10 replies to this topic

[old_timbo]

Went to Detling on Saturday. Thought things had been getting a bit noisey lately, but when I started-up to come home it sounded like a bag of spanners. By the time I got home the exhaust note had changed too. So on inspection this morning I found 3 failed cam followers, and worst of all one of them has wrecked a cam lobe too. Exit a Piper 285 after less than 3000 miles . Can't see any reason for the failure. Plenty of lube, cam run in correctly, springs not coil bound, and all the other followers and lobes look fine, so presume the hardening has failed. Just hope the rest of the engine is OK, not full of swarf and I can get away with an oil change and a new filter. Got to get it fixed for Barkston!!

Attached Files

•  Cyl 1 Exhaust Lobe (2).jpg   70.89K   85 downloads
•  P1010012 (2).jpg   59.52K   86 downloads

[woolly]

thats tuff luck did you buy and fit a full cam kit

[Snapperpaul]

Possibly the cam lobes are wiping past the end of the follower pad, the Pinto cam geometry is suspect from the start, correct valve stem length is the key but it is a complex fix.
How to modify SOHC by Dave Hamill has some diagrams of rocker geometry tast gauges, may be worth a look.
If the rocker posts are high making the follower angle to steep you can fit lash caps to the valve stem top, if the angle is to shallow, shorter valves are needed.

Another thought, have you fitted an unleaded head? If leaded you may have suffered exhaust valve seat regression, closing the rocker gaps, that would wear out the pads double quick.

Edited by Snapperpaul, 23 May 2011 - 05:39 AM.

[Dave R]

how old was your cam kit ?
mine has recently done exactly the same
piper 285
cant remember how old mine is, but mileage would have been similar

[mower man]

Imay be preaching to the  well experienced so please don't be offended  is te spray bar ok? is the cantre feed banjo and seal ok? Sorry to be pedantic    Rgards mowerman

[Simon]

old_timbo, on 22 May 2011 - 10:20 PM, said:

Went to Detling on Saturday. Thought things had been getting a bit noisey lately, but when I started-up to come home it sounded like a bag of spanners. By the time I got home the exhaust note had changed too. So on inspection this morning I found 3 failed cam followers, and worst of all one of them has wrecked a cam lobe too. Exit a Piper 285 after less than 3000 miles . Can't see any reason for the failure. Plenty of lube, cam run in correctly, springs not coil bound, and all the other followers and lobes look fine, so presume the hardening has failed. Just hope the rest of the engine is OK, not full of swarf and I can get away with an oil change and a new filter. Got to get it fixed for Barkston!!

Exactly the same happened to mine last year on the way to Newark. I'd only covered 300 miles on new cam. Phoned Burton power on my return and got them to send a new cam and followers at their expense. Followers that were sent on the second occasion were from a different manufacturer, and since sending the old (new)ones back for them to have tested, they hav'nt pesude me for paymant of the second cam and followers they supplied. One was so badly worn, the follower turned through 90 degrees, and promptly refused to open the exhaust valve any more so had to limp off the motorway.

Might be worth checking with supplier of cam for free replacement.

Also after 2 oild changes, I still found a load of swarf in the sump.

Si

[old_timbo]

Did everything by the book and have checked everything I can think of. Can only be a follower hardening fault I think as although the lobes under the knackered followers are scuffed, there is no wear. I spun it over on the starter this morning and this is a photo of the oil flow. Looks good to me. Have thrown myself on Piper's mercy - got the cam in a full kit 4 years ago so I've had it a while.

Attached Files

•  P1010044 (2).jpg   79.14K   41 downloads

[Snapperpaul]

You can clean up the lobe a bit with some very carefull fine emery then polish to a shine, not ideal but could save the cam then fit new followers and run.

[old_timbo]

Well hats-off to Piper. They said they had a problem with cam followers a few years ago when I bought my cam kit. So today a complete new cam kit arrived (only really needed the cam and followers) in time for me to fit this weekend. It has enabled me to change from a 285 to a 134 injection cam which is what I need now I've gone away from carbs, so every cloud has a silver lining. The new followers are obviously higher quality than the failed ones.

[whiz]

Thats what you call customer service. Its good that a company with such big reputation is honest & realised that there had been a problem.Hats off to them.It would be more than the bad publicity is worth.

Well done
Andy

[MarkBzero]

Customer is king! Excelent service from piper.