Hi the web address is:
http://www.abarth-andronico.com/carburatori e tromboncini.asp

They have many for sale....so give them a call.
I haven't finished building the engine yet...should be finished in a fortnight - i'm not intending on trying to use the choke. The bracket is missing and cannot be bought so....foot to the floor and don't stop!!!

:slayer:

I've put about 300 miles on my FZD 32/28 in the past month. Still learning the best way to start it hot or cold - use the choke, or not, or pump it once or not. I'm usually in a hurry and don't note which is the best method.

My setup as it came with the carb (off a Mini) and/or from the rebuild kit:
190 Air Corrector Jet
6747-3 Emulsion Tube
135 Main Jet
50 Accelerator Pump Jet
3458 1.50 Needle valve assembly

I haven't changed a thing, just adjusted the mixture to run well enough. I know Chris has the 6747-8 emulsion tube and 132 main jet. No idea if I would benefit from those changes or not. Seems to run OK but it could be slightly lean or rich and I wouldn't know it.

I modified the air filter cover in our machine shop at work. I had an old metal cover that I cut the center tube out of and enlarged the hole. Machined down a piece of pipe to give me 2" OD, a collar to sit on the cover, and then 2" OD to fit in to the filter. Tacked welded this to the cover. To fit it over the stock air filter required cutting away some of the rubber on the filter. The black U-shaped hose was bought off the internet as a 'Turbo' inlet hose which I cut down to fit. Looks pretty good but is surely a tight fit in there!

I ran the stock vent hose from the valve cover right to the small tube on the inlet of the FZD. They're different sizes so had to put a thin rubber tube over the inlet and then attach the vent hose over this.

Replaced the solid wire throttle cable with a stranded wire bike shift cable, then moved the old throttle wire to the choke so it would be long enough to reach. Replaced the old chewed up choke cable jacket with one from a bike cable. Lot of fiddling but it all works smoothly now. Still not thrilled with the pivot assembly between the cable and the carb so that will likely get re-engineered soon.

Tuning is all trial and error. I know our local dyno would be useless tuning a rare Dellorto! If anyone has a FZD setup on a 650cc that works great or has been tuned on a dyno, let me know and I'll source those parts to try. Not sure which parts make the most difference, the main jet or emulsion tube or both? I don't have the tuning guide if there is one.

The problem I had on day 1 with the carb vapor-locking was apparently due to the winter-mix fuel left in the car from the Fall. Our fuel is oxygenated for winter to reduce emissions and is more prone to this when hot. Haven't had the issue since running through that tank.

Mark

Hi all. I'm running an FZD 32/28 on my 695cc engine. I went with the same setup as Chris and she's running very sweetly. I only have 400kms on the clock so far though and want about 1000 before I'll be happy to rev it out on the dyno. I have a great dyno guy to use so will be sure to post up the results.

The weather is mild here in Auckland so the car will be used in temperatures from about 10-30 degrees C. Due to this, and the fact that I was missing a few choke bits I removed the choke entirely. I have had no issues with this.

I'm running a ramflow filter. You can't see it in the pic but I have drilled the rear steel plate and added a brass hose fitting to allow the rockerbox cover breather to vent into the filter.


I have a spacer between the carb and the manifold to keep the carb cool. I am surprised others don't as the manifold gets pretty hot. In fact I am thinking of adding another, thinner, spacer between the carb and the head to lower the manifold temperature.


Chris, since our engines are very similar and run in similar climates (at least at some times of the year) I would be really keen to get some temp readings off various parts of your engine if you have a laser thermometer?

Cheers
Roger

sheylings said:

Pump weight/ value/ ball bearing (#s 25,26,27) - pretty critical and fortunately 26/27 are available, alhtough I am not sure what [URL=https://www.fiatforum.com/usertag.php?do=list&action=hash&hash=25]#25 [/URL] is - could be the valve? I looks from one of your the photos in this thread that it could just be a retaining clip.

Pump rod (#s 38,39) - again, pretty critical, but not readily available. I'm hoping I can source this from DHLA carb part suppliers.

Choke rod and associated parts (51,59,67,68,69,70,71,72) - perhaps not critical and only some are available. #69 looks to engage the choke when accelerator pressed and so is required, but I'm hoping I can forego the choke-related parts. #69 is not available, alhtough maybe I could fashion a non-OEM part out a paperclip!?

And finally, #s 53/54 - I'm not sure what these do, but I certainly don't have them!

Click to expand...

Hi Steve,

I've just returned from holidays to your queries and will try to answer them as best I can. As you say, you may be lucky with parts from other Dellortos, particularly the DHLA. I won't be much help there as I don't have much experience with other Dellorto carbies - I've mainly worked with Webers.

To your questions -

You are right about #25 - it is a retaining clip. The pump jet spacer rod and check ball in the DHLA are held in using a grub screw, so you may have to make your own clip.

The pump pull rod, #38 , may be shared with the DHLA - I'm not sure, sorry. If it is missing, once again, it could be fairly easily made. It is threaded at each end and if you wish, I can remove mine and measure it for you.

As to the choke parts, as you state, they may not be necessary.

Parts #53 & #54 seem to be just guides for the choke cable. I don't have them either and they are not necessary.

Please let me know if I can be of any help.

Chris

RogerNZ said:

Chris, since our engines are very similar and run in similar climates (at least at some times of the year) I would be really keen to get some temp readings off various parts of your engine if you have a laser thermometer?

Click to expand...

Hi Roger,

First, I think you've convinced me to fit a spacer between the manifold and the carby - I have one, so I'll install it soon.

Unfortunately I don't have a laser or IR thermometer though I may be able to borrow one. I did a few rather rudimentary experiments a few years ago measuring engine bay temperatures using a remote digital thermometer but nothing terribly sophisticated.

My car, like yours, is also running very nicely. I may get it on a dyno one day just to measure the power output and map the curves but I'm in no real hurry. My output estimate came from the guys who did my balancing and head work. The engineer who'd built and tuned many motorbike engines over many years looked at what I was doing and said with confidence - 'she'll be good for around 35bhp at peak revs, mate'.

Chris

A couple more photos -

The first is of the accelerator pump return ball valve, weight and retainer. The retainer has the following dimensions - OD 5.0mm ID 3.0mm Height 2.5mm with a 1.0mm slot cut longitudinally. Mine is not chamfered.
5.0/3.0 brass tubing is available so this part should be fairly easy to make. I wonder how much a 2.5mm length costs? (Reminds me of my experience buying lead shot a while ago when I was rebuilding a pair of Webers ...)

The second is the pump pull rod. It's dimensions are - length 62mm, height 11mm, length of thread A 18mm, length of thread B 6mm and the distance to the spring stop is 45mm. The rod diameter is 3.0mm and the thread is a metric M3x0.50. The spring stop could be made by drilling a small hole and using a fine split pin and flat washer.
I reckon you can easily make one of these too - I might have a crack myself as mine looks like its seen better days.

Hope this helps.

Cheers,
Chris

I've found a source of Dellorto FZD parts:
http://www.dmdautomotors.it/epages/990470325.sf/en_GB/?ObjectPath=/Shops/990470325/Categories

Postage was criminal BUT they had what I was after......

Chris - that's great - thanks so much for your help!

I have ordered a pump pull rod for a DHLA in the hope that it's the same size or at least can be adapted, failing that I will see what I can make myself. I have also just ordered some brass tubing - the shortest length I could buy was 300mm! Should anyone require part #25 let me know, I should be good for hundred of so with the left over that I'll have!

I'll let you know how I get on - suspect it won't be the last you hear from me on this!

Andrew, thanks for the link - looks like a rather useful find for some otherwise hard to find parts if you can stomach their delivery prices.

Steve

Hi Steve,

Let us know if the pump rod fits - might save me the trouble of making a new one.

Chris

Hi Chris,

It arrived yesterday and sadly does not fit - too long and too great a gauge, alhtough the spring could prove useful. I have just ordered a length of alu rod - I'll let you know how I get on - depending on the number of failed attempts and how much rod I have left over, I'll drop one in the post to you!

Steve

Hi Chris,

I tried making the pump rod, however, the rod I was sent was 3.5mm rather than 3mm and so I couldn't cut a thread in. I have ordered some M3 steel rod, which I hope to bend into shape and cut.

I have, however, had great success with the pump weight retainer! Thanks again for your detailed explanation, which was perfect.

Steve

Steve

Happy to help.

Let us know how you get on with the rest of it.

Chris

How do you know how to set the length of the pump rod? It has a double-nut holding the spring on the rod, so it was made to be adjusted. Anyone know what the right adjustment should be?

I'm getting a hesitation on throttle tip-in. Ordered the emulsion tube and jet that Chris is using to see if that is the issue. Until they arrive, I tried tightening up on the pump rod. If it made a difference, it may be worse. Haven't tried backing it off, but it looks like it would essentially eliminate the pump entirely if you back it off too far.

Hi Marcus,

Mine is set about halfway, but to answer your question, I don't know for sure. Enough, I guess.

The Dellorto DHLA has a similar setup as do many of the older style Solexes.

I'll hunt around and try to get more information for you.

Your problem may have more to do with jetting than with the accelerator pump. Hesitation in going from a closed to an open throttle can be cured with progression holes (eg: DCOEs) but I wouldn't suggest that for the FZDs. Be aware though that with any carburettor switching between internal circuits will always cause a hesitation, though it can be minimised. The only real cure is fuel injection.

Chris

As I prepare my new engine for take off - any FZD users use a thermal spacer between carb and manifold? I've read that it stops heat soak from the head which can lead to fueling issues?

Just installed the same main jet and emulsion tube as Chris. It may have a bit more top end, I hit 100kph in 4th (didn't have room for 5th). The throttle tip-in is still a great big hole. Also, with the FZD, it always backfires when I shut it off. I have about 3/8" threaded rod past the last nut on the pump jet. Chris, yours is halfway?



Sent from my iPad using FIAT Forum

It's a bit hard to measure now as the carby is back on the car, but I've taken a photo which might help.

The photo also answers another question - I don't have a thermal spacer between the carby and the manifold, just the standard gasket.

Chris

PS: Backfiring and rough running may be timing and/or valve clearances.

Hi Chris

I just bought Mark's spare FZD. Looking at the pics I assume that I'm going to have to swap around the throttle linkage to get it to work on the 500. In the first page of this thread, you say this is possible, but not all of the parts are available - is it just a case of replicating the linkage on the other side? So for example making the reverse of what's on the rear and fitting it to the front?

Thanks

Steve

A full list of available spares and drawings are available from dellortto UK website
I've found spares available elsewhere if I can be of help

AndrewHarvey said:

A full list of available spares and drawings are available from dellortto UK website
I've found spares available elsewhere if I can be of help

Click to expand...

Thanks Andrew I'll keep that in mind.

I forgot to add one of Mark's pics in earlier post...