In retrospect, maybe I should put this on my web site. It turned up fun.
At 09:39 PM 11/8/98 EST, GMGoodman@aol.com wrote:
>Saw the mail about the sport coil---would like a little bolt on pep if
possible, but have been nervous about a hotter spark ---- old valves,
guides and all.
First the quick and easy answers. Lucas Sport coil for 40K volts, open the
spark plug gaps up to .035, and you'll have all the reliable spark you
need. It might not add much to the top end performance, but it'll never
miss a beat and will will be easier to start. All other ignition parts can
remain stock.
>Also thought of running some real high octane but have same concern.....am
I nuts, can these things cause some damage?
Not nuts, and not damaging. But if you just switch from regular gas to
premium, you probably won't notice much difference except for the size of
the fuel bill.
Start by setting the spark timing at 20 degrees BTDC at idle with a strobe
light. I think that translates to about 12 to 15 degrees static timing.
It sounds like a lot for an MG, but your car will really appreciate it and
will reward you accordingly. If the engine pings at 2500 rpm under hard
throttle, put in premium grade pump gas, about 97 octane. If it still
pings, back off the timing about 2 degrees. If it still pings, clean the
carbon out of the cylinder head and try spark plugs one grade cooler. If
it still pings, do a compression check. If you get 175 psi you have flat
top pistions and/or a shaved head, in which case you may need fuel in the
range of 100 to 104 octane. Where you find that stuff depends a lot on
where you live.
So far your bolt-on pep is on the cheap. Beyond that you need to ask and
answer a few questions about how you want to use the car. If you want hot
wheels for street use, you might like a fast street cam or mild road cam,
larger carburetors, exhaust headers, and maybe a lighter flywheel and
competition clutch. Of course you would also be spending more on tires
after all that.
If you want to go autocrossing with SCCA, forget everything in the previous
paragraph because it will kick you right out of two racing classes. Stay
in Stock class for a while, and go for a new set of racing tires and a
large front anti-sway bar. SCCA Stock class also allows any exhaust
changes after the stock manifold, so big pipes and free flow muffler may
help a bit. Beyond that the greatest increase in performance comes from
seat time, lots of seat time. A roll bar is not required, but recommended.
A LBC can be quite competitive in Stock class once the driver has enough
experience. For a quick intro check out my web site for the MGA with an
attitude:
http://www.ntsource.com/~barneymg
Hint: Poke the wheel and follow the green arrows. There is also a link to
the SCCA national web site, which will in turn link to many, many local
SCCA club web sites, probably one in your area.
If you like bolt on performance parts, you may like to try Street Prepared
class with SCCA. This allows nearly anything than can be bolted on without
cutting or welding and without removing the cylinder head (no hot cam).
So, any intake and carbs, any exhaust headers and pipes, and any suspension
height change, springs, sway bars, transverse links that can be bolted on.
Also any size wheels and DOT approved tires (anything with a tread pattern,
not slicks), as long as they don't bump or rub anywhere (includes road
racing tires). Ventilated disk brakes with 4-piston calipers and carbon
pads are popular. Posi-traction and gear ratio changes are allowed. Super
chargers are not allowed. A roll bar is not required, but highly
recommended. You will not be allowed to use a shoulder harness (except
stock style) in an open car unless you install a roll bar first. Be aware
that this class has to run about 3-1/2 seconds faster in a 60 second lap to
be competitive. That puts your 4-cylinder LBC right up there with a
factory stock Porsche 911.
The next step up is Prepared class, where the prep rules are very similar
to vintage racing. You can do almost any internal engine modification with
the original block and head (including a hot cam and pistons). Nearly any
intake and exhaust is allowed except that you have to use the original
carburetor bodies (I think). Nearly any suspension mods are allowed
including fabricating custom parts. Lightening is allowed, so strip out
the interior and all the lights and glass (except the windshield), ditch
the bumpers, and lose about 400 pounds of dead weight. A racing seat,
slick tires and flared plastic fenders are also allowed, but by this time
the car is definitely not street legal, so figure in the cost of a trailer
and tow vehicle, and the cost of another more stock LBC to run on the
street. This class requires a roll bar, and you will need to cut another
2-1/2 seconds off the lap time to earn the trophy.
And if you're still crazier than all this, you can try Modified class and
really cook your checkbook. Here anything goes, including engine
transplants and wings. Heck, you can even build any kind of car of your
own choosing completely from scratch. The only determining factors for
your racing class is engine displacement and grose weight. Take off
another 4 to 6 seconds, depending on the class you end up in, and find a
new insurance agent.
If you're serious about any of this, give a hoot and maybe we'll do lunch.
Cheers,
Barney Gaylord
1958 MGA with an attitude
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