Performance Mods

[fazersix]

I have a stock 1981 Alfetta (116) GTV 2.0 with Momo star wheels 16" with 205/65 tyres. Have just finished the body work (respray) and want to give it a little extra performance. Are cams the way to go? Not sure what are in my engine, but 10548 appear to be a good option - possibly second hand or are these rare? What other cost effective upgrades would be good on a low budget?  Thanks

[carlo rossi]

it really depends on what you want to achieve
certainly 10548 are a start and with them more importantly is the timing caps have to be set at 104 and 102deg
look up centre line downloads for the template
the carbs need to be changed internally a little as well
if you search the forum all the info is there," how to tune" or others

[fazersix]

Thanks Carlo, that looks the way to go. I have just done compression test and come up with around #1 125 #2 125 #3 155 #4 155. I know the rule of thumb is around 10% between cylinders, the engine feels strong, do you think it is worth it to add the cams?

[Citroënbender]

Was that a hot test, and with oil or not?

[fazersix]

Yes, that was about an hour or so after I had been driving it so it was still pretty warm. No oil, but I did have the carbs wide open and all plugs out and cranked about 5-6 revolutions

[fazersix]

Hi Carlo, the centre line drawings onl y have 102 and 108 degree markings, so is mid point less a little good enough or is there a better way??

[carlo rossi]

yes thats ok but i think your bigger issue is the compression
bizare that they are 2 lots of equal valkues
you should re do it
pull all the plugs out get someone to throttle full
then test after 10 revolutions
each one something is wrong here

[fazersix]

Thanks Carlo, will do that soon!

Is it necessary to re-jet the carbs - stock Dellorto 40mm initially. Was planning to install the cams, run it then tinker with the jets.

[carlo rossi]

everytime you change cams, it changes the engines ability to take a charge.
by increasing its ability to ingest you have to re jet accordingly or you are virtually waisting time
i have seen many a blog saying put this or that cam in didn't notice much difference or lost all bottom end
they have just thrown the cam in without tuning
ie carbs but also event times of the cam and the outcome required
the 10548 is quite a simple upgrade but the timing is important ( cam that is not ignition)
but remember the basic carby setup is from a 1750 even if its a 40mm carb the important [part is
the secondary venturi which chokes it back to 32mm ( too small) meaning reving over 5000rpm gains little
you really need to go to 34mm secondaries in the 40mm carbs
ps very easy done

[fazersix]

Thanks Carlo and Spotiva. I have picked up some good used 10548 cams, will install those first. I am definitely up for tinkering with the carbs, i have seen Carlo's post which has the suggest jet sizes.
It might be a while but I will post my results. Cheers