In a message dated 96-05-29 22:43:30 EDT, you write:
>In a message dated 96-05-29 09:27:18 EDT, you write:
>
>>I'm the proud new owner of a "barely used" '78 Spit. In addition to a
>>couple of new gaskets, plugs, wires, cap & rotor I've added a great set
>>of new tires (the car hadn't been used since 1985 so the original rubber
>>was "well aged" to put it kindly). What I need now is some more speed.
>>Its all stock which I understand means its under carburated?
>>Performance being an objective, I've considered straight through
>>exhaust, and a larger carburetor. Any comments/suggestions/words of
>>wisdom?
>>
>>Cheers
>>
>>Mike
>
Mike,
(I sent this out last night and I think there was a problem. This is a copy)
Anytime to want to improve performance on a 1500 engine, the best place to
start is with the breathing. Be careful though. Depending on where you live,
and vehicle safety and emissions tests of the state, province, or country,
you may be in for some problems. If your car is beyond the age of testing, go
for it.
The most original proper conversion would be to twin SU HS4s (European spec
for 1500s). If you can find the carbs w/ manifold, that would be your
simplist conversion. The next step up would be to a single 40 or 45 DCOE
Weber. They're sold as kits w/ manifold and are a little more performance
oriented, but a little more patience and money (for different jet
combinations) are required. If you order them for a 1500 from a reliable
source, they will have jets that are fairly close, but final tweaking will
probably be required. Finally, for all out performance, twin Webers are your
route. This set-up is far more sensitive than the single unit and will
require yet more diddling to get them sorted out. And, oh remember, with the
twin carbs, you have to buy your jets four at a time. But, when they're
right, and the engine has been improved internally (strongly recommended),
they're great!
You're going to be sucking in a lot more air with new carbs, so you'll need a
set of headers and a free flow exhaust to get it all out the rear. Monza is
the most common brand, but shop wisely. Their prices have gone up lately and
they may not be the best deal around. A few ANSAs are still out there and
they're not as noisy. Other performance outlets can supply headers. Like I
said, shop around.
As far as internal engine work goes, get yourself a Competition Prep Manual,
available from the aftermarket suppliers, and follow those recommendations as
closely as you feel necessary. I did a few years ago for my autocross 1500. I
stopped short at their 13-14/1 compression ratios and full race cam, opting
for a 10/1 ratio and a slightly milder cam. I did go .040 over with stock TR6
pistons (the block has to be milled), had everything balanced (very critical
with these engines - must do!) and ported, polished, and cc'ed the head. I
put a baffle in the sump to keep the oil from sloshing around.
Remember the old addage: Speed is money. How fast do you want to go?
One final thought. Before you go putting all this new found power to the
ground, make sure the rest of the car is up to it. Check your brakes,
suspension, bearings, bushings and attachment points for all these
components. If you want more power to go faster, do it safely.
Have fun
Charlie B.
Capital Triumph Register
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