> Hi list! after 22 years, the roadster is again a going, if
> somewhat wobbly
> concern!
Congratulations !
> I am having several problems, which the collective list may be
> able to shed some light on. First I brought the car here from new York to
> new mwxico and am now at 6500 feet elevation. I have a street grind isky
> cam and header, but the car starts without choke and runs very rich. do I
> need leaner jets?
Rob, the original needles should work OK even with that cam and elevation.
If you cannot set the mixture lean at idle, first double check your float
level, that the float valves are not leaking, and that the pistons move
freely. With the damper removed, they should rise and fall with no
resistance at all. With the damper installed, they should take a fair
amount of force to lift but rise smoothly and then fall much faster, landing
with a distinct click. If that doesn't help, then try replacing with stock
needles and jets. It is very possible for the jets to wear, particularly if
they were not centered properly at some previous point, and the result is a
very rich mixture at idle (with a correspondingly lean mixture at throttle).
The needle is what's normally changed to alter the overall mixture profile,
you could certain try the factory 'lean' needles (available from TRF &
Moss). But, they don't normally change the mixture at idle, only the
relationship of the mixture at wider throttle openings to the mixture at
idle.
> also the oil pressure is only about 15 pounds
> at idle, but
> gets 65 or better at 2500 rpm, suspect gas contamination or is
> low pressure
> at idle related to the external oil pressure line feeding the valve train,
> ( necessary due to some obstruction at cam bearing oil feed to valves)
Could be gas contamination, or just 'tired' multiweight oil. Put a drop on
your finger from the dipstick, rub it, and compare to what a drop of new oil
feels like. You can easily feel any substantial difference in viscosity.
If it feels thin, change it and try again.
More likely it's tired bearings, combined with the extra oil going to the
valve train. Don't know that I would recommend it, but it is possible to
remove the head and clear the oil feed from the rear cam bearing with a long
drill bit. Even if the bearing insert was installed wrong, you can drill
through the insert. The nick in the cam lobe won't hurt anything, much. Of
course then you'll need a way to clean the swarf out of the hole, I used one
of those air-operated 'vacuum pumps' from HF linked to a length of thinwall
brass tubing.
> also, with the isky cam the valve timing calls for .015 Hot and I
> did set it
> last at the stock setting which I believe is .012 cold???
Stock setting is actually .010" cold. It's not likely you've hurt anything
with the too-tight setting, but it could have an effect on the mixture, so
retest after setting the valve lash.
Randall
/// triumphs@autox.team.net mailing list
/// To unsubscribe send a plain text message to majordomo@autox.team.net
/// with nothing in it but
///
/// unsubscribe triumphs
///
/// or try http://www.team.net/cgi-bin/majorcool
|