I have a '67 - here is what is important. Dual SU's (I think the note below is
right - HS4's) and no emissions equip. No gulp valve, no air pump, no power
anything, just a simple high compression engine with dual SU's, good timing and
a good cam (they do have a PCV, unlike the old MGA specs where that positive
crancase ventilation was just an inverted J shaped pipe) - I think oil coolers
were optional, but they are a definite benefit. They are not stellar performers
by today's standards (when I had a honda, it could out perform the MG any day of
the week), but they are good and fun, simple, and fairly trouble free. The peak
in horsepower was in '67, after that power levels only went down due to
emissions and misc other strangulations on the engine.
"Dodd, Kelvin" wrote:
> 1967 Specs.
>
> 372-248 HS4 carb. set Or rebuilt HS4 Carbs. Simpler than HIF and are
> easier to set idle. Also have the correct port to operate.
>
> 143-110 Replacement 62-71 Distributor. This unit is new, and is based on
> the later distributor body that has better wear and anti short
> characteristics than the original 25D dizzy. The new unit has the same
> characteristics exactly as the original unit. This dizzy will only work
> with the ported HS4 carb.
>
> 8.7:1 Pistons to fit your press fit pin rods. (420-430 or equiv.)
>
> Dual Row Timing Gears and Chain.
>
> Camshaft: I like the 222-270 Camshaft that is made by Crane Cams. It is
> the only new billet, high quality cam that I'm aware of. Timed to stock
> spec. it gives more oomf in the low and mid range for around town driving.
> With an advance key it wakens up the upper end for open road motoring (your
> choice).
>
> The two major areas of problem. (carb. dist.) are replaced with new
> items that work together correctly. Tune the engine right out of the owners
> manual for a 63-67 spec. car.
>
> Watch out on the 3 angle grind of the valves. It is a lot of labor for
> limited street improvement. The more complex grind does flow better, but
> tends to wear out sooner. Typical trade off.
>
> Kelvin.
>
> > -----Original Message-----
> > From: Chris Thompson [mailto:ct@cthompson.com]
> > Sent: Thursday, October 26, 2000 1:33 PM
> > To: mgs@autox.team.net
> > Subject: What the heck is 1967 spec?
> >
> >
> > Some of you guru's help me here please...
> >
> > I'm pulling the engine out of my 73 B roadster this weekend to begin a
> > complete rebuild, with a "When in doubt, replace it" mentality.
> >
> > Based on what I've read here recently, I'm planning to ditch
> > the single DGV
> > that's in it now and replace with dual HIF4's. Standard head
> > with three
> > angle valve job, perhaps 0.060 over (still havent decided).
> >
> > REASON: Dual DCOE's lose power a the bottom end, and only
> > gain at high rpm's
> > I dont think are going to occur that often in a daily driver.
> > DGV's dont
> > seem to be hugely liked here, and almost 100% of the
> > responses I saw said
> > that properly configured SU's are better. the HS6 SU's
> > suffered from the
> > same topheavy problem (According to the Burgess tuning book)
> > Also Crossflow
> > heads suffered from the same problems at a high dollar point.
> >
> > Did I miss anything?
> >
> > OK, the next think suggested to me has been "Take that bad boy to 1967
> > specs."
> >
> > What exactly does that mean? I live in Ohio where any car
> > older than 25
> > years isnt emissions checked. What exactly does 1967 spec
> > mean? What should
> > be removed? what changed? what added?
> >
> > The block and head going to a good shop to get ported,
> > polished, tweaked,
> > massaged, what have you. I fully expect to buy new pistons,
> > valves, valve
> > guides, springs, bearings, etc.
> >
> > So I guess the question is, If you had a 73 B engine out and
> > apart, getting
> > machined, with a slew of parts getting swapped out, what
> > would you change?
> >
> > This car is to be my daily driver and weekend stress
> > reliever. I dont plan
> > to race it on track, maybe a road rally if I got the urge. I'm not
> > interested in concours at all (Hence the Fiero Seats and
> > planned 60's grille
> > and full chrome bumper overriders.) I just want a good balance of
> > driveability with that elusive and undefinable "Zip".
> >
> > ______________________________________________________________
> > __________
> > | Chris Thompson
> > ct@cthompson.com |
> > | 1973 MGB
> > http://cthompson.com/mg/ |
> >
> > +-------------------------------------------------------------
> > ---------+
> >
|