M116 3.5 Headbolts

[smueller99au]

Hi all.
(Posted to wrong category first time...)

I'm about to refit a set of heads to my M116 3.5 cast block engine (from 1971 W109 actually). I was after an opinion on the head bolts. They're damn expensive...

Can I reuse the old ones? The engine was rebuilt in 1995 and the bolts came out nicely - they had heaps of antisieze grease on their shaft. Also, what about the washers on top? Do I replace those even if I reuse the same bolts?

Anyone know of a well priced supplier for these head bolts? There is lots. They come to around $400 landed from US (autohauz arizona). I'll try MB Spares this morning I think - see what they've got.

Cheers.
Steve.

ps. also, which of the timing chain slide rails is the one that most often breaks? The ones in the heads or the ones down below - the hard to get to ones.

 

[John S]

Usually it’s one of the top timing chain rails that breaks, unless something drastic has happened and the chain whipping breaks the bottom one. It would pay to check the bottom one if you have access to a scope.

 

[smueller99au]

Thanks John. I have the heads off so I can see the bottom rails. They both look ok - they were most likely replaced in 1995.

The top ones will be new when I put the heads back in with new cam sprockets, timing chain and tensioner.

Steve.

 

[Michel]

The bolts should be reusable...

 

[TJ 450]

You could get away with reusing those bolts on the cast iron block M116. The bolts for the alloy block engines are the ones that are not to be reused under any circumstances.

The lower rails are very unlikely to break, it is indeed the upper ones, in particular those near the LH cam sprocket.

Tim

 

[smueller99au]

Thanks all for your comments. I will proceed with just replacing the upper slide rails and reusing the existing bolts with existing washers.

Cheers.
Steve.

ps. Anyone got the 8mm hex allen sockets that are needed to torque down the head when hot? Otherwise I'll have to bend something up. I'm in Vic.