'Performance' cams, worth fitting?
Posted: July 21st, 2012, 9:47 pm
Hi Guy,
My Monte's currently running std cams but has a DIY modded Volumex head and twin DCNFs, it has 150bhp at 6krpm / 142 ft/lb at 4.5krpm so goes pretty well. I'm not in a position to buy a pair of steel billet cams at the moment with too many other projects on the go. However, I've just picked up a pair of 'performance' cams for not much money. They were apparently reground (I know, I know, they never work!!) by an employee of a well known tuning company for his own engine and allegedly made 160bhp in a 1600, which sounded a tad optimistic to me. Rather than just steam in and fit these unknown cams I thought I'd plot one against a std 2.0 131 cam that I had laid about to see what I've got. I've got to say I'm less than blown away by the profile. Yes it's got more lift, about 10% up everywhere, but has only gained about 5deg of duration and the progressive opening / closing ramps of the std cam are missing. The base circle has been reduced by 2mm to gain the lift, down to about 24mm now.
Sorry I haven't had chance to plot it onto a graph, but here's the figures at 5deg intervals-
DEG / STD 131 / ‘Performance’ PROFILE
0-----0
5-----0.1
10----0.2
15----0.3
20----0.35
25----0.4
30----0.5---------0
35----0.55-------- 0.15
40----0.85-------- 0.8
45----1.8--------- 2.0
50----2.9--------- 3.3
55----4.1--------- 4.55
60----5.2--------- 5.7
65----6.2--------- 6.8
70----7.0--------- 7.75
75----7.8--------- 8.6
80----8.4--------- 9.25
85----8.9--------- 9.75
90----9.25-------- 10.15
95----9.45-------- 10.4
100----9.5--------- 10.5
105---9.45-------- 10.45
110---9.25--------- 10.25
115---8.85-------- 10.00
120---8.4-------- 9.5
125---7.7-------- 8.9
130---7.0--------- 8.15
135---6.0--------- 7.35
140---4.9--------- 6.35
145---3.75--------- 5.3
150---2.45--------- 4.2
155---1.3-------- 3.0
160---0.65-------- 1.7
165---0.5--------- 0.65
170---0.45-------- 0.1
175---0.4--------- 0
180---0.3
185---0.25
190---0.15
195---0.05
200---0
Std cam duration (0.8-0.6mm lift) 120deg.
'Perf' cam duration (0.8-0.6mm lift) 125deg.
Please give your honest opinion if it's worth my time and effort to fit these, it's not the end of the world if I don't fit them. I wouldn't be looking/expecting miracles from them, but would probably go ahead if I thought there was 10-15bhp to be gained.
Thanks in advance,
Nick
My Monte's currently running std cams but has a DIY modded Volumex head and twin DCNFs, it has 150bhp at 6krpm / 142 ft/lb at 4.5krpm so goes pretty well. I'm not in a position to buy a pair of steel billet cams at the moment with too many other projects on the go. However, I've just picked up a pair of 'performance' cams for not much money. They were apparently reground (I know, I know, they never work!!) by an employee of a well known tuning company for his own engine and allegedly made 160bhp in a 1600, which sounded a tad optimistic to me. Rather than just steam in and fit these unknown cams I thought I'd plot one against a std 2.0 131 cam that I had laid about to see what I've got. I've got to say I'm less than blown away by the profile. Yes it's got more lift, about 10% up everywhere, but has only gained about 5deg of duration and the progressive opening / closing ramps of the std cam are missing. The base circle has been reduced by 2mm to gain the lift, down to about 24mm now.
Sorry I haven't had chance to plot it onto a graph, but here's the figures at 5deg intervals-
DEG / STD 131 / ‘Performance’ PROFILE
0-----0
5-----0.1
10----0.2
15----0.3
20----0.35
25----0.4
30----0.5---------0
35----0.55-------- 0.15
40----0.85-------- 0.8
45----1.8--------- 2.0
50----2.9--------- 3.3
55----4.1--------- 4.55
60----5.2--------- 5.7
65----6.2--------- 6.8
70----7.0--------- 7.75
75----7.8--------- 8.6
80----8.4--------- 9.25
85----8.9--------- 9.75
90----9.25-------- 10.15
95----9.45-------- 10.4
100----9.5--------- 10.5
105---9.45-------- 10.45
110---9.25--------- 10.25
115---8.85-------- 10.00
120---8.4-------- 9.5
125---7.7-------- 8.9
130---7.0--------- 8.15
135---6.0--------- 7.35
140---4.9--------- 6.35
145---3.75--------- 5.3
150---2.45--------- 4.2
155---1.3-------- 3.0
160---0.65-------- 1.7
165---0.5--------- 0.65
170---0.45-------- 0.1
175---0.4--------- 0
180---0.3
185---0.25
190---0.15
195---0.05
200---0
Std cam duration (0.8-0.6mm lift) 120deg.
'Perf' cam duration (0.8-0.6mm lift) 125deg.
Please give your honest opinion if it's worth my time and effort to fit these, it's not the end of the world if I don't fit them. I wouldn't be looking/expecting miracles from them, but would probably go ahead if I thought there was 10-15bhp to be gained.
Thanks in advance,
Nick