Sunday, October 23, 2005

Roller Rockers

Fitted them. Had to polish the head a bit as the pushrods rubbed it.

Spent all afternoon trying to get it to run under 2000rpm, fluffy misfire, having tried 46-47-48-50-52-53 idle jets and a range of idle holders it was present on all, so I gave up.

Its mechanical happening, I think gas speed is non existance due to the increased lift, during lower rpm, it comes on cam @ 2500 properly when if feels life the intake gets into cycle. Anyway, the timing on this standard engines cam is 18-58 58-18, way to early for use on sidedraughts anyway, they like 33-45 or so to get some suck in the chamber me thinks, hense modified engines have far more pronouced pulse in the intake...This cams suits constant draw I think, 1 carb into 4 cylinders, so the other cylinders keep some gas speed in the inlet, with sidedraughts each cylinder becomes a lone operative...Hense needs a different cam type without air box use.... Without the use of atleast a Mk3 cam or something with 275degrees the sidedraughts are just mute.

I'd think on the proper engine the rockers would work well all over...

Anyway, a bit more mid range kind of 3500 up feels like...Also the idle is clocklike! Loads better, smooth, no noise or ticking if the exhaust was quiet and carbs not so barky you'd be hard pressed to know it was running....Roller Rockers are worth the dollars for that alone, also the idle mixture seems easier to set with a wider band of adjustment...odd...idle is a pleasure! it purrs. Shame from there to 2K is untuneable...every jet stumbled, lean and rich and the correct one, plus all holder combo's and ones that I know work perfectly on both engines ,so you what can you do!! nothing with fuelling, will play with ignition curve and few things tomorrow.

So wont be using them anymore on this spare motor after this, think it needs more advance and recurving and most important a suitable cam to get anywhere....its also lost all torque off idle and at idle, you could just let the clutch out slowly in reverse without revs before on both engines and get rolling'll be going back to mini lift to suit the mini power cam!

You can see the extra lift visually, its all of the 2mm odd, that it should be.

The rollers should really come into their own in the high rev band 5000 up says Bowlers software, which is 7K is useable in a daily sense. My proper engine is smootherand more balanced at 7250-7500 than this one is at 5000....

Anyway hoping for big things with Megajolt 3D ignition, RRockers, new engine...I think based on the old engine which I happy with at the end, that production car driveability and flexibilty can be maintained, with a shed load more power and 1500rpm more revs, like two engines in one without ANY downsides at all.....rather like a preppy standard engine with wicked torque to 5000 then a rocketship afterwards.

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