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Re: Oversize valve guides

Ian, thanks for the dimensions. I'll pass them on to the engineers. One of the replacement guides I had supplied was NOS the other new.

Ian, This gets more fun. I mentioned a couple of guys from SoD Branch I just found out had current jobs there but I didn't know you had as well!

PS has anyone had cams reprofiled and if so by whom? Pre war BSA but not M20 sadly or I'd just buy new ones, which is not an option for 1928 model.

Re: Oversize valve guides

There are no oversize M20 guides that I'm aware of...They've made them for years for alloy head Triumph twins which are known for rattling them loose over time...I think they do them for A10s these days as well....

The first question is were your guides NOS or after market?...The original guides are actually tapered (theoretically)...When new they should measure .624"- .626" at one end and .625"-.627" at the other end ....

However if you look at those tolerances they could be .625" or .626" at both ends!!...Anyway, ideally they should measure up within that range somewhere...Ian

email (option): ian@wright52.plus.com

Re: Oversize valve guides

I have bought new made guides years ago. They turned out to be to wide, so had to be changed.
There is a story of someone who got a crack in his cilinder because of this.

Re: Oversize valve guides

['PS has anyone had cams reprofiled and if so by whom? Pre war BSA but not M20 sadly or I'd just buy new ones, which is not an option for 1928 model...']

Try David Newman Camshafts in Orpington (01689 857109)...They made me a cam for an early rigid A7 from an A65 blank and did a cracking job...They also do reprofiling I believe...I buy all my Goldie cams from them as well...Ian

email (option): ian@wright52.plus.com

Re: Oversize valve guides

Thanks Ian

Re: Oversize valve guides

Warning newman cams almost put me out of business. I commissioned them to make a batch of cams. I gave them the profile, material spec and heat treatment details. They decided to do there own thing. The cams failed and filled the engines with swarf. I had to do a lot of engine rebuilds for free. Newman's would not except responsibility. This was some years ago and I guess they have learned by that mistake.
We now make our own cams, but don't want any more work at the moment.

email (option): pes.sales@btconnect.com

Re: Oversize valve guides

Interesting...I've bought multiple Goldie cams off them in the last 25 years and have never had any durability issues...I did have one cam that had the valve timing mark one tooth out and that had me scratching my head for a while but that was a one off..

Generally I've been very happy with their products...Ian

email (option): ian@wright52.plus.com

Re: Oversize valve guides

The unit single cams are marginal at best. Case hardened mild steel might work for a lot of application, not for what I do with them.
Funnily enough, they advertise using my specifications now!

email (option): pes.sales@btconnect.com

Re: Oversize valve guides

This bike was used for sprinting and had a very non standard 600cc engine...Also used for track days before a new engine was built and it was converted to a Jawa chain driven DOHC top end..Up to that point it was running Newman Cams without any problems...In fact the original engine still has the same cams.....

This is one of many tuned BSA engines I've built and I've no complaints myself....Personally I'm happy to recommend the company based on my experiences...I guess anyone following this thread must consider the comments before making a decision..Ian

email (option): ian@wright52.plus.com

Re: Oversize valve guides

I tried to fit a new guide to a customers bike he supplied it hepolite stamped on it always measure first it was a standard guide but was 8 thou oversize he got it from a well respected bike shop i sent him to another who specialise in BSA on the phone yes correct gave him a measure turned out the same so if you want an oversize guide go and measure

email (option): malmotorcycles@gmail.com

Re: Oversize valve guides

What a lovely looking bike Ian ,very very nice

email (option): warbikes at gee male shot Cummins

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