Mi16 Head Gasket

[ANDYMISIXTEEN 0]

Think the head gasket has gone on my Mi16. Unless its a liner or something else. Ive just had the cams and carbs setup on the rollers but i think it was on its way out when being set up. Will this effect how it was set up? It was down on power. I had just changed the cambelt, tensioners and water pump.

How easy is the head to get off? Any tips or thing i need to look out for? Are the headbolts under the cams?

[Tom Fenton 1,542]

Head gasket isn't tha difficult, I've done one with a mate in about 6 hours,in a 205. If you've previously had the cambelt off then you are half way there TBH. The headbolts are under the cams yes. The 405 Haynes manual covers it in good detail.

[ANDYMISIXTEEN 0]

Got the head back from a Pressure test, clean and skim. They have rounded most of the cam bearing allen key bolts, rubbed off all my timming marks and cracked the inner cambelt cover. Ive also noticed one of the veniers looks like it has been dropped resulting in a bend and sharpish edge. Do you think this is exceptable? Im not sure if the allen key bolts have been torqued up correctly as they have been rounded.

Some photos from before the head went off and after : http://s237.photobucket.com/albums/ff298/ANDYMISIXTEEN/Head/

[philfingers 5]

Got the head back from a Pressure test, clean and skim. They have rounded most of the cam bearing allen key bolts, rubbed off all my timming marks and cracked the inner cambelt cover. Ive also noticed one of the veniers looks like it has been dropped resulting in a bend and sharpish edge. Do you think this is exceptable? Im not sure if the allen key bolts have been torqued up correctly as they have been rounded.

Some photos from before the head went off and after : http://s237.photobucket.com/albums/ff298/ANDYMISIXTEEN/Head/

unacceptable totally! Have you paid them, i guess so as you have it

[mickie 3]

nasty, id take them bolts out and re torque them. also while ya on those valves look like they need lapping in..

 

did you even do a compression test before ya pulled it apart ?

[welshpug 1,657]

bugger! definitely replace those bolts, there's a tightening sequence for them detailed in the Haynes manual too.

[Tom Fenton 1,542]

Its not fair that they have damaged your verniers.

 

But it is very easy to round those bolts out, they are a bit of a swine to be honest.

 

I have to say though really you should have taken the head to them stripped, e.g. cam caps off, cam removed, followers removed, cambelt cover removed. I always do this as its easy work and it means they are not going to charge me an hours labour or whatever for someone to stand there and do it for me.

[ANDYMISIXTEEN 0]

I was going to strip it down a bit more but i couldnt get one of the venier bolts undone even with a braker bar.

I didnt do a compression test, what would it have told me?

What do i have to do to lap the valves in and what does it do?

[mickie 3]

a compression test would have told you if it was the head gasket and also could tell you what cylinders are down on power..

 

also a leak down test with a compressor could have told you if your valves were seated well or not..

 

to lap the valves in you need to take the valve springs out with a valve spring compressor, its a tricky job mainly due to valve keepers, once you have the springs out, you need to take out the valve stem seals, replace these later.

 

then you grind the valves in using a valve lapping tool and some grinding paste, make sure the valves go back in the same order you took them out of the head..

 

the idea is, the better the engine holds pressure/compression, the better the engine is and as you have the cylinder head off, if it were me, i'd sort out the rest of the cylinderhead..