Hardened valve seats

[Windsor]

I have searched on here and on google to try to find a picture showing the difference. What I am trying to figure out is if my 906's have had hardened seats installed.. Does anyone have a picture or two showing the difference between hardened seats installed and stock 906's? Or even just a picture of a stock 906 (preferably with valves in but a clean combustion chamber). I am trying to figure out if I will have to put some in (valves are not recessed), or if it has already been done and I can spend my money on something else to get the car (1940 Chrysler) driving again. Just dropped $1500 on parts for the car to get it back on the road, and all I have left to order is radiator, drive shaft, and brake master cylinder.

[cudaken]

While I do not have any pictures, I all so never had to add harden seats either. 

Last motor I had to retire had 98,000 miles on it with stock seats and it whole life was on unleaded gas.

Cuda Ken

[Pete in NH]

Back when leaded gas went away my 71 383 had real problems very quickly. After several 6 hour, 300 mile trips at highway speeds, I had three burned exhaust valves. They really did count on the lead to cool and lubricate those valve seats. The earlier leaded gas heads only had induction hardened valve seats which gives you a very thin hardened surface that failed very quickly. The solution at the time was put on a set of later heads from the last of the B blocks in 78-79. These heads had stellite hardened seats from the factory. I was able to find a set of NOS head castings and build them up with Mopar Direct Connection parts in the early 80's. Those heads are still on the car and doing just fine.

[b5blue]

Hardened seats look like steel rings inset at the heads valve seat. You would clearly see the ring if you had it. I have 346 heads that are induction hardened, my heads are good to go as they were very original condition when installed. (Stored for many many years with very little use.)   

[Windsor]

You say it would look like a steel ring inset into the head. So a plain unaltered set of 906's wouldn't have what looks like a dropped machined surface that makes a circle around each valve? I know it's a stupid question, but often that's the bet way to learn.
The "machined" section is slightly lower than the head surface and on both valves. There is an identifiable ridge that is seen all the way around each valve except where the two meet.

[b5blue]

Got a pic? 

[Sublime/Sixpack]

FWIW In the past when I had head/valve work done on big block heads I had the machinist install hardened seats for the exhaust valves, but on the last pair of heads (915's) I had done, the machinist (different shop) said you really don't need hardened seats on these Mopar heads because of their high nickel content , and because you chose to go with stainless steel valves, and your valve springs aren't all that stiff.
This guy is pretty sharp, so I passed on having the hardened seats installed. I haven't used these heads yet but I hope they work out okay.

[cdr]

i would not waist my money on stock heads,you can buy some stealth heads for just a little more than it cost to fix those old stock heads.

[Windsor]

Went up to look at the heads today. There is 1 valve that has a hardened seat already installed, but the rest need it done. Talked to the owner of another machine shop, he said $120 max for all exhaust seats installed. If there wasn't more to be done to get the car back up and running, I would go with new heads. However, a driveshaft and new radiator will take up the extra $.

[Supercharged Riot]

If you look at my build thread.
I got plenty of close up pictures of my 906 heads
I have a set of pictures with only my stock intake seats and press fitted hardened exhaust seats
I eventually got the all done
Here's a sample
There you'll see the difference with them next to each other.
Hardened seats are the light silver ring seats.
If you're concerned about the valve sitting too deep, you need to grind the seats down until the get the proper valve stem height
You basically need to do a complete valve job after pressing the seats in
Hope this helps




My thread here...
http://www.dodgecharger.com/forum/index.php/topic,62064.msg1125796.html#msg1125796

[Windsor]

Thanks Supercharged Riot. That's exactly what I needed to see. I am going to have new seats installed next week.

[b5blue]

We want PICS!!! 

[Windsor]

We want PICS!!! 

I'll get pics when I start putting it back together. Right now the front clip is off the car. I have the engine oiled and wrapped since its been real foggy lately and it doesn't seem to burn off until around 3pm. Heads should be out of one shop on Monday and into the other right after that.

[Challenger340]

Personally, I just never bother with putting hard exhaust seats in ?
A little bit of 2 stroke Oil per tank of Gas lubricates the Seats same as the old Leaded Fuel used to ? about 200ml per 10 gallons... and NO it won't smoke like a 2 stroke !

The ONLY reason I can find to install hard seats.....
is IF the original seats are already sunk to China, and it HAS TO have them for a restoration ?
and even if they are...
far easier to just enlarge the sunk seat for a larger Valve ? ... so still makes seats redundant ?

[cudaken]

Personally, I just never bother with putting hard exhaust seats in ?
A little bit of 2 stroke Oil per tank of Gas lubricates the Seats same as the old Leaded Fuel used to ? about 200ml per 10 gallons... and NO it won't smoke like a 2 stroke !

The ONLY reason I can find to install hard seats.....
is IF the original seats are already sunk to China, and it HAS TO have them for a restoration ?
and even if they are...
far easier to just enlarge the sunk seat for a larger Valve ? ... so still makes seats redundant ?

 

[A383Wing]

Personally, I just never bother with putting hard exhaust seats in ?
A little bit of 2 stroke Oil per tank of Gas lubricates the Seats same as the old Leaded Fuel used to ? about 200ml per 10 gallons... and NO it won't smoke like a 2 stroke !

The ONLY reason I can find to install hard seats.....
is IF the original seats are already sunk to China, and it HAS TO have them for a restoration ?
and even if they are...
far easier to just enlarge the sunk seat for a larger Valve ? ... so still makes seats redundant ?

 

  me too....I have never had to put them in any of my cars

[BSB67]

Personally, I just never bother with putting hard exhaust seats in ?
A little bit of 2 stroke Oil per tank of Gas lubricates the Seats same as the old Leaded Fuel used to ? about 200ml per 10 gallons... and NO it won't smoke like a 2 stroke !

The ONLY reason I can find to install hard seats.....
is IF the original seats are already sunk to China, and it HAS TO have them for a restoration ?
and even if they are...
far easier to just enlarge the sunk seat for a larger Valve ? ... so still makes seats redundant ?

 

  me too....I have never had to put them in any of my cars

Competition valve grind, new valves, new guides, mild .455" lift cam (120lb seat, 320lb over the nose). After about 5000 miles, the exhaust seats were pretty bad.

[Windsor]

I have seen a lot of people saying do it, and a lot saying I don't need to. Really, I am looking at it as insurance. Kind of like replacing my heavy duty 74 year old radiator with a custom made aluminum one. I'd rather spend the money now instead of having to rip it apart again to do it later. I am buiilding the car to drive, it isn't a show car and definitely not numbers matching. So I figure that driving it every day that has decent weather would cause more wear if I don't do it. One day, maybe I'll get new heads.

[Supercharged Riot]

I personally think if you plan on driving it on a regular basis, you might as well bring the heads up to par with modern cylinder heads  (which have hardend seats as well).
The only other alternative is to buy aluminum heads.

THe only reason why I chose to put that much work on my heads was to see how far and efficient I can make a set of iron heads (with a moderate consideration of costs)


Good luck with your project!

[b5blue]

I have seen a lot of people saying do it, and a lot saying I don't need to. Really, I am looking at it as insurance. Kind of like replacing my heavy duty 74 year old radiator with a custom made aluminum one. I'd rather spend the money now instead of having to rip it apart again to do it later. I am building the car to drive, it isn't a show car and definitely not numbers matching. So I figure that driving it every day that has decent weather would cause more wear if I don't do it. One day, maybe I'll get new heads.

A daily driver has to factor durability. Multiple daily cold starts with start, stop, long idle in traffic cycles are stressful to parts a weekend user never get the full treatment of. Just like Viton valve seals, I found reference that they could starve lubrication so I went with out them. All these factors were discussed with my engine rebuild mechanic. I wanted forged pistons but they must sit looser in the bore to allow for expansion, my daily drive to work is 2 miles so Hypers were a better pick given my use. My builder has a long history with Mopar builds and is a racer also so he understood what/how the engine was to be used.
  At the point you are in your build it only makes good sense to do the exhaust seats, big blocks like the seat high in the hole for flow anyway. Be certain to degree the cam exactly before install gets too far along and be very through with valve train geometry. Get an adjustable checking pushrod now so you can find the correct length push rod for proper lifter pre load. It would be a good time to go through cylinder volume measurements to nail down exact compression ratio also. All of this greatly helps when later your tuning ignition and carburetor. You'll want the vacuum advance run off manifold not carb and knowing all the data you find now helps with initial, vacuum and total mechanical advance along with figuring power valve, accelerator pump and jetting the carburetor.
  Sounds like a pain in the butt but it's actually not that costly in time or money and priceless later!          

[Windsor]

If I can get my Thompson sold, maybe I'll buy new heads. If not, then I wont. There is a set of 452 heads in Tacoma, WA for $50 but it would cost me another $120 for the trip. 
Radiator is being built, waiting for my new slip yoke to get here so I can go ahead and get a driveshaft made. Hoping the weather clears up a bit, have to drill out a bolt that was broke off in my pinion yoke when I got the rear end.

[b5blue]

120.00 for valve seats isn't bad and you'll have a great set of iron heads. 

[cudaken]

If I can get my Thompson sold, maybe I'll buy new heads. If not, then I wont. There is a set of 452 heads in Tacoma, WA for $50 but it would cost me another $120 for the trip. 
Radiator is being built, waiting for my new slip yoke to get here so I can go ahead and get a driveshaft made. Hoping the weather clears up a bit, have to drill out a bolt that was broke off in my pinion yoke when I got the rear end.

Thompson Machine Gun? 

If you need to replaces the seats, better save than sorry. But like I said, last motor I wore out was a daily driver. I put 98,000 on it in 4 years.

Cuda Ken

[squeakfinder]

We want PICS!!!  

I'll get pics when I start putting it back together. Right now the front clip is off the car. I have the engine oiled and wrapped since its been real foggy lately and it doesn't seem to burn off until around 3pm. Heads should be out of one shop on Monday and into the other right after that.

When you said fog, I knew you had to live in Oregon   At least with your 906 heads and $120 worth of seats you'll know what you have. And won't spend any more time and money shopping for another set that might have questionable quality.

[Windsor]

Thompson Machine Gun?  

If you need to replaces the seats, better save than sorry. But like I said, last motor I wore out was a daily driver. I put 98,000 on it in 4 years.

Cuda Ken

Not a true SMG but a 101st Airborne Task Force Attack commemorative. #50 of 101

[Challenger340]

Personally, I just never bother with putting hard exhaust seats in ?
A little bit of 2 stroke Oil per tank of Gas lubricates the Seats same as the old Leaded Fuel used to ? about 200ml per 10 gallons... and NO it won't smoke like a 2 stroke !

The ONLY reason I can find to install hard seats.....
is IF the original seats are already sunk to China, and it HAS TO have them for a restoration ?
and even if they are...
far easier to just enlarge the sunk seat for a larger Valve ? ... so still makes seats redundant ?

 

 me too....I have never had to put them in any of my cars

Competition valve grind, new valves, new guides, mild .455" lift cam (120lb seat, 320lb over the nose). After about 5000 miles, the exhaust seats were pretty bad.

Were you adding about 200ml of 2 Stroke Oil per Tank of Gas to lubricate the Seats ? or just running the dry unleaded fuel straight out of the pump ?
Just wondering, any idea how high your EGT's were running ?

[BSB67]

Personally, I just never bother with putting hard exhaust seats in ?
A little bit of 2 stroke Oil per tank of Gas lubricates the Seats same as the old Leaded Fuel used to ? about 200ml per 10 gallons... and NO it won't smoke like a 2 stroke !

The ONLY reason I can find to install hard seats.....
is IF the original seats are already sunk to China, and it HAS TO have them for a restoration ?
and even if they are...
far easier to just enlarge the sunk seat for a larger Valve ? ... so still makes seats redundant ?

 

 me too....I have never had to put them in any of my cars

Competition valve grind, new valves, new guides, mild .455" lift cam (120lb seat, 320lb over the nose). After about 5000 miles, the exhaust seats were pretty bad.

Were you adding about 200ml of 2 Stroke Oil per Tank of Gas to lubricate the Seats ? or just running the dry unleaded fuel straight out of the pump ?
Just wondering, any idea how high your EGT's were running ?

No oil.  No measured EGTs.  EGTs low enough to keep the paint on the exhaust manifolds.