Mike, the engine builder..i have a question concerning a chevy block

[Brucer]

i had an old block setting out in the shed, been there for near 10 years.. it was a goodwrench 350 crate engine, it come out of a state truck...

here's where it gets wierd, well i guess its wierd.. i call the machine shop to check on progress of my block, heads and crank.. the guy answers the phone and says it'll be the end of the week and alls looking good so far.. then he asks where i got my block.. i told him i bought a complete engine in pennsylvania in a junkyard for $100 and they pulled it.

i ask why whats up, he says do you know what you have there, and i was like yea a 350 4 bolt main yada yada.. he says its a mexican block, high nickel, and casted heavier than normal, casted somewhere in mexico.. i did notice when loading it in the truck while i was catching my breath, that the lifter bores had a deep counter-bore and a heavy chamfer on them, but didnt give it anymore thought until after i talked to the machine shop...

could this block be anything special? i dont have any casting numbers yet, i can run them when i get them..

i've just never heard of a chevrolet mexican block.. i have heard of mexican ford windsor blocks.

any idea?

 

[Yogi]

I think I have one of those too. Mine is stamped right on the block (drivers side) on the rear behind the cylinder head. I don't know the history too much, but the PO said it was a crate engine from GM, but thats all he knew. I'll get the numbers tonight and look it up and see what they say.

 

[RPM]

A lot of that stuff is from Mexico.

 

[donsrods]

I installed a GM crate engine in a guys Vette for him a few years ago and the crate had Mexico stamped all over it. It was a regular $1300 GM replacement engine, nothing special. GM has a plant there I think.

I know that Ford 302 blocks from Mexico can be high nickel content and sought after somewhat, and perhaps your machinist is confusing those engines with yours?

Don

 

[Brucer]

ok, got the block back today casting number is 3970010, right above the casting number it says encho in mexico.. heres a pic
also one of the lifter counter bores and chamfer i wrote of..

i ran the numbers, it says used/casted from 1969 to 1979 car, truck, or corvette, 2 bolt or 4 bolt, low horspower rating was 185hp, high horspower rating was 370hp... i know my block is a 4bolt main and it had factory flat tops with 4 valve reliefs,no dish, heads were run of the mill 76cc heads.. nonetheless it'll make a good foundation for an engine..

 

[Rick]

Where do i run my Ford 351 numbers?

 

[Brucer]

see if these will help you.

Ford Block Casting Numbers

Reading casting numbers

Cylinder Head Basic Casting numbers

Ford motor general info

 

[Rick]

Thanks now to figure out what i have.

 

[Lee_in_KC]

Brucer, was your block decked? If not, or if only slightly, there should be some numbers stamped on a pad at the front of the passenger side deck. There will be one letter, then four numbers, then two or three letters. When you get those, either post them here and I'll look it up for you, or you can go to http://www.nastyz28.com/index.php?page=smallblockchevyblockindentification and look it up yourself.

Now that I think about it, I'm not absolutely sure crate engines would have these numbers. You might check anyway.

 

[Brucer]

hey lee, i got the number on the pad. MBO28OO...


only thing i found was the 28OO means crate motor i think

 

[Lee_in_KC]

I can't find anything on that code at NastyZ28 or ChevyMania or with google search. A typical seven or eight character code starting with M would indicate a Mexico-manufactured motor, so that jives. So if you found something that indicates 2800 is a crate motor, then we know you have a Mexican crate motor, which you already knew. Glad I could be so helpful!

 

[Brucer]

yep, a mexican block i did find somemore stuff..

3970010 1969 350 255-350 4 Truck/Passenger/Chevelle/Chevy II/Corvette/Camaro 3970010 1970-80 350 145-350 2/4 Truck/Passenger/Chevelle/Chevy II/Corvette/Camaro


the head casting # put it at..
3998993 350, 76cc, 72-73, 15-164/64cc ports, 73 had hard seats
3998993 350 Crate motor, current, Hecho En Mexico, 159/64cc ports


the heads i'm going to put on it
3782461 327, 64-66 Double hump or Camel hump 161/62cc port

 

[Mike]

That 010 casting number is identifying it as a 4" bore block. It won't tell you any more than that.

As for the high nickel blocks, it seems there were a few of those floating around without rhyme or reason. If I were looking to build something with extremely high compression (14:1 - 16:1) and had to use a production block, then the high nickel block would sure be a good one to have. With the aftermarket blocks that are available today, pretty much everyone uses one of them instead. When you can get things like thicker decks, thicker cylinders, priority oiling, etc. for the same kind of money you spend on a good core, then adding steel caps and all the machine work, the aftermarket blocks are a bargain.

Whilst a good 4-bolt block is nice to have, I don't get too excited about trying to find one for a good street motor. A pal and I ran an A/ED about 20 years ago and used 2-bolt 454 blocks because they were so much lighter. As long as we located the rear cap with dowels, we never had any bearing issues. It was a chore keeping head gaskets in it, but the lower end was always sweet.

Something you might consider - if you do have a high nickel block, you might keep your eye out for a good standard production block and sell the nickel block to someone that thinks they really need to have it. The difference in price would likely let you buy some other parts. Unless you are really going all-out, a 2-bolt block with a set of studs will work just fine. Just don't tell the potential buyer that bit. :shhh:

 

[Brucer]

yea, thats what i was thinking of doing if any numbers showed anything, but for the hassle of getting another block and taking it to the machine shop, think i'll just use it... it'll make a nice engine.

 

[Martin]

Here's a quote from the Chevrolet Small Block V8 Interchange Manual.
" Metal alloy identification is usually located on the front face of the block under the timing cover. This identification indicates the presence of tin and nickel. Tin helps the block heat and cool more evenly, and nickel hardens the metal. If two numbers, 10 and 20, one over the other, are located near the camshaft bore, then 10% tin and 20% nickel are present in the block. If only one number is present, 10 or 20, this number represents the percentage of nickel in the casting. Any other numbers under the cover are casting identification. The absence of the numbers 10, 20, or both indicates that only trace amounts of other metals are present.
Hope this helps.

 

[LumenAl]

Here's a quote from the Chevrolet Small Block V8 Interchange Manual.
" Metal alloy identification is usually located on the front face of the block under the timing cover. This identification indicates the presence of tin and nickel. Tin helps the block heat and cool more evenly, and nickel hardens the metal. If two numbers, 10 and 20, one over the other, are located near the camshaft bore, then 10% tin and 20% nickel are present in the block. If only one number is present, 10 or 20, this number represents the percentage of nickel in the casting. Any other numbers under the cover are casting identification. The absence of the numbers 10, 20, or both indicates that only trace amounts of other metals are present.
Hope this helps.

This needs to be posted in our tech area... question, does it say what years these numbering systems were in use?

 

[GT63]

This needs to be posted in our tech area... question, does it say what years these numbering systems were in use?

Check out MorTec, Inc. Chevy Smallblock V-8 Casting Numbers List for Chevy casting numbers for blocks and heads

 

[GT63]

yea, thats what i was thinking of doing if any numbers showed anything, but for the hassle of getting another block and taking it to the machine shop, think i'll just use it... it'll make a nice engine.

From Mortec.com

3970010....302.....69....4...Z-28 Camaro
3970010....327.....69....2...Trucks and industrial
3970010....350...69-80...2 or 4


HEADS

3998993....current..350.........Goodwrench crate motors,"Hecho en Mexico", 75cc chambers