44 replies to this topic

[HUBBA.HUBBA]

It is usual to fully assemble the block before putting it back on the transmission, but there is nothing that says that you have to do it that way. At one time it was common to cut out the metal between two of the slots in the inner wing, so that with the radiator removed, also rocker cover, rocker assembly and push rods, it was possible to change the camshaft in situ. Easier on a non-A+, or non-1275, because you had to be able to raise the cam followers somehow.

The half moon seal is nowhere near the camshaft, and if the lower part of the engine front plate has been torqued down correctly against the gasket, I can't see why it would have anything to do with the problem, which would seem to be due only to the sprocket not seating fully on the camshaft. It is the gap between the back face of the sprocket and the fromt face of the camshaft journal, as has been said, which sets the gap into which the thrust plate runs, and even if the thrust plate was not fully in position, it would still run with the same clearance.

Is there a bit of dirt or swarf, or something else, between the sprocket and camshaft?

Well, after taking it all apart, cleaning and putting it back together its now nearer 0.020". Tried it with and with out the oil pump on and it came out the same. Am I right in thinking, If there is wear on the old triangle plate, then presumeably there will be wear on the cam. Anybody recommend a good quality timing gear or shall i go bananas and get a belt driven or veneer set up?

Venier, even

[HUBBA.HUBBA]

The only parts involved are the camshaft, sprocket, thrust plate, and the woodruff key & nut.

Assemble them off the the engine to get a better look:

Does the sprocket fit cleanly on the cam with the woodruff key installed? Try with & without the key, but with the slots aligned. Make sure the mating faces of the cam and sprocket are clean & burr free, if the sprocket's bore has a sharp edge you could try chamfering it so it can't "shoulder" against the corresponding corner on the cam.
Can the nut be screwed far enough on to the cam? Make sure the gap between it and the pulley is less than the thickness of the lock washer.
Measure the thickness of the thrust plate and compare it with any others you can lay your hands on.
While it's installed on the engine, measure the gap with your feelers in several places to ensure it's equal & the faces are parallel to each other.

Out of interest, how do you keep the cam followers in place when taking the cam out?

[Ethel]

The plate is softer than the cam so it wears instead, if the cam was worn it'd leave a shoulder where the sprocket sits.

Turn it upside down to keep the followers in - without pushrods too, of course.


Am I wrong in assuming the engine was stripped? Just ease the cam over a fraction (1/4") instead - without any valve springs loading the pushrods.

[dklawson]

I didn't see this thread yesterday or I would have posted early. Thank you all for not going postal and starting a flame war.

In answer to your last question, I don't think many people ever pull the cam without having the head off the engine and the engine disassembled. You would have to improvise some form of gripper or magnet holder to keep the followers "up" to remove the cam and leave the followers in the block.

I am not sure from some of the earlier posts if this was clear yet but as Ethel said, the cam endfloat topic has come up before so there are numerous old threads to read on the subject. Endfloat is the fore/aft motion of the cam when it is resting in the block. It is not sideways radial play due to clearance in the bearings. The triangle plate that bolts to the front of the engine is sandwiched between a boss on the front of the cam and a shoulder on the timing gear. The endfloat is controlled by the gap between the plate and the cam & sprocket. For the endfloat to be measured accurately the cam needs to be in the block, the cam needs to pass through the triangle plate which has been torqued to the front of the engine, and the timing sprocket needs to be on the cam with its nut torqued properly. While a general measurement can be made with the parts not installed in the block, to be accurate the measurements need to be made as installed.

If your 0.020" measurements were made on the bench and/or without the timing sprocket torqued to the cam you need to re-do the measurements as I described above.

[Ethel]

I'm assuming he's done that, I suggested investigating the fit off the engine to help identify the cause.

Clear a few things up for us Hubba,

Is the engine still in the car, or on the gearbox? What bits are new?

[HUBBA.HUBBA]

I would post a pic, but I can not find where to add a pic to my attachments.I've found Its never been straight forward downloading pictures! very fustrating.
Any way block is on gearbox, in the car, no head on, cam in, timing plate on, woodruff on, sproket and bolt on. FYI flip front.

[sonikk4]

I would post a pic, but I can not find where to add a pic to my attachments.I've found Its never been straight forward downloading pictures! very fustrating.
Any way block is on gearbox, in the car, no head on, cam in, timing plate on, woodruff on, sproket and bolt on. FYI flip front.

Open a Photobucket account its free. load your pictures on there then hover over the picture you want to post. A drop down box will appear, click on IMG Code. This should automatically copy then paste it onto your thread. Jobs a good un. Good luck with this cam issue.

[dklawson]

With a flip front I understand why you might want to pull the cam and leave the block in place in the car.

Repeating my earlier suggestion, try small rare earth magnets on strings to pull the followers up and then tie the strings off to keep the followers up out f the way.

[Ethel]

Sounds like a plan for a new Mini service tool, but I might opt for wood dowelling or welding rod to make it easier to insert. I can't see you gaining a lot by removing the cam fully, just shunt it over a tad from the pump end so it's just clear of the end plate, 1/4" should be safe.

Out of all I've said, I reckon chamfering the sprocket bore is the most likely cure, if anything can be done short of a trip to the machine shop - you didn't say if it was a new sprocket?

[HUBBA.HUBBA]

I would post a pic, but I can not find where to add a pic to my attachments.I've found Its never been straight forward downloading pictures! very fustrating.
Any way block is on gearbox, in the car, no head on, cam in, timing plate on, woodruff on, sproket and bolt on. FYI flip front.

Open a Photobucket account its free. load your pictures on there then hover over the picture you want to post. A drop down box will appear, click on IMG Code. This should automatically copy then paste it onto your thread. Jobs a good un. Good luck with this cam issue.

how do you load a pic onto tmf these days? i've done before. has it changed? i can't seem to find any download section or 'find file' button.

[Ethel]

Click on "more reply options" to use the full editor then select the little photo of the green lollipop (could be a tree )

"Attach files" is under the full editor pane if you want to upload direct to the TMF server rather than photobucket.

[HUBBA.HUBBA]

Cheers ethel. This is were I am at on the pic

[attachment=133696:TMF timing gear.jpg]

[ACDodd]

Is that a new timing gear set?

AC

[HUBBA.HUBBA]

Is that a new timing gear set?

AC

no. only things that are new are oil pump, triangle plate and tab washer

[ACDodd]

Thre triangle plate is also subject to tolerances. Did you check the endfloat the last time you built the engine, if not it could have been large then.

Machining the cam sprocket is the way forward.

AC