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View Full Version : What exactly do vernier pulleys do?



dunova
02-06-04, 08:34 AM
As the subject says-I just don't see how/why they would be good (obviously with a cam). Does it play with the timing or something?!?! :idea:

Stuart
02-06-04, 08:49 AM
its adjustable around the cam. eg the outter edge of the pulley "remains in place" with the crank timing, and the inner section which is bolted to the cam is rotated to advance or retard the opening/closing times.

obv on an 8V nova cam then it will only swing the opening and closing the same ammount.

on a twin cam setup then you have a little more freedoms to play about.


they are worth it on "highly" modified engines, but for regular engines very little is to be gained

dunova
02-06-04, 09:10 AM
Cheers mate i thought that must have something to do with it but wasn't sure. I'm think it'd be worth gettin one though coz i have big engine plans. While i'm here does anyone know if i get my cylinders bored to around 1700 if i'll need weber twin 45's rather than 40's or will i just about get away with it? I think i should prob get away with although 45's may deliver abit more power

rikih
02-06-04, 11:21 AM
a guy on here called breeny had his 1.4sr fully done, in the end it was a 1650 on twin 40's and apparently did 10miles to a tenner fully openend up LOL :D

Stuart
02-06-04, 11:24 AM
well that was helpful :roll:

dunova
02-06-04, 11:31 AM
1400 bored to 1650?!?!? :o
Bit extreme i feel-has his engine given up yet?!
Anyway back to my last question-if i had mine bored out to 1700-1710 would it be advisable to have 45's rather than 40's? Anyone know?

Will
02-06-04, 12:38 PM
a guy on here called breeny had his 1.4sr fully done, in the end it was a 1650 on twin 40's and apparently did 10miles to a tenner fully openend up LOL :D

no the 1400 engine i had in my car the engine in that car was a 1.6 GTE engine overbored to 1650cc with twin carbs, 285 cam and B+ head etc etc etc

at its worst (when racing) we did 34 miles to ?10

pmsl

rallyxnova
02-06-04, 12:39 PM
they are a must have on hydralic profiles

dunova
02-06-04, 12:55 PM
Sounds more like it. I should be okay then. I've been told the largest you can bore out to on 1.6 block is 1710 but i'm not sure if this is pushing it abit to far. It might be better to stick to 1650 and 40's should be fine. What bhp was that running at?

Barn
02-06-04, 12:57 PM
no the 1400 engine i had in my car the engine in that car was a 1.6 GTE engine overbored to 1650cc with twin carbs, 285 cam and B+ head etc etc etc

at its worst (when racing) we did 34 miles to ?10
man, that is shocking!

34 miles

bet the car went well though?

Stuart
02-06-04, 12:57 PM
id suggest sticking to 1650, as that allows you to damage the bores and have them taken out to larger if need be.

a well built 8v engine should see between 130 and 150.

if you start playing big boys games look at 150+ lol

dunova
02-06-04, 01:00 PM
If i start reaching 130-150bhp would you suggest getting a strenghening kit?Coz that almost equivilant to a 2lt 16v but about 80kg lighter (engine wise)

Stuart
02-06-04, 01:03 PM
have the bay stitch welded, thats all you need. unless you plan on taking road humps at full speed lol

Barn
02-06-04, 01:39 PM
would you need something like the hh kit also cambridge or would that be OTT?

Stuart
02-06-04, 01:50 PM
ott for most peoples applications


and too expensive lol

dunova
02-06-04, 02:01 PM
How much does stitch welding your bay cost?

Philsutton
02-06-04, 06:07 PM
well im off to weld my engine bay up tomorrow, cost me a whole ?10 for some welding wire its fooking expensive stuff.

m.d.
02-06-04, 06:57 PM
yeah but that tenner would get enough wire to do 50 novas lol

i have a vernier but its doing nothing but looking good at the mo as the engine runs best with it set to 0