Edited by scottv1025, 06 November 2020 - 05:00 AM.
Cam And Head Suggestions
#1
Posted 06 November 2020 - 04:59 AM
#2
Posted 06 November 2020 - 08:35 AM
Ac
#3
Posted 06 November 2020 - 05:47 PM
You will get a lot of very different opinions.
In the end it comes down to personal preferences, but one thing to do is not to 'over cam' the engine and thus end up with good power, but at very high rpm's.
My personal preference is for a nicely gas-flowed head with 35.6 mm inlet valves and 29.5 mm exhausts. A compression ratio of just below 10:1 should be ok for most quality petrol in the USA so long as the distributor has the correct advance curve.
For the cam, a Kent 266 or equivalent always works well and gives good mid-range power & torque. There are other good options, but look at the cam graphs as a comparison. Ideally you need peak power around the 5500 to 5700 rpm and peak torque at c.4000 rpm with useable torque from about 2200 rpm. Torque is more important than outright power.
With regard to the carbs, my personal preference is for twin hS4's, but that's because I grew up with 1275 Cooper 'S;' cars in competition and we always used twin 1.5 carbs. A single HIF44 would give as good a result so long as a good inlet manifold is fitted, but the twin HS4's do look and sound great.
The exhaust system needs to be efficient and an LCB with a 1.75" diameter twin silencer box RC40 or Maniflow is always a good choice.
However, the really important thing is to have a top quality and accurate engine build. Time the camshaft in to the right figure using either a vernier adjustable sprocket or offset woodruff key (lots of stuff on here about how to do this).
A slightly lightened flywheel helps with acceleration and a final drive ratio of 3.44:1 works well (that is the original Cooper 'S' ratio).
As I said, this is just me personal preference which I know works well on the road.
#4
Posted 17 September 2021 - 01:16 PM
You will get a lot of very different opinions.
In the end it comes down to personal preferences, but one thing to do is not to 'over cam' the engine and thus end up with good power, but at very high rpm's.
My personal preference is for a nicely gas-flowed head with 35.6 mm inlet valves and 29.5 mm exhausts. A compression ratio of just below 10:1 should be ok for most quality petrol in the USA so long as the distributor has the correct advance curve.
For the cam, a Kent 266 or equivalent always works well and gives good mid-range power & torque. There are other good options, but look at the cam graphs as a comparison. Ideally you need peak power around the 5500 to 5700 rpm and peak torque at c.4000 rpm with useable torque from about 2200 rpm. Torque is more important than outright power.
With regard to the carbs, my personal preference is for twin hS4's, but that's because I grew up with 1275 Cooper 'S;' cars in competition and we always used twin 1.5 carbs. A single HIF44 would give as good a result so long as a good inlet manifold is fitted, but the twin HS4's do look and sound great.
The exhaust system needs to be efficient and an LCB with a 1.75" diameter twin silencer box RC40 or Maniflow is always a good choice.
However, the really important thing is to have a top quality and accurate engine build. Time the camshaft in to the right figure using either a vernier adjustable sprocket or offset woodruff key (lots of stuff on here about how to do this).
A slightly lightened flywheel helps with acceleration and a final drive ratio of 3.44:1 works well (that is the original Cooper 'S' ratio).
As I said, this is just me personal preference which I know works well on the road.
#5
Posted 17 September 2021 - 01:22 PM
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