The standard 2600 inlet cam timing is 20 degrees before TDC and 70 after BDC
All other alfa engines 1300/1600/1750/1800/ 2000 CC with weber ,dellorto and solex double sidedraft carbs have inlet cam timing between 34-41 degrees before TDC and 58-61 after BDC.
Is this for the solex 44PHH and also for weber 45DCOE9 ??
I can't find a different cam timing for the weber 45DCOE9 set up in my alfa 2600 documentation/data sheets .
I think the engine performes better with inlet cam timing between 34-41 degrees before TDC and 58-61 after BDC with the weber 45DCOE9 set up.
Does someone have experience ?
rgds Franco
Last edited by franco-veloce; 08-06-2009 at 05:22 PM.
FYI, to address some off-BB questions: The cams for the 2600 SZ are the same as for Sprint/Spider (106.01.03.200.00). So far, I have not seen any information that would suggest different timing settings.
The only significant difference between 2600 SZ engines and Sprint/Spider engines are the engine mounts (the engine is placed 8 mm lower on 2600 SZ).
BTW: It's a myth that these cars were supplied with Webers as factory standard. Webers were optional the same way they were optional on Sprint/Spider. Most cars seem to have been sold with Solex carbs but quite a few were converted to Webers.
__________________
Ruedi
'63 2600 Touring Spider (reassembly in progress)
'65 2600 SZ (resto project)
Maintainer of a 2600 SZ register (not the Dutch one).
FYI, to address some off-BB questions: The cams for the 2600 SZ are the same as for Sprint/Spider (106.01.03.200.00). So far, I have not seen any information that would suggest different timing settings.
The only significant difference between 2600 SZ engines and Sprint/Spider engines are the engine mounts (the engine is placed 8 mm lower on 2600 SZ).
BTW: It's a myth that these cars were supplied with Webers as factory standard. Webers were optional the same way they were optional on Sprint/Spider. Most cars seem to have been sold with Solex carbs but quite a few were converted to Webers.
It seems like a fair number of sprints came with Webers (including the 2600 sprint raced by Elio Zagato), but I don't know of a single spider that came from the factory with Webers.
The Webers were also an option on the OSI 2600 berlina...but I don't know of any that had this option! (54 OSI's were made, only 2 are know left, both at the Alfa Blue Team in Italy)
Ian (RedMerlin)
Were the piper cams new or did they grind (reprofile) a spare set. Just wondering as I am way off the point where I need to worry about cams, but its all useful info for the (hopefully not too distant) future!
(apologies to Franco for thread hijack!)
Regards
Bryan
I have read this thread (and other Weber related threads) as I am seriously considering changing out the Solex's on my 2600 spider.
You seem to be having good success with your Weber set up, and I have some questions that I hope you can answer:
It sounds like you have gone with 45DCOE9's. Can you tell us what the sizes of the variable parts are (venturis, main jets, Aux jets, Emulsion tube, Air correction, Idle jet, Slow(start) jet and pump jet (to name a few!))?
Also did you only adjust your inlet cam 10 degrees advanced, or did you also adjust your exhaust as Adrian did (inlet cam advanced one hole, exhaust retarded one hole).
Are you running the original Solex manifold or did you de-siamese it?
I have an original weber inlet,
original standard 45 dcoe 9 with only change of the venturi to a 33mm and I only adjust inlet cam 10 degrees advanced.
but the jet settings must be changed for fine tuning in future...........
In my fascinating journey into Alfa arcana, and my attempt to bring my 2600 spider in the 21st century (without scarring it permanently) there are a couple things that many people seem to agree on: 123 ignition, new coil, and a GM alternator. Iridium plugs seem like a good idea too. I hear power, rather than armstrong, steering would be nice, but believe that is a bridge too far...
I also plan to change out the Solex carbs for Webers, and I am trying to get a consensus on the best approach to fit them to a 2600, but am not having much luck!
Many people advocate modifying the Solex manifold, but some have reported good results without any changes. All seem to agree the original Weber manifold/set up is best - however this seems to not be a valid option...
Some like DCOE 40's and some like 45's (I understand both can work).
The procedure for determining carb and venturi size seems a bit of a black art, as when I extrapolate from the graph on page 2 of the "Selection and tuning of Weber DCOE Carburettors" pdf (attached) - I get a venturi size of 40, giving a barrel size of 50! (interestingly I see OK parts offers a 50 DCOE...)
When I look at another graph which uses cylinder capacity (see below) I get a venturi size of 34mm using a per cylinder capacity of 433cc.
Franco tells us he has had good luck with 33mm Venturis on otherwise standard 45DCOE9's (through an original Weber manifold).
Adrian (in other posts) advocates 40's with 33 venturis, or factory standard 45's (36mm venturis) through, I believe, an unmodified Solex manifold.
So what to do?
I guess I'm leaning toward buying three new 45DCOE 152's, and see how they go through my unmodified Solex manifold.
I am also leaning to following Franco's lead and advancing the inlet valve timing 10 degrees
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