

Oh, it was going so well. Whatever I tried I could not get sufficient tension on the cable, with the adjuster nut wound right out there is just enough to apply the brakes. You can still roll the chassis forward though so that's not much use!

This sequence helps explain it. With the nut wound right in and up against the handbrake frame you can see how far the top hat section sticks out the end of the lever. With the top hat pushed home you can see how far the adjuster nut needs to be wound out.

After a call to Simon (cheers mate!) we concluded that there must be something wrong, either the cable inner is too long or the cable outer is too short or a mix of both!

I called Andy at GD and the cable was dispatched on Saturday to them for analysis and replacement.

Watch this space.....