looking for some clarification on 455 block manufacture year.....
March 1st, 2010, 09:45 PM
#1
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looking for some clarification on 455 block manufacture year.....
this question may be best adressed by mr Padavano due to the source im referencing....(http://www.442.com/oldsfaq/ofblk.htm...965%20-%201976) but would like opinions from anyone that also has knowledge of the casting history. i have read the referenced document and checked out my engine block, due to the 396021F casting number i know i have a 455 olds. it is my understanding that of the "F" (not to be confused with the later "Fa") blocks there are two type "F" marks that designate '68-'70 and '70-'72. I am thinking my block is a
68-70 manufacture due to the "stick type F". on the rear of my 455 block, behind where the flywheel would be there is a "68 F3" cast in rather large letters.
near the bottom of the referenced document in the section "general" the large rear "F1, F2, F3, F4, etc" cast marks are adressed. it explains that the lower f-numbers mean earlier production years and better metal composition. makes sense. there is a chart in that section that states an "F3" casting is a 1973 manufactured block.
so what do i have here, a 68-70 or a 1973 engine block?
68-70 manufacture due to the "stick type F". on the rear of my 455 block, behind where the flywheel would be there is a "68 F3" cast in rather large letters.
near the bottom of the referenced document in the section "general" the large rear "F1, F2, F3, F4, etc" cast marks are adressed. it explains that the lower f-numbers mean earlier production years and better metal composition. makes sense. there is a chart in that section that states an "F3" casting is a 1973 manufactured block.
so what do i have here, a 68-70 or a 1973 engine block?
March 1st, 2010, 11:07 PM
#3
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ok, i missed that completely.... even after looking! i scraped the paint off the pad near the head surface on the front drivers side and found a number under there..... 39c111056. number is in near perfect condition, well protected by looks like 2 layers of the same paint
this would mean: olds, 1969, made at plant ?, 111056 serial#
sound right? what does the "C" indicate? couldnt find the city code for that letter
when i took this engine apart i pulled a pair of "J" heads off it. did use those smogger heads in 69 or should this motor have "C" heads on it?
this would mean: olds, 1969, made at plant ?, 111056 serial#
sound right? what does the "C" indicate? couldnt find the city code for that letter
when i took this engine apart i pulled a pair of "J" heads off it. did use those smogger heads in 69 or should this motor have "C" heads on it?
March 2nd, 2010, 12:03 AM
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so theres a possibility my J heads have been worked over before they went on this motor. what should i look for to tell if my heads are stock j's or had some performance mods done to them?
March 2nd, 2010, 09:28 AM
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The whole myth about the number after the "F" being related to nickel content is false & inconsistent.For example,I took a 69 F1 block,and a 70 F5 block,& did a rockwell hardness test,& the 70 F5 block had a higher nickel content.I have done other camparisons like this with the same and opposite results.Others have done the same.Regardless,the Olds blocks don't have any substantial amount of nickel to get excited about.
As far the the style of lettering,the earlier blocks had the stick letters,& the later ones had the fancier font,along with the Fa blocks.If you want to know the exact year of the block,look at the second digit in the VIN that is stamped on the pad,directly below the head on the #1 cylinder. That can tell you the year of the car.The blocks were normally cast about 30-45 days before the car was built,but that is just a rough figure.There were shut-downs,& other events that might have left the blocks sitting for a longer period of time.I have a number matching & documented 70 Cutlass 4-spd,that was built the end of September,but the block was cast in May.
As far the the style of lettering,the earlier blocks had the stick letters,& the later ones had the fancier font,along with the Fa blocks.If you want to know the exact year of the block,look at the second digit in the VIN that is stamped on the pad,directly below the head on the #1 cylinder. That can tell you the year of the car.The blocks were normally cast about 30-45 days before the car was built,but that is just a rough figure.There were shut-downs,& other events that might have left the blocks sitting for a longer period of time.I have a number matching & documented 70 Cutlass 4-spd,that was built the end of September,but the block was cast in May.
March 2nd, 2010, 12:37 PM
#11
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the letter in my vin derrivative is without a doubt a "C". i looked at it under a jewlers loupe and its clear as day.
as far as the nickel content in olds motors i cant say as i know ANYTHING about the subject but i do know that a rockwell test will by no means determine metalurgy or alloy content of a cast piece of metal. i regularly perform tests on lead for casting bullets and modifying the tin and linotype content of my lead. as a metal cools, particles of the different minerals in its content will sort of coagulate together and may or may not affect the hardness test as its performed on a miniscule section of the surface. many many tests over all areas of the part would have to be done and surface texture can also come into play. taking it to a smelter or a steel recycler and having it graphed would be the only way to know what it was made out of. depending on what they melted down to make each batch of blocks there may be some better than others, even in years that it was not the norm.
as far as the nickel content in olds motors i cant say as i know ANYTHING about the subject but i do know that a rockwell test will by no means determine metalurgy or alloy content of a cast piece of metal. i regularly perform tests on lead for casting bullets and modifying the tin and linotype content of my lead. as a metal cools, particles of the different minerals in its content will sort of coagulate together and may or may not affect the hardness test as its performed on a miniscule section of the surface. many many tests over all areas of the part would have to be done and surface texture can also come into play. taking it to a smelter or a steel recycler and having it graphed would be the only way to know what it was made out of. depending on what they melted down to make each batch of blocks there may be some better than others, even in years that it was not the norm.
March 2nd, 2010, 01:53 PM
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The Olds blocks still don't have that much nickel to get picky about.Any machinist that has ever done work on one will tell you that.Yes,they are other methods to study the metallurgy.
What is the 2nd digit in the VIN stamped on your block?It should start with a "3",for Oldsmobile,then the second digit is the year.
What is the 2nd digit in the VIN stamped on your block?It should start with a "3",for Oldsmobile,then the second digit is the year.
March 2nd, 2010, 02:04 PM
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my vin derrivative # is 39c111056. an olds 1969 455 built at (C?) number 111056. bored .030 over. motor had "J" heads which were incorrect for the year, an olds EGR 4bbl intake which is also incorrect for the year, crank is right- all journals turned under, melling hv oil pump and stock pan, still trying to narrow down what i have for a cam(#3984107 CFD cast between the lobes). havent gotten into the heads yet....
March 3rd, 2010, 10:53 AM
#21
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CFD = Central Foundry Division (of GM) Where the majority of GM's castings were produced.
35 Julian date code. 35th calendar day of the year. Should be 1969 in this case. Notice the screw heads on either side of the "tag" the 35 is on. This indicates how the tag was changed every day on the pattern.
35 Julian date code. 35th calendar day of the year. Should be 1969 in this case. Notice the screw heads on either side of the "tag" the 35 is on. This indicates how the tag was changed every day on the pattern.
March 3rd, 2010, 01:07 PM
#22
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This is where some of the gods will argue,& again,i have found a small amount of inconsistency in this:
Yes,the 35 is the julian date,so it was cast on Febrauary 4th. The larger number is where there is some question.Most would say that it was cast February 4th,1968,& that does make pretty good sense. The low VIN tells that the car itself was a late-68 or fall/68 car,but a 1969 model.What does the large number mean? This is MY thought,so please add your info & opinions:
The large number indicates the number of years produced.1967 was actually the 1st year they started casting 455 blocks,for the 1968 model year cars.The "2" in the picture suggests it was cast in 1968,so:
1=67
2=68
3=69
4=70
5=71
6=72
etc.
Is this theory 100% foolproof? NO. I had a complete,unmolested 69 455,with a 69 VIN,C-heads,& matching 69 TH400,& it said "4" "175" by the distributor hole.This engine,& one other engine that I had are the only one that are throwing my theory off,but most say this theory is correct. I do know that all of my 70 cars that were built in the fall of 69,have a "3",and all of my 70's that were built in the spring of 70,have a "4".
Thoughts anyone?
Yes,the 35 is the julian date,so it was cast on Febrauary 4th. The larger number is where there is some question.Most would say that it was cast February 4th,1968,& that does make pretty good sense. The low VIN tells that the car itself was a late-68 or fall/68 car,but a 1969 model.What does the large number mean? This is MY thought,so please add your info & opinions:
The large number indicates the number of years produced.1967 was actually the 1st year they started casting 455 blocks,for the 1968 model year cars.The "2" in the picture suggests it was cast in 1968,so:
1=67
2=68
3=69
4=70
5=71
6=72
etc.
Is this theory 100% foolproof? NO. I had a complete,unmolested 69 455,with a 69 VIN,C-heads,& matching 69 TH400,& it said "4" "175" by the distributor hole.This engine,& one other engine that I had are the only one that are throwing my theory off,but most say this theory is correct. I do know that all of my 70 cars that were built in the fall of 69,have a "3",and all of my 70's that were built in the spring of 70,have a "4".
Thoughts anyone?
March 6th, 2010, 05:15 PM
#24
Texas Jim
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This is where some of the gods will argue,& again,i have found a small amount of inconsistency in this:
Yes,the 35 is the julian date,so it was cast on Febrauary 4th. The larger number is where there is some question.Most would say that it was cast February 4th,1968,& that does make pretty good sense. The low VIN tells that the car itself was a late-68 or fall/68 car,but a 1969 model.What does the large number mean? This is MY thought,so please add your info & opinions:
The large number indicates the number of years produced.1967 was actually the 1st year they started casting 455 blocks,for the 1968 model year cars.The "2" in the picture suggests it was cast in 1968,so:
1=67
2=68
3=69
4=70
5=71
6=72
etc.
Is this theory 100% foolproof? NO. I had a complete,unmolested 69 455,with a 69 VIN,C-heads,& matching 69 TH400,& it said "4" "175" by the distributor hole.This engine,& one other engine that I had are the only one that are throwing my theory off,but most say this theory is correct. I do know that all of my 70 cars that were built in the fall of 69,have a "3",and all of my 70's that were built in the spring of 70,have a "4".
Thoughts anyone?
Yes,the 35 is the julian date,so it was cast on Febrauary 4th. The larger number is where there is some question.Most would say that it was cast February 4th,1968,& that does make pretty good sense. The low VIN tells that the car itself was a late-68 or fall/68 car,but a 1969 model.What does the large number mean? This is MY thought,so please add your info & opinions:
The large number indicates the number of years produced.1967 was actually the 1st year they started casting 455 blocks,for the 1968 model year cars.The "2" in the picture suggests it was cast in 1968,so:
1=67
2=68
3=69
4=70
5=71
6=72
etc.
Is this theory 100% foolproof? NO. I had a complete,unmolested 69 455,with a 69 VIN,C-heads,& matching 69 TH400,& it said "4" "175" by the distributor hole.This engine,& one other engine that I had are the only one that are throwing my theory off,but most say this theory is correct. I do know that all of my 70 cars that were built in the fall of 69,have a "3",and all of my 70's that were built in the spring of 70,have a "4".
Thoughts anyone?
507OLDS,
My block is a '71 and next to the distributor hole is a "5" and under it is an "82." So this goes along w/ your theory; 5=1971.
Please explain these other numbers to me: On the back of the block, under the flywheel is: F4 68
On the little pad on the driverside of the block is: 31m477453.
I posted many times that the engine came out of a '71 Olds 98. The car had 94,000 miles on it when I pulled the engine. I thought it had never been apart, until, my assuming had me snowed, and one of the guys on the site spotted the Fel-Pro gasket markings on the head when I posted a pic of it. So we knew that the heads had been off the car. Now today I looked at the pistons closely, w/ my glasses on, and there's no markings of over-size (boring), but someone stamped "B" on some pistons along w/ the "B" stamped on the block, above the bolt hole to the right of the cylinder and other pistons had a "C" stamped on them and the "C" stamped on the block, again, to the right of the cylinder over the bolt hole, w/ no pattern or sequence to the Bs and Cs. Now I'm wondering if the engine had been taken down at some time f/ whatever reason by a machine shop or the dealer-way after the warranty, and put back together w/ the standard bore. Does the "B" and "C" denote anything specific in a machine shop/dealer rebuild? I also noticed that there's over-spray on the flywheel and on the starter nose cone (Olds blue engine paint). I'll post more when I pull the oil pan. Maybe there's more evidence in there. It's clean as can be inside and it ran great in the big 98, no smoke/oil burning, and had plenty of pep.
Any help would be appreciated. Thanks in advance.
March 7th, 2010, 10:39 PM
#25
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The B and C you saw were factory bore size markings. They match the slight mismatch bore with pistons sized to them. That's why you see the B on both the block and pistons.
I'll have top grab my service manual and find that page and scan it for you.
I'll have top grab my service manual and find that page and scan it for you.
March 8th, 2010, 03:47 AM
#26
Texas Jim
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Location: Killeen, Texas
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March 8th, 2010, 07:30 AM
#27
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Yes,it appears your block was cast the 82nd day of 1971,and judging by the VIN number stamped on it,the car was built in the spring or early summer,so that all makes sense.
So far the 68 and the F4 don't seem to mean anything substantial.Just about every block I have ever had,came with the 68and an F-number on it,but I have one block that does not have the 68 on it.I also have one block with a 68 ,but no F or F-number.I have yet another block that has 68 and F,but no F-number.
So far the 68 and the F4 don't seem to mean anything substantial.Just about every block I have ever had,came with the 68and an F-number on it,but I have one block that does not have the 68 on it.I also have one block with a 68 ,but no F or F-number.I have yet another block that has 68 and F,but no F-number.
May 16th, 2013, 07:05 AM
#28
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This is where some of the gods will argue,& again,i have found a small amount of inconsistency in this:
Yes,the 35 is the julian date,so it was cast on Febrauary 4th. The larger number is where there is some question.Most would say that it was cast February 4th,1968,& that does make pretty good sense. The low VIN tells that the car itself was a late-68 or fall/68 car,but a 1969 model.What does the large number mean? This is MY thought,so please add your info & opinions:
The large number indicates the number of years produced.1967 was actually the 1st year they started casting 455 blocks,for the 1968 model year cars.The "2" in the picture suggests it was cast in 1968,so:
1=67
2=68
3=69
4=70
5=71
6=72
etc.
Is this theory 100% foolproof? NO. I had a complete,unmolested 69 455,with a 69 VIN,C-heads,& matching 69 TH400,& it said "4" "175" by the distributor hole.This engine,& one other engine that I had are the only one that are throwing my theory off,but most say this theory is correct. I do know that all of my 70 cars that were built in the fall of 69,have a "3",and all of my 70's that were built in the spring of 70,have a "4".
Thoughts anyone?
Yes,the 35 is the julian date,so it was cast on Febrauary 4th. The larger number is where there is some question.Most would say that it was cast February 4th,1968,& that does make pretty good sense. The low VIN tells that the car itself was a late-68 or fall/68 car,but a 1969 model.What does the large number mean? This is MY thought,so please add your info & opinions:
The large number indicates the number of years produced.1967 was actually the 1st year they started casting 455 blocks,for the 1968 model year cars.The "2" in the picture suggests it was cast in 1968,so:
1=67
2=68
3=69
4=70
5=71
6=72
etc.
Is this theory 100% foolproof? NO. I had a complete,unmolested 69 455,with a 69 VIN,C-heads,& matching 69 TH400,& it said "4" "175" by the distributor hole.This engine,& one other engine that I had are the only one that are throwing my theory off,but most say this theory is correct. I do know that all of my 70 cars that were built in the fall of 69,have a "3",and all of my 70's that were built in the spring of 70,have a "4".
Thoughts anyone?
My question is when did the F on front of blocks add the serif?
Regards, Steve
Yo
May 16th, 2013, 07:37 AM
#29
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Posts: 4,112
Hi Brian, this numbering scheme works for two 455 blocks I have: an early '69 big car: 2 & 309 (F sans serif), 68F3 on back, looks like a late '68 casting; and a '70 big car 4 & 29 (F w/serif), 68F4 on back, early '70 casting.
My question is when did the F on front of blocks add the serif?
Regards, Steve
Yo
My question is when did the F on front of blocks add the serif?
Regards, Steve
Yo
May 16th, 2013, 08:02 AM
#30
Old(s) Fart
Join Date: Mar 2007
Location: Northern VA
Posts: 47,255
Regarding the single digit number, we have since been able to determine (positively sure) that the single digit number by the distributor is a "mold number". It identifies the foundry pattern number to identify what pattern was used to cast the block. Thus it has nothing directly to do with the date.
Awesome factory documentation, as usual. Thanks.
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