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Valve Clearance Adjustment

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shorn

Jedi Knight
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The brass tag on the engine of my BJ8 indicates the valve clearance should be .012 for a HOT engine. Yet, my Haynes workshop manual suggests .012 for a COLD engine. Which is correct? What is your experience with the click adjust tool? Seems like it might make the job somewhat easier. Otherwise a third hand might help.
 
Hi Shorn, No experience with the click adjust tool. Adjusting the valves hot or cold does not seem to cause a problem.-FWIW---Keoke
 
when you're running the engine hard, a little looser seemes to be the rule, with".015 for competition work..."( Haynes- pg.52 para 58-5)being suggested for safety. It seems that the main thing is not to get them TOO TIGHT-
 
Just get a good pair of feeler gauges and set them at a loose .012. That means the gauge slides between the valve stem and the rocker without a lot of binding, if you can slide the gauge with 2 fingers lock it down. Be sure the piston is at TDC on the compression stroke. Skip
 
We once did this discussion about 2 years ago and reached no conclusion. My BJ8 also says HOT. But as stated, it seems to make very little difference. I'm not that fast and the last valve to be adjusted will be cooler than the first anyway. I think cool would be more uniform.
 
Shorn, I bought the 'click adjust' tool several month ago and I tell you there's nothing more exactly than adjusting the rockers by the good old method.

By the way, I do the adjusting with cold engine @ 0.012" and the gauge sliding through the gap. Engine runs smooth as it should.

Regards
 
Feeler gauges work fine on brand new rockers and push rods. However, on an older engine ,the wear on the rockers and push rods tends to form a "cup" shape. So the feeler will set a gap that is too large, because it slides on the edges of the "cup". The Clickadjust is one method of getting around this because it works out the gap based on the number of turns of the threaded adjuster. If you know the thread form TPI then it is possible to adjust the gap by turning the adjuster to "no gap" and then turning it back the number of turns to get the exact required gap.

Mike
 
Patton, Keep your $50.00 in your pocket. ---Keoke /ubbthreads/images/graemlins/driving.gif
 
Patton,
I agree with Keoke, which I do more often than not. Even very visible wear, in reality, is not likely to make more than .001" difference in the lash setting. I have checked the difference with a dial indicator. Not enough to worry about. Just set them at .012" cold & relax.
D
 
Patton, Mike is comletely right with what he is saying - but - I have bought the clickadjust (it sells here in Germany for about 35$) and found out, that it is not as accurate as adjusting the rockers with a feeler gauge. Maybe it's a matter of familiarization to handle the tool. I'll give it a try next time I have to adjust the rockers.

Regards
 
Patton,

It probably depends how worn the push rods and rockers are - but if Dave has checked the difference with a dial gauge and it's only one thou, that's good enough for me!!

Mike
 
RE - Click-Adjust

Thanks guys,

I still have the valve cover off the head from adjusting the valves a couple of weeks ago , and would get a Click-adjust if their was a real reason to. Sounds like their isn't unless someone wants to sell one cheap.

While we are talking about it, I am getting an extra Longbridge head, rockershalf and arms this week. Is it worth the time to swap rockershafts to see if the "new" one doesn't have the small fountain I referred to in a post a couple weeks ago?

Patton

Patton
 
Yes Patton, getting rid of the small fountains wil improve your oil pressure and give you peace of mind.-FWIW---Keoke /ubbthreads/images/graemlins/driving.gif
 
Yes Patton,a good approximation of the condition of a rocker shaft can be made while it is off the car.However, expediancy might dictate that you just put it on and give it a try. To check it off the car requires that it be dismantled so that the shaft can be inspected.A worn shaft will exhibit excessive ridges on its outer surface and worn oil passage holes.Just rebushing the rockers will not comphensate for the shaft's worn condition-FWIW---Keoke
 
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