Rusty bores - machining
 

I know it's hard to tell from pictures, but reckon this will machine out? It's a stock bore at 92mm, but sadly the engine has had water in it, which somehow left rust on the bores (even though it's an aluminium block, not sure how..)

I've got a set of 92.5mm pistons I want to use, but if the block needs to go higher than that it's effectively scrap to me. Might just send it off somewhere locally, but ideally I'd have wanted to get it CDB converted at ASP or someone else offering a similar service :(

https://cimg3.ibsrv.net/gimg/www.sco...5b08cd4dd0.jpg

https://cimg9.ibsrv.net/gimg/www.sco...0f2d792fc2.jpg

It's an aluminium block with steel liners for strength, hence the corrosion.

It depends how deep the pitting is from the corrosion which you can't tell from an image. If you have a 92mm bore and pistons for 92.5 that's only a depth of 0.25mm on the surface which isn't a lot really. If the corrosion is deeper then it's shot.

The only way you'll know for sure is to bore the worst one and see if it cleans up.

Those blocks will take a plus 1mm bore no problem. Alternatively it should be easy to find another open deck block to take its place. Give us a call if you're stuck!

Thanks everyone, I think it looks like it might be worth getting another block, sadly... I specifically want to use the 92.50mm pistons I have (they're wiseco's from an ET build, which I broke through my own stupidity), as it will work out cheaper to buy another block than to buy new pistons.

Alan, will keep you in mind. I'll see if I can pick one up locally from the wanted section on here first, as it seems easier than couriering stuff around.


At least I'm getting adept at taking Scooby engines apart. Amazing how much faster it is the second time around :)

Plenty blocks on eBay, £250 delivered

yeah but 250 + machining is still a bit of money :)

You can buy a honing tool that goes into a drill quite cheaply ish £20, look at some vids on youtube and see if you can clean them up yourself before sending off to a machine shop, you'll only be taking a fraction of what a rebore will with a honing tool, so maybe worth a punt to tell you if the block is scrap for you or not.:thumb:

You will get £80 back from the 2l crank though.

not going to work on pitting. Bore deglazer is only going to make the surface matt, won't remove enough to take away pitting. Microns not thous.

Which is why I suggested it, 0.5mm is a fair amount of metal to have rusted through, the honing tool will take all the surface stuff off and then he'll get an idea of how deep any pitting is, as he'll then be able to see the worst of it.