Phillip Island…

June 10, 2010

We got there in the end…well I got there in the end. Dave was unfortunately committed for the weekend so he left if to me to do our first shakedown run in quite a while! The weather didn’t look to crash hot heading down to the Island with grey skies and sideways rain. Once the car was off the trailer, the weather had thankfully decided it had rained enough and would be happy blowing a bitterly cold wind.

A quick scrutineering session where the absence of headlights was questioned…and out onto the track.

Over the next few sessions the track dried out and I slowly remembered how to drive. Apart from a the crummy Fiat windscreen wiper coming loose when barrelling over Lukey Heights and a less than confidence inspiring brake pedal…we seem to have a bloody good car.

The motor now makes good power, pulling strongly past the redline in fourth and the grip with the new Kumhos is superb. It proved it’s corner speed against a few well prepped clubmans, just not having the same pull as a 2l out of the corner. Something to aim for.

The last session was cut short by an unfortunate ‘too many tubes in one empty thinners container’ excuse for a catch tank we had. Some degreaser and a rethink of our catchtank config will sort this for next time.

Thanks must go once again for John for lending us his trusty trailer and tyre tools and also to dad for coming down in the crummy weather with an esky full of lunch.

Autobella 2010

February 21, 2010

Autobella

The FIAT Car Club of Victoria held its annual concourse, and we invited ourselves to attend.

Bianca. Competition category winner Phil Buggee's orange Punto Diesel is in BG

We’re lucky we didn’t have to drive the 15 kays to Como Park because we were fouling plugs even getting onto the trailer. This is a car that does not like to idle. Theories of cause could possibly be due to oversized pump jets or the dizzy arrangement. We will be able to isolate that soon if we move to a Megajolt system which would allow us to control our spark a lot more accurately and send bigger sparks into the cylinder. It will also give a more reliable spark at high RPM. There will be no movement on that front until the first couple of track days prove that the plugs will be a problem. There wasn’t so much as a mutter when it was running properly on the dyno. so we’ll see.

My pick for people's choice

It was nice to see so many Italian classics, including this Stirling Moss Masarati, which sent grown men running in its direction. Also-rans include a fleet of Ferraris, Lancias and a few Alfas.

Stirling Moss Masarati

Although we didn’t exactly bring home the silverware, there was some encouraging interest in the car. Comments about our preparation were positive, and hopefully this will translate into reliability and consistency when we finally hit the track.

Julian, Sam and Andy

The only thing missing in the end was stickers to make our X look like a proper racer – ‘home brand’ racing obviously doesn’t win the judge’s vote. Phil Buggee’s orange Punto Diesel ended up winning the competition category. It was by far the most prepared (and probably most raced) entry, but being a fairly stock diesel, it was a bit boring when compared with some of the other modifications and older exotica in attendance.

Next stop, Phillip Island.

Jetting

February 14, 2010

As promised, our jetting for twin Dellorto DHLA 40, emissions version.

NOTE: This will probably NOT WORK well for non-emission spec Dellorto or Weber sidedrafts on a similar engine.

Idle: 65 (this must be around the 45 mark if you run non-emissions series)

Air Corrector: 150

Emulsion tube: 7772.11

Main jet: 130 (probably needs to be 135 or so. Gets a little lean on high RPM)

Engine: SOHC 1300cc head worked with larger valves and mystery cam

1 1/2″ headers, 4 into 1 exhaust, 3″ secondary, high flow muffler

At the moment, got 35 degree of advance dialled in. The dizzy-less Megajolt ignition system is currently being perused as an alternative.

Industrial espionage is probably not an issue for 30 year old technology. If anyone has thoughts or comments on these figures, we’d love to hear from you.

Research, then trial and error.

Research was teh crucial part, and the reason why it has taken us nearly a year to progress to the point where the car will start and idle successfully. I haven’t written on this blog for many months because it has been just too embarrassingly disheartening. For a while I lost faith, thought we’d spent too much on some crappy leaky sidedrafts which didn’t bloody work. Research shed some light. Here’s the saga as it unfolded.

Synch Carbs

Juice Synching Carbs

Possibly as far back as 12 months ago, some reading on Guy Croft’s excellent forum turned up the holy grail of 40mm Weber sidedraft jetting for our particular application. Some careful fudging of these figures to allow for a smaller displacement went on in Julian’s head, and we came up with a theoretically perfect jet combination. The carbs were already rebuilt, the world’s sexiest airbox was welded up so all that was left was to insert textbook jets and race.

Not quite.

To cut a year-long story short, we found out that there are many different series of Dellorto DHLA carburetors (See this article, possibly originating from the Sideways Technologies forum). Our particular ones came off an Alfa, so were probably emissions, meaning that the progression circuit was designed to meet the US emissions laws, and thus less tunable than earlier non-emissions (and most Weber) carbs. Thus the textbook idle jets we forked out for were way too lean (we’d planned on 47, currently running 60) and air correctors were too small (details to follow soon!).

The Interrogator

Pross, 'The Interrogator'

This much we now knew, so we booked in to see Pross at Enhanced Motorworks in Fairfield. After 5 or so dyno runs, and a consultation by a talking computer called the Interrogator, we had eliminated the lean idle, synch’d the throats, discovered the rich spots and dialed the advance. It took a morning, but Bianca is finally dialled for race. The final figure was about 60kW / 80 HP at the wheels. I guesstimate that the whole package weighs less than 800 kg wringing wet, which brings us close to 100HP/ton. I’m off to the Alfa club website to book us in for 14 March. Watch this space!

P.S. Thanks go to Woppy for his thoughts on why it wouldn’t hold idle, and Peter at Thornbury Carbureters for being so conveniently located.