no compression after head change

[stuart8862]

Hi I have just changed the head of my 1098cc to unleaded with a new Head Gasket, but when i try and start the engine turns withought firing. I have used a compression guage to test compression but there doesnt appear to be any compression, can anyone pls help.......

[aupickup]

well first why did you change the head

have you torqued the head down properly then retorqued after first heat cycle

i take it the spark plugs are in place

[stuart8862]

Hi
I changed the head due to head gasket failure and thought i'd kill to birds with one stone!
I have torqued head down, but cant get the first heat cycle as it wont start.

[aupickup]

plugs in the right order 1342
valves gaps correct
gasket on the right way
have you checked to see if there is a spark at the spark plug

[stuart8862]

Maybe im being a little dumb, but is there a wrong way to put the gasket on??
Do i need to set the valve gaps on a new head?

[aupickup]

thegasket would have had top front stamped on thegasket
and yes you will need to set the valve gaps

[brucek]

Yes you do - in removing the head you will have had to remove the rocker assembly. On reassembly, no matter how accurate the torque setting is, the valve gaps will need to be reset. It is easy enough if you have not done it before - just let us know and we'll tell you how. Alternatively, check the procedure in the workshop manual if you have one. If not, I know a few people have them as a pdf file so will be able to send you one via e mail or private message(pm).

[stuart8862]

Hi
Many many thanks, guess i best start again!!
Thanks for your help on this, I do have a manual, so i will start again, do you recommend new head studs??

[aupickup]

only if yours are stretched or threads stripped but many use the same studs

[brucek]

Agree with aupickup - only need to change studs and/or nuts if they are damaged. Make sure everything is scrupulously clean - esp on the block and cylinder head faces that meet together. If possible, use the copper faced head gasket rather than the fibre type - whilst they are both fine, the fibre type does tend to leave more of itself attached to both faces if you have to remove them again at a later stage. Some suggest a light smear of grease on both gasket faces too. Follow the torque sequence and then follow the sequence for setting up the valve gaps. If you have done this, and you have a spark, and the plug leads are on and in the right order, and you have fuel getting through, the engine should fire up. Allow the engine to get warm and then don't forget to retorque after the first heat cycle. Good luck

[bmcecosse]

It is obviously the valve gaps! OF COURSE you need to reset them.....12 thou inlets and 15 thou exhausts...... And yes - retorque after the first heat cycle and then reset the valave gaps. Studs will be fine - torque to 44 ft.lbf in steps round the head.

[aupickup]

we all said the same
perhaps some one else will be along to say the same thing

[Bazzalucas]

One would think that there would be SOME compression, on at least one cylinder, just by dumb luck...

[brucek]

Well, we all have to start somewhere let's face it, we all learned how to do it right AFTER we did it wrong my guess is that once the head is back on and the correct sequence is followed, our new friend will know next time he needs to do it. As Yoda says "In a dark place we find ourselves, and a little more knowledge lights our way." Sorry - more Star Wars there

[beero]

Assuming your compression gauge may be at fault...... can you feel any compression when turning it with the handle?
Oh, and welcome to the forum.

[lambrettalad]

makes one wonder which manual or did it have pages missing?