SW5 and MD266 cam comparison

[btetley]

For what it is worth I did some measurements on the 266 and sw5 i'm installing on two engines I'm building just to see how they actually differ, and because I wanted to compare apples with apples so far as the checking height was concerned. I thought others might be interested. I only claim a decree or two accuracy, but its close to any published values I've seen. Spreadsheet data available if anyone is interested.

cam comparison.JPG

[Supersonic]

Thanks for plotting out the profiles for comparison of both the Swiftune SW5 and the Kent 266 camshafts. I’ve never been able to relate camshaft profiles on paper to the way they feel in an actual car. I’ve four 1293cc engines and all have different camshafts for fast road use. If you can live with a slightly lumpy idle the Kent 266 is the best by a country mile. My second favourite is the MED HT camshaft; it is close to the 266 top end but has a smoother idle. The Kent 256 and Swiftune SW5 camshafts are good but feel to mild and lack top end performance.

Alan

[Hipwell]

So what we need is a 266 with the extra half a mm of lift.

Can you calculate the duration at 1mm from your figures for the SW5? Its quoted at 221° Inlet / 236° Exhaust for the MD266 on Kents website.

[Polarsilver]

Someone other than me put a MD286 into my 1300GT Engine that had then been left idle for 28 years .. I came along checked the engine out & i am very surprised that in this road car the 286cam is a nice easy drive car on 1.5 SU,s just give it some revs..my GT does go up the hills which i read was an issue for some others with a 286 cam.
Sorry i know this topic is not discussing the 286 cam

[Exminiman]

Thanks for doing this, really interesting, but to be honest I am not sure what would make the SW5 cam better or worse than the MD266 cam.

Graph shows SW5 has more lift, but is more lift better or worse ? - guess it depends on what you want to use it for ?

Using a new blank, you could grind any amount of lift, duration or overlap you want........so cant be the only factors

Head with Siamesed ports is also going to confuse matters, I would think.

[Dearg1275]

So what we need is a 266 with the extra half a mm of lift.

Can you calculate the duration at 1mm from your figures for the SW5? Its quoted at 221° Inlet / 236° Exhaust for the MD266 on Kents website.

David Vizard was involved with the design of the MD266 and in his tome said it was intended for full effect to be used with high lift rockers. There you have your extra lift. My concern with high lift cams is that they may wear quickly and could suffer follower throw at high revs, leading to further valve train damage. Control that with heavier springs and you increase the wear rate and sap the power. It’s all a trade off.

D

[btetley]

So what we need is a 266 with the extra half a mm of lift.

Can you calculate the duration at 1mm from your figures for the SW5? Its quoted at 221° Inlet / 236° Exhaust for the MD266 on Kents website.

Hi. It looks like 216 intake and 217 exhaust for sw5

[btetley]

"I put a sw5 in my Mrs Mini just because I didn't have anything else, personally I think it's an excellent road cam, loads of power down low, no hesitation or holding back, just what you need, apart from the cam everything is standard even down the the air filter, it still made 78 ftlb of torque and 76bhp which I didn't think was too shabby, I've got an MG head to put on which should hopefully release a few more ftlb.
"

Nice to hear that. I'm putting the sw5 into an 1100 and the md266 into a 998. It will be interesting to see how they compare on the road.