worn valve stem

huh..found my noise..

one of these things, is not like the other...


Anyone have a good used 1.45" 351W exhaust valve and a pedestal rocker laying about i can buy and compensate to put in a box?

Yay!
This is an '82 model year PCM Joe

Thanks for looking Joe!

KENO wrote: I figure you could get a new valve and rocker arm from a reputable outfit like Melling or Sealed Power just for a couple of examples, for around 20 bucks total through about any local auto parts store, so why go used?

You have to be careful letting new parts into your engine, they are like shots of Tequila, once you let in one new part next thing he sneaking friends in pretty soon you have aluminum heads, a cam, and an intake on a perfectly good engine. Better just to never open the parts book up.

What would make 1 stem wear so much faster than the others? A bad lifter?

SNobsessed wrote: What would make 1 stem wear so much faster than the others? A bad lifter?

I suspect Tom either knows or will know when he takes it apart -

Could be a material defect somewhere,, rocker, valve stem - ear starts and once you aren't pushing polished surfaces things start go bad.. but not likely

Could be lack of oil through the pushrod serving the rocker worth checking the lifter and the pushrod,

Or either the rocker sticks/has stuck at one point or the valve sticks/has stuck at one point .

The valve is stuck down, That is normally outside influence.
If someone started that engine with old gas in the tank this can happen.
Old gas turns to varnish when you try to run it.
The varnish coats the valves and valve stems. It makes them stick.
Then a piston can tag them, now the valve is bent and will never close.
With one bad valve you can run and ski with 7 good cylinders, a little weak and rough idle but not too bad.    I did it for half a summer years ago while I gathered parts for my preferred repair.
A broken valve spring can do the same thing. They can break due to a factory defect or due to an over rev situation.
You are doing all the work to fix it, take a little time and do it right.
You never hear anyone complain because they fixed it right.
But on the other hand...............................

Looking at your photos again it is odd. Nearly a 1/4 inch of your valve stem is not there but the spring is still on which means the keepers are still there.
That is a rotocap design on the spring. I wonder if the wrong valve was installed at the wrong installed height to begin with or if the valve tip has worn down that much.
What does that rocker arm look like?? I have never seen a valve tip wear like yours.
I have seen them wear at a slight angle at high miles but never 1/4" gone like that.

I would not think a lash cap would be more than .080 thick.   Looking at his picture it appears to be .250 lower than the other valves.   Something is wrong.

Oh my, I hadn't considered that it was incorrect from a repair long before i got it

I'll take some closeup pictures, for posterity. Plus its fall, what else we going to discuss

Remarkably little wear on the rocker, but it feels as if the original profile is slightly worn.

May be a day or so

Seems healthy enough to me, a good bit better than stock.

Thanks men,

been a while, but I think i've sorted on a plan of action.
My aim is firstly to get it operating solidly while going though the trouble, exercise my long desire to remove substantial weight from the boat to make it even more spectacular for slalom, and a tangible but not scary power increase in two steps.
secondly to make some more rpm available as it runs out of steam very early.

For this season.. stage 1 ...
First install these 4 parts i have had in hand and had gotten at a steal a long time ago when i first considered attacking the noisy valvetrain.
the hyd flat cam above with the rhodes lifters, Roller chain and oil pump.
So that just costs me some gaskets.
Inspect and gauge the mains while its open.
This '82 351 has as-expected cylinder ridge but no bad jugs or slugs.
recall this is a LH engine
Regarding 'budget' heads, I had considered the tri-state large-valved GT40P, and TS Flo-Tek 180 203505 with 1.94 Intake valves, the edelbrock e-street, and lastly TF twisted wedge 170.
For both low weight and decade+ durability chose the TW 170 with 58cc chambers vs 61 cc. for a modest amount more than the others, it has the longevity of good guides, valves and can be setup for roller cam someday with just new springs plus has 2.02 intake valves.
Appears with this < .500 lift cam, i wont have issues with clearance to these stock pistons.
Looks like my pistons are heavily dished, flycut, and also look to be put on a lathe and another circle cut out of the them even deeper than the dish, so appears to be 18cc or more is gone, hence choosing the 58cc chambers vs 61.
1.6:1 Scorpion rockers
Edelbrock performer or weiland stealth,
std pcm manifolds.
net about 85-90 pounds gone from intake, heads, and rockers.
and get this sorted out by spring.

Stage two will be another season or three away, but utilize the top end above except the intake, which i should find a new home for easily.
This will go upon a 331 stroker shortblock with the appropiate TW pistons for clearance, and dished to keep the 9.3 cr.
Now the system can go roller cam inexpensively and go .550 lift.
With the lower deck height, i can go to a taller duel-plane intake like an air-gap.
Aluminum front cover and convert the sherwood pump with a new flange to work like a crank-driven Johnson like indmar does. Save 70# on the shortblock, and another 20# on the iron front cover and pump bracket. 180# or more total is gone at this point.
This step will be to maintain the improved power while finally loosing the combined weight of one grownazz man from the boat.

well thats my secret evil plan right now
heh, I know, , you'll shoot my eye out kid..
Any inputs on if i should set the Cam straight up or +/- any degrees off?
and of course any other considerations would be welcome to complete the thought experiment before engaging

Good to hear Tim

I see, yeah i'd like to keep the 4-hole spacer in use if possible, so lower is better else i run out of height

Ok, I'll keep that cr in mind!

I think something is lost in the translation Mark,he says he has a 351 now, later stage 2 will be a 331??

GottaSki wrote: Oh my, I hadn't considered that it was incorrect from a repair long before i got it I'll take some closeup pictures, for posterity. Plus its fall, what else we going to discuss Remarkably little wear on the rocker, but it feels as if the original profile is slightly worn. May be a day or so

Where are those pictures for posterity?