hardened seats after 72?

[Omie01]

I just read last night that most car manufacturers switched to hardened seats in their heads around 1972. Does this mean my late 1973 heads have hardened seats so I can run regular Premium Unleaded gas? I did have stainless Ferrea valves put in my heads. Any insight? Thanks!!

 

[mrmach1]

Good question. I'm not sure but I think the answer is yes. Now that said I'm sure somebody will tell you otherwise. I'm usually wrong just ask my wife.

 

[RacerX]

As I recall, the hardened seats weren't installed until 1975 when they switched to unleaded at the pumps. Your machine shop might have put hardened seats in your heads when they did the valve machining. Check your invoice perhaps?

 

[Don C]

I wouldn't count on it. The only way to know for sure is if the engine was used on a vehicle that had a catalytic converter, which required unleaded gas.

To add to the confusion, valve seats received a flame hardening treatment for many years prior to unleaded gas. However, these seats were not hard enough for unleaded, and induction hardening of the seats was started for engines that were required to use unleaded. Some truck engines apparently didn't start getting them until the late '70s or early '80s.

 

[timachone]

+1

I do not count on it and always fill in some additive every refueling...

Some say so, other so - nothing really reliable.

Tim

 

[72HCODE]

my understanding after talking to builders and other people in clubs:

it isn't much of an issue unless you tow heavy loads or put A lot of mileage on the car each year.

i don't use additive in my car,, lead additive is known as a 'rob peter to pay paul' type of deal.

basically the lead gives the valve seats protection but it wears out the bottom end of the engine(bushings).

my feeling is it is easy to take the heads off and have them machined verse pulling the engine.

I've put about 30,000 miles on my car in 10 years which is like 2000-3000 miles a year average for summer use and put away when it gets rainy and cold and didn't have an issue. i've known original owners of early mustangs and our years that stopped using lead additive in the 1980s or 1990s and are still going on original engines without issue.

on the other side of the spectrum are early camaro owners whom have to pour additive into the tanks to keep the engine going as the valve seat design on the chevy engines is really soft and a known problem.

i asked my engine builder about hardened seats and he said they were not worth the trouble unless i planed to drag race the car all the time.

so really you can go either way with the additive, if the previous owner put the lead additive in then you can feel obligated to keep doing it.

me i just fill up and go when my transmission was working lol...

 

[timachone]

+1

good way of looking at things ::thumb::

I like 'rob peter to pay paul type of deal'

But that lets me sleeping calmer - it is only a psychological deal

 

[Carolina_Mountain_Mustangs]

I have a 1956 ford that the original owner only use Amoco white gas in. That was their term for unleaded and dates way back into the 50's or beyond you could use it in your Coleman camp stove since there was no lead. The car never had a valve issue and it had over 90,000 miles on it. Yes the seats were induction hardened on some cars to make them a little tougher. The only way to get a true hard seat in and iron head it to insert the seat. The old flathead fords engines used stellite inserts in I think all of them. The valves might have also been stellite. This link tells the history of the material.

http://en.wikipedia.org/wiki/Stellite

My opinion is I don't think I would worry about wearing them out most of our cars are not driven that much. If it keeps you awake at night have them inserted.

David

 

[Don C]

I had a '64 F100 that I put a '70 390 and C6 into. It ran well for 15 years, or so, and started running rough. All of the exhaust valves were recessed, a couple of them enough so the valves didn't seat. It was just driven occasionally.

I put the 292 Y block from the F100 into a 1955 Willys Wagon 4X4 and it was my daily driver for 25 years, plus many off road excursions into the mountains. Never had a problem with it.

 

[Omie01]

Thanks for the replies gents. I have a gas station near me that sells 110 octane leaded fuel. My engine builder told me to run 2 gallons of that with the rest of the tank with unleaded premium, but the stuff costs $8 a gallon. Was just wondering if there was a way around it. Maybe I will run a couple gallons every couple of tanks to be safe. Again, Thanks!!

 

[mustang7173]

Omie01

Plus 1 also. Definitely get the harden seats! It will protect the heads and valves. I have a oil company right down the road that have premium unleaded with NO, that is right No ethanol. It is not cheap, I use it in my 1971 Mustang, lawn mower and other small lawn equipment.

Apple Apps Store has this App called Pure Gas. Here is the website: http://pure-gas.org/

Are you sure the 110 octane is leaded fuel? Please correct me If I am wrong, I thought they, The Government and EPA, completely phased out leaded fuels.

mustang7173

 

[barnett468]

my understanding after talking to builders and other people in clubs:

it isn't much of an issue unless you tow heavy loads or put A lot of mileage on the car...

this is correct, however, non hardened seats will last longer if around 1 oz of transmission fluid is added to a tank of gas . . this reduces the chance of "micro welding" that can be caused by tier 1 gasolines.

my friend put 150,000 miles on a 289 in a fully loaded wagon with original 66 heads with stock orig valve seats using unleaded gas.

 

[JimNiki]

Good question. I'm not sure but I think the answer is yes. Now that said I'm sure somebody will tell you otherwise. I'm usually wrong just ask my wife.

Same here matey. I sold my set of encyclopaedia Britannica because the bloody wife knows everything!

 

[barnett468]

.

the problem with hardened seats is that you need to find a good shop to do them because they will fall out if improperly installed . . i have seen it a few times.

 

[Carolina_Mountain_Mustangs]

Do you need the high octane for compression reasons, spark knock?? I worked in the lawn equipment business for several years and during that time me an my son raced go carts. We ran testing on engines every day and never stopped. In the air cooled engines on lawn equipment running higher octane fuels reduced the life of the engine significantly like 50%. It burnt with higher heat and the air cooling could not handle it. When racing we used alcohol and you poured about twice as much through the engine as gasoline and you had to tape up the air intake to get the engine to optimum temp.

If you are not spark knocking you are not slamming the valves into the seat and you should not have an issue.

I am not expert but you have to do what makes you feel good about the engine.

David

 

[4Vforever]

Ok, personally seen many, many Cleveland heads over the years and all open chambered heads except for very early ones are inserted on the exhaust seat. I don't know when exactly they started doing this over there in the U.S. but have seen early 70's castings (maybe 71 or 72, too long ago now) onwards with inserts on the exhaust seat and have seen them without them on very early castings of the 2V. All 4V open chambered heads I've seen over the years have the exhaust seats inserted. Here in Australia all open chambered heads were inserted on the exhaust seat as they copied the U.S. design exactly at the time of doing our own casting, but all closed chambered heads here do not have an insert on the exhaust seat. Also here in Australia, they never made a proper 4V cylinder head, our 4V engines here were only 2V headed engines with 4 barrel carb and intake manifold and no 351 engine here came with 2V closed chamber heads.

 

[barnett468]

.

us cleveland heads never had seats in them from the factory . . the hard seats on the 74 and later engines were just stock seats that were induction hardened.

 

[4Vforever]

.

us cleveland heads never had seats in them from the factory . . the hard seats on the 74 and later engines were just stock seats that were induction hardened.

From personal experience, every open chambered 4V head I've ever done has had inserts under the exhaust seats, the first time I came across the small valved 73 on 4V heads, I wasn't sure about machining the exhaust insert out to 4V valve size, but that was no problem. Anyway I use to strip down complete virgin engines (both 2V and 4V) that were imported from the U.S. (Part of my job as a young apprentice, lol) and that's how I came to the conclusion about roughly the times that the heads were inserted. I never ever came across any other engine that came with inserts and all other engines no matter what make from around that period were induction hardened on the exhaust seats. I'm more than happy to be proven wrong, just know what I've seen and done over many years and what I read about on Cleveland engines over many years, both US and Australian varieties.

 

[mweeps]

I found a fuel insert in the glove box of the 73 Mach 1 I had in high school that said 93 octane unleaded fuel minimum to be used in car. 351 2v H code Cleveland.