OK:
The D shaped pockets
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Don't mind the crude drawing. The D shaped pockets should be set up such
that the large flat section (on the left in the above) faces the intake
opening, in the vertical position when mounted on the engine. i.e. most of
the flat section will not be there as that is where the intake enters the
pocket. Go straight down from the valve seat, and make a turn at the
bottom of the pocket, into the intake. Not too gradual, and not to sharp.
Be wary that the pockets need to match. So don't complete one then move on
to the next. Do them in stages, and remember to cc them along the way. I
didn't, and the machine shop had to cc them, and then balance (match) them
as they were a little off. I found the best method was to use a craftsman
dremel, with the flex extension and the aluminum oxide grinding stones. Try
to keep the RPM at 20K. Faster and the stone will load up, and slower it'll
eat away too quickly. Vizard's book on Chamber and cylinder head
modification is really a must, with the BL competition manual for specifics
a must. Also, don't be too tempted to polish the intake and exhaust
smooth. There should be a little drag for better flow. One of those two
books explains why. Just remove all the burrs, and casting marks. Open it
up so the opening on the intake of the head is larger than the exit on the
intake manifold. No obstruction that way. Just don't make it too big or
you get a air curling effect.
As for the list below, I wouldn't use the DGV. As far as I know, it's a
great carb for regular use, but not exactly the best thing around for
performance. Have you bought it yet? If not, pick up a set of HS4's or a
Weber DCOE. The DGV is better than the ZS, but nothing compared to those
two. If you get the HS4s, you can retrofit a set of 1/4" stock MGB ram air
stacks inside a set of K&N 6" filters. Nice flow there.
Remember to have the oil galleries opened up. Contact University motors on
that. THey wrote up a paper on the 1500 engine that tells how much they
should be opened for optimal flow. And get the larger oil pump. Actually,
here's the link to the paper: http://www.mgcars.org.uk/namgbr/driver.htm#1
Here's exactly what they say:
"If damage has occurred to the engine (run bearings, for example), make
certain that the following machine shop functions occur! Align bore the
bottom end; machine the rear of the rear main cap to accept two thrust
washers (top and bottom) and hold them in place with dowel pins; draw out
the oil pump shaft housing and increase the diameter of the centre oil
gallery from 1/4 inch to 5/16 inch (doubling the cross sectional area, hence
doubling the oil available). The usual machine shop functions: grinding the
crankshaft, recircling the connecting rods, etc, are always essential in
every rebuild. The Midget 1500 does not use camshaft bearings-the cam
journals ride against the cast iron block. Spitfire 1300 cam bearings are a
direct fit, but then the 1500 cam journals need to be reduced in diameter
(and new oil scroll threads cut) or a suitable 1300 camshaft should be
fitted. "
As for cams, take a look at www.elgincams.com. They have quite an
assortment of cams for the 1500. I used a 285 Piper that I'm happy with. A
friend of mine went milder with a 276. I think it was a Kent he bought from
Ted Schumacher. Ted did his machine work, too.
I didn't plane the head too much. Just had it skimmed to remove any warpage
(there was hardly any) and had the same done to the block so there would be
a perfect fit between the two. If you want greater than 9:1, I remember
reading somewhere that there are pistons with a reverse dish for higher
compression. If you don't want too high a compression, but still want to
shave the head, then open up the combustion chambers a bit after you shave
it. The Spit Comp manual had pictures and drawings of the best design for
the chamber, and this'll lower the compression.
It would be a shame to spend all that money and then cook the oil. Spend
the extra cash and put an oil cooler. And the alternator conversion was
less than $50.
I think the gauge I bought was from CB performance as well. Are they the VW
shop?
Hope this helps.
Mike
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