TR6 Top End Chatter

J

JWDH

Freshman Member

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• Oct 7, 2020

• #1

I have a 75 TR 6 and I am wondering how much chatter from the valve train is OK. Mine I think is a bit noisy. When doing the head job it seemed that it was some what dry up there but I really have nothing to compare it to. which is causing me concern. Any thoughts out there about this.

 

poolboy

Yoda

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• Oct 7, 2020

• #2

It's OK to remove the valve cover and let the engine idle...you won't get oil splattering everywhere, but you should see oil dripping from each and every rocker arm....maybe a drop or two a second once the rocker shaft fills up

 

Madflyer

Jedi Knight

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• Oct 8, 2020

• #3

If you have the stock cam valve adjustment may be lose as to more performance cams adjustments. oil at head important add oil line to head there is a kit and plug at the back of the head just for that reason. added oil to head does two things, lub of course and extra oil as cooling also. The stock valve cover is a can as to a alum. cover could make a differents also. I have both line and alum cover and hot cam.
Madflyer

 

OP

J

JWDH

Freshman Member

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• Oct 16, 2020

• #4

I have had the valve cover off and it has plenty of oil but after setting the clearance three times there seems to be to much clearance. I am wondering if this could be caused by worn rocker surfaces? I think this is the problem. Can I resurface the wear points or must I replace them? Probably replacing them is the best thing to do but I like pushing things.

 

poolboy

Yoda

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• Oct 16, 2020

• #5

JWDH said:

....... after setting the clearance three times there seems to be to much clearance. .

Click to expand...

I don't quite understand that part. Can you explain in a little more detail ?

 

OP

J

JWDH

Freshman Member

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• Oct 17, 2020

• #6

I have set the value clearance to 10000 of an inch three different times thinking I must be making an error somehow. With the feeler gauge I set it so it has a little drag and then tighten the lock nut. I then recheck to confirm accuracy. With the feeler gauge it is say tight. But, if I physically move the rocker back and forth I can feel movement. More than I think is 10000". I am thinking my rockers are concave. Am I wrong? Is it possible? Too much noise but runs fine.

 

poolboy

Yoda

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• Oct 17, 2020

• #7

For the stock cams, the book says .010" = 1/100 of an inch

 

OP

J

JWDH

Freshman Member

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• Oct 17, 2020

• #8

So I put down the wrong fraction. The setting is correct one as per the manual and feeler gauge. But it is still loose. So is it possible that the rocker is worn in a concave?

 

charlie74

Jedi Warrior

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• Oct 17, 2020

• #9

Yes, they can develop a depression where the rocker arm contacts the valve stem. I modified my 10thou feeler gauge so it is narrow at the tip just because of this.

 

poolboy

Yoda

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• Oct 17, 2020

• #10

I'd have a close look at the contact patch between the valve stem and the tip of the rocker arm...See if there is a solid and even contact between the surface of the two.
The engine's valve train sounds similar to sewing machine at what's sometimes called 'tickover'

 

OP

J

JWDH

Freshman Member

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• Oct 17, 2020

• #11

Thank you for a great idea.

 

Madflyer

Jedi Knight

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• Oct 19, 2020

• #12

If your rocker to shaft are OK and your rocker shaft is not worn to much rockers can be ground smooth again but as they are cast and harden at tip best changed with new shaft also. Intake and Ex are different so 6 of each. Valves are much harder so best left alone. 0.010 was that cold ?? Madflyer