Line boring advice needed
Turbo Mini Forums

Engine had 100k miles on it, and the main bearings failed due to high revs, bad lubrication (oil too hot) and and a cluch that was out of balance (one of the verto spring fingers had snapped off and was rattling around inside). Front and centre main straps are "ok"; back strap is a slightly tight fit when the alignment dowels are in place, and had a black, scorched look to the surface when dismantled.

I had engine shop line hone the main bearings in the hope they could recover it, but they've properly f**ked it up - The rear-most strap has been sanded down badly(it doesn't sit flat), and they didn't insert the alignment dowels for any of the straps when they honed it (WTF ).

I've only managed to find one place that does line boring (Coventry Boring & Metalling Co.) and they suggested it would be arround £200 + VAT, so does anyone know if I can get it done for less (where?) or should I just get a new block.

Ideas please. HELP !

Can't comment on the cost of line boring but Coventry Boring and Metalling were the cheapest I found for other engine work, I had them fit a liner and bore the block and they did a good job of that.

I think MED can do it?

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

line bores/hones always seem to be pricey, 200 sounds in the right ball bark

Try mja engineering in bromsgrove martin can do most things

Drop me a PM i have a guy i use who you could try.

Does it matter what it costs? Surely the halfwhit that fucked it up will be paying to sort it out.

Southam mini and metro centre 01926 815681 they sorted mine. I know they were really cautious who they used

Avon 2010 class c 3rd
Avon 2011 class c 2nd 13.8 @ 98mph

I used service garage in ockbrook derby, although I had new pistons they wanted everyone so they could match the tolerance on each bore to each piston. I only paid £120 also. I was very impressed.

Id get a new block. Especially as your in a worse place then before you started.

My machinist uses a place in St Helens for line boring. Made a good job of mine. Look at MED or Swiftune as it might be worth the little extra for a full set of steel caps along with the line bore

Schrödinger's cat - so which one am I ???

I can recommend Coventry boring, we use them for most of our boring at work. Paynes near Oxford is another place, but they seem a bit hit or miss on quality.

The only way I can see to recover it is to measure the centre line of the caps and block, and work out how far off centre line they have bored it, or if its on centre line. If it is biased the caps (which sounds like it could be) then you may get away with another set of caps (good time to fit cast 4 bolt centre main). Skim the new caps, then line hone. A good line honing company should be able to pick up the bore and only take say half a thou out of the crankcase so won't effect any other dimensions on engine.

We quite often have to recover crank cases that have been repaired/welded and line honed back inline. It can be a pain..especially scraping in bearing caps.

Edited by matty on 20th Oct, 2014.

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

having been a sucker to a bad shop myself i feel your frustration man

best advice i can give is use a guy that is known for doing good work by peoples say that you know well

as said above

Apart from skimming, can they build them back up with weld, or bore them oversize and fill them with spacers? - Need to know what options there are so I'm not put on the spot and make the wrong decision if options are offered

Edited by PhilR on 20th Oct, 2014.

Find another block.....

Too be honest not much can be done that'll be cheaper than starting again with another block. Especially in a hurry. The main thing that needs to be determined is how much has been bored out of the block side, and if its still been bored on centreline of caps.

I'm happy to have a look for you, but you are a bit far from me really.

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

Don,t mess around any more just get another block - it should be cheaper than paying to (maybe) fix yours.

Edited by Rod S on 21st Oct, 2014.

Schrödinger's cat - so which one am I ???

Thanks for the suggestions all, I'm putting it away until next year and going to build up one of my 998 blocks

coventry metalling and boring have an excellent reputation and I have used them 30 years, southam dont do line boring nor do MED.