Tuning Looking to go faster

[the hobbler]

A lot of the Polish gear is quite well made---definately better than the 'Chinese' gear. If the barrels and pistons are a matched set, and at a sensible price, it would seem to be sensible to go for it! Just be careful that you put the pistons in facing the correct way and use plenty of lube. I would also reccomend that you run the pistons/barrels in properly. I normally run in a engine for 800 miles (1300 km) using a proper 'running-in' lubricant (one with a high zinc content such as Morris's 'pistoneeze'), and do a complete oil change at 400 miles (650 km). I limit the 'running'revs to about 3,500 (4,000on 'off-load down-changes')

Sorry about that Thomas---the incomplete reply just seemed to "go through"! What I was going to continue with is that I limit the revs to 3,550 rpm for the first 400 miles (650km) and then increase them to about 4,000 rpm (4,500 rpm on the 'off-load' down changes) for the rest of the running in. I still believe that a well run-in engine performs better and last longer than an engine thrashed from the very start of its life. All the best with the 'enhancement'--it will definatly run better (and quieter!) than the old engine.

 

[gordinir8]

I was lucky enough (searching for two days now) and found a set of OEM fiat pistons 77.40 at a very reasonable price Tom. In Greece "breaking in" takes 1000 kilometres and oil change at 500 lol. Good thing is that weather is appropriate for breaking in so I guess I will take it easy up to 1000-1500 kilometres and then switch carburettor and see what's the difference.

 

[gordinir8]

Sorry about that Thomas---the incomplete reply just seemed to "go through"! What I was going to continue with is that I limit the revs to 3,550 rpm for the first 400 miles (650km) and then increase them to about 4,000 rpm (4,500 rpm on the 'off-load' down changes) for the rest of the running in. I still believe that a well run-in engine performs better and last longer than an engine thrashed from the very start of its life. All the best with the 'enhancement'--it will definatly run better (and quieter!) than the old engine.

Yes I totally agree, from my scooter tuned engines I can tell you that first kilometres are quite hard and hot, so at the beginning small 15-20 min runs to keep temp down.

 

[gordinir8]

I was about to order 35mm inlet valves from fiat 126 BIS for my 126 head modification but i can't locate them, Axel that has those valves is out of stock. Any alternatives about where to find a set? The next alternative i can find is 34x8x115 which is also 05cm shorter but i prefer since all this trouble and overall cost to go for 35mm

 

[the hobbler]

I was about to order 35mm inlet valves from fiat 126 BIS for my 126 head modification but i can't locate them, Axel that has those valves is out of stock. Any alternatives about where to find a set? The next alternative i can find is 34x8x115 which is also 05cm shorter but i prefer since all this trouble and overall cost to go for 35mm

Hi Thomas---"D'angelo Motori" have 35mm valves (with 8mm stem) in stock---about E39 each. I have bought from this company on a number of occasions; their quality is good, never had a problem with quality or fitment.

 

[Toshi 975]

Ricambio are showing them in stock , just over £12 each

 

[gordinir8]

Ricambio are showing them in stock , just over £12 each

He has 34mm

Ricambio are showing them in stock , just over £12 each

He has only 34 mm, Now 40 euros for a valve looks pretty expensive from diangelo ( from which I have already ordered my synched cam) so I might use 34mm instead and keep stock 28mm for the exhaust. Very confused with what to choose I am overthinking again and better slow down, 1mm doesn't make the difference.

 

[gordinir8]

Mail call and 35/75 synced cam is here along with twin Webber mount. Still waiting for other parts and head repair from cracks. Can't wait to put little car back on the road since it is my daily car.

 

[the hobbler]

Mail call and 35/75 synced cam is here along with twin Webber mount. Still waiting for other parts and head repair from cracks. Can't wait to put little car back on the road since it is my daily car.
View attachment 400832

Hi Thomas----the fiddly bit is lining up the timing marks on the 2 sprockets and fitting BOTH the sprockets AND the chain all on at the same time--have fun!

 

[gordinir8]

Yes I know, thing is that the holes in the gear are oval and there is no guide to align cam and gear anymore so I wonder if with only the four bolts it is safe without the risk of misalignment during operation. This makes me think how wise would be to mark it, remove it and add a screw at the spare hole that camshaft has.

 

[the hobbler]

Yes I know, thing is that the holes in the gear are oval and there is no guide to align cam and gear anymore so I wonder if with only the four bolts it is safe without the risk of misalignment during operation. This makes me think how wise would be to mark it, remove it and add a screw at the spare hole that camshaft has.

I am running the 'synched' cam as it came---and so far, no problem. The problem with threading a hole in the 'spare' hole in the camshaft is that (as I have found out) the camshaft material is HARD. The trick with fitting the cam, chain and crank sprocket all at the same time, is to align the 2 sprockets WITHOUT the chain, so you know where they should go. Then, fit all 3 parts together---the crank sprocket will 'fit' first, keep them aligned and side the cam in as you tap the crank sprocket onto the crank. Being serious, it is not as difficult as it sounds. By checking the alignment (without the chain) first of all and getting it all set up, I was (luckily!) able to do it first time--phew!

 

[gordinir8]

Will do that Tom thanks. Was your chain free of those little weights too?

 

[Toshi 975]

That type of chain was fitted on the 126 Bis engines

 

[gordinir8]

I already installed it, I don't think it will be a problem. Besides last time one of those weights fall of and I found it at the bottom of the oil pan

 

[Toshi 975]

I didn‘t think the timing chain would be a problem as the Bis engine was the most powerful of the standard 2 cylinder engines

 

[Toshi 975]

Ideally with that manifold you will need some sort of thermal break spacer to reduce heat conduction especially in the conditions you drive in. The carbs you are looking at were originally fitted with either a plain spacer or a Bakelite drip tray spacer under the carb. Bit of a story but I had a new cylinder head prepped for me by a very talented guy who runs a 100+ hp turbo charged 126 engine that he developed over many years. Apart from porting, skimming and larger inlet valves he told me he could see a further improvement but would not tell me what it was. At the same time I was playing with fitting a Weber 30DIC carb at home. Some how over the years I had picked up a mystery carb spacer I did not recognise. When I offered it up to the base of the manifold like the one you have it was a perfect fit so I used it and it worked well. The spacer was from a Giardiniera. When I collected my new head my pal had machined a similar item from solid alloy.

 

[gordinir8]

Ideally with that manifold you will need some sort of thermal break spacer to reduce heat conduction especially in the conditions you drive in. The carbs you are looking at were originally fitted with either a plain spacer or a Bakelite drip tray spacer under the carb. Bit of a story but I had a new cylinder head prepped for me by a very talented guy who runs a 100+ hp turbo charged 126 engine that he developed over many years. Apart from porting, skimming and larger inlet valves he told me he could see a further improvement but would not tell me what it was. At the same time I was playing with fitting a Weber 30DIC carb at home. Some how over the years I had picked up a mystery carb spacer I did not recognise. When I offered it up to the base of the manifold like the one you have it was a perfect fit so I used it and it worked well. The spacer was from a Giardiniera. When I collected my new head my pal had machined a similar item from solid alloy.View attachment 400836View attachment 400837

Nice tip, thanks i will look for it, but also looking for a Panda 30 weber which i will install only after i break in the engine at 1000 kilometers so i can tell what is the difference with all the other mods before the carb. The reason i am looking for the panda 30 carb is that it is ready to installed with all the jets there. Otherwise i have found a weber 30 dgf 23/23 from citroen gs, have seen at ebay, italians are selling this for 126 tune but then i will have to replace all the jets, something i am trying to avoid.

 

[gordinir8]

Guys is this piston supposed to be 04 oversize? Because I am measuring it and it is 77.28 more or less but not 77.40 plus that it came with broken ring but that's another story.

 

[fiat500]

Guys is this piston supposed to be 04 oversize? Because I am measuring it and it is 77.28 more or less but not 77.40 plus that it came with broken ring but that's another story.

Could it be that it's measured in Imperial...that does seem to happen sometimes with engine component dimensions. 0.010" oversize would be 0.254mm.

Sorry to hear about the broken ring.

 

[Bleeding Knuckles]

Hi Thomas, if you look at my old thread @

Weber 30 DGF 1/252 service​

you will find all the information you need about the correct jets for the carb. Just in case the carb you find does not have the original jetting.
For information It was recommended by my engine man that I use a new set of jets - All one size above standard to help with the running in process - the richer jets help keep the piston crown cooler and when run in change back to the leaner original jets. Hope this helps.
Ian.