53 VHA ASSEMBLE TOLARANCE

[jim.dumont]

THE 53 VHA I BOUGHT IS PARTIALLY ASSEMBLED AND WAS OVER HAULED I WAS TOLD . THE HEAD IS NOT ASEMBLED AND THE BORE SHOWS HONE MARKS, EVERY THING LOOKS AND FEELS THIGHT EXCEPT THE CRANK HAS .015 END PLAY VS.008 TO .012. THE SUMP IS VERY CLEAN.
WHAT CONCERNS ME IS THE CAM SHAFT HAS .040 END PLAY AND WHEN I ASSEMBLE THE OIL PUMP THERES . 07GAP BETWEEN THE SHAFT AND THE OIL PUMP BLOCK. I CAN"T FIND ANY INFO ON THESE TOLARENCES ,PARTS LIST DOESN"T SHOW SHIMS. ANY ONE HAVE KNOWLEDGE TO HELP?

[nevhunter]

the extra end float on the bigend will not be a problem. Make sure the conrod is aligned well. I would like to see the camshaft end float reduced. If you fit a steel washer between the camshaft and the crankcase and reduce the play to about .005, that would be ok and it will reduce the play (gap) between the oil pump block and the camshaft to an acceptable amount at the same time. Nev

[nevhunter]

duplicated and then deleted. Nev

[adrie.degraaff]

"The end play of the crank", do you mean the play when the shock absorber is not yet in place? in that case, when this is in place the play is gone becouse the crank is pulled to one side.

Don't worry about some cam play, it wil bring you anywhere.

[pete.collings]

You can adjust camshaft endfloat by carefully tapping (or less carefully if necessary!) the camshaft bush in the timing cover, with the timing cover fully home and fitted with any gaskets used. I use a box spanner to spread the load, but a drift turned to fit the bush size would be better. Do the adjustment a little at a time, as you do not want to remove all of the end float, leave just enough for the cam to turn freely. I also check the followers end float with the timing cover in place, and shim these to minimise end float, dependent on shim sizes available. This can help reduce cam/follower noise, although wear on the cam pinions (and especially the halftime pinion) will still generate some noise.

[jim.dumont]

FOUND THAT THE CAM BUSH WAS INSTALLED TO FAR INTO THE CASE,SO I DISSEMBLED THE CASE AND PUSHED THE BUSH OUT A LITTLE I"LL ADJUST IT TO GET THE RIGHT END PLAY AFTER I ASSEMBLE THE CASE THANKS PETE NEVHUNTER NOTED THAT I SHOULD BE SURE THE CON ROD IS WELL ALIGNED. NOT SURE HOW TO DO THAT, I ASSUME YOU SHIM THE CRANK BUT HOW DO YOU MEASURE THE ROD LOCATION TO THE BORE JIM

[adrie.degraaff]

The mid rod to mid crankcase line.

[nevhunter]

That's true adrie.
The conrod could have twist or bend (or both). I put the gudgeon pin in the chuck of a lathe and have the small end pivotting on it and touch the side faces of the bigend with the back of a lathe tool holder in the tool post.. If your gudgeon bush is the same amount out each side, or flush, when you reverse it and the contact is even on both sides of the big end face there is no offset problem and no twist exists if the contact is the same on both edges of the one side. ( hope this makes sense)
The rod could still be bent close to the big end eye. ( not that likely but possible) A close fitting mandrel in the steel bush will enable the check of parallelism to be made with a similar one in the gudgeon eye. If you think it is bent have a good look along the rod to try and determine where the bend is and correct it and recheck. Ariel rods are made of good stuff ( EN 26?) and need to be pressed to straighten them. Use soft metals to contact, so as not to mark the surfaces of the rod. Nicks can start cracks so don't make any. If there is a bend, overcorrect it slightly and then bring it back a little.. Metal tends to stress relieve itself and go back to where it has been for a while.. Nev

[jim.dumont]

NEV & ADRIE THANKS FOR THE INFO. WHAT AMOUNT OF VARIATION IS ACCEPTABLE ?

[jim.dumont]

I HAVE ASSEMBLED THE ENGINE UP TO THE POINT WHEN I NEED TO PUT THE OIL PUMP ON, WITH ONE GASKET ,BOOK SAYS TWO, I HAVE .028 GAP BETWEEN THE BACK OF THE BLOCK AND PUMP. BLOCK ISN"T WORM . NOT SURE HOW TO REDUCE CLEARANCE, SHIMING DOESN"T SOUND LIKE A GOOD IDEA. I COULD MACH .02 OFF FACE OF PUMP? WHAT DO YOU THINK. THE REST OF CLEARANCES CAME OUT GOOD. JIM