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.

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sumps up

November 9, 2009

The weather have been fantastic for the garage lately, a night or two throwing the spanners round after work and Bianca is all but buttoned up again. Last week the super special sump went on to save the main bearings from our sticky kumhos.

<sump

Thanks once again go to John for letting us know this had to be done!
Dyno bloke will have be called upon shortly.

A long time between drinks

September 26, 2009

It feels like a glacial age has occurred since the last efforts to get Bianca’s motor running. And it kinda has been. Finally though, we both have the ability to throw some time at the problems which have faced us. Winter’s almost over and you can venture out into the garage again without fear of frostbite.

Now that Bianca has mean rubber (Kumho V700’s) the time has come to bastardize a set of wheel nuts to get them on. And in true ER fashion, we set to work on the lathe. If it was simple, everyone would have one. End result is a car with probably more rubber than it will need. I mean to test that in the near future. Dyno this week, wish her luck.

Jets

May 26, 2009

So we missed another deadline.

With the motor now being buttoned up the challenge is to get the thing running well. We got our greasy hands on some bloody expensive dellorto jets and stuck them in. That just proved to us that the carbies need going over with the screwdriver as it runs like a bucket of rubbish. Screws should be turned this weekend so it can visit the dyno man. Why is it the more you spend on a race engine the unhappier it sounds?

Edit: Changed the fuel, and it runs much better now. Apparently BP Ultimate doesn’t cellar well…

A quick aside

April 23, 2009

I was reading “The Grapevine” at Autosport.com and came across this story. It’s second story the article.

http://www.autosport.com/news/grapevine.php/id/74664

Apparently we’re not the only ones naming our race car (Not that I’m claiming that we invented the phenomenon). Let’s hope we don’t total Bianca and have to contend with building Bianca’s Dirty Sister. Although if we built up a Motec fed 1600…

Deadline set – 30 May

April 19, 2009

We managed to spend a couple of hours on Bianca yesterday. She got a re-shim, and we realised just how well the head had been machined! The shims were all within about .05 mm of one-another.

The next job was to pay John a visit, and he pressed our wheel bearing into the new front stub axle. Once more, the small jobs on the list are taking the time, but we’ve set a deadline.

30 May, Alfa club sprint at Phillip Island. We will be there, rain (probably) hail (likely) or shine (with luck). This means that we have much to do in 5 short weeks. The car will be at the Island, whether it is going or not!

Tuba’s, not trumpets.

April 6, 2009

The intake system is nearly all together. Clearances are tighter than the current economic climate, and a few special tools may have to be found to make servicing quicker and easier due to the locations of some of the fasteners, but it all fits.

Full Up!

Full Up!


Throats that will swallow Phillip Island birdlife whole...

Throats that will swallow Phillip Island birdlife whole...

Check the sexy vernier cam wheel, epic ‘bespoke’ air box and tuba’s (not trumpets).

Still on the list is the wheel bearing, catch can, dyno and tune to name a few. The end of the tunnel is in sight!