New head gasket differences

[TriggerFish]

Hi all,

Currently (slowly!) rebuilding my M20 into a B28. Over easter, I was hoping to put the head on, check the clearances etc. I stupidly binned the old head gasket, and I tried to take the one out of my old, dead M20B25, but it got ruined in the process.

So I ordered a second head gasket to test the clearances with, but when comparing it to the one I had already, I noticed there were differences with some of the port cut outs.







(Sorry for the awful photo of the engine - my camera went flat, and the engine was upside down on the stand, so I only had one shot)

As you can see, the engine has two ports in the yellow circle, as does the Payen HG, but the Elring one has one large hole. I don't know what flows through these, or in which direction, so I don't know if it's a problem or not (I'll just use the Payen one anyway), but it piqued my curiosity.

Cheers,
Joe

[Brianmoooore]

It's the oil feed to the rocker shaft and cam. Oil comes up the hole in the block, then up to the rocker shaft alongside the head bolt.

[TriggerFish]

Thanks. So the fact that the HGs are different isn't a problem? I checked the one from my old engine, and that only had one large hole.

[tomson]

Use the Elring one on the final build, very good quality parts.

[TriggerFish]

Thanks - that was my plan - to use the Elring, if it were compatible, which it seems to be. (I didn't want to find the two holes were setup with one for oil, one for water, and that they'd mix with the single port on the HG. Not a problem if the other hole on the block is for the bolt )

It seems much nicer made than the Payen part, and was the cheapest one I could find on eBay at ~£15.

[TriggerFish]

Well, I've committed now - I've tested it all fits properly with the Payen HG, so I'll use the Elring one for the proper build up.

Happily, everything fits, as expected, without any piston/valve interference, according to the plasticine test. Tomorrow's job is to reassemble with new bolts/HG and cam belt and to fit the new con rod stretch bolts now I know they don't need to be removed again.

[HairyScreech]

I have always had good success with the Elring gaskets just to back up what was said above.