Club126UK
Fiat 126 Chat => Fiat 126 Mechanical Problem Solving => Topic started by: SteveLaverty on September 21, 2006, 09:48:22 AM
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does any one know what would happen if you didn't put any lead replacement in an aircooled that hasn't been converted. I assume it would destroy the engine? What symptoms do you think would occur
Is there anyway of telling if a car has been converted
Just interested
Steve
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126s have alloy heads so already have hardened valve seats, so in theory they should run fine on unleaded for years without the valve seat recession associated with cast iron heads.
If it was a water cooled car driven gently I wouldn't worry, but 126 valve seats were never designed for the extra heat produced by unleaded (it burns hotter) and were designed with the expectation of lead protecting the valve seats, so they might not last well without an additive. These aircooled engines run extremely hot anyway and is routinely running at 4,000rpm - gentle driving isn't really an option.
Symptoms of seat recession are hard to spot on a 126 - in theory the engine would get quieter as the valves clatter less on the seats but you'd probably never notice over all the other engine noise, and it would be a gradual change. As things got worse, you'd get back firing as the exhuast valves never closed properly - again a common problem anyway with ignition and timing, and finally in extreme cases you might have a wrecked head and pistons - a bit late then.
For that reason I'd recommend using an additive as its better safe than sorry.
Alternatively, you could have some hardened seats fitted. There's no way of knowing if this has been done already without a receipt.
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i use castrol valve master plus in mine,ups the octane as well..£10.00 a bottle.cheap insurance
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hi dave, just gone and bought some after reading that, got mine off ebay.
i didnt buy the one with octane boost, as i always use the premium unleaded anyway. Which is 97.
regards
Chris
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nice one chris,i use premium as well as the additive.................
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What about the BIS?
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i use the same in my bis,(now retired to back of workshop)premium, and the castrol valve master.they use so little fuel,why not use the best??? :cool:........
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What about the BIS?
No problem with the Bis on unleaded they are designed for unleaded
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I don't think 126 engines would benefit at all from premium fuels or octane boosting additives. The boost to performance requires a performance engine that can exploit the higher octane, so you need a big powerful highly tuned engine to start with.
here's a typical review of these fuels:
http://fifthgear.five.tv/jsp/5gmain.jsp?lnk=601&featureid=143&pageid=-1
I use regular valvemaster and have never had any pinking.
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nanni recommended uping the octane a little with the amount of advance im running with the fast road cam they supplied.......it has enabled me to keep to their setting without pinking,and also ,the price of panda 30 heads as it is,im taking all precautions........... :)
i also put a spoonfull of castrol R in sometimes....gives a fantastic aroma!!! :lol:
evryone has different views on this im sure,bit i do what makes my buzzbomb run as well as possible,i just keep the habit with the bis(and rangy and 3 bikes). :)
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I expect that as you've tuned your engine to the edge of its performance you'd notice the benefit? For a stock engine, and for most small economy cars, I think its probably just lining fat cat's pockets. :x
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i agree,stock small/big lazy motors (without ecu's) would get very little/no benifit from higher grade fuel without ignition timing mods..... :)