17 replies to this topic

[mickyh]

hi, i have a little problem rebuilding my block i have the new main bearings, everything has been cleaned correctly and everything is been put on correctly and i have then oiled the top of the bearings, tightened the bolts up to the correct talk settings. i thought the crank should still move by hand. because mine will not move at all.

regards mike

[Pauly]

Sounds like the main caps are pinching the crank up, slacken off the bolts and see if it turns. Did you fit the center cap with the tabs on the same side?

[Frog]

hi, i have a little problem rebuilding my block i have the new main bearings, everything has been cleaned correctly and everything is been put on correctly and i have then oiled the top of the bearings, tightened the bolts up to the correct talk settings. i thought the crank should still move by hand. because mine will not move at all.

regards mike

Hi Mike,
Has the crank been re-ground at all or is it all standard. I take it you have oiled the mains, fitted new main shells to the caps, fitted new thrust bearings, everything well oiled, placed the crank in, fitted the main caps & torqued down squarely. It should still turn freely. if not then something is pinching up. Have you checked you have the correct main bearings, I ordered a standard set before & got sent a +.010" set.

[bigminiandy]

Have you fitted the bearing caps in the exact same place they came from. There all matched so one wont line up with another

[mickyh]

Sounds like the main caps are pinching the crank up, slacken off the bolts and see if it turns. Did you fit the center cap with the tabs on the same side?

can you explain further on what you mean about the centre cap please,
regards mike

[Sprocket]

check each big end still has a little side movement, thus indicating they are ok, also ensure that all main bearing caps have all the numbers reading the same way.

If new rings have been fitted and there is a fresh hone on the bore, there is no way you will turn the engine by hand, and is the reason you should build the engine without rings first. Twice the work, but then you know for sure that any tightness is purely down to the rings

[mickyh]

check each big end still has a little side movement, thus indicating they are ok, also ensure that all main bearing caps have all the numbers reading the same way.

If new rings have been fitted and there is a fresh hone on the bore, there is no way you will turn the engine by hand, and is the reason you should build the engine without rings first. Twice the work, but then you know for sure that any tightness is purely down to the rings

i havent even got new piston rings yet the pistons arent on everything seem right the caps are 030 and the crank shaft been ground to that and 030 main bearings everything seems fine just will not move atall.

[Pauly]

030, thats quite a lot. Has the crank be re-ground before?

[mickyh]

I will take it back to Crewe Engineering and get its measured, as I can the number see 020 on the inside of one in the bearing caps but it is a mirror image as though it has been transfered from a bearing; if it had been reground further this would not be there I think!

[bmcecosse]

The mirror image 20 thou you see - could be from the previous shells - when the crank was 20 thou undersize! Anyway - l - 20 thou shells on a 30 thou crank would be a rattling loose fit! So it's not that. Undo the mains - and then do them up ONE AT A TIME - gently at first - turning the crank all the time - stop immediately if the crank stops turning. It MUST be able to turn easily - really easily! So something is very wrong. As others have suggested - you may have the centre cap on wrong way round - and make SURE the thrust washers are all in correct way round - or you will ruin both crank and block !!

Edited by bmcecosse, 24 January 2010 - 10:56 PM.

[Sprocket]

check each big end still has a little side movement, thus indicating they are ok, also ensure that all main bearing caps have all the numbers reading the same way.

[mickyh]

Hi,

I have just recieved word from Crewe engineering that the bearing caps are the wrong ones potentially!!

Do know how this can be, anybody what number caps should go with a 1275 A+!

I bought this a short kit, Crewe had done most of the work but not seen the caps!

[GraemeC]

Hi,

I have just recieved word from Crewe engineering that the bearing caps are the wrong ones potentially!!

Do know how this can be, anybody what number caps should go with a 1275 A+!

I bought this a short kit, Crewe had done most of the work but not seen the caps!

The numbers are irrelevant really - you either need the correct caps for that particular block (ie not any old 1275 A+ caps) or else you will need to get any replacement caps machined and line bored to match them with the block.

[Cooperman]

The main bearing caps are specific to the block. They are not just a replacement part number. When the block is machined at the fatory, the caps are fitted then the whole thing is 'line-bored'. So, if the caps are the wrong ones it is probably cheaper to get another block complete with its correct caps and machining the excisting caps by taking a few thou off the base of the caps and then line boring would be very expensive.
If you bought a block non-matching caps you were 'done over'. Demand your money back!
If you are in trouble I may have a short A+ engine in good condition for a sensible price. Let me know if I can help.

Edited by Cooperman, 25 January 2010 - 05:10 PM.

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