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105 2000 GTV camshaft question

21K views 35 replies 14 participants last post by  goats 
#1 ·
Hello everyone out there in ALFA land and merry Christmas to you.

Was wondering if anyone had experience with Colombo and Barriani 10.9 camshafts fron Classic Alfa on a 2000 L nord (otherwise standard). Have a spare head I thought I would rebuild, port and put on my engine but am considering changing cams.

I am on ly interested in mild performance gains. Still want a smooth idle as it is definatelly a road car only.

Any suggestions or experience welcome.

cheers
 
#3 ·
The Classic Alfa web page shows these cams as 280 degree. For fast road use on 1300 and 1600 motors. Good idle and low speed smoothness.
Recomend the 11.6 cams for 1750 or 2.0 motors.
They have a lot of experience with these and supply many happy owners!
 
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#4 ·
Cams

There are far better cams available if you research the BB.

As usual, 101-105 guy recommends things he knows nothing about, only what he reads!:
The Classic Alfa web page shows these cams as 280 degree. For fast road use on 1300 and 1600 motors. Good idle and low speed smoothness.
Recomend the 11.6 cams for 1750 or 2.0 motors.
They have a lot of experience with these and supply many happy owners!
FYI, 12.6mm cams will not fit in an unmodified head. C&B build their cams to a very small base circle (1.020 stock is 1.085) so the lobes will clear the cam follower bores. But unless you have shorter guides, short seals, and the correct springs, the lift will bind on the internals as there is no room for the lift.
 
#5 ·
I ran C&B CB47 10.9 mm cams in two different engines in a 2L GTV and a 2L Spider. They definitely produced more top end than the "Euro" cams that I had previously and I considered them to be an improvement. Then I swapped out the CB47 intake cam for an RJ136 cam from Richard Jemison and there was a big improvement. The engine was better everywhere and the mid range torque improvement was the most impressive. I also got an extra 2 mpg. Then I swapped out the CB47 on the exhaust for an RJ785 and there was more improvement. That motor made 169 HP and 149 ft-lb on the dyno with a very flat torque curve. It was also very civilized and it got 24 mpg. If you were offered a pair of CB47's for say $150 - $200 then they might be a good buy but if you are buying new ones then I recommend that you get a pair from Richard.
 
#6 · (Edited)
We are talking 10.9 cams here, so there is no problem fitting them.
"better" is a relative term. I have used a wide variety of cams and find C&B better than most for my needs. And yes, I used to race my Alfa !

When I want to find out about an unknown part, I go to a world renowned source with decades of experience and a sterling record for quality and customer service. Most of those for Alfas are in Europe.
 
#21 ·
As I said, C&B are well known for quality cams and are widely used around the world.
C&B are well known for old lobe designs, loud valve train in combination with huge gaps.

There are FAR better cams today than C&B. But that only people can state who have tried several different cams instead of preaching C&B's only.
 
#10 · (Edited)
Hey guys,

Thanks for the replies and sorry to restart a controversial subject! (I did find a previous post on this from a while ago).

So does everyone agree the C & B cams wont go into a standard GTV 2000 head without modification to the head?

And Richard do your cams go in without any modification or different springs etc? And which of your cams would you recommend for a mild upgrade and good idle?

And are "Euro spec cams" different to factory standard or jusrt what was fitted to these in Europe? Not sure what was fitted in Australia.

cheers
 
#11 ·
I'm working from memory, but believe the 10548 came in with the 1750, was the standard cam for carbureted 1750 and 2000 cars worldwide. US cars all had Spica, got the 10502, then 10520 cams. So "euro" is the common name, but really means "all but US."

Andrew
 
#12 · (Edited)
cams

Pull your cam cover and see whats in your motor. The cam # is cast in the cam. The 105480320001 is not a performance cam, but it`s better than the junk emission cams we got in the USA.

The small 10.6 cams will fit in the unmodified head, the 11.6 pair will not regardless of the small BCs used by C&B on their Alfa cams.

While on the subject of Base Circles, the stock cams are 1.085 BC and going to a 1.020 BC (C&B) will require shim thickness increase of .033 to get back to the same "lash setting" as stock.

Let`s say .018 for stock Alfa setting. The Aftermarket cams will all call for tighter lash settings so if the lash setting is .012 with aftermarket that adds again .004 additional thickness to needed shims to get to the correct lash.

In any case using the same cams on both intake and exhaust will never allow correct valve timing events to maximize the engines power potential. The same cam on the intake matched with a correctly designed exhaust cam will allow valve events that will improve the power stroke and combustion pressures.

The C&B 10.6 (and the rest) are all "older designs) with excessive overlap. (look at the valve events published by them) They will never match output made by modern cam designs.

There are several of my lobe designs that can be paired that can be fitted in an unmodified head. To suggest the designs without you understanding and seeing the differences in the lobe designs would give you no information. If you will send me an email to Alfar7@aol.com or a PM with your email address on it, I will send you a PDF file that contains most of my commonly used lobes in full "numerical duration at lifts" profiles.
It also contains all of the Alfa profiles, the Alfa/Autodelta profiles and many competitor profiles I have CamDoctored over the years.
With this you can see the real differences in lobe design.

Based on your cars engine build, and particularly it`s use I can make suggestions that will truly fit and produce results as you expect.
 
#15 ·
cams

what is the most aggressive camshaft that will work? 11.6?
You have to furnish any supplier with the actual lift clearances built into the head to get a good pairing of intake and exhaust cams for your application.

A unmodified head will not clear more than 11mm.
 
#17 ·
Rocking the Swiss Alps

I just wanted to give my experience with RJR’s camshafts. Didn’t know where to post this but I figured people looking for new cams would come across this thread.

My background: I had my 2L Nord engine completely rebuilt last winter to original specs. Only thing I optimized was a lightened flywheel. Pretty much every part was replaced, except the camshafts.

Since then I did about 3000 km’s with the „new“ engine. Last week I finally exchanged my old, original camshafts with a set of Richard Jemison’s camshafts (RJR 429/1195). Furthermore, the jetting of the Weber’s was slightly optimized.

I only did about 100+ km’s with the new cams today but it was enough to lure me out of the car and in front of my computer:

The most impressing power range is between 2500 - 4000 revs. The engine develops clearly more torque, compared to the original cams. In the range above 4000 revs, the engine seems to have more „breath“. At the same time, it does it in a rather effortless manner. The engine revs more freely and feels light-footed.

To sum it up, the car feels much more modern to drive while not losing its typical character at all. Without wanting to sound philosophical, the car feels woken up. Only thing that I regret is not having had them already 3000 km’s ago!

Cheers from Switzerland,
Sergio
 
#18 ·
I just wanted to give my experience with RJR’s camshafts. Didn’t know where to post this but I figured people looking for new cams would come across this thread.

My background: I had my 2L Nord engine completely rebuilt last winter to original specs. Only thing I optimized was a lightened flywheel. Pretty much every part was replaced, except the camshafts.

Since then I did about 3000 km’s with the „new“ engine. Last week I finally exchanged my old, original camshafts with a set of Richard Jemison’s camshafts (RJR 429/1195). Furthermore, the jetting of the Weber’s was slightly optimized.

I only did about 100+ km’s with the new cams today but it was enough to lure me out of the car and in front of my computer:

The most impressing power range is between 2500 - 4000 revs. The engine develops clearly more torque, compared to the original cams. In the range above 4000 revs, the engine seems to have more „breath“. At the same time, it does it in a rather effortless manner. The engine revs more freely and feels light-footed.

To sum it up, the car feels much more modern to drive while not losing its typical character at all. Without wanting to sound philosophical, the car feels woken up. Only thing that I regret is not having had them already 3000 km’s ago!

Cheers from Switzerland,
Sergio
It's not like some people told him 3000 kilometers ago. >:)
 
#23 ·
19548 cams were standard fitment cams for 1750 series 2 and all 2 litre 105 engines till 1975 here in Australia.
Also ,,LSD ( Limited Slip Diffs) were standard fitment in all 2 litre cars delivered to Australia.
Coupe + Spider had 4.1 LSD,,and Berlina had 4.3 LSD
 
#25 ·
The longer the cam duration and the larger the carburetor venturis then the more time you will spend tinkering with the ignition, valve timing and carburetor setup to get nice low end performance. Don't expect a 170+ HP Nord motor with Webers to pull cleanly from 2000 rpm in 5th gear.
 
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#26 ·
Don't expect a 170+ HP Nord motor with Webers to pull cleanly from 2000 rpm in 5th gear.
But you are running the same 13+mm lift cam pairings that I have in both my race cars and that Jim uses in race engines. I bet your cams will pull from 3k in 5th pretty well if you don`t stomp the accelerator wide open. That kills the signal (low pressure) in the intake to pull fuel from the carb body into the Aux Venturi for atomization. I wouldn`t expect factory cams to be any different with the excess overlap inherent in their design..

The cams I suggest for non modified heads probably will be drivable at 2K in fifth. But who would do that?
 
#30 · (Edited)
Thanks Hunttheshunt.

Sergio, which spark plugs are you using please? Cheers. James
Hi James, sorry for the late reply.

I got the leads from Classic Alfa.

As for the spark plugs... Depends on your set up. I first used the recommended NGK BP7ES (No. 2412) for the stock setting, but then switched to NGK B7ES (No. 1111). They are shorter and don't reach as far into the combustion chamber.

Remember, more cam lift = valve will open further. So don't forget indexing the plugs, or get the NGK 1111 ones. I still indexed the shorter ones, for efficiency. Electrode facing the intake valve.

I had to find out the hard way with the 2412 and smaller tolerances after the cam installation (more lift = valve will open futher). Richard wrote it in his documents, but to be honest I forgot about it by the time the cams got installed ?‍♂

Best,
Sergio

1613495
 
#34 ·
I too am running 429/1195 RJR cams. They really woke up the motor. Very easy breathing and quick response, with plenty of power (for a 2L motor!).
 
#36 ·
I was getting along great until I blew either the head gasket, or cracked rings/ liners. Motor waiting for me to get to it ....
 
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