Hemi valve seals , options ????? UPDATED

Ive see all kinds of different valve stem seals for a street hemi. Deep down I have my doubts it will change anything , But decided to do them while I have it opened up

Some say valve guide machining is required, yet some say not, but show what appears to be the same exact style of seal. AKA called a Positive Lock seal .. ( and it appears thats the style on the car now ???????)

Ive found what looks like a normal umbrella seal . yet others say this type will not work with dual springs

Silver Seal # 65120 silicone seals worked great on mine.

This is on your Satellite? What are you doing with double springs?

yes, on the Satellite.

I had a long conversation today with the man who built the engine back in the early 90s

We've come to the conclusion its ring seal he remembers early on it had a fuel pump issue the owner put on it and seriously flooded it , and he feels it washed the rings out of it.

I bought it knowing full on compression was a little high for a street car. Knowing I would want to do a piston swap at some point. to make it a little more pump gas friendly

SO,,,,,,,, plan is put it back together for now and save some pennies up for a piston change maybe next year or so

As for the valve springs. No idea , but thought all Hemis had double springs ??????

If I read the parts book accurately, single spring with dampener.

There is not one answer to your question. You need to know the inside diameter of the inner valve spring and outside diameter of the top of the valve guide. Measure with a dial caliper. Once you have these dimensions, Give me a call and I look in our supply of seals. I use the super blue seals, they work best. They let in enough oil to lube but not enough to burn. They will probably outlast your car.

Hemi Cylinder head guy since 1984, I've tried them all.
Best regards!

Outer spring with surge damper and inner spring without. They were dual spring according to service manual.

As stated it really depends on how the heads were modified if they were. I used FP SS 72522 valve guide seals on my 66 heads, but I had new bronze valve guides installed. 2.2/2.5L seals.

Thanks for the replies all.
Like I said I talked to the gent who built it.
We came to the conclusion pretty good odds its ring seal.
But he gave me some ideas and things to try ( heavier oil weight , with a zinc additive , change pcv valve etc etc )

I knew going in a piston change was in my future with the car and those plans havent changed in that respect. I just need to rebuild the piggy bank before I can cross that bridge .

Again, many thansk for all the replies.

But yes it has both inner and out springs AND a dampner between said springs .
I dont think my hand held spring compressor will do the springs anyway so cyl head removal would be required either way

While we’re here, would you use a different seal for the exhaust and intake since the exhaust is down in the oil more and intake is up top?
And should the intake spring get more oil splash then the exhaust because of how they set on the head?

Just an FYI to anybody reading this thread, 5.2 & 5.9 Magnum umbrella seals fit a Gen 2 Hemi as well. I'm running them on stock Iron heads with beehive springs.

I had my 1970 parts book handy and it list 3418491 as the Hemi valve spring. Looking at the picture in this eBay ad for allegedly NOS springs, 3418491 is a single spring with dampener.

3418491

If you trace this from 66 to 71, you will see changes made wrt to the heads. Mechanical to hydraulic and spring changes. But OPs car is 66.

You've piqued my interest once more. I'll drag out my '66 parts book and take a look tonight.

I also have to consider my car IS NOT oe stock either.

It has a comp cams kit in it. I do not know if said kit included and/or required updating to dual springs or not

Builder doesnt remember ( engine was built late 90s or very early 2000s time frame ) BUT he thinks the seals are from Comp Cams as well

here is the cam card if it helps / matters

PS, i plan to maybe pull it down further either next year or year after. Actual time frame will be determined by the end result when I get it back together this time with the changes Im making
But I will have the heads looked at then and make sure all is right

You are right on. 1966 parts book calls for 2780682 outers and 2780693 inners. What is even more interesting is I found this brochure that has the spring rates for both inner and outer springs and mentions that a surge damper was used also.

1966 Street Hemi Brochure

I love minutia. Good job!

The service manual is your friend to Just went through a lot of this building this

I thought I would update this,.

I just changed the oil in mine ( street hemi with approx 2500 miles on it.)
Went to a Rotella T straight 30 weight and added the Lucas oil ZDDP additive per recommendation of the man who built it. And So far ,,,,,,( knocks on wood ) ,,,,,, it has helped my oil consumption issue . I was going thru almost a qt of oil every 150 / 200 miles. Since the change Ive put almost 200 miles on it and its still on the full mark The only other thing I did was I welded a piece of sheet metal to block off one port in the valve cover that is under the PCV valve to help limit as little oil as possible getting under the valve and possibly being sucked in the intake. Also added an nos PCV valve as well
I did NOT change valve stem seals . After my talk with the builder we both decided it was 100% waste of time and money

PS, The engine builder and myself had a long talk and he highly recommended these changes ,,especially the oil recommendation. And in 100% honesty , Never in my wildest dreams would I have thought the changes I did would have made such a change

Now, I will add. Do I think it cured it ? , absolutely not. But it sure made a change for the better,,,,at least so far so good anyway

The PCV not baffled could suck a lot of oil. It is like a vacuum running all the time. One thing you could of done before the baffle being installed would be to install a catch can in the PCV hose to allow the droplets to drop into the container. After 50 miles you could of opened it to see what accumulated.

To be honest, I didnt think about a catch can. The baffle plate under the valve in the cover has some huge holes in it and I felt far to big especially the one along the upper side of the cover. So I welded in a small piece of sheet metal to cover about 90% of the upper hole( there were still 2 large lower holes )

Ok, hear me out as you guys are gonna think Ive lost my mind.

Drove the car to a local cruise nite last weekend. approx 90 miles round trip, some hiway some inter city driving . Car used just a tad under a qt of oil round trip.
Oil is now straight 30wt with a ZDDP additive

Drove it yesterday to Phoenix ( taking an extra qt of oil with me to top it off when needed. ) just a click over 350 miles ROUND TRIP .........

I ckd it about halfway back on the return trip , was maybe MAYBE a tad over 1/2 qt low. Ckd when I go home and its still less than a qt low. Shows right above the add mark.
Both times I verified it was right on the full mark when I left

WTH ????????

Have you tried leaving it a quart low to see if it would drop lower?

No, I have not might give that a try,
BUT,,,,Im stumped. This makes NO sense .

The car does belch a little smoke on warm startups. We can drive it somewhere. Sit maybe an hour or 2 and it will puff out a decent cloud of blue on restart. Then nothing. In my gut it tells me its a valve guide issue.
BUT ,,,,,,

The guy that followed me up the entire drive yesterday said he so NO blue smoke the entire trip and its a tad over 125 miles one way from where we met up to the show we went to

It will keep a little drip of oil on the bottom of the oil pan and / or trans bell housing. But the underside of the car is bone dry so I dont think its a leak ,,,,at least not enough it leaves a drip ANYWHERE I park it

If you are 100 percent sure the valve seals are doing their job then I would do compression and leak down tests. The one other thing I hear and I am new to hemi's is lower intake gaskets leaking. It could be sucking oil in. I read where you need to torque repeatedly to keep them sealed. Once they are sealed you wont see any more bolt twist. I have my own way of testing for the gaskets leaking.

Ive already done compression ck- all 8 within 200 - 220 psi range


leak down test with 100psi of regulated air - 7 of the 8 are approx 15 % loss. , cyl #2 is the worst at 20% loss.
Put my hand over the crankcase breather and thats where I feel air escaping.

Had both valve covers off , taking a mirror and probe around under the intake and NO signs of a gap anywhere between the intake and cylinder head on either side

The fact I get a puff of blue smoke on warm startups makes me think valve seals or guides maybe ??????


BUT, why such a dramatic difference in oil consumption. Simply because of one trip was almost entirely expressway versus other trip was 50-50 split hiway and city driving

Like I said,,,,,Im at a total loss and stumped. I truly expected it to use at least 2 maybe 3 qts on this trip and it didnt .

Here is one simple test I use. Not sure how you are set up on crankcase venting. Plug the PCV . I make sure everything is sealed except for one point. Run the engine until hot. At the one crankcase venting point see if you have positive pressure. It should haze out. If there is no haze or possible slight vacuum the intake is leaking.

Bill, you seem to be plagued with cars eating up oil by the quart. Didn't you used to have a blue GTX that did the same thing too?

Wow, Good memory.
But yes. My old 69 GTX vert . And that was another one i didnt build.Best i remember That one was pretty consistent, a qt of oil pretty much every couple hundred miles regardless of trip type .

That car is now in NJ completely redone top to bottom - front to rear . Brian found out it had low compression truck pistons in it


I had my head wrapped around this was gonna need rings .

But Why such a dramatic difference in consumption on an all hiway mile trip versus a much MUCH shorter yet city trip . I dont get it

Its all stock with a stock PCV on pass side and the OEM breather on drivers side

I got nothing to lose so will give this a try

When engines consume oil they either burn it, leak it, or a combination of both. It can't just magically disappear. What do your plugs look like? What does the interior of your PCV hose look like?

The one thing consistent highway speeds vs town driving is vacuum levels. Even highway speeds should equate to more and higher vacuum levels. So it could suck more oil if in fact the intake gaskets are not sealing. Have you tried re-torquing the intake bolts?

[quote]The car does belch a little smoke on warm startups. We can drive it somewhere. Sit maybe an hour or 2 and it will puff out a decent cloud of blue on restart. Then nothing. In my gut it tells me its a valve guide issue.

The above statement is a pretty strong indicator. As an Old German physicist that i work for used to say. "DO NOT allow yourself to start chasing ghosts" gather your data and analyze it.

IMO, the above pretty much identifies the issue. My guess is one of the 3.
1.I strongly suspect you have either excessive guide clearance/ bad seals.
2. Possible intake leak.
Pulling the intake will likely confirm the backsides of the intake valves are coated with burnt oil and also allow you to check the gasket seal.
or you could try snaking a camera into the intake ports for a looksee.
3. If you do not have the milodon or equivalent lower tube seals installed you should. TUBE SEALS LINK
Even if you do have the seals installed, inspect the outside of the tubes where the O ring seal sits. i have found the tubes to be of very poor quality with lateral scratches and rippled sides.
Also check the ends of the tubes on both side of where the tube seals against the head for gouging etc.

My guess is #1 good luck and keep us posted

Agree, sounds like valve guide/seal issue with that restart symptom.
I'll assume it's not fat-rich, washing the walls & screwing the ring seal.
Mine had the stock PCV setup, and it was never an issue.
Before its rebuild, it'd trail oil smoke from the tailpipes; it was tired but still strong.
It didn't have those seals TJP linked, just the regular O-ring deal on the tubes.
While oil would get onto the threads when removing spark plugs, the motor used very little oil; nothing measurable in 100 miles.
It initially (post-rebuild) had some oil usage that was through the guides (mostly showed up on spark plugs), fixed it with the Silver Seal seals I mentioned way back on this thread.

FWIW, I had a rule that every time out, at some point it would see WOT and 6500-7000 RPM, and I never lugged it.
My point being, I didn't baby it once it was warmed up (not saying that's the problem with Bill's issue).

Also, be careful with intake-bolt torque; dinky little fasteners...

car is a touch rich . Not horrible but enough you can notice it if standing behind it while idling and a strong black cloud when I nail it . But other than the odor no black smoke at idle.


OE stock PCV valve arrangement and no signs of oil inside the hose that I can see

Plus were black or REALLY dark grey ,,,,,but I didnt see any signs of deposits on them . At a qt per 100 miles I would think the plugs would have some heavy deposits on them


Engine builder did NOT do the heads,, they were farmed out to a local guy he trusted to do them right but ,,,,that man has long since retired now . And he has no idea brand of stem seal he used or clearances back then. ( engine was built back approx 2000 )


On extended idling time engine will get up over 210 degrees and I can detect blue smoke out the tail pipes more so than any other time.. This is the warmest it will ever get and is also the longest time it will be ax max vacuum . Thus one of the reasons why my gut tells me its valve guide issue.
Once running back down the road and it cools back down to running temps in the 180 range I see nothing.

I bought the car knowing full well a piston change was in my future ,,,,was planning maybe 2 or 3 years down the road ,,,aka post retirement . ( car is aprox 11.5 -1 compression )

But was not expecting it so soon from oil consumption issue . The previous owner is a very good friend of mine and I trust him to not feed me a line of BS. And he said he didnt remember ever having to add oil to it. BUT he only drove the car 850 miles in 16 years



This all said, IF I can confidently rule out a ring seal issue . Im ok with leaving the shortblock alone just have the heads redone. And install a much thicker head gasket to bring the compression back down a tad and make it much more pump gas friendly. Mixing with 110 octane gets expensive at 5-6 miles per gallon.

Ive owned it right at 6 months and have put almost 1800 miles on ,,,,,,so far and that number will continue to rise going forward


Also, I pulled the plug wires off last week for a look see inside the tubes just for grins . As someone else suggest the Milodon tube seals . and I can detect a small trace amount of oil inside the tubes . mind you not enough the plugs are submerged . But enough I can see its wet at the bottom of the tube . And IMO the only way that can happen is oil seeping in between the tubes and the head . And if its getting inside the tube it can just as easily get inside the cylinder.

If the PCV hose is "dry", then that probably isn't the problem. It's too bad the exhaust manifolds are such a PITA on a Hemi to remove, if you have excessive oil past the guides you should see it on the back of the exhaust valves. Likewise on the intakes which you should be able to see with one of those cheap boroscopes by pulling a carb. As to the spark plug tubes, I'm no expert but my buds that run 2nd Gen Hemis say a common problem with spark plugs is that owners don't remove the gasket on the plug before installing them. The tubes are intended to be the gasket.

But what do I know.

Pull the sparkplugs and see if they are shiny or dull looking
If they are shiny it means unburnt oil probably from the valve guides and seals

Thanks gents for all the info so far. Its given me some ideas to move forward with .

I'll get a cheap bore scope ordered up this weekend .

Then Plan is pull the carbs and ck backside of intake valves . I would think it it was a valve guide issue intake is most likely as they have vacuum on them. Exhaust is on the push side

I just ordered new plug tubes from Summit ,,,,,

The plug tubes that are currently being made are pretty bad and all but useless with the milodon style seals unless one polishes out the imperfections where the milodon O-ring sits. This is best done on a lathe. I'm going to bet your issue is the guide clearance /and or seals

Deep down I agree.

I just cant get past WHY such a dramatic difference in consumption on one trip versus the other.

Im gonna change the tubes ,,with oil inside them it cant be a good thing
BUT car will hibernate come around June thru Late Aug time frame ,,,,110-115 degree temps in a black car with no A/C doesnt sound like fun.

Im thinking at that time I'll pull the valve covers back off and set up a dial indicator and see if I can get any movement on the valves. if so,,,I'll pull the heads and get them redone. If not ,,,,remove springs and replace seals

Like I said, If I can confidently rule out rings I have no issue leaving the short block alone and just install some thicker Cometic head gaskets to drop compression down a touch . Car has thin steel shim head gaskets on it now

I am comfortable with it if it uses maybe a qt every 300-500 miles with no complaints. Every 100 miles is a to much


Again many thanks to all for the feedback

Do you have a mechanical oil pressure gauge and how is pressure at various operating conditions? If this is a car you intend to keep and drive seems like getting motor done completely and to your liking maybe in order. When I did my motor, it turns out the valve guides for the head had a tap ran through instead of properly sized by previous owner. My buddy who does heads, showed me how much clearance the valves had. So he custom ordered bronze guides and installed them, with an otherwise stock valve job. I provided new valves. Generic stuff you can buy was too loose in his opinion. Once done, I did the valve and spring install under the guidance of master engine builder. Many older block have restrictors in the oil passage that many now think are not necessary/wrong. Might be worth the time and expense to do it right, especially for a car you intend to drive a lot.

As far as the tube conversation, mine are originals, but I was told it was OK to use gasket. Helps make the heat range a little hotter. You just can't torque it down to some of the high values I have seen in after market head instructions. The whole oil in the tube thing seems like a red herring to where is the oil going. You will always get some leakage into the tube when the plug is removed. But the head is sealed off when plug installed properly.

Before you pull the heads inspect your intake manifold to head fit once it is removeable. China wall gap large or small. You can't see all ports but you can see some for fit, plus gauge the gap. I imagine if it was bad, you would have drivability issues which I do not think you have.

Thanks.

No oil gauge.....just the stock idiot light.

I fully intend to keep this car and pass it on to my daughters. It gets driven quite a bit.
Not everyday...but usually 2 or 3 times a week. Even if just for the wife and I take it out for dinner. Or sunday cruise with no real destination in mind.....just out.

We are hitting a local cars and coffee Saturday morning.....then may hit a show by lunch time. So probably another 200 miles on it again this weekend.

I knew when i bought it a piston change was in its future. And that may still happen. Im just trying to get some kind of handle on oil consumption if possible


Planning to retorque the intake and replace the tubes maybe early next week once they arrive


Ps. Car runs fine btw

I just follow what the FSM calls for.

Performed this trick today . It builds pressure pretty quick. . SO Im fairly confident the intake is sealed up fine

New spark plug tubes will be here in a few days..
Regardless of what changes they make ,,,If any.
I will live with the results till maybe next year And as the piggy bank rebuilds I'll decided how deep to go into the engine in regards to just piston rings, possibility still may be a complete piston change or just have heads done

Sounds like you eliminated that possibility. That little trick sorted many issues on the old paper gasket 360 and the magnums with the plenum gaskets. Once I had a 383 Road Runner low miles that used oil. I was told no smoke but I had a friend drive while I followed. There was a haze at times but not real heavy smoke. Valve seals did not help. Back then we just did compression which was good. End result when I tore it down was the 2nd compression ring on one cylinder was in two pieces.

Yep that is what the FSM said, but a builder uses them on street build. So I asked why. Since he has built quite a few winning motors and won a world championship I figured his advice was sound.