piper camshaft

[jowley]

hey all i had my camshafts reprofiled to ultimate and when it came to rebuild my engine center said i need modified buckets and shims so i spoke to piper and they said they didnt they just needed bigger shims. does anyone know where to get them from
i cant just shim it either cause the gap is just under 5mm and the engine center said there is a high risk of the cam throwing the shim out.

 

[frank]

jowley

my piper exhaust cam has got ground down shims (70thou" thick) under the buckets.
the autosprint inlet cam had 2.5mm ground off to achieve a better profile and it also meant i could use stock shims above and below the buckets

 

[Ed]

The engine centre is right. It winds me up that piper will grind the cams but don't supply suitable shims. You need top hat shims, that will fit over the stems and replace the bucket type.

http://en.wikipedia.org/wiki/Top-hat_shim

Something from this lot,

http://www.arrowprecision.co.uk/details.php?id=70140

Check the stem diameter however I cannot remember what the K11 one is off hand.

 

[frank]

ed

there is,nt enough valve stem sticking out on cg,s for tophat,s to fit on, i believe cga,s can use them tho

 

[Ed]

hmm, again possible... Not something I have had to deal with directly, or measured. Which even more highlights the point what were piper doing, as it puts the shims totally out of the Nissan shim range.. New valves with longer stems perhaps.

 

[Craig]

I am not afraid to look a fool, but why is the top hat shape so much more suitable than a disk shim?

THanks

 

[Ed]

Huge weight saving see the wikipedia article.

 

[frank]

craig

i might be wrong, but i assume cga,s have factory top hats and buckets with no shim recess (so that the top of the bucket is the cam follower)

 

[jowley]

oh dear starting to sound expensive ive had to put standrad cams in to get it running loan car insurance ran out lol hmm not sure what to do now or how to go about it

ed on the fusion website it advertises piper shim have they stopped these now?

 

[Craig]

Huge weight saving see the wikipedia article.

Oh aye, I saw that, so the only advantage is a (massive) weight saving not that it is any more stable due to fit? Does that mean that one could modify their standard shims to save a few g?

Craig

 

[frank]

Oh aye, I saw that, so the only advantage is a (massive) weight saving not that it is any more stable due to fit? Does that mean that one could modify their standard shims to save a few g?

Craig

i doubt if it,s worth it craig, mine had no valvebounce at near 9000rpm with double the shims in :glance:

 

[Ed]

Frank I gotta admit I admire your ideas but I do shudder at some of the stuff you do!! lol

Craig, you couldn't modify the bucket ones to do this.

 

[Craig]

Ahhhh, so they don't sit under the bucket, they replace the bucket+original shim totally.

Now I see.

Thanks

 

[mph]

If you get really stuck remember I have in stock brand new 773 rally cams which use standard Nissan shims. Fit and forget no need to start running around looking for special shims and by the time you have paid for these you could have brought the new cams.

 

[jowley]

ive just paid for theses cams so itt'll be a waste to not use them