Alfa Romeo Forums banner

21 - 34 of 34 Posts

·
Registered
Joined
·
1,102 Posts
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.
 

·
Registered
Joined
·
1,128 Posts
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
 

·
Registered
Joined
·
17 Posts
Hi James

How does the engine perform below 2500.
It performs smoothly, the engine clearly develops more torque than original.

Does it pull smoothly without any hesitation / miss firing etc
Yes. Surely it will depend on how you install and time the cams, but I guess the hesitation and miss firing will depend more on your ignition. If you experience hesitation, try the blue/transparent lumenition ignition leads, did the trick for me. After the engine rebuild I was running the red leads (new ones) with a 123 electronic ignition and I had hesitation while stepping on the gas. This problem was gone after fitting the lumenition leads.

Also how did you choose the RJR cams, I assume they are different cams for the inlet and exhaust. Did RJR recommend them based on your engine specification ?
Send Richard a message and specify how you want the engine to behave and what your plans are, e.g. if you want to leave the cylinder head unmodified (as in my case).

Richard will give you recommendations regarding the best combination of cams.

My recommendation is to go with a lightened flywheel too.

Cheers
Sergio
 

·
Premium Member
Joined
·
13,510 Posts
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.
 

·
Richard Jemison
Joined
·
7,190 Posts
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?
 

·
Registered
Joined
·
33 Posts
H
Hi James



It performs smoothly, the engine clearly develops more torque than original.



Yes. Surely it will depend on how you install and time the cams, but I guess the hesitation and miss firing will depend more on your ignition. If you experience hesitation, try the blue/transparent lumenition ignition leads, did the trick for me. After the engine rebuild I was running the red leads (new ones) with a 123 electronic ignition and I had hesitation while stepping on the gas. This problem was gone after fitting the lumenition leads.



Send Richard a message and specify how you want the engine to behave and what your plans are, e.g. if you want to leave the cylinder head unmodified (as in my case).

Richard will give you recommendations regarding the best combination of cams.

My recommendation is to go with a lightened flywheel too.

Cheers
Sergio
Hi Sergio,

Thanks for the reply. Where did you get the leads? I’ll get some, it’s worth a try. I too have a 123 ignition with red leads.

I‘ve contacted RJR. Shame he’s not based in the UK, I’d just take the car to him!

Cheers,

James.
 

·
Registered
Joined
·
17 Posts
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
 

·
Registered
Joined
·
33 Posts
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

View attachment 1613495
Hi Sergio

Thank you for the reply and picture.

I now have a set of the leads from Classicalfa, also I bought a new coil at the same time. On the plug front I have NGK br7es - the R is for resistor - otherwise they are the same as the b7es. I’m getting radio interference and thought the resistor may help, which it didn’t! - old radio and old alternator, both of which will now need checking.

I think the leads have helped a bit with the low end misfire, but it’s still there which I think is more to do with cam timing / excessive overlap. It’s been re jetted / setup by two different rolling road companies to no avail. The car is due to be looked at by a recommended Alfa tuning specialist in the next month or so I hope, it’s at that point that I may be having the cams changed which is why I was interested in your experience with Richards cams, as I think your engine and mine are quite similar. Mine was rebuilt using high compression pistons, Jim Evans 11.2 mm cams inlet and exhaust, a lighter flywheel and 123 tuneable ignition all from Classicalfa. The sport exhaust system came from Alfaholics. Since having the engine rebuild a number of people have said that a matched pair of cams isn’t the way to go!

Again many thanks for your experiences, the Alfa BB really does have some excellent and helpful people contributing to it.

All the best,

James.
 

·
Registered
Joined
·
17 Posts
Hi Sergio

Thank you for the reply and picture.

I now have a set of the leads from Classicalfa, also I bought a new coil at the same time. On the plug front I have NGK br7es - the R is for resistor - otherwise they are the same as the b7es. I’m getting radio interference and thought the resistor may help, which it didn’t! - old radio and old alternator, both of which will now need checking.

I think the leads have helped a bit with the low end misfire, but it’s still there which I think is more to do with cam timing / excessive overlap. It’s been re jetted / setup by two different rolling road companies to no avail. The car is due to be looked at by a recommended Alfa tuning specialist in the next month or so I hope, it’s at that point that I may be having the cams changed which is why I was interested in your experience with Richards cams, as I think your engine and mine are quite similar. Mine was rebuilt using high compression pistons, Jim Evans 11.2 mm cams inlet and exhaust, a lighter flywheel and 123 tuneable ignition all from Classicalfa. The sport exhaust system came from Alfaholics. Since having the engine rebuild a number of people have said that a matched pair of cams isn’t the way to go!

Again many thanks for your experiences, the Alfa BB really does have some excellent and helpful people contributing to it.

All the best,

James.
Hi James

Many thanks for the update and please keep us posted about the progress on your tuning journey! Very interested to hear what you'll find out.

Unfortunately I have no experience with Jim Evans camshafts, but I can recommend the RJR 429/1195 combination without hesitation. My ignition coil is a BOSCH 0 221 119 027 (the blue one, made in Brazil).

Best,
Sergio
 

·
Richard Jemison
Joined
·
7,190 Posts
In a stock Nord engine extended tip plugs are fine, and will likely give better ignition.
Only when running large intake valves will extended tip plugs need to be indexed to prevent valve contact with the ground electrode.
 

·
Registered
Joined
·
5,365 Posts
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!).
 
21 - 34 of 34 Posts
Top