FiatGuy

Cracking job Bernie! Making great progress considering its been less than a year. Looks like you may have the drag link installed back to front though, the cushioned end with the springs is suppose to go up the steering box end. It probably matters not in the long run, I cant think of any side affects of having it installed this way so long as you've still got the full range of motion lock to lock.

Congrats Berny, a massive milestone! Not long now and you'll be driving it around with a milk crate clamped to the chassis like I did! As for the difference, is the left hand spring mounted back to front? The rear hanger is at a different angle compared to the right one!

Hey Berny, the 501 cylinder head had the spark plugs offset to the side of each cylinder, where as a 503 cylinder head had them evenly spaced which was much better for combustion efficiency and torque! There was also whats known as a Ricardo cylinder head developed before the 503 came out, which had the even plug spacing, and the combustion chamber was smaller which bumped the comression ratio up and gave a bunch more torque. I haven't heard of any plug depth differences, but haven't compared the heads myself either! From what I understand the 503 head adopted this combustion chamber design. The way to tell is the 501 head is ballooned out, while the Ricardo/503 head is chamfered over the piston (and the plugs are evenly spaced). Both are interchangable on a 501 block, but the head gasket needs to suit the cylinder head from what I've been told. While im at it, the 503 oil pump has a bigger capacity over the 501 and its reccomended to be installed in conjunction with the head. You can visually tell the difference as the 501 pump has a flat base, while the 503 bulges out. Hope that helps! Brodie

Looking good Bernie! I like the shade of red on the block and head, I painted mine black but its a bit generic. Where'd you source the new spark plugs from? I've got a feeling my spark is breaking down under cylinder pressure occasionally causing missfire. Brodie

Hi Bernie, 501s run a 12v system with a positive ground. On the topic of electrics, we bought a wiring harness from a company named "vintage wiring harnesses" I believe, all original cloth braided wire and the fit was perfect. It was a bit pricey, but nice to have something that was plug and play for a change! Cheers, Brodie

Hi Bernie, Diff's are a sour talking point for most 501 owners. OnSafari is correct in saying they're the weakest link, being made of cast aluminium certainly doesn't fair well against abuse! Thankfully us enthusiasts are much more gentle when it comes to driving them, but I've heard horror stories of people Blowing the diff just by leaving the handbrake on and trying to drive off!! Mine was in several pieces when i bought the car, both the pinion, ring gear and both halves of the diff assembly. Not sure which gave way first, but the resultant mess is the same either way... I installed a 503 unit to be sure, which bumps the thickness of the weakest point from 5mm to 10mm or thereabouts. You can also drill and tap the torque tube housing amd install grub screws that secure the aluminium housing where the pinion bearing lies. This relieves some of the torsional stress sent through the housing. Cheers, Brodie

Hi Bj, I found this thread last night and couldn't resist the urge to sign-up and say g'day! I'm nearing the end of a 10 year restoration of a 1923 501c, and seeing your photos brings back many memories. I bought mine as a resto project when I was 15, and have thoroughly enjoyed the adventure of becoming a backyard mechanic, panel beater and motor trimmer along the way. I've attached some photos below showing the restored running chassis and the current state of the vehicle as it sits now. The hood and rear seat is all that is needed to say this car is finally "finished". If you're ever in need of any detailed photos or answers to questions let me know and I'd be happy to help. By the looks of things you're based in Victoria, Australia, like myself. If you find yourself at a loose end tomorrow there is an Italian car show called Autobella at Como Park North, South Yarra. In previous years theres been a few 501/3s so I'd suspect a similar turn out this year if you'd like to have a look at one in the flesh. My 501 is still in Adelaide at my parents house, but I'll be attending as a spectator in my 124 spider. Keep up the good work! Cheers, Brodie