Reground cam

[tom16v]

Hi all

I have a reground Piper cam I am thinking of using in a Sprint head rebuild.
I wondered if anyone knows where to get a vernier sprocket to time it up right and also the thick shims I will need to fill the huge valve gaps?

Cheers

Tom.

[Mad Mart]

You can get the Vernier from Piper Cams (like the one I just fitted). I have a few thick shims from when I had my reprofiled cam installed. Sprintparts made them to my specs.

[tony g]

When I rebuilt my sprint head after a 3 angle valve job etc I started with the stock cam and the clearances were very small due to the recession of the valves after cutting. I put the reground cam in I was saving for later and the shims needed were all in the range I had so it may be worth checking first.

Tony

[80Sprint]

I think you were lucky Tony. Generally I think fat shims are needed.

[tony g]

Lucky I had a reground cam or I would have been machining the tips off the valves

Tony

[tom16v]

Cheers folks.

Sprintparts in Australia Martin?
I might get their vernier if I am ordering from Aus anyway!

I was thinking of having the seats 3 angled too. Am I right that it is not good to have the valves sunk too deep in the seat though?
Would this just reduce the effective lift generated by the cam as it has to lift further to clear the roof of the combustion chamber?

Thanks for the input.

Tom.

[dailysprinter]

If you want bigger shims Rover SD1 fit

[Mad Mart]

Yes, Sprintparts, Australia.

The Rover shims do fit but I'm sure when I was looking they still don't do them thick enough.

[Triumph1300]

If QED still exist, they use to do thick shims

[tony g]

Cheers folks.

Sprintparts in Australia Martin?
I might get their vernier if I am ordering from Aus anyway!

I was thinking of having the seats 3 angled too. Am I right that it is not good to have the valves sunk too deep in the seat though?
Would this just reduce the effective lift generated by the cam as it has to lift further to clear the roof of the combustion chamber?

Thanks for the input.

Tom.

The slight shrouding caused by the seats going into the head a tad more is nothing to worry about. The gains from a proper valve job far outway that and you will still get gains.
Im always a bit nervous of really thick shims, they look like theyre ready to leap out of the retainer to me

Tony

[bodgerben]

I really don't like the huge shims you need with reground cams.

TriumphTune (Moss) used to do extra long versions of their stainless steel valves - could be worth asking Moss if any are available - they won't be cheap, failing that, I think G&S valves (Godalming) actually made them for Moss - so could be worth giving them a call.

Big shims or long valves have the same problem - they lift the cam follower up higher and reduces the bearing area, a lot of reground cams (though not all) have a very short opening ramp, they push the cam follower sideways, with the reduced bearing area the followers wear very quickly - not so much of a problem if you aim to replace them every few thousand miles, or if the car does very few miles. When these were daily runners and people were putting a thousand miles a month on them you'd aim to replace the followers every two to three months. Not so much of an issue on the 8 valve cars, but a sprint is a little bit more involved.

As there are so many new cams available, I'd always go for a new cam - even preferring a new standard cam to a reground one.

Another thing to check with any cam is the journals - fit the cam to the head with no valves and check the bearing clearances - use a bit of plastiguage. Does it turn freely, do any journals have huge clearance - compare each journal. You can get the cam journals recovered - add chrome to increase the size. But that has mixed results. Sometimes the head is scrap - or you can attempt a repair like Hans does with his heads.

[trackerjack]

Yes and the ex ones sometimes do jump out happily never on any of my engines so far.
Did the team know that Ford CVH engines (XR3 etc) fit solid lifters that are modified to fit Dolomite sprint shims.

[tom16v]

I don't think I am going to use the reground cam I have, as I don't want too much cam bucket wear on this engine, so would like to stick with one with a standard base circle diameter.

I know this has been done to death recently, but I can't find a link to the chart of the Sprint cam specs that I know I have seen on here in the past?

There is a link to Triumphowners, but that doesn't seem to work any more.

Anybody got a copy?

Cheers

Tom.

[tony g]

Tom are you selling the piper? I may be interested

Cheers

Tony

[tony g]

Found the cam spec list in this thread:
viewtopic.php?f=3&t=27694&hilit=cam+specs

Tony