Hi all I'm rebuilding my 2001 st4 engine after a belt slip caused the vertical belt to slip and bend 2 valves. I've just unpacked my new genuine ducati head gasket, it was half stuck to the card it was sealed in. The "laminations" of the gasket appear to be not bonded properly, eg there is a gap between them. Before I assemble the engine, is this normal please? Cheers Kevin
Does the gasket lay flat? Check on a known flat surface like a sheet of glass. Any kinks? Are the oil way galleries intact? Sticking and some de-lamination at the edges is normal.
Hi chris It's flat, no kinks, no signs of damage. Thank you for the reply. I didn't want to build engine if the gasket is faulty. Cheers
That’s normal. Make sure the old one you took off is the same thickness. Earlier incarnations of the 916 engine used a thicker head gasket and a thin base gasket, the later type use a thicker base gasket. Should be the OK on a 2001, but worth checking
Thank you both. I ordered parts based on the ducati parts websites so I'm hoping all good. Just managed to get it back together before mate turned up, so sociability has halted play .
My ('98) 916 originally had the thicker (paper?) head gasket with the thin base gasket. The rear cylinder head gasket failed and was leaking coolant down the back of the engine, I bought a head gasket kit from a Ducati dealer which comprised of the newer metallic head gasket and thicker base gaskets plus all other relevant gaskets & 'O' rings (though it had the wrong S4 style rocker cover gaskets). IIRC the original setup with the 'paper' gaskets was 1mm head/0.4mm base and the newer 'metallic' are 0.4mm head/1mm base, so overall the same but shouldn't be mixed or you'll mess up the piston to head clearance. I replaced both head gaskets whilst I was in there but, one mistake I made was that the rear cylinder has an oil feed which is sealed with an 'O' ring between cylinder and crankcase however, it requires a thicker 'O' ring when using the thicker base gasket and the kit I bought came with the older, thinner 'O' ring so as soon as I started it up, oil leaked from the cylinder base. Obviously this meant doing the job again and it was at this point that I discovered that the oil feed (a leftover from SS/Monster engines) is redundant as the cylinder has no oil gallery to require it so, I tapped a thread into the hole and loctited a grub screw into it to seal it for good - I also fitted the thicker 'O' ring for good measure. Just a heads up, it could save you doing the job twice.
Thank you for the info. I notice the hole in thecrankwase but no hole in the barrel. The removed 0.4mm metal base gasket didn't have an o-ring in it, so I'm assuming the sealant will stop any oil leaks from happening. Cheers
If there was no 'O' ring and it wasn't leaking then maybe later engines have this sealed internally? However I'd want to be double sure that it won't leak, as you can imagine, I was not happy having to do the job twice (I might have actually sworn at this point!). But for what it takes compared to the inconvenience it could cause, I'd be permanently plugging the hole just in case.
Thank you to everyone for the advice. I've managed to get the engine back together (out of the bike) and run it up. I used the gates app at 110hz for belt tensioning. I've only had engine running for approx 30secs, do these marks on the 'exact' belts look OK. I'm paranoid I've over tensioned them. Cheers Kevin
