alfa 33 identification

[greku]

Quote:

Originally Posted by keith_h Here in Australia regular unleaded causes pinging. Using premium unleaded which has more octane stops it. Maybe that could also be your problem.

[keith_h]

Yes, I a referring to your issue. Using regular unleaded here causes pinging in my cars, 84 and 85 33 carburetted.

From this website: Fuel Types

Unleaded Petrol (ULP)

Unleaded Petrol is the most common fuel type in Australia for passenger vehicles.

ULP has a Research Octane Number (RON) of between 91 and 93. RON is a measure of a fuel's compression performance and the RON rating given translates into the amount of engine power. RON requirements vary according to engine type.

Premium Unleaded Petrol (PULP)

PULP is a special blend of petrol designed to bring high octane, and hence high engine power, as well as knock- free performance to unleaded cars with a high-octane requirement.

A knocking noise can occur in an engine when there is a mismatch between the fuel characteristics and the engine's design, particularly its compression ratio, resulting in pre-ignition (also known as 'pinging').

Selecting fuel with the correct RON for your engine will prevent the knocking fuel effect caused when the fuel combusts in the compression chamber too early.

PULP has a Research Octane Number (RON) of 95.

Anyway my experience is that the cars work better on premium unleaded which stops the pinging.

According to the same article, it says that LRP (which is no longer available here) has even higher RON of 96. NOt sure if that is the case in Malta but if it is then there should be no problem unless the timing is way advanced. Articles on chemical additives that claim to boost octane in fuels indicate they are expensive do not help significantly.

Anyway, maybe the timing should be checked to ensure it is not improperly advanced.

[gti_rsi]

well i use 98 (aus rating) octane or premium unleaded all the time as i did with my old car. the metallic noise i suspect is the unburnt fuel igniting as i was told by an alfa mechanic, im not so worried with power figures i just want that gargle sound amplified with the stacks. will get the car tuned soon when i have the money too aswell.

also with the air filter, i didnt have a proper paper filter in there when i bought it, there was only a peice of fine mesh plastic. and the airbox was missing its cold air pipe so really it wasnt doing much good from the state it is in atm from how i bought it.

and cone filters do improve airflow and power *if* they are setup right with cold air readily accessible (but most cars have an internal throttle body heater where the coolant runs through the throttle body and helps heat up the motor quicker, there is a known method to stop the coolant from entering the TB but it can cause erratic idling problems, this method is known as a tb coolant bypass). the filtration of them really depends on what brand you buy, recently they tested a bunch of them at a local autosalon and the cheapest of the cone filters tested (3a Racing) was the best with power, 4hp increase and better filtration than a stock paper or panel filter. and K&N came in at 4th place with ok filtration and ok power gains. big disappointment for such a well known brand.

cheers guys

[Greek]

if you have a pinging problem with unleaded just follow the guide and change the ignition advance to 3 degrees (i think ) and it will stop. Boxer engines can work with unleaded since they have hardened valves so there will not be a problem. i am using unleaded with no problem in my sprint and from time to time i am using a mix of unleaded and 100 ron unleaded in 3 to 1 mixture for better results. Oh and the cars goes very well with that mixture....

[kid808]

Kool great 2 c another 1 of these around and this answers sum of my own questions as i have a gold leaf and 2 green leaves whats the difference with the quadrifoglio i recently swapped the gear box (wat a nitemare lol) and theres no way the quad box is the same ratio as the green leaf .....