End Float

before stripping my engine, I measured the end float of my crank [ 17thou ]and cam[ 34 thou ]. 16 thou for the crank is acceptable according to the comments on this forum though I might prefer 10 thou. I think 34 thou on the cam is too much but there doesn't seem to be different size thrust washers listed to take care of this.
Dereck

kerinorton said:

I think 34 thou on the cam is too much

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What does the book say ?
When all else fails, read the manual...

No end thrust applied to the cam, is it going to matter ?

My cam end float was 20 thou and i asked Mick Hemmings (always helpful pleasant and knowledgeable) about this he said he has had no problems with end float of up to 40 thou even on racing engines. He said more than 40 may lead to issues with chain wear but that as the cam is pressing on one tappit or another for most of the time then it is not like it can move about freely plus the driving force of the chain an rev counter scroll may help to.
You could temporarily refit the timing cover an check through the points cover to see if it helps to reduce the float but it does seem to be a none issue. Mick also added that if shims where used to reduce it as they sometimes are with the crank then there is a risk that if they manage to become free inside the engine they will do more harm than good. So don't lose sleep over it there are far far worse things to worry about

I think Mick is probably right about cam end float, but I go ahead and tighten it up anyhow. Just compulsive, I guess. I do it by making up new spacers (the one between camshaft and inner crankcase wall, with the tapered end towards the speedo gear) that are wider than the stock spacer. I used to just use shims, but worried about them wearing enough to come apart and do damage to the internals. I make them out of drill rod stock, but I suspect a bronze alloy might be even better. For years I've expected someone like RGM or Norvil to make them in various sizes, and sell them individually or in sets, but have never seen them offered.

Ken

the manual says permissible end float 0.005 to 0.015 in.
Shimming is not an option.
In my case, a 25-30 thou thicker thrust washer would be the only option. I suspect it would need to be hardened as well.
Dereck

kerinorton said:

the manual says permissible end float 0.005 to 0.015 in.
Shimming is not an option.
In my case, a 25-30 thou thicker thrust washer would be the only option. I suspect it would need to be hardened as well.
Dereck

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As i remember (i could be wrong here) that is the crank end float and as you yourself stated there is no cam end float figures given. I like you was concerned that is why i checked with Mick also there is no torque figure for the LH nut that drives oil pump and holds timing gear in place. The manual does have a few errors (clutch nut on main shaft ) and some omissions. Check carefully the wording of what you have read in it and there are a few different manuals which may say different information.

That was definitely the cam end float figure I quoted out of the manual. It is not written where you would expect it to be in the camshaft description area. It was mentioned on a page or so earlier. I was nearly about to say it wasn't in the manual so glad I checked again.
Probably 10 thou end float would be the minimum I would give the crank shaft because there is a large distance between the bearings whereas with the camshaft, the play is taken up either side face of one bearing. With automotive crank shafts the end float can go down to 1.5 thou because the end float is taken up across only one of the main bearings. If it was take up between the front and rear main bearings then you would have to allow a lot bigger clearance. [ Ie the Commando ]

Dereck

ps it might be a good idea to leave the end float large because it would help reduce wear on the cam lobes. Lukily my cam looks good and will be going back again.i

Apologies. I checked again and yes it was the crankshaft end float which was listed as 5-15 thou.
Dereck