Not a problem more of a question

[guest27]

If I grind away the base circle of a cam to increase the lift, do I have to have it re-hardened - I am guessing no as it does not have any real pressure against it, and the warning on grinding back cam followers is not to break through the hardening - but I would like to know for sure - at some point I have this CG engine that needs turning to scrap.  Well taking apart and putting in a box like all the rest.  Actually it is already in bits in a box.

Oh I have just bought a TZR frame for 99p now I need a use for it, that does not include ring binders.

R

[Ian]

I bought an engine a few months ago with a freshly re-ground cam and it had been re-hardened .

Dose the heat from the grinding soften it up ? Just a thought . ouch
 
Now on the garage floor in bits .

[andy230]

Oh I have just bought a TZR frame for 99p now I need a use for it, that does not include ring binders.

Build a supermono!

a

[Steve H]

If I grind away the base circle of a cam to increase the lift

Reading between the lines this sounds like your planning to grind this away yourself. I which case hardenning will probabaly be the least of the engines problems

[guest27]

Thank you Steve for your comments and your confidence....

Doing it my self - maybe maybe not, I would not think of it on a multi cam as all the base circles would need to match etc, but the CG has just the one lobe working two followers for the inlet and exhaust, so the timing is pretty much the same for both - if I remember right the fingers of the followers are the same length, shape etc.  It is one of those idle moment thoughts as I have too much to do and no energy to do it with to even contemplate getting the motor out of its box, but it is a question I have often pondered and do not know the answer.

On pushrod Triumphs you can increase the duration by reshaping the follower heads, the "R" followers have a greater radius anyway, but it is possible to increase duration by lightly stoning the follower face without breaking through the stellite, care and a test gauge allow you to match the two barrels.

It was a passing idea of a few years back, having given up on tuning an Ariel 3, to see if we could bu66er up a CG.. Simple engine and no tuning parts available so no compulsion to cheat.

It has been a long winter... lol

R

[J Hop]

I have no idea how it is possible to grind the cam yourself, but I think it would need to be re-hardened (turns ALOT of times per minute, EVERY minute).

Don't know if he is still going?  but Phil Joy was a "name" for cam base circle re-grinds.

[cloggy]

You definately will have a problem if you attempt that. It's not a black and decker job
The case hardening is built up and finished to a very high standard. It's not even a job for a machinist
I too have a Phil Joy cam and need to get in touch with him

[guest27]

Hi all

I have been digging further - apparently many of the Honda cams are not hardened on the base - rather than case hardening the whole lot either just the working surface (the base circle should have no contact to speak of if the tappets are right - or the lobe nose is built up of a harder material on a steel base.  Have to agree that on anything of real value, or where there is more than one lobe this needs to be done by someone with the proper kit.  But I may just dig out the spare CG cam to see if the base is hardened on it.  Being as it has just the one lobe - works both the inlet and exhaust - not going to get odd timings and there should be nothing in the way of the grinder.

There again I have so many jobs to get on with it will probably fall off of the radar.  Afterall there is that T500 I started tuning - oh 15 years ago...

R