Thread: Piston top markings

Also, the piston "grade" should be stamped on the block too, down on the sump joint face. If you've got the sump off, you can check if that's the size pistons that went in originally.

Sump isn't off yet.

This weekend didn't quite go to plan.

I put the engine on the engine stand on Tuesday night but I had just bolted it to the flywheel shroud. As Garrycol pointed out, that was going to make it difficult to get the crankshaft out.

So... lightening the load, I took the head off yesterday after pressure washing it all - and decided to take the flywheel off. (I won't mention how I managed to get the engine stand bogged on the front lawn as a result of all the liquid I was splashing everywhere - or how I resorted to using the engine crane to lift it up off the grass and bring it back onto cement)

I put it all back on the crane and got the flywheel and flywheel shroud off - to discover that the block has UNF threads whereas the flywheel shroud was UNC thread - so all was put on hold until the shops opened this morning and I went and bought some UNF bolts of the right length and put it all back on the stand again. (I also bought a new oil filter and a few other bits and pieces for it).

Since then, I have been stripping the head down - that was a bit of a mission - the Super Crap Auto valve spring compressor isn't very good. I managed, however. The head is now completely bare - I even took the valve guide oil seals off (I have some new ones here) - and ready for a thorough cleaning and valve grind - or maybe more. I am tempted to have the valve seats replaced so I can run unleaded without problems - just have to find out how much that will cost as it will mean new valves, too.

The block has most of the fittings removed. Timing chain cover and bits therein and sump will be next.

The head is a heavy little bugger, isn't it.

Watchin and gigglin from a distance

Ask

Originally Posted by drifter

Dave, what tells you it's been apart before? Just wondering - or, rather, trying to see what I have missed.

And ye shall recieve

Originally Posted by slug_burner

Piston do not normally come with their corresponding cylinder number marked on them, when new they can go in any cylinder of the appropriate size. Therefore if yours are marked 1 to 4 it is becasue someone was going to take the engine apart and wanted to ensure that the pistons went back into their corresponding bore.

and the X's indicate which side is to the front in case someone other than the person who did the removal does the install. If they were worth their salt you will also find similar marks on, rockers, rods+ caps, valves, gudgeons and the cam followers.

Most mechanics have their own methodology of marking I tend to do all my marking from the left side of the block (when you look at the block from the side if the flywheel is to your left you are on the left side of the block even if its upside down) so unless someone else is doing the rebuild I dont mark fronts as the orientation of the numbers gives away the orientation of the piece.

Some guys mark with X's to the front some with X's to the rear others mark an arrow to the front (which is always the pulley side of the engine) and others use a series of center punch marks on the front edge of the part. There is as many methods of marking as there are mechanics BUT generally the marking method is always clear enough that with a bit of time and measuring another mechanic will be able to work out what goes where (which annoys engineers who all want us to use the same marking methodology)

If I recall correctly the P in a circle is either a manufacturers mark or denotes a Petrol Piston

Originally Posted by Blknight.aus

If I recall correctly the P in a circle is either a manufacturers mark or denotes a Petrol Piston

That was going to be my guess.

Originally Posted by d@rk51d3

The head is a heavy little bugger, isn't it.

Oh yeah. My back is certainly feeling it.

Actually, I did help myself a bit. Repco are/were selling 3-shelf workshop carts for $59 ($61 off) so I got one of those and the head is sitting on the top of that. I was worried it was going to bend it all when I first felt the weight of the head - it certainly 'settled'

Originally Posted by garrycol

Watchin and gigglin from a distance

Don't be shy - you are always welcome to come over and watch/help/laugh in person. We even have a secure yard so your dog can run and play with our little ones.

Originally Posted by Blknight.aus

Ask


And ye shall recieve



and the X's indicate which side is to the front in case someone other than the person who did the removal does the install. If they were worth their salt you will also find similar marks on, rockers, rods+ caps, valves, gudgeons and the cam followers.

Most mechanics have their own methodology of marking I tend to do all my marking from the left side of the block (when you look at the block from the side if the flywheel is to your left you are on the left side of the block even if its upside down) so unless someone else is doing the rebuild I dont mark fronts as the orientation of the numbers gives away the orientation of the piece.

Some guys mark with X's to the front some with X's to the rear others mark an arrow to the front (which is always the pulley side of the engine) and others use a series of center punch marks on the front edge of the part. There is as many methods of marking as there are mechanics BUT generally the marking method is always clear enough that with a bit of time and measuring another mechanic will be able to work out what goes where (which annoys engineers who all want us to use the same marking methodology)

If I recall correctly the P in a circle is either a manufacturers mark or denotes a Petrol Piston

Whoa fantastic! I marked things myself When I took the clutch off I hit the clutch assy and the firewall with a centre punch so I knew which way to re-assemble it (no, it wasn't a 'Drifter original' idea - it was in the engine book...).

Thanks for all that info - all of you. Dave, yes, standing on the side of the engine with the flywheel to the left, the marks on the pistons are the 'right' way up.

Originally Posted by drifter

Don't be shy - you are always welcome to come over and watch/help/laugh in person. We even have a secure yard so your dog can run and play with our little ones.

Always happy to help if needed - just holla.

I have my own hell at the moment trying to remove my water pump - it is the easy bit - the hard bit is the alternators, tensioners, radiator and other bits of plumping that has to come off first that is the pain.