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Sorry I did not see this sooner, you need to reply direct to my post for the BrickBoard to notify me that you replied.
36mm chokes look to be the correct size based on the comparison of main jet to main air correctors. I am interested to learn more about your exhaust, are the secondaies (downpipes) still 1.75" OD? What is the length? Is the collector 2.125" and how long? What size is the exhaust and are the mufflers straight through type?
Headflow? Has it been flowbenched? What size valves? The R cam is single pattern, so you need a bigger exhaust valve for it, while the F cam , which is dual pattern, goes with a stock 35mm valve. What is the compression ratio? This alters the cam requirements too.
Ignition? What is going on there with the advance? You want to find out what is required on the dyno by adjusting it while loaded at peak torque rpm. You initial timing can be whatever works best at idle, then you adjust the speed of advance by brining total timining in as soon as possible.
Modern cams have lots of advantages: more lift, more area under the curve, faster from off the seat to .050" and kinder on the valvetrain has a whole are the advantages.
Schneider 284F has 240°@.050", this is comparable to the R cam. You can get it in .300" and .320" lobe lift, but the one you choose depends on how good your head flows. If your head lacks work in the SSR area, then the flow will back up starting around .25D and this will make the higher lift lobe no better and add unneccesary wear and tear. If you only have a 35mm exhaust, you would use a longer duration exhaust lobe with lower lift. If it turns out your head has a poor SSR and doesn't need the .320" version, then you won't get any real gain since the R cam has a touch more than .300" lobe lift.
FYI, The Schneider 274F is comparable to the Isky VV-71, they both have 228°@.050", 108°LSA, the Schneider will give you an extra .020" maximum lift at the valve, so should produce a few lb-ft more throughout. This level of duration would be good for a big bore twin SU engine, K-Jet or MS, so you can see why ipd sold the vv-71 as their 'street performer' cam. The slight decrease in LSA makes the powerband sligtly noticable, but for engines using the stock style exhaust, I would keep the stock LSA, which is good for getting healthy stock cams reground.
So, see if you have 8 good lobes while you set the tappets to .020", make sure your ignition is good, change out your old fuel and give it a tank of the brand and octane rating you intend to use, stick it on the dyno and install a set of new NGK BP7HS, get your max timing set to lowest best torque, and see what that is like, then it should be a matter of tweaking your advance speed.
What it should feel like is compared to a healthy stock B20B is 35+% more torque and easily 50% more power. When the DCOE'S are fully sorted, you should be able to flatten it from idle on flat ground, it should start to go at 2000 and by 2500, it should feel like a hidden 5th cylinder has kicked in.
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69 142S Overdrive + 69 164S Manual
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