7 replies to this topic

[olliewiltshire]

Hi guys, 

i have a 1275 metro engine which i was going to get re bored to a 1295 or 1310 but i have just found out by the engineering shop that it has already been re sleeved in its past life. Is it possible to re bore the standard cylinders even though its been sleeved?

Many thanks 

Ollie 

[kezzkitkat]

Depends on the condition of the sleeves but yes it can be rebored up to a limit . Go the lowest bore size possibly 1293 if you can 1310 if needed any more I'd suggest either resleving or another engine block

[olliewiltshire]

Depends on the condition of the sleeves but yes it can be rebored up to a limit . Go the lowest bore size possibly 1293 if you can 1310 if needed any more I'd suggest either resleving or another engine block

thanks very much for your help mate, i will go for the 1295 then . i will let you know how it turns out ahah

[Spider]

As kezzkitkat has said, generally, speaking, yes. Even if the sleeves that are there are poor, they can be bored right out and complete new ones fitted, which is generally what is done.

 

It appears some machine shops don't like taking on jobs like these as they can be a fiddly job to do, as the old sleeves are not completely machined out, but cut wafer thin to the point where they can be collapsed in so as no fresh material is cut from the original bores. The next dilemma can be how and in what order were the last sleeves fitted as this may dictate if the bores that are left are actually round as is or not.

 

ie, the way it is recommended to sleeve a block from scratch is to do each alternate cylinders first, then do the others, so say No. 1 and 3 would be bored to size for the sleeves and the sleeved pressed in, at this point. this will distort the shape of Cylinders 2 (in particular) and 4. So, Cyls No. 2 & 4 will be bored true round in shape from a distorted one and with all sleeves removed, cylinders 2 and 4 should measure as a distorted shape, if they were done this way. Mind you, some shops will bore all 4 cylinders and then just press in all 4 sleeves.

 

The Machine Shop should be able to measure and nut this out, it's not rocket science just takes a little extra time.

 

If you have the block re-sleeved, usually you'll find the bores and rings last much longer.

 

Tip; Some shops also bore them right through for the sleeves and some leave a register at the bottom of the bore for the sleeve to land on. I would suggest the later method, the only down side is it makes it a little more tricky to remove the sleeves at a later time, but again, no big deal.

 

<edits to fix my butter fingers >

Edited by Moke Spider, 03 March 2016 - 06:46 PM.

[Matt's Dad]

Many of the 1275cc Metro blocks were linered in the factory from new, often to address block porosity from what I understand. The factory liner job on ours looks a halfway decent job. A factory liner will take +0.040".
Going for +0.020" is a good choice, as it'll give you another rebore before re-sleeving is on the cards.

[MRA]

There is no need to bore alternate bores, simply because you will have to hone them anyway, and honing will true up an out of round bore a lot better then boring ever will, if you are boring in liners and the block distorts that much you have more issues than you need already, unless you are trying to re-liner a wet block, in this case doing alternate bores helps to stop chatter on the "weakened" block

[Magneto]

My shop bolts a big thick plate to the top of the block before they bore or hone it to make sure it mimics how the block will be with the head on and torqued down.

[MRA]

My shop bolts a big thick plate to the top of the block before they bore or hone it to make sure it mimics how the block will be with the head on and torqued down.

 

Same, I have a cast iron plate that I use, I made it as a guide for offset boring some years ago, but CNC boring means I can easily do offsets in any direction or combination.....  sort of how they came from the factory ! lol