Pump gas 440 advice

[Dusty997]

With a 516 or 915 closed chamber head, quench is possible.
With a stock 69 906, with its completely open chamber, the is NO QUENCH, NONE, unless aftermarket quench reverse dome pistons are installed (or the heads milled about .125!)
I believe the o.p. is anticipating problems. He might not have any. It kinda depends on the quality of fuel available in his area. If he had to run California Cat cat piss 15% he might have problems. 93 available where he is? Probably not a problem.

Your correct. Just trying to stay ahead of any potential issues based on stuff ive read. I might be swapping to aluminum heads too. Not totally sure yet. Taking all winter to do my research before i touch anything.

 

[BSB67]

I'm picking up a bone stock all original 1969 Chrysler 440 motor tomorrow that is advertised as a 10:1 compression.

Curious as to how you know this? It’s 56 years old.

 

[Dusty997]

Curious as to how you know this? It’s 5original own

Curious as to how you know this? It’s 56 years old.

got it from the original owner, came out of a 55,000 miles car.

 

[BSB67]

got it from the original owner, came out of a 55,000 miles car.

So he’s 80, and the motor probably sat for 40 years, assuming he drove it 3,500 mi/yr for 17 years. Wonder how it was stored. Anything is possible.

 

[69conv]

If u do the aluminum heads you will also solve the leaded gas problem. Back in the day we had leaded gas, today no lead means the exhaust valves run hotter and will recede into the head or even burn. Later engines used hardened valves to solve this problem, and modern aluminum heads do also. I did stealth heads from 440 source and am very happy with them. store.440source.com

 

[Dusty997]

If u do the aluminum heads you will also solve the leaded gas problem. Back in the day we had leaded gas, today no lead means the exhaust valves run hotter and will recede into the head or even burn. Later engines used hardened valves to solve this problem, and modern aluminum heads do also. I did stealth heads from 440 source and am very happy with them. store.440source.com

those are the heads i was looking at

 

[69conv]

They used to have cheesy locks but they upgraded. My 400 dyno with those heads.

 

[Jerry Hall]

the stock piston is about .051 in the hole plus .020 steel head gasket = .071. adding a .039 head gasket plus .051=.090 in the hole. does it really matter for quench if it's .071 or .090 ? I am thinking if it's more than .055 in the hole does .071 or .090 really matter ? what I heard more than .055 hole it does not matter there is no quench.

Stock 67 383 not bored.

 

[gtxrt]

Stock 67 383 not bored.

View attachment 1948402

yes my 67 383 was 75-80 that I measured fast with feeler gauges. what does that have to do with my quote on a 1969 440 deck height ?

 

[ynst]

premium gas
Lucas ethanol additive
hardened exhaust valve seats (on any pre-'72 vintage cylinder heads)

I've always run premium since I bought the GTX in '68.
I put the hardened seats in when unleaded gas was mandated and the ethanol treatment when the fuel lines and fuel pump diaphragm started to deteriorate.

 

[Jerry Hall]

yes my 67 383 was 75-80 that I measured fast with feeler gauges. what does that have to do with my quote on a 1969 440 deck height ?

I'm really just saying that compression ratios were not as advertised in the service manual, but we're much closer than some of the figures I have read in this thread. I'm not trying to call anyone out. I know from past experience that supposedly exact cars don't always perform the same.

 

[gtxrt]

I'm really just saying that compression ratios were not as advertised in the service manual, but we're much closer than some of the figures I have read in this thread. I'm not trying to call anyone out. I know from past experience that supposedly exact cars don't always perform the same.

in 1967 the pin height was 1.99 and in 1968 on the piston pin height was 2.030 to make up for the 906 open chamber heads with more cc's. so yes 80-85 in 67 and 50-55 in 1969 in the hole. yes your right never what the factory said they were.

 

[BSB67]

67 was actually 2.00”. Maybe 1971 was 1.99” for which the popular replacement piston was fashioned.

 

[thegarage]

I'm picking up a bone stock all original 1969 Chrysler 440 motor tomorrow that is advertised as a 10:1 compression.

My plans are to run it in my duster on the street and id like to get it as pump gas friendly as possible without having to change pistons. Ive heard that certain camshaft profiles can lower dynamic compression, but im also not sure what compression translates to needing what type of fuel ext, ive always run stock 360 magnums that are 9:1

Open to all tips and suggestions, this will be my first big block ever.

Sunoco Ultra 94 works! It does the job for my 0.60 over 383 with Ross 10.00-1 pistons with (proper) full advance timing. No pinging or knocking, and it's what a lot of the auto manufacturers recommend today, such as BMW, Porsche, Lexus, Volvo and many more. Premium fuel will be here indefinitely and at least Sunoco continues to offer 94 octane which will do you just fine.

 

[Dusty997]

So its sounding like i should be just fine on pump 93 running some stealth heads and a higher duration cam that will bleed off some cylinder pressure

 

[BSB67]

…my 0.60 over 383 with Ross 10.00-1 pistons with (proper) full advance timing. No pinging or knocking, and it's what a lot……..

Very interested in this 10:1 Ross piston for a 383. Is that a standard stroke? What cylinder heads? What’s the part number?

Thanks