Texx
Super Moderator
If the valve timing was set correctly, the valve heads shouldn't have been touching the pistons.
Wont start
- Thread starter turboflow
- Start date
If the valve timing was set correctly, the valve heads shouldn't have been touching the pistons.
Bud did you throw petrol in the head ports to check if valves are leaking?
Plug wires on where they should be? Dizzy timing on around 10 DEG?
Does your crank pulley have a proper TDC mark?
5 skipped teeth is rather a lot! I've skipped 2 teeth before and bent 16 valves. Have you stripped the valves from the head? How are the valve springs looking?
Throw petrol in the head port and see if any comes out at the valves?
Texx
Super Moderator
Remove the camshafts, turn the head upside down, fill the combustion chamber with petrol (obviously the spark plugs need to be in the head) and then check for any drop in the level of petrol you've poured in. If you can see a leak, pull the valves out of the head, then one at a time clamp the stem in the chuck of a drill and spin it up. If it's bent you'll be able to see the head wobble.
weeJohn
Lifer
The 4E engine series are non interfeerance engines, the valves should never touch the pistons unless there is a massive ammount of lift on them. They still need checked as described above but there is another issue there as well.
Was the coolant in the block from vacuum and water pipes being mixed up on the throttle body?
Was the coolant in the block from vacuum and water pipes being mixed up on the throttle body?
Texx
Super Moderator
The belt was 5 teeth out John before being corrected.
The head is of an unknown origin, then skimmed and the pistons have previously been replaced. There is a potential for piston > valve contact.
weeJohn
Lifer
Still wont touch Texx on standard cams.
Texx
Super Moderator
I've not checked the clearance and never messed the valve timing up, so was only assuming. That's good to know then.
Any idea how much clearance there is in a stock engine, between a valve head at full lift and the piston at TDC?
the shims will fall out when you take the cams out and turn the head upside down , you need to take them out too and keep them, in order or number them . this will save you re-shiming your head if they get mixed up or fall out
weeJohn
Lifer
Easy to test, the crown of the pistons only just come over the block at TDC so all you need to do is measure how far the valves come down into the combustion chamber when the cam has them fully lifted. I would doubt there is much in it as they notch the piston crowns for stock pistons for clearance.
Ok so i have replaced all the inlet valves as they were bent........re-seated them......put it back together she still wont fire.....compression test was saying no1 70 no2 95 no3 80 no4 70 so after all the reading i agree that the shims prob have not been correctly done so i shall take the cam cover off and test tomorrow to see that distance there is between the shims and cams......
Texx
Super Moderator
So you did all that and didn't check the valve clearance before reinstalling the head? Replacing the valves would most likely result in a tighter clearance for a start, if there wasn't any valve clearance to begin with you can almost guarantee the valves aren't closing now.