Bad B-rad
Well-Known Member
I was looking though my collection of vintage Chilton's repair manuals, some are from my grand pa, some from my father in-law, and some I have picked up over the years.
And in one of them, printed in 1970, it's cover states: contains info for 1963 to 1970 American cars, PLUS Volkswagon.(plus Volkswagon LOL!!!!)
In the general engine spec/Tune up spec section, along with all the regular stuff,you find, like cubic inch, carb size, HP&torque spec, bore and stroke, compression ratio, normal oil psi, spark plug used, and so on.
It also has a spec for cranking compression pressure,(in PSI)
This is a spec that I have not found in any of my other 15-20+ Chilton's books.
In all of my other books it wont contain an exact PSI for any given engine.
It reads more along the lines of: min pressure of 100PSI, and look for uniform PSI numbers across the engine, with no more then 10% change from cylinder to cylinder.
With that being said, this one book, 1963-1970 Chiltons, not only will it give a you a PSI spec for any given engine, but I noticed that the Dodge PSI is higher then the Plymouth one?
Same engine, same year, same bore, and stroke, and compression ratio, but the Dodge section claims 150 psi for 1968-1970 383 or 440, and 140 psi for the 1968-1970 383-440.
What is up with that? Just a printing error?
So I will post a few of them and maybe someone with more experience can tell if they sound correct:
1968 DODGE: 383 4bbl 10 to 1 CR= 150PSI
440 4bbl 10.10 to 1 CR= 150PSI
426 Hemi 10.25 to 1CR=175 PSI
1969 FORD:302 2bbl 9.5 to 1 CR=150PSI
429 4bbl 10.50 to 1 CR=180PSI
1970 GM 250 1bbl 8.50 to 1 CR=130psi
350 4bbl 10.50 to 1 CR=160PSI
427 3X2bbl 10.25 to 1 CR= 160PSI
Do these numbers seam correct, or should it be read as: NO LESS then the given PSI for that engine?
Meaning if you test it, the number should be greater then the given PSI, and if less then, the engine has a leak/or is worn?
I found it interesting that it gave a spec for cranking psi, again as I do not recall seeing this in other Chilton books, and thought that I would look at the PSI of a 1969 440, at 10 to 1 compression ratio, and compare it to 1973 440 with 8 to 1 compression ratio. But again only this one manual, that I have, has this specific info listed.
I wanted to take this cranking psi # for a stock 1969 440 Magnum/Super Commando, and compare it to a smog 8.2 to one 440.
Then use these numbers to see what my buddies 440 has, as his engine was supposed to be rebuilt to factory 1969 specs.
I also have noticed this book, under the valve specifications has valve lift for intake and exhaust.
I found this info really cool because it let me see what camshaft was shared between what engines.
So much GREAT info in these things!!
AS a young guy, I used to enjoy looking over the model identification section, with its combo of drawings, and photographs of the car models each year.
Back when the look of cars changed from year to year!!!
And in one of them, printed in 1970, it's cover states: contains info for 1963 to 1970 American cars, PLUS Volkswagon.(plus Volkswagon LOL!!!!)
In the general engine spec/Tune up spec section, along with all the regular stuff,you find, like cubic inch, carb size, HP&torque spec, bore and stroke, compression ratio, normal oil psi, spark plug used, and so on.
It also has a spec for cranking compression pressure,(in PSI)
This is a spec that I have not found in any of my other 15-20+ Chilton's books.
In all of my other books it wont contain an exact PSI for any given engine.
It reads more along the lines of: min pressure of 100PSI, and look for uniform PSI numbers across the engine, with no more then 10% change from cylinder to cylinder.
With that being said, this one book, 1963-1970 Chiltons, not only will it give a you a PSI spec for any given engine, but I noticed that the Dodge PSI is higher then the Plymouth one?
Same engine, same year, same bore, and stroke, and compression ratio, but the Dodge section claims 150 psi for 1968-1970 383 or 440, and 140 psi for the 1968-1970 383-440.
What is up with that? Just a printing error?
So I will post a few of them and maybe someone with more experience can tell if they sound correct:
1968 DODGE: 383 4bbl 10 to 1 CR= 150PSI
440 4bbl 10.10 to 1 CR= 150PSI
426 Hemi 10.25 to 1CR=175 PSI
1969 FORD:302 2bbl 9.5 to 1 CR=150PSI
429 4bbl 10.50 to 1 CR=180PSI
1970 GM 250 1bbl 8.50 to 1 CR=130psi
350 4bbl 10.50 to 1 CR=160PSI
427 3X2bbl 10.25 to 1 CR= 160PSI
Do these numbers seam correct, or should it be read as: NO LESS then the given PSI for that engine?
Meaning if you test it, the number should be greater then the given PSI, and if less then, the engine has a leak/or is worn?
I found it interesting that it gave a spec for cranking psi, again as I do not recall seeing this in other Chilton books, and thought that I would look at the PSI of a 1969 440, at 10 to 1 compression ratio, and compare it to 1973 440 with 8 to 1 compression ratio. But again only this one manual, that I have, has this specific info listed.
I wanted to take this cranking psi # for a stock 1969 440 Magnum/Super Commando, and compare it to a smog 8.2 to one 440.
Then use these numbers to see what my buddies 440 has, as his engine was supposed to be rebuilt to factory 1969 specs.
I also have noticed this book, under the valve specifications has valve lift for intake and exhaust.
I found this info really cool because it let me see what camshaft was shared between what engines.
So much GREAT info in these things!!
AS a young guy, I used to enjoy looking over the model identification section, with its combo of drawings, and photographs of the car models each year.
Back when the look of cars changed from year to year!!!
