can this block be rebored ?

[oliver90owner]

Burnham, big and small ends refer to the con rods. Main bearings are fitted to suspend the crank in the block. You had me going there, for a moment, when I read the torque for the big ends!

Are you cleaning off the bearing shells before fitting? Is it one cap that is going tight? I always fit pistons sequentially, checking the drag on each one as they are fitted. Are you oiling the caps and rods?

Has the crank been reground? Are you checking clearances with plastigauge?

You are going to be loosening them, for sure. You may well see where the bearings were rubbing. Make sure caps have not been swapped between rods.

Last but not least, is your torque wrench accurate (although it would need an excessive over-tightening to distort the rods to that degree. In days of old, caps were tightened onto rods until the bores were round; that was then the torque for that particular rod when it was fitted in the engine.

Edited to add: Did you check ring clearances before fitting the pistons?

[burnham28]

I think I have found the cause of the tightness in turning the engine over. I undid the big end bearings and turned the caps round and torqued each one up then tried turning the crankshaft again each time I tightened the bearings up. The engine now turns over fairly easily albeit a bit stiff but I suppose thats only to be expected when everything is new.

[philthehill]

Well done for finding the problem.

The rods and caps are usually stamped 1-1, 2-2, 3-3 & 4-4, the numbers go together.

The rod / cap contact face is usually stained where the bearing cap shell tang recess fits against the rod. Fitting the tang recess to the stain is another way of identifying the correct way round for the cap.

[oliver90owner]

To add to Phil’s comments. The convention for marking parts is that they are always marked on the camshaft side of the engine (the timing side) for these engines. There is no guarantee, if the marks are made by a non-engineer! I always check old tractor engines as they are often marked by the first engineer who dismantled it (usually with dot-punch marks).

Pistons often have an arrow pointing to the front (gudgeon pins can be off-set to one side or they may have split skirts), cylinders and valves are counted from the timing end of the engine, too. Some con rods were even made with ‘front’ marked on them.

I always admired the Japanese motorcycles where no two bearings and shafts were the same size, so absolutely no chance of getting anything in the wrong way. Not even a gasket between crankcase halves on the Honda twin power units in the 1960s - just a smear of sealant on the horizontal joint surfaces was all that was required to prevent oil leakage (compare that to home-produced machines of the time, which were often mobile oil slicks!).

[les]

Yes, I asked a neighbour working on his bike recently, if he was sure it was British, because there wasn’t a pool of oil under it ! he wasn’t amused.

[burnham28]

The rebuild is coming along slowly. Two questions, I have installed the oil pump after priming it with oil, there is a tin lid that sits in the back plate covering the oil pump in the workshop manual it shows it as a potential source of oil leakage but there doesn't appear to be any gasket or sealant required. Is this just a push fit ? The second question is I have purchased a duplex timing kit but I can't get the gear on the shafts as they are very tight do I heed to heat them up ? and do I have to put them on all at once as I don't think the chain will have enough give on it to put it on when the gear wheels are in place. Advice will be appreciated.

[Banned User]

There isn't (shouldn't be) any oil in that area.

The gears are a nice tight fit on the cam and crank, both should push on together with the chain fitted. Make sure you have the appropriate shim(s) on the crank so that the chain is aligned.

[burnham28]

The timing gears will certainly not just push on, they are extremely tight do they need heating ?

[Banned User]

No heating should be needed, check the surface for any imperfections, some fine emery can be used if there are any marks, but it shouldn't need more than that. They are a very good fit though, and don't bash the cam through the oil pump, if it's fitted.

[philthehill]

The oil pump cover is sealed by the rear engine plate gasket. The oil pump cover is pressed onto the gasket by the rear engine plate. No sealant is required but I do always lightly grease both gasket faces.

Terminology:- The timing gears are actually timing sprockets but for the purposes of the exercise are termed gears.

The duplex timing gears should be a snug to tight fit on the front of the camshaft and the nose of the crankshaft. Lightly polish the crankshaft nose if the crank gear is really tight with oiled fine wet and dry, regularly try the timing gear on the crank nose until it fits nicely. Make sure that the crankshaft nose is clean before fitting the crank timing gear. Make sure that the woodruff keys are fitted correctly in the crankshaft and camshaft before fitting the crank and camshaft timing gears.

There is absolutely no need for heat.

Put the crankshaft pulley on first but before it is home fit the chain and camshaft gear making sure that the timing marks are aligned.

Align the gears by adding or subtracting the shims behind the crankshaft gear by using a straight edge placed over the front face of both sprockets.

Use the camshaft nut and crankshaft dog nut/pulley to push both gears onto the camshaft and crank.

The torque of the camshaft nut is 60 - 70lbf ft.

The camshaft end float should be 0.003" - 0.007".

[burnham28]

Thanks guys timing sprockets and chain now on. A bit of a struggle as the woodruff key kept popping out but all now in place. Cant thank you enough.

[burnham28]

Timing gears all on but I'm a bit mystified. In the kit that a came with the duplex gear there is a lock washer, a felt seal which I know goes on the crankshaft together with the oil thrower with the stamped F to the front but there is a domed washer in the kit the hole in the centre is too small to fit over the crankshaft. Where does it go ?

[Banned User]

Camshaft lock washer?

Who did the kit come from?

[Declan_Burns]

It could be a shim to align the starter dog which is worth doing by the way.
Regards
Declan

[philthehill]

The cup washer is indeed a lock washer and goes between the starter dog and the crankshaft pulley.

https://www.ebay.co.uk/itm/CLASSIC-MINI ... SwpvRcYWVM

Part of the lip of the washer is knocked back and down into the recesses of the crankshaft pulley and up against one of the flat sides of the starter dog hexagon so as to lock the starter dog/crankshaft bolts..

The felt seal is for fitting into the early timing chain cover seal locating channel and it rubs on the crankshaft pulley. It does not fit anywhere else. The better timing chain cover is the later type with the rubber lip seal.

The 'F' stamped flat oil thrower washer is not suitable for use with the felt seal and should only be used with the lip seal timing cover.

The felt seal timing cover requires the cup type oil thrower shield/thrower washer. The concave of the washer faces forward and covers the felt seal housing so as to make it difficult for oil to reach the felt seal.

If you do use the felt seal it must be soaked in engine oil overnight before fitting.

[burnham28]

Hi Phill

The picture on Ebay certainly looks like the washer I'm talking about but the hole in the centre is too small to go over the crankshaft but it would go over the camshaft and the starter dog.

[philthehill]

As I said above the lock washer in question fits between the pulley and the starter dog - it does not fit anywhere else. It does not go over the crankshaft nose.