Hardened valve seats

[Michael_]

I wanted to use lead additive (not substitute) but it seems really hard to get in my area.
Its also illegal in my area.

There is a hardened valve upgrade set available (its from indy)
https://www.moparshop.com/Online-Shop/Motoren-Teile/16219/Upgrade-gehaertete-Ventilsitze

its just about 200 usd.

How much work would that upgrade be?
Would you have to remove the cylinder heads?
If so can you do this without removing the engine?
Is there anything you should pay attention to? Especially if i want to push the engine hard from time to time.

Car is a 69 charger rt with the 440cui engine.

 

[Curiousyellow71]

Yes.. heads come off and machining required for hardened seats. Try looking for a lead substitute. Lead adds lubrication but there are other substitutes for lead that should help if you are concerned. Just googling "lead substitute " this is one of many that showed up in a search..it contains no lead. https://www.walmart.com/ip/Lead-Sub...MIlpXgwsuZ6gIVTr7ACh16-QPmEAQYAiABEgKY3_D_BwE

 

[Michael_]

Thanks for the info!
But i dont trust the substitutes all that much.

Can you remove the heads without removing the engine?

I will look again for the additive but if i cant get it i think i have to get the valve job done.

 

[Demonic]

Can you remove the heads without removing the engine?

Yes.

 

[1 Wild R/T]

Thanks for the info!
But i dont trust the substitutes all that much.

Can you remove the heads without removing the engine?

I will look again for the additive but if i cant get it i think i have to get the valve job done.

In Germany finding a shop with the machine tools to put hardened seats in a 440 might be a challenge... Cylinder head machining equipment is pretty specialized, I'm sure you can find a shop with that, but the cutter to install seats in an American V8 (exhaust valve is about 45MM) might be a problem.... If the shop buys one just for you they need to build that into their pricing.... Expect to pay an extra $120.. Now they need a cutter to finish the seats... That they may have... Or may not...

Seats, valves, guides, machine work could easily be $800-$1000, actually in Germany it could be more, I have no idea...

Anyway point is by the time your done your car will be down for a couple months, your wallet will be considerably lighter.... And depending on how you drive the regular seats might be fine.... But if you use the car hard the seats will fail...

And if you use the car hard you might be better off to add aluminum heads which will have hardened seats and will out flow your stock heads & therefore make more HP which translates into more smiles when you hit the loud pedal....

 

[steve340]

The unleaded fuel we have here does not seem to cause undue valve recession.
Have you actually experienced a problem???
The problem with installed valve seats is if the valve seats are not installed absolutely correctly they can drop out and destroy the rest of a perfectly good motor.
As Wild R/T said put your money towards new heads.

 

[Curiousyellow71]

I agree w steve340. Chrysler used some hard cast iron which does help our exhaust valves last compared 2 other brands that used soft cast iron. It could be quite sometime before you have a issue and more then likely you will just notice it down on power and a different exhaust note when a exhaust valve gets a burnt spot, and it likely will get you back home. If that happens then it's time to pull the heads and upgrade exhaust valves and seats. Put money in the heads or go aftermarket.
Keeping the engine cool will also help as well, run a cooler thermostat. Heat typically will burnt out a exhaust valve, it's why industrial engine have hardened seats and better quality valves then the passenger cars. Late 70's bb 452s heads had hardened seats from the factory and could replace the 906's if you can find them...but most old iron heads need work by now.

Recently we took apart a factory rebuilt engine that got hot causing a valve seat to fall out and brake apart and pieces got into both banks. It destroyed everything cracked the block up by the cylinder head on both banks and even bent a rod. We saved the crank and seven rods the rest was junk. But fortunately it was just a 454 chev. LOL

 

[HawkRod]

If you tow heavy loads with an engine that does not have hardened valve seats, you will mess up the seats much sooner. I'm quite sure you don't tow with your car, but the idea is you need prolonged and continuous heavy load to really speed up the damage. Otherwise, your stock, non-hardened valve seats will probably last about 30,000 miles. How long will it take before you put that many on the car?

I say drive it and don't worry about it. If they go bad, THEN fix them. Until that time, just drive and enjoy.

Hawk

 

[IQ52]

In Germany finding a shop with the machine tools to put hardened seats in a 440 might be a challenge... Cylinder head machining equipment is pretty specialized, I'm sure you can find a shop with that, but the cutter to install seats in an American V8 (exhaust valve is about 45MM) might be a problem.... If the shop buys one just for you they need to build that into their pricing.... Expect to pay an extra $120.. Now they need a cutter to finish the seats... That they may have... Or may not...

Seats, valves, guides, machine work could easily be $800-$1000, actually in Germany it could be more, I have no idea...

Anyway point is by the time your done your car will be down for a couple months, your wallet will be considerably lighter.... And depending on how you drive the regular seats might be fine.... But if you use the car hard the seats will fail...

And if you use the car hard you might be better off to add aluminum heads which will have hardened seats and will out flow your stock heads & therefore make more HP which translates into more smiles when you hit the loud pedal....

I think this is my first disagree. I'm just sitting here laughing as I've a lot more faith in the Germans being able to install hard exhaust seats than you do. They are a pretty modern country. I haven't been in Germany since 1969 but they were fairly advanced at that time. Defund aluminum cylinder heads.

Oh, and with a little time on the internet, you can find German shops that specialize in American cars.

 

[69Bee]

While it was hard to find shops in the '80s, things have grown since then. I have a Rottler Seat & Guide, and they (Rottler) sell their equipment WORLDWIDE. It is not hard to install seat rings with the proper equipment, as I do it all of the time here. While Chrysler heads do have better iron with higher nickle content, NO 906 heads had induction hardened seats. Also, one or two valve jobs will remove the induction hardening anyway. Chrysler's "seat fall out" issue with '99 to 2010 heads and shops incorrectly installing seats have really given them a bad name. Not only does new seats fix a valve recession problem, but also puts the valve back to the proper height for correct geometry and non-adjustable valve train. It is getting harder to get shorter pushrods (Ford small blocks), and requires seats or custom/adjustable pushrods.

 

[Don Frelier]

The cast iron is 50 years old and has been heat cycled. It's hard.
I've been running my 906 heads for the past 15 years with no lead additive.
No issues

 

[1 Wild R/T]

I think this is my first disagree. I'm just sitting here laughing as I've a lot more faith in the Germans being able to install hard exhaust seats than you do. They are a pretty modern country. I haven't been in Germany since 1969 but they were fairly advanced at that time. Defund aluminum cylinder heads.

Oh, and with a little time on the internet, you can find German shops that specialize in American cars.

I'm not saying you won't find folks with the skills or the major equipment... I'm saying the cutters might be an issue.... European cars tend to have smaller valves.... They use allot of four valve heads, they use allot of smaller displacement engines...

 

[RJRENTON]

The issue of hardened exhaust valve seats is problematic. Some say absolutely needed, some say only if high use, heavy load (what ever that means...racing (?) And if used, whst is the best way to proceed.
Re cut the seat, piloting with the guide to maintain concentricity, shrink fit the valve seat using....stellite (tm Haines-Stellite Corp)....or induction hardening the seat area then regrinding the seat (3 angle for increased flow) for correct contact angle the same as the valve head seat angle.

Stellite alloys composed of various amounts of cobalt, nickel, iron, aluminium, boron, carbon, chromium, manganese, molybdenum, phosphorus, sulfur, silicon, and titanium, in various proportions, most alloys containing four to six of these elements. Its property is high hardness and the ability to withstand high temps. Which of the different alloys is best depends on the intended use.
Need more info? https://www.enginebuildermag.com/2016/03/valves-and-seats/
Very informative on several variations.
BOB RENTON

 

[Michael_]

It could be quite sometime before you have a issue and more then likely you will just notice it down on power and a different exhaust
note when a exhaust valve gets a burnt spot, and it likely will get you back home.
If that happens then it's time to pull the heads and upgrade exhaust valves and seats.

I say drive it and don't worry about it. If they go bad, THEN fix them. Until that time, just drive and enjoy.

So i can simply add a lead substitute and see if it prevents failure or not?
It cant damage the whole engine if i should expierience valve failure? Even if the failure occurs while the engine is on heavy load?

And if you use the car hard you might be better off to add aluminum heads which will have hardened seats and will out flow your stock heads & therefore make more HP which translates into more smiles when you hit the loud pedal....

Sounds like a good idea compared to the hassle of finding someone to modify my current ones correctly.
Which heads would you guys recommend? The engine is 100% stock.
More power would of course always be nice.
Is there a whole kit with everything i need?

I'm quite sure you don't tow with your car, but the idea is you need prolonged and continuous heavy load to really speed up the damage.

Im not towing but i will be accelerating and driving fast from time to time.
So i do put some strain on the engine at times. Not just cruising.

Otherwise, your stock, non-hardened valve seats will probably last about 30,000 miles. How long will it take before you put that many on the car?

I guess about 5 years.

 

[Michael_]

The problem with installed valve seats is if the valve seats are not installed absolutely correctly they can drop out and destroy the rest of a perfectly good motor.

Is this also true if the stock valves fail due to unleaded fuel or snake oil substitute?

 

[Curiousyellow71]

No the hardened seat is a round ring that is pressed into a machined surface in the head. If it's not done properly the seat can drop out and the valve beats it up till in break's apart. All the new vehicles have seats installed and they rarely give trouble. Aftermarket aluminum heads also have steel seat inserts. From the factory on BB mopars the seat is just machined into the cast iron head, their is no seat to fall out. What will likely happen is the seat will get wide as it wears and burn a valve out. They started induction hardening the seats in 73 and the process got better by the last of the BB. But still, a couple valve jobs and you are through the hardening. I bet someone on here has pictures of installing a seat if your curious. I know I have a BB mopar burnt valve somewhere for a picture. Typically without hardened seats if you have trouble the engine will develop a miss. Because the exhaust valve no longer will hold compression. If you keep driving with a miss a more catastrophic failure can happen. But it will be down on power and you will likely know what's up if that day comes.

 

[Michael_]

Thanks that answers almost all my questions.

Now i basically have 3 choices:

A: Using lead additive if i can find it
B: Using lead substitute and wait until/if the failure occurs
C: Going straight to aluminum heads which would also gain some extra horses

So if i should go for aluminum heads.
Which ones should i buy? Is there a Kit with everything needed to install? (Do i need the heads and gaskets only?)
How much horsepower can i gain with aluminum heads? (Without further mods)

 

[Johnpat]

How many miles a year do you drive this car?
In my estimation unless you drive it over 2000
miles a year, it's a waste of money.
You could spend a lot of money & end up with
cracks around the valve seats from the machining
Necessary to install hardened seats.

 

[69Bee]

How many miles a year do you drive this car?
In my estimation unless you drive it over 2000
miles a year, it's a waste of money.
You could spend a lot of money & end up with
cracks around the valve seats from the machining
Necessary to install hardened seats.

It is misconceptions like this, myths, and plain old outright lies that prevent a person from fixing their heads correctly. A seat installed with a "Fixed" cutter will NEVER fall out short of severe overheating. A seat installed with adjustable tooling, with the proper interference fit (0.004"-0.005" for a cast head and 0.007"-0.010" for aluminum), will NOT fall out either, short of the aforementioned overheating issue. You will NEVER get cracks around a seat due to machining, and needing seats is NEVER decided on how many miles you drive it. As far as the money, if you call $96 ($12 per seat) and usually $3.66 per seat, for a total of $125.28 + tax (my fee), then...

I ONLY do things the correct and proper way in my shop, and my customers appreciate that and show it by the amount of work I have.

 

[1967coronet]

Call me crazy but before we spend all this guys hard earned $$ lets have him pop a valve cover and see what heads he has on it.
He says 69 charger with a 440 , he may have a set or 452s or 346s on it already. Over the years stuff like that happens.