Triumph Repair: valve tap, mechanical advice, old ford

Question
QUESTION: 1974 tvr[tr6 engine] I have an unusual valve tap,or what seems to be a valve tap. It only does it at idle after the car has been run. It lasts a few seconds then quiets down. I dont hear any noise when driving the car.It does have a slight clatter at cold start-up.

ANSWER: Hi Duane,
There are several things that can give valve noise so each needs to be examined. First is valve lash. It should be .010" on both intake and exhaust. Worn valve guides can also make valve noise. An old mechanics test is to press a hammer handle against the side of the valve collar while the noise is active to see if it effects the noise. Another possible cause is a worn camshaft or pitted and worn lifters.
Howard

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QUESTION: Is there a way to adjust the valves when the car is running?

ANSWER: Hi Duane,
No, and why would you want to do that? It was a time saver on old Ford V-8s if you were doing dozens a day when they had self locking adjusting screws but the TR-6 engine does not have self locking adjusting screws. Thus it would require three hands and would be quit humorous to watch your try.
The standard method of adjusting valves on a TR-6 engine is not hard and does not take long. If you want that procedure let me know and I will go over it for you.
Howard


---------- FOLLOW-UP ----------

QUESTION: Great mechanical advice & a little humor. Im not sure where i got the idea you could do that..it may have been an mg video. It would be greatly appreciated if you could let me know about the standard method. Thanks,Duane

Answer
In the dealerships we were paid by commission so we could not waste any time when adjusting valves and the quickest way was to remove the spark plugs and put the car in 4th gear with the brake off. We could then role the car (usually backwards) by either putting a hand on the top of the front tire or use a leg against the front bumper. Two methods were commonly used by mechanics. I used what was called a "Mirror" method where I imagined a mirror was placed across the center of the head and I rolled the car until two valves were compressed. For example #1 %26 #3 valves. At that time #10 and #12 could be adjusted. Other words the opposite valve that was compressed could be adjusted. So when #10 and #12 were compressed I could set #1 and #3 valves. Two valve springs are always compressed at one time so that means two valves can be set. Always thinking of a half of the engine. As you rotate the engine by moving the car you will see the next two have one on the front half and the other on the rear half but always set the opposite valve from the one that is compressed. This works on 4 cylinder engines too (MG, Triumph and A-H) (4s and 6s).

The other method is to get #1 cylinder intake and exhaust valves so they are rocking and just each slightly opened about the same amount. That means that the piston of #1 cylinder is at TDC of the exhaust stroke and both valves are very slightly open. This means that both intake and exhaust valves of #6 cylinder can be adjusted because #6 is at TDC of the compression stroke. (All inline 6 cylinder engines are like that) On all 6 cylinder inline engines #1 and #6 pistons are at the top at the same time and #2 %26 #5 are up at the same time and #3 %26 #4 are up at the same time and one of them is on the compression stroke and the other is on the exhaust stroke.
The same with a 4 cylinder inline engine, #1 it up with #4 and #2 is up with #3 so that method works well too.

Since you can set two valves at a time you don't have to move the car very far to get all valves adjusted in the shortest time.

Some cars set cold and some hot so I tested many of the British car to see how much difference there was because a car would quote "Cold" setting and some customers wanted to wait for their car and "Cold" could take half a day from when they drove in. I found that most British cars, MG, Triumph %26 A-H only changed about from .001" to .0015" between cold and hot and since most factory settings were wrong to start with. I found for example when an MGB quoted .014" clearance cold I could set the valves hot or cold at .012" This made the valves quieter and the settings lasted longer. Not all were like that. The Austin Healey 3000 needed the valves set exactly to factory specs. Most of the other cars could be set .001" closer than what the factory quoted without any problems. The TR-6 quoted .010" cold and I would not go any closer than .009"
.001" difference is just a matter of feel when adjusting and it takes a long time to get a feel of the difference of only .001" from specs. Most DIY mechanics and some pros are lucky to get within .002" of specs.
Howard