can i run a piper 285 cam on standard followers?

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can i run a piper 285 cam on standard followers?

Postby ross.cheeks » 22 Mar 2009, 01:09

basically ive got a piper 285 cam that i was gonna use for an engine i was gonna build up but now ive decided to go c16xe eventually so dont wanna throw loads at the 1256, but ive already got the cam, jsut wondering how the standard followers etc will stand up to it?
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Postby Shoveitpusher » 22 Mar 2009, 08:47

usually the issue is with using old followers and a new cam, leading to increased wear on the cam until it settles down.

no idea if the rockers will be ok but it isn't the most racy of cams.

i have used old followers and a new cam with no ill effects on an escort.
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Postby V8-CHEVETTE » 22 Mar 2009, 12:28

Never use old followers with a new cam, you'll soon be needing another cam.
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Postby Shoveitpusher » 23 Mar 2009, 09:57

ok the science:

cams and followers work harden to get the shiny mating surfaces. in doing this they form an exact surface match. the depth of the hard surface varies depending on the steel used, surface treatments and other such magic.

if you mix up the followers or use a used cam with used followers they have to re match the surfaces. this means wear. if one or other wears through the hardened surface you will get greatly accelerated wear leading to failure.

since you really don't want to wear the cam lobes it is best to have new followers in all cases but why don't you have to replace tappets? the higher lift loads are put on a different part of the bearing face.

you could try removing the top layer of hardened steel on the followers, the idea being to make it easier for the follower to match to the cam, keep an eye on the tappets to see if you get accelerated wear.

it is possible the 'must use new followers' idea has come from the popularity of reground cams, the manufacturing process eats away some of the hardened layer, making it harder to accomodate the bedding in process. it would be very difficult to re-harden the cam, followers are easy.
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Postby Doive » 23 Mar 2009, 16:28

Just been speaking to Kent cams last week about followers, their advice was never to re-use old followers with new cams as the followers will eat the cam lobes in an attempt to wear them to shape. Unfortunately Kent no longer supply the followers for the 1256, and could not advise on any alternatives.
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Postby Herbie_Flowers » 24 Mar 2009, 04:42

you have to draw the line somewhere as ideally you would replace the old camshaft bearings with new ones as well.

camshaft followers have a very slight convex shape to them so they rotate as the cam rubs over it to prevent them wearing in the same place....a shape someone with a file and emery cloth would find hard to replicate Pete :D
clean 'em up with some paraffin and 1200 wet and dry and discard any with pits/visible wear they'll be ok mate :wink:
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Postby Shoveitpusher » 24 Mar 2009, 09:29

i've reshaped conrods with such tools, followers are no problem. :wink:

as with all things there's the right way and the affordable way (or in this case the available way)
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Postby ross.cheeks » 12 Jun 2009, 12:51

well ive got new followers now, any thing else i should look out for when fitting the new cam?
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Postby Gordo » 13 Jun 2009, 03:46

Lots of cam lube or molybdemum di-sulphate (or is that -ide?) paste and keep the rpm up around 2k for the first 20 minutes of so of running - they use oil splash lubrication and initial start up is when they do the initial bedding in.

Forgot something VERY important - lost a couple of engines from dropped valves - the stock keepers/collets are made of plasticine - check them over very carefully and if possible, fit new ones - as you're in the UK, I would do some investigation if machined, heavier duty ones were available - perhaps Mini ones for a 7mm valve stem? Bit of stuffing around but may save you hundreds in the long run and if I were to build up another engine I'd regard it as money VERY well spent!

BTW, as a matter of course, I would always get the rods and crank crack tested - only found a slight crack in one crank when a valve had dropped and destroyed a piston.
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