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View Full Version : Will adjusting a Vernier pully cure a lumpy idle?


Adam
08-12-06, 02:12 PM
As above.
Got a Piper blue vernier, but its a square tooth version and mines a round tooth engine,Lol, but i know someone with the opposite situation who wants to swap pullys.

Anyway, would adjusting the vernier have any effect on the inevitable lumpy idle i'll get on my 1400 8v when i fit the Kent AST2,Lol.
Also would it lower the power band? As the cam's band is 3k to 7k rpm, which isn't too useful to me with a 6100rpm rev limit. :roll: lol

Any info? :thumb:
Ash
08-12-06, 02:31 PM
i dont know if it will sort the lumpy idle or not, but from asking around the AST2 is as smooth as standard on idle, but it could be the cam - i believe the AST* range is made for carb'd engines where as NV0** range are for injection.

Ash
Adam
08-12-06, 02:33 PM
Yeah the AST2 will be as smooth as std with mappable management or T40s.

But not on Gm SPI lol
Stuart
08-12-06, 02:43 PM
its feesable that you could "fix" a lumpy idle, BUT you will possibly sacrifice driveability and peak power...

plus a lumpy idle is an old wives tale. im sure the SPI will do its best to sort idle out.... if not then bum Ms on ;)
Adam
08-12-06, 02:47 PM
its feesable that you could "fix" a lumpy idle, BUT you will possibly sacrifice driveability and peak power...

plus a lumpy idle is an old wives tale. im sure the SPI will do its best to sort idle out.... if not then bum Ms on ;)
Lol, aye, i'll see how spi copes with it,Lol.
If i go ms, spi will be dumped anyway :D
Dan
08-12-06, 06:31 PM
its probably no help as my engine is alot different but i dont bother running one at all. I did have one but when it wore i just stuck to a standard one as the vernier was always sat at 0 anyway with this cam.

Again dont believe the exact powerband they quote, alot will depend on how the engine is set out other than just the cam. Mine pulls strongly from tickover with no sudden change
Adam
08-12-06, 06:35 PM
Aye i think im just going keep with the std pulley and flog this one,Lol.
womble sri
09-12-06, 12:22 PM
Again dont believe the exact powerband they quote, alot will depend on how the engine is set out other than just the cam. Mine pulls strongly from tickover with no sudden change

it should be alright with the spi i thought it was down to fuel pressure i.e pump and regulator opposed to mechanical pump running off the cam?

my cam used to kick in at about 4.5k till about 8.5k and that wasnt what they stated but that is probably down to the rough figure the nova dials give youlol