CooperTune wrote: A+block with steel four bolt center cap. .
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I wouldn't bother with the hassle and expense of a four bolt on a 1071
my race car does run a strap, but the 1071 in my gtm is a full budget spec so doesn't, I just don't think 1071s need them
I wouldn't bother with a fancy cap or strap on any of these engines. Just adjust the clutch overthrow stops properly and the centre cap won't give any trouble.
mk1 wrote:Fair enough, I understand where you are coming from now, I am sorry if my last answer looked a bit smug, it wasn't supposed to be.
I have attached a chart of many A Series can shafts, that allow you to compare the characteristics of one against another. For what you are after a 266 is probably a good bet, as has already been suggested. The original 1.3:1 forged rockers are available from the usual Mini parts suppliers.
I hope that this data is useful.
Just my experience, but the forged S rockers I bought a few years back from Minispares had two issues. First the end pads were not parallel to valve tips, several were significatly twisted out of line (maybe from heat treatment). This twist can be sorted by brute force, but the other issue is more fundamental. Very low lift ratio.
I fitted a set of these rockers with offset bushes, and even then the measured lift ratio is at best 1.25:1. With standard bushes I would reckon the forged S rocker may struggle to get more than 1.2:1 and with MD266 being low lift at lobe this really does not do the MD266 cam justice.
To late, when I was doing Vintage race engines I bought 5 Metro Turbo blocks and had them fitted with four bolt center caps and line bored only one left. Also did one Cooper S block with all three steel caps fitted and line bored. I don't think it will hurt, and yes the 1071 crank should be stiffer than a 1275. Not concerned with thrust issues, just want to keep the center bearing supported.
In regard the S rockers I'm sure they have always been short of lift. Some machine shops have the ability to resurface the rocker face true to shaft. I have a set of NOS Kieth Dodd 1.5s ( not the ones supplied now ) but my cam does not like high lift rockers, loose bottom end for little on the top. While it's fine to ask what people think having tried it yourself is much better info. It seems to much cam and or carb. is a common mistake. Steve (CTR)
CooperTune wrote:I have the correct 1071 from my 64 S. I have also had a SA 1100 crank restroked and ground to S size rod journals. I have also recently picked up another correct 1071 crank. Seems I should be busy building a 1071 for something. I also have a NOS 643 ST cam which seems to work well from 2000 with a little help from the CWP gears. I have also found that the 643 does not like 1.5 rockers. Steve (CTR)
Which 648, the kent or the bl profile? Mine (which has got the bl profile) came alive when I fitted 1.5 rockers?
my 1275 with a 649 was quick before I fitted 1.5 rockers, even quicker after. What new part number on the list is a 648/649
