Hello everyone,

I took apart my old broken engine with 160k miles on it and am very surprised that the cams and bores virtually look like new. I thought the block had a crack between cylinder 3/4 but it's only the HG which went between said cylinders so I want to rescue the engine and give it an overhaul. Cylinder 4 is also very clean - I guess it burnt some coolant there. I did not inspect the crank shaft so far but I guess it is also in good shape.

The thing is that there is some material gone on the block between those cylinders / there is a flat area. Is it possible to skim the block to get a nice and even surface for the headgasket or will I run into problems doing so? AFAIK the head has never been skimmed before.

Another s**t is that somehow the cam belt skipped a tooth. Therefore I could not lock the cam pulleys and crank in place at the same time before taking off the cam belt (crank pulley has NOT slipped). Instead of fixing the cam pulleys into position and then taking off the cam belt, I only fixed the crank on the flywheel side before I took off the belt. I thought, somehow I would manage to just rotate the cam pulleys back by hand and then fix them. Wasn't very careful as I thought the engine was fuked anyway. Guess what happened. Both cam pulleys forcefully turned to the right...When I took off the head, I could not see any marks on the valves and pistons. Am I lucky or is it impossible that the valves have not touched the pistons?

Here some pics:

My local place charges the same to skim a block as he does a head, he did our S2000 block when I rebuilt it to go in the buggy.

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yes its perfectly possible, main issue is reducing the deck height and therefore the valve clearance.

its called decking the block.

another typical issue with a block with that many miles on it is the bores will be worn out, especially when the HG goes and washes the oil away and runs the piston rings dry on the bores.

you can see the shiny bore with the cleaner piston is oval, there's a larger gap on the thrust face.


if the block has a groove I'd hazard a guess that the head will also, which will need welding as you can't remove more than 0.2mm safely (standard head is 137mm, min height 136.8 +/- 0.05)

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Bring on the Trumpets.

there is only a +0.2mm gasket, so if your cylinder head has also been skimmed you may need the pistons machined.

________________________________________

need a part number? get on here - http://public.servicebox.peugeot.com

Bring on the Trumpets.

Topic revival

What's the main reason one may only take away 0.2 mm from the head (respectively block)? Is it piston-to-valve clearance or the higher compression ratio which would lead to knock or maybe something else?

Would it suffice to enlargen the valve cutouts in the pistons to be able to take more meat off the block or head than 0.2 mm? I would not mind a slightly higher compression ratio as I'm running LPG anyway.

I think on a new enginw there is only 2mm clearance

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nloody ell!!

1mm on a cutout makes far less difference than a 0.75mm skim im sure!!

________________________________________

need a part number? get on here - http://public.servicebox.peugeot.com

Bring on the Trumpets.

Thanks for the answers guys!

Is there a special way of enlargening the cutouts? I can imagine doing that with a Dremel and a steady hand but don't know if slight irregularities would affect compression ratio and combustion between cylinders too much.