Valve stem play, how much is too much?

[bobs409]

Valve stem play. How much is too much?

I just got the valves out of my 454 heads (the iron ones from 454 #1) and while some have no movement, there are some that have just a bit of side to side movement. How do I know what's too much?

Parts will be here tomorrow to put this together. I didn't think I would have to visit my machine shop so soon. :eek: Hoping a little is ok.

 

[MRHP]

About 2 thou is o.k. Maybe a touch more on the exhaust.

 

[Don Jacks]

If you can feel movement with the valve just off the seat,youre borderline.The valve stems,and valve guides need to be measured.[most likely machine shop time]

 

[bobs409]

Not sure what to do. Most are the exhaust valves. I think only 1 intake has it. It's not alot of movement.

What is the average price of a valve guide job anyway? Do they normally only fix the ones that need it or is it typically done to all no matter?

I suspect the valves should be good, they were new when I bought the heads.

The odd thing is I don't recall these having ANY movement when I got them. I had the valves out then to give the heads a good cleaning. I'm pretty sure they were all tight then. ???


Thanks again,


Bob

 

[Don Jacks]

Did you oil the valve stems before putting the heads back together,or put them up dry
. Make sure there are no scratches on the stems and that the valve stem bores look smoth.With the compression the other engine had,and the results from the cylinder leak tests,you do not need a valve job.You can "mike"the stems,but youre not likely to have a tool for measuring the valve guide bore.On the exhaust side,if you have .0025 movement or less,y ou'll be ok.You oil consumpton problem,as it relates to guides,is normally a problem on the intake side anyway.I suspect bad oil seals to account for the amount of build up on the intake valves in the pictures.













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[bobs409]

I did oil the stems when I put them back together.

I think alot of the oil was getting sucked in from the lifter valley. It showed signs of getting past the gasket and into the ports.


Thanks,

Bob

 

[Don Jacks]

Good,clean them up,new seals,get an intake gasket from GM.Often times some of the Fel-Pro's are too "hard"to seal properly with an alloy intake manifold.Ive seen this a lot on smallblocks.

 

[58 Apache]

Are they all apart now?

Lets start with some basic measurements like valve lenght and stem diameter. What tool did you remove and install the seals with last time? look inside the guide to see if they were previously knurled or there are scores in the guide. I believe the intake runners were your major source of the problem with oil. I say if the valves are longer then stock and you used stock lenght push rods would be a reason for the exhaust guides to be tight and then wear that much in a short time or the previous owner knurled the exhaust guides.

 

[bobs409]

I'll check those things out later this afternoon. I have a day of junkyarding to do first. I have a shopping list of parts to get from that Torino GT. Parts are flying off the shelf!

The valve seals just push on, no tools needed. Brand unknown on those ones. I bought a new set from Comp cams that also install without tools. (both are the positive stop type)

I'll report in later.


Thanks,

Bob

 

[bobs409]

Wow, sorry for the late report. Been busy putting some of the engine together and crusing 454 #1. The gas station sure loves me now. :evil

I checked the valve lengths against some originals and they are the same. Looking down the guides it looks smooth to me, I see no grooves.

Still unsure what I want to do about these heads but I have all winter to decide.