Valves on last thread

[Jim]

Hey guys, another issue i have stumbled upon is that there is no thread left on the adjusting part of the valve in order to create the correct gap? Or am I not doing it right?

Basically I'm trying to increase the gap on the exhaust, the adjusting nut is right at the bottom of the locking nut and the clearance still isnt enough?


...I'm expecting the worst right now.

[stevemarl]

Could it be VSR, the va;lves have sunk into the head so far they`re beyond adjustment? Suppose you could take the ball pin thing out and shave a mm off the threaded end as a temporary measure?

[Jim]

It really better not be, the cylinder head had hardened seat valves installed to deal with unleaded fuel but it don't know what else it could be...

[340truck]

Don't think you're doing it right - with the adjuster fully down you can remove the follower with the cam in situ. Are you sure the cam lobe is pointing upwards when you are doing this?

[Jim]

The locknut is as low as it can go and so is the adjuster and there is no visible thread showing to adjust it further down. The adjuster just hits the lock nut and the locknut will turn no further down. The pointy bit of the camshaft is pointing upwards.

[Peter-S]

The locknut 'C' is always at the bottom with no thread showing beneath it:



You need to turn the nut anti clock wise which will then enable you to adjust the central stud 'B'. Tighten it up again when you've set the gap and then rotate the camshaft and recheck it.

[Jim]

The locknut 'C' is always at the bottom with no thread showing beneath it:



You need to turn the nut anti clock wise which will then enable you to adjust the central stud 'B'. Tighten it up again when you've set the gap and then rotate the camshaft and recheck it.

Thanks for the diagram above. The situation I have is that the adjuster nut above is directly on top of the locknut below, with the locknut at the bottom and no thread left and the gap still isn't big enough I.e. No thread left between b and c. Only seems to be on a few of them though, the others I've been able to set.

Another thing I've noticed though is that when checking the clearances is that one side (on the same valve) is tighter than the other I.e. the cam follower is not giving a consistent gap along its width. Should I set the clearance to the correct spec at its tightest spot along the width of the follower or at the central point?

Many thanks for the responses guys and I appreciate your patience.

[stevemarl]

The situation I have is that the adjuster nut above is directly on top of the locknut below, with the locknut at the bottom and no thread left and the gap still isn't big enough I.e. No thread left between b and c.

If that`s the case, I can only assume that hardened seats or no hardened seats, the valve IS burrowing into the head. I can`t see any other course than to whip the head off to see what`s going on.
Re. the clearance being tighter at one side, the follower should be loose enough on it`s ball mounting that it should automatically position itself parallel to the cam surface. That again sounds worrying.

[Peter-S]

What's brought about the need for the adjustment, have you fitted some new parts?
Just wondering if you have fitted some longer studs designed for high lift cams rather than standard studs by mistake.
If everything is standard than, as Steve says, the head needs to come off by the sounds of it.

[Paul G]

The situation I have is that the adjuster nut above is directly on top of the locknut below, with the locknut at the bottom and no thread left and the gap still isn't big enough I.e. No thread left between b and c.

If that`s the case, I can only assume that hardened seats or no hardened seats, the valve IS burrowing into the head. I can`t see any other course than to whip the head off to see what`s going on.
Re. the clearance being tighter at one side, the follower should be loose enough on it`s ball mounting that it should automatically position itself parallel to the cam surface. That again sounds worrying.

Get the head off asap. If you can stop driving the car if it's as bad as that. If not there is the risk that valve head could snap off and drop into the cylinder then you will need a new engine rather than new valves and seats.

Capri engines were not designed to run on unleaded petrol (although a few late Sierra ones could) and even with the very late ones Ford stated in the handbook that every fourth tank full had to be leaded. I wouldn't trust most lead replacement additives in a hard driven car to stop a bit of valve seat recession.

Don't know if this helps

http://www.burtonpower.com/tuning-guide ... -fuel.html

[Jim]

Thanks for the replies guys, much appreciated. I've halted all work and have bought a second hand head which I'm going to get reconditioned and install that. I was hoping I could amend the head temporarily somehow and get it driving again but it seems that is not an option. I was going to put everything back together last night and start driving it again but I'm glad I didn't as judging by your replies it was only a matter of time before something bad was going to happen.

What's brought about the need for the adjustment, have you fitted some new parts?
Just wondering if you have fitted some longer studs designed for high lift cams rather than standard studs by mistake.
If everything is standard than, as Steve says, the head needs to come off by the sounds of it.

I wanted to adjust the valves as the car hasn't been idling very well for a long time, and I had checked everything else it could possibly be. The valves I'm assuming were last checked about two years ago when I had another bottom end installed. I'm glad I checked them now/wish I had checked them sooner.

[Paul G]

Hi all, I've bumped this thread up again as I've been helping James this morning to get the head off the car. The head is one that was supplied by Tickover about 10 years ago and has been converted for unleaded - ie hardened valve seats.

As James said in an earlier post, the adjuster on no 1 exhaust was wound all the way into the locknut housing but the clearance was still tight. I took the valve out and it and the seat looked perfectly ok with no sign of erosion (I have seen erosion before on a non-hardened seat) as did the valve face, although slightly blackened. I measured the valve with a vernier and compared measurements to a known good genuine Ford valve (both valves were genuine Ford) and and all dimensions were within a gnat's dick of each other and the specifications on Burton's website. The valve margin (thickness of the head) on the suspect valve was a tiny bit smaller than the spare but again nothing much. I tried fitting the replacement valve in the head and the clearance was still tight.

All 8 clearance adjusters are well wound down with not much adjustment left.

Now for the crunchy bit. I decided to try one of the cam followers from the second head that James has bought in place of the one in the Tickover supplied head and guess what - we had to wind the adjuster nut up until about 1/2 inch of thread was showing - ie what I would call normal - to set the clearance. I just wondered if anyone else had come across similar with a pattern cam?

My experience and gut feeling says that I'm going to decoke the head and lap all the valves in then fit the camshaft and followers (which are still excellent) from the second head. I will also put some top hat CVH valve oil seals on it. Before then I will get my local engineer who I know well to have a look at the valve seats even though I feel they are OK.

Just throwing this out there for your opinions guys, I've never seen anything like this but what do you think?

[Peter-S]

Be interesting to see a profile picture of one of the 'rogue' followers. Is the pad a lot thicker than normal or something?

[stevemarl]

Thanks for the follow up, it`s always good to follow to a conclusion. As Peter says, pics would be interesting. Do you think the rockers could be off a completely different engine, quite a few makes in the 80s used finger type followers (IIRC Lada ones look almost identical)?

[Mc Tool]

Not 2.3l pinto ?