Omega Owners Forum

Chat Area => General Discussion Area => Topic started by: RolandL on 12 February 2009, 19:23:45

Title: Valve Shims
Post by: RolandL on 12 February 2009, 19:23:45

Can anyone point me in the direction of a valve shim supplier that charges a reasonable price, need some for my Corsa 1.5td

Thanks

Roland
 :)

Title: Re: Valve Shims
Post by: Andy B on 12 February 2009, 19:26:14

I thought shims for ordinary road going cars had gone out with the ark, and we'd progressed to hydraulic 'tappets' ....... I know they're not as direct as solid lifters etc

Title: Re: Valve Shims
Post by: Marks DTM Calib on 12 February 2009, 19:48:24

Quote

I thought shims for ordinary road going cars had gone out with the ark, and we'd progressed to hydraulic 'tappets' ....... I know they're not as direct as solid lifters etc

Well you would be wrong......Renault never stopped using them even on petrol engines!

Also, they are becoming more common on diesel cars as the long intervals between oil changes dont do hydraulic lifters any good!

As for the 1.5TD, one option is to get the ones you have machined down by a local engineering shop as the inlets recessinto the seats on the Isuzu lump resulting in the need for thinner shims.

Title: Re: Valve Shims
Post by: albitz on 12 February 2009, 19:51:19

Afaik know high revving /high performance engines usually use inverted bucket/shim set up rather than hydraulic tappets,I think its because the hydraulic versions arent up to very high rpm. :-/

Title: Re: Valve Shims
Post by: Martin_1962 on 12 February 2009, 22:58:15

I remember doing the tappets on my 600 bike, being tight I serviced it myself and all I had were valve clearances, so I scaled up the measuring from my 250.

Takes a little while to check and adjust 16 of them!

All were TSCC just one was 27bhp and the other 84bhp

Title: Re: Valve Shims
Post by: Andy B on 12 February 2009, 23:04:45

Quote

......
Well you would be wrong...... .....

They should have then. :y
 Adjustable tappets are bad enough, but when you have to start piddling about adding up what size shim goes here there & where ever .....

Title: Re: Valve Shims
Post by: Tawfield on 13 February 2009, 00:59:51

Ah the hillman Imp Jaguar appy days

Title: Re: Valve Shims
Post by: Marks DTM Calib on 13 February 2009, 08:09:24

Quote

Quote

......
Well you would be wrong...... .....

They should have then. :y
 Adjustable tappets are bad enough, but when you have to start piddling about adding up what size shim goes here there & where ever .....

Horses for courses, in the case of a diesel engine, followers are not ideal as they clog up with carbon from the blow by gasses

Only need setting every 40-60K miles, there not like the crappy push rod ford engine where they stay quiet for about 378m after the  clearances have been adjusted.

Title: Re: Valve Shims
Post by: Marks DTM Calib on 13 February 2009, 08:11:36

Quote

Afaik know high revving /high performance engines usually use inverted bucket/shim set up rather than hydraulic tappets,I think its because the hydraulic versions arent up to very high rpm. :-/

Correct, they normaly use a solid lifter instead of a hydraulic one (on modified production engiens)

The trouble with a hydraulic lifter is that at higher revs the 'pump up' and effectively keep the valve open (although Rhodes and a few others do an antipump type which helps raise the rev limit a bit).

The down side of solid lifters is that they are noisier.