24 replies to this topic

[Jamie]

Hi all, i really need your help.

I have decided to rebuild my 1275 spi as the one of the planet wheels broke up in the diff and ended up in a million pieces in the bottom of the gearbox.
(sorry if i use the wrong name for things)

This is my first complete engine rebuild (i thought it would be the best way to learn) and need some help with checking the condtion of some parts.

I've striped the engine down checking a taking pictures of most things i'm not sure about???

The head and gearbox i'm ok with its the block componets i'm not sure on. i.e. crank, cam, pistons, bearings etc.

1. This is the condition of the crank and bearings, there is some wear on both the bearings and crank the 4th con rod bearing is the worst with pitting and the centre crank bearing hole has also worn badly. (see pictures) Is this crank salvagable or would it be best to get a replacement with new bearings. If so where is the best place to get one from.

2. The piston cambers seem ok apart from camber 2 as the head gasket was blown and there was water in that camber. There is also very very slight vertical scoring but i'm not sure what is normal??? (see pictures). Is it just the case of have them honed out??

3. The centre and flywheel end bearing for the cam shaft are quite worn. I'm not sure how to replace these??? (see pictures)

I'

thanks for any help.

[Dog]

Bearing could do with changing IMHO...
and may benifit from a hone down the bores, with new rings...

[Jamie]

Sorry didn't finish my post hit submit accidently. I'm only really after rebuilding it to the standard spec.

[vasi]

At the least new mains. That centre main hole I'd have checked out, looks like more of a manufacturing defect. Bores don't seem too worn, honing and a fresh ringset should sort them out.

[Jamie]

Thanks guys, the engine has only done 60k with fsh

it was the condition of the crank that was worrying me the most especially the centre hole that has gone. and Weither it needed re grinding. I've attach a few more pictures.

Where would be the best place to get rings and bearings from and which type would i need??

[mini23]

I'd go for a regrind on the crank, it looks like its picked up some debris at some time and that oil way is a bit suspect, that needs cleaning up.

[fikus01]

i wouldnt have said it'd need a grind, new bearings and rings shud be fine! and run a honer/deglazer down the bores slowly to clean them up a bit, just make sure all the oil ways are totally clear from debris.

dont forget to fit a new oil pump and since u have it all apart a magnetic oil pickup in the back of the gearbox(behind the pickup pipe) to make sure u dont get any steel floating round ur engine again, i kno the filter shud take it out but the filter housing does have a oil bypass!!!!

[Jamie]

i was looking at these Link if the crank need grinding is this the best thing to go for???

[fikus01]

depends if u want to spend £70 odd plus suitably oversized bearings or jsut a new set of std bearings with ur current crank!

[Sprocket]

I found a winner.

Fresh regrind crank, complete with a full set of new bearings. Crank balanced and ready to fit, £85 all in excluding exchange unit.

http://www.minisport...or-product.html

At that price why worry whether the original is good or not, you'd pay near that for a full set of bearings anyway. I walked into the shop yesterday with a crank in need of a regrind, half an hour later walked out with a Nitrocarburised 10/10 regrind crank and a full set of bearings for £145. Now that is service. The machine shop I use couldn't even touch it for that price.

[Sprocket]

depends if u want to spend £70 odd plus suitably oversized bearings or jsut a new set of std bearings with ur current crank!

Thats £72.50 plus VAT and includes bearings, all of them!!

Edited by Mini Sprocket, 31 January 2007 - 01:32 AM.

[Sprocket]

fit a new oil pump and since u have it all apart a magnetic oil pickup in the back of the gearbox(behind the pickup pipe) to make sure u dont get any steel floating round ur engine again, i kno the filter shud take it out but the filter housing does have a oil bypass!!!!

Fit only the magnet that has a gauze, the one without has potential to kill the oil pump in one foul sweep!!

http://www.minispare....aspx?pid=35169

[fikus01]

i wasnt aware thre was another type!

[Sprocket]

Now you are enlightened

Now do you know why the others are BAD!! ?.....................

[Guess-Works.com]

Personally I've never used one.... mainly because the last thing I want to be doing is introducing a potential blockage into the oil feed...

And one without a trap ... just imagine a lump of collected sediment (or even the magnet itself) being washed off straight into the pump...

Whats the thought on putting a strong magnet into the oil filter ?