V8 engine build part 1 – new main bearings and piston rings

V8 engine build part 1 – new main bearings and piston rings

So, now I’m happily settled into the new garage it’s time to get back to work. I can’t quite bring myself to get stuck into that rusty rear arch and make a mess of the place yet, so I decided to ease myself back in to the project by starting to build the engine back up.

Just to recap, I didn’t originally plan to do a full rebuild of the engine, but when I decided to have the crankshaft modified I was kind of forced into it! It will obviously still be quite a long time before this goes into the car, but since I have boxes of engine parts now taking up very precious storage space it seems like a good time to start putting it back together. Hopefully having a freshly rebuilt V8 sat on the stand will also give me a bit of an ongoing boost to try and get eveything else finished.

Here’s my stripped down block just as I left it in a previous update. It’s been stored outside under a tarp for the last 6 months whilst it was homeless, but thankfully I oiled the bores beforehand to make sure it didn’t pick up any rust. I started off by giving the bores a light hone, then cleaned and oiled them again, ready for the pistons and new rings to be dropped in later on.

Next step, upper bearing shells slotted into place with a generous serving of engine oil.

I then dropped the crankshaft back into position on the new upper bearings, and got as far as bringing the bearing caps into place before I realised something was not right. The crank was not able to rotate at all, and I found it was sticking on the centre bearing shell. This middle bearing has thrust faces (on the upper part of the shell only on these later engines), which determine the endfloat – end to end movement – of the crank. I had purchased aftermarket ‘standard’ bearings, and although they seem to be a perfect fit for the crank journals themselves, the thrust faces are slightly too thick for some reason. The wisdom of the internet tells me that the solution to this is to have the thrust faces of the crankshaft itself machined to accept the bearings, but that seems a bit back to front to me. I’ve decided to take a gamble on it being a poor manufacturing tolerance in the cheap-o bearings and ordered a set of genuine LR ones to see if they fit any better.

Of course, everywhere is closed until new year now, so this has become a job for another day.

I consoled myself by removing all of the old pistons rings and cleaning the pistons thoroughly to get them ready for refitting. I checked and measured each of them according to the overhaul manual at the same time to make sure they are all serviceable.

Once cleaned up I fitted the new standard piston rings, a time-consuming but strangely enjoyable little job.

That’s it for now – stay tuned for part 2 where I hopefully have more success with fitting the crankshaft. I’m also expecting a delivery of goodies from RPI Engineering (Rover V8 specialists) in the new year, including the new camshaft and everything else I need to fully complete this build up. In the meantime, I guess that wheel arch is not going to cut itself out…

Leave a Reply

Your email address will not be published. Required fields are marked *

%d bloggers like this: