Lawrie
I don't have the original post inquiring about the 1 1/2 inch
SUs, but as I read it, I thought the inquirer wasn't aware that 1
1/2's could be used on the TC's slightly different engine. I
believe I did say the original air cleaner system would not fit.
As for the "milled and ported", this is a gray area as you may
know. According to my sources, the MKIIs and the TF 1250s had
8.2:1 compression ratios while the TBs, TCs, and standard TDs had
7.25:1 compression ratios. So, the factory must have had to
mill the MKIIs, especially the first cars, before they changed to
the TF. In fact, I believe I read somewhere that the first MKIIs
were the cars specially made for Dick Jacobson, et al. and these
were modified standard cars. Are these first cars really MKIIs or
not? It would depend on how you want to define the MKII.
As the MKIIs used the larger valves, were they ported? Another
interesting question which has no definite answer.
When would MG have changed, if ever, the core molds for the
heads? I would think that as the standard TD and the MKII were
both produced at the same time, the MKII head was a "modified"
standard head. Only when the TF 1250 came out they may have
changed molds. Since the factory could could still modify the
head which production method was cheaper?
I was a little off on the BHP. The modified standard TD engine,
ported and milled, changed to Stage 2 is listed as giving 68
BHP. The TF 1250 with the raised 9.3:1, (not ported, but milled,
and otherwise standard) is listed as giving 64 BHP and that
perhaps should have been the power rating I should have used.
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