Hi guys,
I’ve just bought a gorgeous series 1 fulvia sport 1,3. It came fitted with the original dual Solex C35 PHH system, however, in a set of additional parts, came a set of dual Solex C40 ADHHE.
My question is: is there any advantage on fitting these bigger carbs? Do they make any difference on performance or they just stress the engine?
Any of you guys has made a similar change? What was the result?
Thanks for your help.
Regards,
Series 1 Fulvia Sport 1,3 carburetors
-
Hugo Ferreira
- Posts: 4
- Joined: 30 Apr 2023, 20:46
- Location: Portugal
Series 1 Fulvia Sport 1,3 carburetors
Regards,
Hugo Ferreira
1968 Lancia Fulvia Sport 1.3
Hugo Ferreira
1968 Lancia Fulvia Sport 1.3
Re: Series 1 Fulvia Sport 1,3 carburetors
Hi Hugo
Welcome to the family. From the IP address you are posting from I guess you post from Portugal.
I was already driving Lancia's in the 60s. We used to say:
With Fiat the accountants are the boss.
With Alfa Romeo the salesmen are the boss.
With Lancia the engineers are the boss.
Lancia's were very expensive cars too. You can be sure that Lancia engineering is ok. They spent all the money necessary. If you want to follow a course how to go bankrupt as a car manufacturer, take apart a Lancia from the sixties. Too good and too expensive to manufacture. Just make sure that everything is within factory specifications to have the best possible balance between engine power, handling, safety, economy, reliability. Restore to original specs and you will have a brilliant car. Your best friend for life.
If you don't find it fast enough. take driving lessons.
An example we currently have in our workshop.
A Fulvia which has to be at the start of the Tulip Rallye by the end of this week. Owner went to a rolling road tester. The size of the idle jets was increased for more power. The car was brought to us to check some other things. We found however that performance changed from one day to the other. We changed the carbs to NOS (loaned from our stock). Solexes wear when used. It is the flip side of being brilliant carbs. In those days no problem. Just put new ones every 200.000km just like you change brake pads. When the carbs wear they suffer from air leakage. They draw false air. The mixture becomes lean. Putting in larger jets is not a good idea. The only good solution is to rebuild the carbs. Have it done by an expert who has all the necessary tools and instruments. If you do not have the set up to measure air leakage, forget it.
If you put larger carbs you MAY have more mixture at high revs but you will certainly loose torque at low revs. How often do you drive at 5500 to 6000 rpm? I never do but I do drive in town every day.
Also remember that because of the narrow V construction the crankshaft is short and has only 3 main bearings. 4 in line engines have 5 main bearings. The crank shaft of the Fulvia is made from the very best crank shaft steel available in the 60s and 70s but still it flexes more than a crankshaft with 5 main bearings. If you go increase power without nitrating (hardening) the crankshaft, the center bearing will suffer and dramatically reduce life time.
What we often do by the way is do the nitrating (3mm) without increasing the power. The crankshaft flexes less so less energy is lost, lifetime increases, consumption is lower, less vibration. We couple this with perfect balancing pof all relevant parts and heavily polished conrods. Simply perfect.
Welcome to the family. From the IP address you are posting from I guess you post from Portugal.
I was already driving Lancia's in the 60s. We used to say:
With Fiat the accountants are the boss.
With Alfa Romeo the salesmen are the boss.
With Lancia the engineers are the boss.
Lancia's were very expensive cars too. You can be sure that Lancia engineering is ok. They spent all the money necessary. If you want to follow a course how to go bankrupt as a car manufacturer, take apart a Lancia from the sixties. Too good and too expensive to manufacture. Just make sure that everything is within factory specifications to have the best possible balance between engine power, handling, safety, economy, reliability. Restore to original specs and you will have a brilliant car. Your best friend for life.
If you don't find it fast enough. take driving lessons.
An example we currently have in our workshop.
A Fulvia which has to be at the start of the Tulip Rallye by the end of this week. Owner went to a rolling road tester. The size of the idle jets was increased for more power. The car was brought to us to check some other things. We found however that performance changed from one day to the other. We changed the carbs to NOS (loaned from our stock). Solexes wear when used. It is the flip side of being brilliant carbs. In those days no problem. Just put new ones every 200.000km just like you change brake pads. When the carbs wear they suffer from air leakage. They draw false air. The mixture becomes lean. Putting in larger jets is not a good idea. The only good solution is to rebuild the carbs. Have it done by an expert who has all the necessary tools and instruments. If you do not have the set up to measure air leakage, forget it.
If you put larger carbs you MAY have more mixture at high revs but you will certainly loose torque at low revs. How often do you drive at 5500 to 6000 rpm? I never do but I do drive in town every day.
Also remember that because of the narrow V construction the crankshaft is short and has only 3 main bearings. 4 in line engines have 5 main bearings. The crank shaft of the Fulvia is made from the very best crank shaft steel available in the 60s and 70s but still it flexes more than a crankshaft with 5 main bearings. If you go increase power without nitrating (hardening) the crankshaft, the center bearing will suffer and dramatically reduce life time.
What we often do by the way is do the nitrating (3mm) without increasing the power. The crankshaft flexes less so less energy is lost, lifetime increases, consumption is lower, less vibration. We couple this with perfect balancing pof all relevant parts and heavily polished conrods. Simply perfect.
