Alfa Romeo Forums banner

1 - 6 of 6 Posts

·
Premium Member
71 Berlina 74 GTV 17 Giulia Q4
Joined
·
6,569 Posts
Discussion Starter #1
I know absolutly nothing about regrinds and these look like they are but I need someone who knows of such things. They are definitly fatter than stock and came as extra parts with the 74 Spider I restored. I've been using the 11mm IAP cams and wonder if it's worth the gamble to use these or get another set of cams. Stock cams are out of the question. Thanks!

 

·
Super Moderator
Joined
·
12,036 Posts
Pictured is the old 101/105 single plug race cam. They were also called the "10.mm single plug" cams. I have used various versions of these since the mid '60's with engines up to 1750's, always with 40 or 45 mm Webers. This is a good design and works well on the street with standard and oversize valves. Unlike some "race" designs, it does not pound valve gear apart.
That said, I still have one new OEM set, factory boxed. Richard Jemison and I were both interested in the good points of these cams that gave them such long term success, so sent them off to WebCam for a computer profile. As Richard will (probably) agree, these were not a bad design except for low end operation. He has used this information to develop some other RJR designs that offer better low end torque, with about the same top end Hp.
As you probably noticed, the cams of yesterday were sort of by-guess-and-by-gosh, whereas today, a computer can both grind an accurate profile and give performance options for specific engines. Not so much trial and error, and less designs that pound valve gear apart.
I had one of the notorious GTA / GTAm cams that was known for snapping the heads off exhaust, or intake valves at higher RPM. It was the "GTA 11 mm" race cam. It has since been reground by WebCam to a less brutal configuration.
My suggestion would be for you to contact Richard with your design wishes. He may have some good suggestions.
 

·
Premium Member
71 Berlina 74 GTV 17 Giulia Q4
Joined
·
6,569 Posts
Discussion Starter #3
Thanks Gordon, you learn something new everyday!
 

·
Richard Jemison
Joined
·
7,778 Posts
Cam profile

Below is profile for cams. They will be poor idle, poor low-moderate RPM cams and make power at high RPM. Very old design.

Cam Profile #101210320001 New 10121 cams profiled Feb. 2009
#101210320001
cam lift .414
.010 345°/
.020 297°/
.040 274°/
.050 265°/
.080 246°/
.100 235°/
.150 235°/
.200 187°/
.250 164°/
.300 136°/
.350 101°/
.400 045°/
.41295maxlift
 

·
Premium Member
71 Berlina 74 GTV 17 Giulia Q4
Joined
·
6,569 Posts
Discussion Starter #5 (Edited)
Thanks, That makes sense since the car had been sitting in a nice and dry shipping container for the last 25 years on the back forty of the PO's property. Cam shopping time and of course I want it all, good low end, mucho hp everywhere and, low fuel consumption.
 

·
Super Moderator
Joined
·
12,036 Posts
Richard can give you the right cams. The 101210320001 cams, in good shape, are still popular with 1300 & 1600 vintage racers as is, though as RJ suggests, there ARE better options. I would use other cam cores for regrinding, and BB sell or e-bay sell the old 10121's (IF they are good!) If they are not so-good, RJ can have them reground to something more useful, though as they are getting scarce, and there is still a demand for them in the original profile, a buyer may value them more, reground as they were. You never know.
 
1 - 6 of 6 Posts
Top