The Stovebolt Site Forums The Shop Area Engine Shop Need help identifying engine. 1952 3100.

I posted some pics of my truck in the welcome section and learned that the motor is from a later model chevy. Took a few more pics of numbers in the block that will be on this thread. I’m a total newbie here, so any help identifying the engine is appreciated.

I think that's a 250 cubic inch engine.

I hope you are right. I looked on youtube and it sure looks to be. Seem to have been good motors.

230 and 250 engines run the same block casting and cylinder head. The difference is the crankshaft stroke. Both have a 3 7/8" bore, same as a 283 V8. Pull a spark plug and stick a borescope into the cylinder. 230s have flat top pistons- - - -250s have a D-shaped recess in the piston crown about 1/4" deep. Pistons for a Chevy 307 V8 are a drop-in swap to raise the compression ratio of a 250 six.
Jerry

Bill - Preliminary research indicates the block casting# 3994257 is probably a 1967-72 Chevy 250.

In your 3rd picture, the date casting code is partially obscured by the dip stick tube. There should be a first character "letter" (currently hidden behind the dipstick tube) followed by a space and one or two numbers, then a space and another single digit number. I can see a "7", space and a "2" to the right of the tube and those should indicate the day of the month and year cast. The first letter indicates the month of the year cast (ie: A=January, B=February, etc). From what we can see the block was cast on the 7th day of the yet unknown month, in 1972.

For the best/most accurate information on what the engine is and what it was installed in originally, we need to see the stamped serial number which can be found on a machined surface pad just to the rear of where the distributor goes into the block. If you can clean that up and add a picture, we can help decode the stamping.

This is the best I could do on the numbers.

Bill - It took some fairly deep diving through various GM resources to decode your stampings on the block. Primarily because in 1972 and similar years the Chevrolet in line 6 cylinder was the GM Corporate engine for various GM lines including Chevrolet, GMC, and Pontiac.

If I've done my work correctly your first line on the block "F0142Y6" decodes as:

F = Flint engine assembly plant
01 = January (assembly month)
4 = 4th day of the assembly month
2 = 1972 model year
Y6 = Pontiac 250 w/1 barrel carb and no specified transmissions (used for both automatic and manual transmission equipped cars)*

The second line of your serial number info "22P194474" decodes as:

2 = GM Pontiac Division
2 = 1972 model year
P = Pontiac, MI vehicle assembly plant
194474 = last 6 digits of the Pontiac car assigned VIN this engine was installed into

Since this is a GM "Corporate" 250, you should be able to use Chevrolet Shop manuals to cover maintenance/repairs and overhaul as well as Chevy listed GM part numbers and engine identification for ordering parts. It might be a good idea to compare timing and related specs between 1972 passenger car and truck 250's as there may be a difference enough to warrant using the passenger car info for best tune ups and operation settings/adjustments.

* The "Y6" code came from this Pontiac Engine Decoder pdf I found on line in my search.

Think this covers your question.

EDIT NOTE: A check of 1972 Pontiac vehicles that came equipped with 250's included the base level models of the Firebird, Lemans, and Ventura II (corporate copy of a Chevy Nova).

Holy smokes!!
I’ve been on the internet more on than off all day trying to figure this out. That more than covers my question. You should have been a detective. Thank you so much!
Ordering parts if needed will be a lot easier, and just as cool is knowing fairly detailed history on the motor. From what I have learned they are reliable power plants. I’m gonna do another post on putting the proper fuel pump on it pretty soon. Has an electric at the moment.
Farnsworth is happy now. Gonna enjoy some fresh air.

Glad to be of help Bill. Just a suggestion, but before you race off to buy a pump, you may want to remove the dummy cover in it's place and check to be sure the lobe on the cam that operates the pump isn't bad. The electric pump could have been a quick fix for a bad cam pump lobe. If that was why the original pump got replaced, going back to a mechanical pump is going to require a new cam, which is going to slow your get it going and drive plan a wee bit.

Here is a tip: when checking the cam lobe (the one that makes your pump work) please do not stick your finger in there and turn the engine over to see if you feel the lift (or more accurately the elliptical motion) of a good lobe. If your finger gets caught in there it hurts like anything and can cause mutilation. Also, if you want info on a good electrical pump, please let us know because getting the right output is very important. I've been using one since 1997 very happily and that same pump costs about $30 today.

Yes- - - -use an inspection mirror and a bright flashlight to visually check the cam lobe- - - - -I've always followed the rule- - - - -"Don't stick a finger anywhere you wouldn't put another important part of your anatomy!" After 65+ years of tinkering with dangerous machinery, I've still got all my fingers, and that other "important part" as well! Scarred, bruised, and painful at times, but still there!
LOL!
Jerry

Hahahahahaa. I hear ya Jerry!! I've had some close calls as well but still intact. lol.

Will definitely do. I appreciate all the advice Jon.

Thanks Dan. I'm bringing the truck home from storage wednesdsay and will take a look. I'll try to get some pics to share.