Engine Rebuild - Update

mrcheese · Post by **mrcheese** » Mon Jul 30, 2007 7:23 pm

Thanks to jrv8 for identifying my engine as a late P6.

It is all stripped down now and the pistons etc are labelled so I know where all the bits come from.

The engine has been stored in a garden, wrapped in a tarp since sometime in the 90s. What oil that was left was thick and black. Two cylinders had emulsified oil in them ( looking at them, they would have been the ones with the exhaust valves open). The rockers were covered in the black death. I was told that the engine had 50K miles on it!!! Not looking great!

I got the heads off and looked to see if the engine would turn using a socket on the crank bolt. To my surprise it had not seized. The cam (in my very limited experience) is not over worn. Certainly better than the cam in my original engine after swallowing mud!!!!

The bearing shells look OK. Evidence of a little brass showing, but not much.

While working on the engine on Sunday a mechanic friend turned up. He is nearly 60 and has been in the trade for years. He had a look over it and despite all the muck, declared it as not bad. He recommends that for a first time build to limit it to a light hone, new rings and shells. All to original spec. There is almost no lip at the top of the bore. I am after an engine with torque for off-road use and not a race engine.

The cam will be replaced. Not sure what yet, but I want bottom end. One from a 3.9 may suit.

Next step is to get the block cleaned. The heads will scrapped as I will use a later type as I want the larger ones running EFI.

Should I have the crank ground and balanced?

Paul.

mrcheese · Post by **mrcheese** » Mon Jul 30, 2007 7:58 pm

I should add that the timing chain was slacker than a slack thing!

Paul.

Post by **katanaman** » Mon Jul 30, 2007 9:29 pm

whether you need the crank ground or not depends on what it measures up as. As for balancing, no that would be a waste of money on a low revving torque engine.

kiwicar · Post by **kiwicar** » Tue Jul 31, 2007 3:35 pm

For a first build like this it sounds like a good plan. I do not see any harm in matching the weights of the pistons and con rods (and end for end matching on the con rods) If you have them apart (are you going to use new pistons? or just re-ring what you have got?) but I wouldn't bother to seperate them specially.
As it has been stood so long I would have a good look at all the gasket surfaces for pitting and check the oil pump is in good condition.
Apart from that its out with the fairy power spray and tooth brushes.
Mike

mrcheese · Post by **mrcheese** » Wed Aug 01, 2007 10:22 am

I am going to clean up the existing pistons and if they are OK then I will just put new rings on.

Paul.

kiwicar · Post by **kiwicar** » Wed Aug 01, 2007 11:05 am

I wouldn't bother ballancing it then, make sure you put the new rings on the right way up.
Mike