MX5 Head Gasket

[samuelt]

Hi all

I am currently stripping down my 1991 1.6 MX5 engine to replace the timing belt etc. It is the first ever engine i have done this to and I am not sure if all of the head gasket has fully been removed when i lifted it off. There seems to be a metal residue left with a golf ball style pattern indented into it.

Please can someone advise me if this is ok to leave or how to remove it? I have tried 3 in 1 cleaner but it makes no difference. if i scrape it with my finger nail i get little metal flakes, i am sure these are not good for the engine.









thank you

[fasteddie]

Hi Sam, you definately need to remove the residues of the old gasket off both faces. I would put some rags in the bores, then get a very sharp wide wood chisel and gently scrape all the crap off both surfaces. when you have done this remove the rags and use compressed air to blow out any remaining bits. It will also pay you to block off all the water and oil holes with some tissue paper. Regards Ted

[samuelt]

hi

thanks for the advice i do not have an air tool (yet) i can always vac out the bores afterwords with the dyson, i will also block the bores. the head has been skimmed so it is ok.

thank you

[h5ngs]

Hi just a metal stanley blade scraper first to get the thick off, then use a sanding block, the rubber type ones and fold some 80 grit paper over it, then use that to sand the top, even strokes across the block and if there is a stubborn part dont just keep rubbing at that part, should be as clean as possible before the next gasket goes back on if the heads been skimmed should look not far off as clean as that does, but dont go over board, you'll see the difference that a few passes will do.

[samuelt]

thanks h5ngs thanks for the advice.

[samuelt]

well i set to work today and with a stanley blade scraper, i teased away the silver "foil" that was on top of the block then cleaned it all up.

I then went back to the workshop manual and followed the re-build procedures, Oil the bores, put on the gasket over the 2 dowels. Looked at the block 1 dowel so checked the head it has 1 in it, so not to worried. then after a after a few good looks at both i realised that the guy at the machine shop has put the dowel he removed to skim the head back in the wrong hole! I am now going to have to take the head back to get him to move it to the correct one.

[h5ngs]

Put a drift of piece of bar into the dowl that just fits inside of it. Then use a pair of mole grips to grip it and twist it out. The drift or metal inside the dowl will stop it from crushing and deforming it

[samuelt]

Thank you, i will give this a go tommorow. Plan to learn a lot doing this project, tips like these are great!

[samuelt]

ok had a quick go, used a socket as it went in well and tried it on the one in the block as it is still in the car (held down well) and had no luck! it is in very tight even with some protection on teh tube I have left some teath marks on it. Are these required or are they simply there to hold the head in place while you bolt it to the block?

[fasteddie]

These have a very important function making sure the two surfaces match up correctly, you must ensure both dowels are in the correct position otherwise there will be no gaurantee that every hole, bore and water passage will have good clean thru ways without steps ect, regards Ted

[samuelt]

Done! I could not get the one in the block to move so i tried the one in the Head it was right down with about 1mm showing. I used a flat head nail clamped into mole grips to catch the bottom of it and pull it up by 10mm then it easily came out with the mole grips. now back in the correct place!

Thanks for all the advice!