Does anyone have the info on what the valve lash gap is

With a stock cam, .019 intake and exhaust, hot or cold.

John - "The Hoosier Hurricane"

I believe Tim McMaster recommends .015 for a stock setup, says it'll help keep the engine quiet without any problems. He has a couple video links on his website about it.

website: http://yblockguy.com/techtips/tech_tips.htm 

Hope that helps

Hey JD, it appears that the link is broken

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South Australia

Aw darn, sorry about that. Let's try these links instead, they are the same videos but on Youtube:

https://www.youtube.com/watch?v=SqG-Q_kVI3s 

https://www.youtube.com/watch?v=PIB9m1Kp61o

Just copy and paste into a tab of your web browser. I checked them this time and they worked ok for me, let me know if you have problems! 

As an FYI......I always set at .019. I went down just one size smaller (.018) and I must say the lifter noise was reduced dramatically. .015 just seems to tight for me, I'll settle for .018 and fairly quiet.

1957 Thunderbird 312 Fordomatic

if the engine has recent work,dun properly(rockers refaced,valve tips flat,you will not have any noise at .019. i set them with the plugs out so the engine can be easly rotated,i go by the fireing order and make sure piston on tdc, if engine is highmiler hard to get acurate seting and  i dought 16-17 would do any harm.

I set my valves on my tractors while they are running,  is this a bad practice?

tom in iowa

54 Merc wagon

54 sunvalley

I won't suggest that I'm in any way better qualified to talk about valve settings than Tim McMaster, but I'm surprised that he would recommend setting them at 0.015". I'll throw the following out there for discussion. When I acquired my 57 Ford & applied for Collector plates, it was required that the car initially pass a basic emissions test. (no I don't know what standard they use) Anyway, the car failed miserably. I had some tuneup done by an authorised shop, but they said it had "internal difficulties" & it failed again even worse. Anyway, to get to the point, with the help of some people on this site, I was refreshed on checking the valve clearances & decided to do that.  I discouvered that some valves were set to tight. Some were as much as about 6 thousands or so under spec. I went thru them twice & used 0.020" cold. The car seemed to idle better after, although when cold there was some that were a bit noisy. Anyway, I had it tested again..and it passed... Any thoughts?      


Paul

  The nice thing about solid lifter camshafts is the ability to actually vary the lash which can alter the way the engine runs.  As a general rule, tightening the lash increases the overlap cycle which in turn reduces the manifold vacuum.  Loosening the lash does the opposite in that the overlap period where both valves are open is reduced and in turn, manifold vacuum is increased.  Taken a step further, tightening the intake valve lash allows that valve to close later which is a result of increasing the workable duration on the camshaft.  This in turn lowers the cranking compression which ultimately results in a lower torque number being produced in the lower rpm band.  Loosening the lash does the exact opposite in that the cranking compression goes up which makes for increased torque in the lower rpm band.

What has to be remembered when dealing with camshaft overlap is that when both valves are open, then another cylinder where the piston is going down and is pulling in the intake charge can actually see all the way out to the exhaust on that cylinder that is in the overlap cycle.  That’s where the engine vacuum sees a decrease as this is simply a vacuum leak to the exhaust.  Maintaining a true 180° or dual plane intake design helps to minimize this but if there are any common open areas under the carburetor that will allow one side of the intake manifold to see the other side, then that overlap cycle becomes very important.  This is why open carb spacers tend to reduce the vacuum signal on true dual plane intakes versus the use of a four hole spacer being used instead.

Lorena, Texas (South of Waco)