Hi Folks

Since the sun is coming out down under (NZ) my Fiat is getting used more. I decided to book a rolling road tune-up. This is happening next Tuesday.

Firstly, I wondered if anyone has any recommendations for this process?

The place I'm taking it is local – about 50 miles / 80kms away, the longest run I've done.

They advertise handling classic cars and apparently have 3 other 500s they take care of, one with a similar set-up to mine.

They also recommend running the car on 95 or 98 octane. Is this normal? Is anyone else doing this? Is it just to get the best readings / performance stats when it's being tested?

timgarman said:

Hi Folks

Since the sun is coming out down under (NZ) my Fiat is getting used more. I decided to book a rolling road tune-up. This is happening next Tuesday.

Firstly, I wondered if anyone has any recommendations for this process?

The place I'm taking it is local – about 50 miles / 80kms away, the longest run I've done.

They advertise handling classic cars and apparently have 3 other 500s they take care of, one with a similar set-up to mine.

They also recommend running the car on 95 or 98 octane. Is this normal? Is anyone else doing this? Is it just to get the best readings / performance stats when it's being tested?

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In the UK 95 octane is standard don't think I know anyplace that sells anything lower then that?

In New Zealand 91 is standard, with 95 and / or 98 available at most petrol stations.

Would 95 be better?

Evening Tim;
Over here in the UK, 98 octane is available from a number of petrol chains---funnily enough just about the best (and sensibly priced) is from 'Tesco'---their 'Momentum' is in fact 99 octane.. I use this all the time in my car, which as you know has a well tuned 652cc engine in it's bum. I would suggest that, if you can, you fill the tank with '98' and run it as much as you can with that fuel prior to it being put onto the 'rolling-road'. Let us know what you come up with please.

timgarman said:

Hi Folks

Since the sun is coming out down under (NZ) my Fiat is getting used more. I decided to book a rolling road tune-up. This is happening next Tuesday.

Firstly, I wondered if anyone has any recommendations for this process?

The place I'm taking it is local – about 50 miles / 80kms away, the longest run I've done.

They advertise handling classic cars and apparently have 3 other 500s they take care of, one with a similar set-up to mine.

They also recommend running the car on 95 or 98 octane. Is this normal? Is anyone else doing this? Is it just to get the best readings / performance stats when it's being tested?

Click to expand...

Hi Tim, I would council the following - firstly check ALL adjustable areas - valves, points, plugs, advance, timing. Make sure you don't have any leaks that could become serious when the engine is under stress. Don't over fill with oil - half way up the dipstick is sufficient, when the engine is revving hard the crankcase pressure builds up and the engine will just blow the oil out of the breather. Make sure you take spare oil anyway. clean the breather too. If you have any spare parts (jets etc) for the carb take them you will save money. Check the gearbox level - don't overfill as it will blow out of the seals. Tell the operator what you want (exactly) and set a limit on the max rpm to use - you have to drive it home after all.
when the run is being completed check for any unusual noises - if there is ANY sign of the engine protesting STOP. Expect to feel nervous during the run it's your baby after all
I would change the engine oil prior to going and clean the filter too. Allow plenty of time and enjoy the experience.
Tyre pressures should be spot on too. Before the run allow the engine to idle for a while to stabilise temperatures and during the run make sure the operator uses the bay cooling fan to max effect - enjoy
Ian.

Thanks Ian, sounds scary. Also sounds like I might have busy weekend preparing for this.

BTW – your 500 looks very like mine – red and white. Like the wheels.

timgarman said:

Thanks Ian, sounds scary. Also sounds like I might have busy weekend preparing for this.

BTW – your 500 looks very like mine – red and white. Like the wheels.

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Hi Tim, the wheels are 5J x 12 (minilight?) wearing Yokohama 165/60 R12 71H
A539 tyres, they seem to be good in most conditions and are quite cheap here.
Ian.

Dyno-tune went well and I need to install a 120 main jet in the FZD, when I can find one.

However, somewhere along the 1 hour drive to the tuners (or on the rolling road) one of my rear axle driveshaft flanges has spun the spline smooth. Is this likely to have happened when being tuned?

Anyway, I can't drive her back till that is fixed. Hopefully tomorrow.

Will post when I've driven her to see how she feels.

timgarman said:

Dyno-tune went well and I need to install a 120 main jet in the FZD, when I can find one.

However, somewhere along the 1 hour drive to the tuners (or on the rolling road) one of my rear axle driveshaft flanges has spun the spline smooth. Is this likely to have happened when being tuned?

Anyway, I can't drive her back till that is fixed. Hopefully tomorrow.

Will post when I've driven her to see how she feels.

Click to expand...

Hi Tim, bad luck with the flange, it may have had a weakness prior to the rolling road and the run has stripped it!!! I have to say that when I changed my drive shafts a while ago the flanges were tight on the shaft splines and needed a lot of grease and a bit of hammer, no problems since though. Change both flanges if you can in case the other side is weak too.
Ian.

Join the club Tim! Same thing happened to me a short while ago (I think there was a thread relating to this problem not so long ago).Mine happened on the edge of Chester as I was pulling away from a set of lights---right in the middle of the morning rush hour. Oh what fun!. As Ian has suggested,I changed both of the couplings. For what they cost, it isn't worth risking it.

With regard to a '120'main jet---Eurocarb have them in stock (392 to be precise!).Might be worth while getting yourself a small order from them--i.e.a gasket set,spare jets etc. They give very good service, I have used them a ;ot.

timgarman said:

Dyno-tune went well and I need to install a 120 main jet in the FZD, when I can find one.

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You could alternatively bore out your existing main jet using a 1.2mm drill bit.

1.2mm = 0.0472 inch

If you don't have a 1.2mm drill, you might use a 3/64 inch drill (= 1.191mm/0.0469inch).

Modelmakers, watchmakers etc. will likely have such small drill bits if you have difficulty in sourcing one. 1.2mm/0.0472in is the tapping drill size for 11BA threads .

If you then find that 1.2mm is now too large, just fill the orifice (=hole ) with solder and re-drill smaller, then buy the correct jet at your leisure when you've finalised which is the optimum size for your engine.

Al.

F123C said:

You could alternatively bore out your existing main jet using a 1.2mm drill bit.

1.2mm = 0.0472 inch

If you don't have a 1.2mm drill, you might use a 3/64 inch drill (= 1.191mm/0.0469inch).

Modelmakers, watchmakers etc. will likely have such small drill bits if you have difficulty in sourcing one. 1.2mm/0.0472in is the tapping drill size for 11BA threads .

If you then find that 1.2mm is now too large, just fill the orifice (=hole ) with solder and re-drill smaller, then buy the correct jet at your leisure when you've finalised which is the optimum size for your engine.

Al.

Click to expand...

this is what I like about this site....
where there is a will there s a way or two....

Hi Folks

Thanks for all the advice. I do have a Dremmel drill with some tiny drill bits.

Currently I've only replaced the one driveshaft flange but will keep an eye on things.

I have a new (old) problem which I'll start a new thread for.

Tim, whilst I realise that you have a fairly major problem on your hands at the moment, just for interest, what was the reading on the dyno? I will be out in my workshop tomorrow, will see if I have a '120' main jet. I realise that it is often done when there is no alternative, but I don't like seeing jets drilled out.

Hi Tom,

While I'd agree that enlarging jets with a drill bit is not the best way to go about things, the reason I suggested it was that I noticed that Tim is in NZ and assuming that he doesn't have a local supplier of carb jets, he might have a not insignificant time delay if he ordered jets from the U.K. My suggestion was made in order to allow him to experiment straight away and at low cost and then when he had determined the optimum jet size for his engine, he could order just 1 jet to replace the one he had 'modified'.

Iirc, some expensive early U.S. cars had adjustable (from the exterior) jets in their carbs. I suppose the nearest we've had was the good old SU carb. - I'm still waiting for someone on here to fit one to their 500

Al.

I completely agree with all your reasoning for drilling out his existing jet Al, that is supposing that he is having to go UP a size, Tim hasn't told us what is in the carb at the moment.
With regard to fitting a SU to a 500, 1 or 2 people have tried it in a fairly desultory manner with mixed results. Fitting a SU would not be a problem; the FZD inlet manifold matches perfectly with it as the flange measurements of the SU vis-a-vie the FZD are exactly the same, as is the angle of fitment. A 1-1/4in SU carb (albeit a horizontal carb) was fitted to the police Triumph motor-bikes, so the settings for that carb would be a fairly sound starting point. If anybody wants those settings, I have them and they have only to ask, I will happily pass them on. What it needs is somebody with a bit of time and access to a rolling-road to fit one and get it set up.
If anybody wants a NEW bigger carb, but not a 'twin-choke' look at the Dellorto "OVC 34/30D" (MUST be the 'D' variant). It is a 'sort-of' horizontal FZD, the manifold is available 'off-the-shelf' from some Italian suppliers. It is fitted to the little "Ape" 3-wheelers, but most importantly are NEW. Lastly, there are always the 'bike' carbs--Mikuni and Keihin. Again, the manifolds for these carbs are available over-the-counter from Italian sources and they are light, plentiful and stay in tune--they also give good power!

timgarman said:

Hi Folks

Since the sun is coming out down under (NZ) my Fiat is getting used more. I decided to book a rolling road tune-up. This is happening next Tuesday.

Firstly, I wondered if anyone has any recommendations for this process?

The place I'm taking it is local – about 50 miles / 80kms away, the longest run I've done.

They advertise handling classic cars and apparently have 3 other 500s they take care of, one with a similar set-up to mine.

They also recommend running the car on 95 or 98 octane. Is this normal? Is anyone else doing this? Is it just to get the best readings / performance stats when it's being tested?

Click to expand...

hi Tim, where did you go for the tune? i am in auckland.
thanks
Michael

Bleeding Knuckles said:

Hi Tim, the wheels are 5J x 12 (minilight?) wearing Yokohama 165/60 R12 71H
A539 tyres, they seem to be good in most conditions and are quite cheap here.
Ian.

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hi Ian, i am considering getting 165/60 on original wheels, do they fit well, no touching, is the car lowered?
thanks
Micheal

Mike r said:

hi Ian, i am considering getting 165/60 on original wheels, do they fit well, no touching, is the car lowered?
thanks
Micheal

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Good evening Tim---just for interest, what was your bhp (and torque) reading on your rolling-road session?