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Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 9:45 am
by shaunroche
Having a Piper 285 cam fitted to my sprint head and it looks like the inlet lobes on 6 and 8 are misaligned.....anyone else seen this problem before?
Being advised not to fit it as it would cause premature wear of the rocker arms/cam lobes......
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 1:05 pm
by Mad Mart
Not sure what you mean Shaun. The lobes do the inlets and exhausts. A picture would be good.
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 1:17 pm
by shaunroche
To be clearer, Jon Jackson is building it up for me and this is what he's found.....I think he has aligned the rockers to be on the lobes which manifests itself as the stud holes not lining up....
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 1:49 pm
by Tony Burd
This is mine running an STR91 cam, 6 & 8 look a bit off aswell, but does look like the full rocker foot width is in contact with the cam lobe, no.6 on yours does look off
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 6:43 pm
by Mad Mart
Agreed, 6 looks iffy and 8 isn't much better. Can you measure the dims. between all the lobes & I can check that against an STR91 I have sat here.
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 9:11 pm
by soe8m
Bend rockers? A non matching bearingcapset/head? I would check with a std cam first.
Jeroen
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 9:15 pm
by Mad Mart
My 91 is a regrind.
Re: Piper 285 cam....doesn't fit?
Posted: Wed Jun 25, 2014 11:35 pm
by trackerjack
Piper cam fitted and 6 and 8 are slightly off cam lobe.
Same set up with a standard cam and they are all on even if not central to lobe.
Will check all alignement now.
My fear is that with a cam lobe too far offset it not only lessens bearing area but causes cam bucket to spin faster hence greater wear.
Re: Piper 285 cam....doesn't fit?
Posted: Sun Jul 06, 2014 12:37 pm
by tinweevil
Is the alignment of the head stud holes as awful in the flesh as it looks in that photo? If so like Jeroen I suspect your rocker pedestals are not matched to the head.
Re: Piper 285 cam....doesn't fit?
Posted: Mon Aug 04, 2014 12:22 pm
by shaunroche
Just by way of an update, the Piper and a std cam were sent back to Piper to be measured and compared.
Piper admitted that their cam was wrong and have issued me with a refund and all expenses.
Ordered a Newman/TT10106 from Jigsaw now, so let's see how much of a debacle I can make from that!
Thanks to all btw for the help and advice.
Re: Piper 285 cam....doesn't fit?
Posted: Wed Aug 06, 2014 10:57 pm
by trackerjack
tinweevil wrote:Is the alignment of the head stud holes as awful in the flesh as it looks in that photo? If so like Jeroen I suspect your rocker pedestals are not matched to the head.
Hi its not out of line its due to the angle of shot as the pedestal holes are much larger than those in the head.
In short, an optical illusion
