How to clean the deck of an engine block and cylinder linings.

[sujitroy]

I have an engine minus the heads on an engine stand. it's been on the stand for years, The face of it, which the heads sit on, has surface rust on it so do the cylinder walls. What is a good way to clean this? When I took the heads of it years back, I should have put a film of grease on it.

Sujit

[Motorsport Micky]

Sounds like the block top surface needs a skim, more importantly the bores need honing at least but depending upon how deep the rust is may not clean up without leaving pitting. Use some 80 grit wet and dry wrapped around your fist and plunge your hand into the bore up and down the length of the bores twisting your hand around as you do it mimicking the honed patterns on the bore to remove the top layer of rust, when you can't feel rust sticking up progress onto a proper hone again rotating the head as it travels up and down. Use plenty of paraffin when using the honing stones and make sure everythings removed underneath (crank if fitted) or covered up in clingfilm, you don't want any rust or stone debris travelling throughout the engine when finished.

Micky

PS: Remember to measure the bores against pistons you want to use for excessive clearance...you know piston aren't round...right ?

[Alanmax]

Where is the best place on the piston to measure the size? And the bore? + What is the Ideal piston to bore clearance?
Alan.

[Motorsport Micky]

Measure the pistons across the centre in two different planes, keep turning the piston until you find the largest measurement, that's it's actual size. Depending upon what you want to do with the engine the liner to piston clearance can be as large as + 5thou (used for competition) down to the tight clearance about 2 1/2 thou for factory spec components as shown in the workshop manual (you've got a workshop manual...right ?).
When you fit the piston rings give them about 15 thou end gaps, don't bust a gut fitting the gaps staggered, the piston rings spin anyway and at some stage they'll all line up underneath one another, no matter, compression isn't lost.

Micky.

[trunt]

Ahh.. I see Micky was typing at the same time as me... made my post look pathetic!

So the only thing i have is that if you install the pistons upside down in the bore it will give you a better "look" at the clearance at the skirt end.