Club Fiat 500 - Argentina

Help wanted
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Autor:  babelhoo [ 01 Ago 2016, 14:56 ]
Asunto:  Re: Help wanted

The car sounds and goes really well! Sorry about the problem with the timing resulting in head damage, hopefully the specialist can sort it.
About the IAVA, I'm pretty sure it wasn't exported, so no luck there.

Autor:  Gasket [ 01 Ago 2016, 15:16 ]
Asunto:  Re: Help wanted

Luckily there wasn't any real damage. I just lifted the head to sleep well. Afterall it took an hour and then I knew for sure if the engine was ok or not. Its just all in the motorsport.

So its not fixing it, its just improving it.

A friend of mine has a spare set of DHLA's. Not sure if I'll fit those or not.. It goes pretty well with the DGAV. Third gear pulls to about 130..140 kph and 0..100 kph is about 8..8,5 s. Not bad for a 40 year old car. I did hassle one 3,0 tdi Audi to about 170 kph before I had to back off as I was at the intersection to my house..

If I can't use the SE or IAVA, then I'll just have to bend the rules. As the inspector told me: The MOT really doesn't care how much power it has, just as long as it looks good on paper..

It is a whole different car now. Before it struggled to hit 130 kph, now it cruises comfortably at 100 kph+. Gearing is long now with the Ritmo 75 gearbox, but to me its not a bad thing and it pulls like a train all the way from down low.

Autor:  Gasket [ 01 Ago 2016, 15:28 ]
Asunto:  Re: Help wanted

This is the multigroove on top of the cam gear:



This is why I think the timing belt jumped. The multigroove got in between the cam belt in the hassle..

I've also installed some old school buckets to it :

It would make things a lot easier if you'd modify the forum to accept 800 pixel pictures instead of 760...

Basically I have two routes now, either to go turbo, or to fit a better cam and the sidedraughts. The turbo would be nicer on the street, but people do regard turbo cars as fast in general, so I'd kind of like to keep it NA.

Autor:  babelhoo [ 01 Ago 2016, 17:21 ]
Asunto:  Re: Help wanted

Good news! I guess the timing shift wasn't bad enough to create contact between the valves and pistons.
Those old-school bucket seats look really nice.
About the images width, I believe you can post wider ones using the rimg tag instead of img.

Autor:  Gasket [ 02 Ago 2016, 13:16 ]
Asunto:  Re: Help wanted

Imagen autoredimensionada

Thanks for the rimg tip! Haven't ran into that anywhere else. Seems to work!

That was as we were heading to the Bella Italia event. Ran into some company at a gas station.

Actually the 3rd and 4th intake valves touched the pistons a bit. The timing was about 36 deg off from the crank, so about 18 at the cam. So two valves touched, but just slightly. Could have been much worse. At least I could drive it back home with the Mrs. and two small kids aboard..

Autor:  Gasket [ 26 Oct 2016, 04:42 ]
Asunto:  Re: Help wanted

Head was taken off, seats and valves reworked and the engine put back together. The camshaft was also changes to a version that has about 1 mm more lift. Now it has 10,2 mm from valve. Duration pretty much the same at around 290 seat to seat.

After some serious tuning again I took it to a dyno:

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Now its time for a winter sleep:

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But don't worry, its going to a dry garage..

Autor:  babelhoo [ 27 Oct 2016, 10:10 ]
Asunto:  Re: Help wanted

Wow, 134CV for an old N.A. 1.6 is great! good job. Does it idle smoothly with that cam?

Autor:  Gasket [ 28 Oct 2016, 02:19 ]
Asunto:  Re: Help wanted

Pretty smoothly at around 1100 rpm. I think it would idle lower as well if I could use more ignition advance at idle. Now its at 12 deg at idle and about 32 max. In the dyno we tried up to 36 where it started to shown signs of slight knock. Power and torque remained virtually unchanged, so we went back to about 32. Below 31 it starts to lose power.

Idle basically is irrelevant because this is old enough that it doesn't have to pass emissions testing. If it were a year younger (-78->) then it would have to idle below 1000 rpm and emit under 1000 ppm of HC and under 4,5% of CO. I don't think it would pass that with this carb because of the cam overlap. With duals that wouldn't be a problem because of individual runners.

Tuning the carb has been quite an effort. Still it isn't perfect, but not much more can be done. There is a lean spot with small throttle openings and at lower rpm it goes too rich if floored. Would need an emulsion tube that doesn't exist for secong barrel. At some point I'll try to solder my own version. E-tubes already have extra holes drilled, but would have to alter the tube thickness. Air correctors are already very small, that also limits the effect of extra holes in E-tubes. I've spent quite many hours with the carb..

This is pretty much the limit with this kind of setup if any driveability is maintained. Can't go any bigger on the carb and it won't tolerate any hotter cam anymore.

During the winter I'll try to improve the exhaust and build a proper tubular manifold. That might help a bit with the carb as well, because now the short primaries cause some unwanted pulsation.

The collector exit in my 2-1 pipes is under 45 mm! Bigger is not always better.

Imagen autoredimensionada

That is a 1 3/4" pipe that is connected to 35 mm ID secondaries.

Imagen autoredimensionada

I think the torque figure comes from that and also the intake length should have a positive effect at around 4500. If both were tuned to 7000 rpm, it would make a pretty nice peak number, but with my long gearing I'd rather have more torque down low and a wide useable rpm range. I succeeded better than I even hoped.

This uses a Fiat Tipo intake manifold:

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Ported and all radiuses blended. 10 mm aluminium spacer to suit the carb bolt pattern. Ports matched to head and actually the manifold is raised in relation to the head to get the port roof higher up.

So it has taken quite many hours to get to that power. Just by bolting these bits together you won't get anywhere near. But I think that this is a pretty good result from using just modified stock Fiat parts from several models.

Autor:  babelhoo [ 28 Oct 2016, 09:51 ]
Asunto:  Re: Help wanted

Congrats! it's clear that you put a lot of thought and effort into getting all these parts to work optimally together. Working with old school cars has some charm that new ones don't have (at least for me). Well done!

Autor:  Gasket [ 28 Dic 2016, 19:24 ]
Asunto:  Re: Help wanted

New year is coming, so its time for some new tricks. I have another engine sitting in my garage..

I dont think that NA has much more to give, so I thought I'd give a bit of boost a try.

I found some iapel turbo pistons. But those are not that well known in Europe. Are those good?

I was thinking of a 1,6l with a modern ball bearing turbo. Nothing crazy, just some 150..200 hp. Going to keep it old school, so I'll give the turbo-dat carb a try. I have one sitting in the shelf.

I have a couple sets of stock na pistons, but I fear that those can't take the power. How much do those iapel pistons go for? I don't want to pay too much. Can't find any kind of price for those to compare. Or any info if those are actually good.

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