Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Topic: Dove a little deeper into the 351 today, more pleasant surprises (now with pics) (Read 1459 times) previous topic - next topic

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

June 05, 2007, 08:43:54 PM

I was gonna do a bit more work to the body of the car, but it's so humid and muggy my sandpaper melted. It's mushy and plugs with dust within seconds, so bodywork was off. Disappointed that one of my few "work on the car" evenings was scuppered I glanced over at the 351 short block sitting on the engine stand. Oooh yeah. I dove into my tool box and tore that sucker down to the bare block. In doing so I got some more surprises:

My first pleasant surprise came when I popped the timing cover off. Double roller timing chain. I had thought that all OEM Ford engines came with a single chain and those stupid nylon gears. As for the timing cover itself - it seems to be of the short variety - there is no way in hell there ever would have been room in that cover for a mechanical fuel pump.

Then the oil pan came off, and I saw markings on the connecting rods, like one would do when disassembling the engine. Strange though, was the fact that instead of numbers it was letters - A, B, C, D and P, R, S, T. Stranger still was that the 1-2-3-4 bank was the ones marked P-R-S-T and the 5-6-7-8 bank was marked A-B-C-D.

I pulled the pistons and every one of them was like new - not so much as a scuff mark to be found. Just as importantly, the crank journals are in perfect, shiny shape. The bearings all showed just the slightest bit of wear. All bearings are standard size (no undersize markings, anyway)

I then removed the carbon from one of the pistons and discovered a faint "020" stamped in the top of it that I could not see before. Another piston revealed the same marking. Sick88TBird was apparently half right - the engine was rebuilt or replaced at some point, but it certainly wasn't recently (my brother put 150k miles on it since he bought it).

'Nuther funny thing - the pistons have a fairly large dish in them. I was expecting cast flat-tops like an SO. Maybe even the HO-style pistons with valve reliefs. Certainly not these bathtubs...

The upshot: Looks like this is gonna be a cheap rebuild - more of a freshening, actually. New bearings, rings, a quick honing, a new timing chain, water pump and oil pump, and we're in business (bottom end wise, anyway) with a .020 over 351!

Quick question: How can one tell a cast iron crank from a steel crank? Everthing else with this engine has gone in my favour, might as well hope for a miracle :D

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #1 – June 05, 2007, 10:12:16 PM

Dished pistons? Boost it, my friend.

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #2 – June 06, 2007, 09:41:13 AM

Quote

Dished pistons? Boost it, my friend.

Either that or a big cam with healthy heads......

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #3 – June 06, 2007, 04:10:18 PM

Pics of what I found:

Dished piston (I think I could put a koi pond in that dish):

The cross hatches still visible in the bores:

Double roller chain:

...And the crank. So again, anyone know how I can tell if this is a steel or iron crank?

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #4 – June 06, 2007, 06:46:49 PM

Holy hell that's a huge dish:hick:

I'm not sure on the crank. I'm pretty sure it's cast, but out of what I don't know.

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #5 – June 07, 2007, 10:17:35 AM

Quote from: Thunder Chicken;152270

...And the crank. So again, anyone know how I can tell if this is a steel or iron crank?

I'm nowhere near an expert but aren't the "parting lines" different? I don't even know for sure which way to go for sure, but I think a forged piece will have a wider parting line than a cast one. The forged pieces are supposed to make a different sound when tapped with a hammer too but I've never personally tested that one.

Are there any numbers stamped into it that may be factory? You might be able to give those to a Ford parts guy and find out what it was originally intended to be used in...

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #6 – June 07, 2007, 11:59:59 AM

No expert here eather, But I would think a forged crank would have no "parting lines" otherwise refered to as "casting marks".

When something is Cast it is liquid poured into a mold. the two (or more) parts of the mold are what leave the "casting marks".

When something is "forged" it is a solid blank heated red hot then bent into shape (rough discription) so there wouldent be any "casting marks".

would there?

my experiance with forging consist of 30 years ago I was in FFA and we made Hay Hooks out of 3/8 rod in a forge... so in otherwords, Not much!

http://www.falcon-metals.com/Forgings/HowForgingsMade.htm

Bending a crank into shape may seem impossable but when you have equiptment like Modern Forge here...
-----------------------------------------
http://www.modernforge.com/equipment/index.htm

Forge Equipment:
Modern Drop Forge and Modern Forge Tennessee

Computer Controlled Hammers21,000 ft. lb. Die Forgers (3)
12,000 ft. lb. Die Forgers (3) Air Driven Forging Hammers8,000 lb. to 5,000 lb. Drop Hammers6,000 lb. to 1,500 lb. Forge Presses4,000-ton (2) to 2,500-ton
-----------------------------------------------

A 4000 ton press can bend a BUNCH of steel!

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #7 – June 07, 2007, 01:43:04 PM

Quote from: Jim_Miller;152471

...When something is "forged" it is a solid blank heated red hot then bent into shape (rough discription) so there wouldent be any "casting marks".

would there?

Based on what I know, which is admittedly just from 2d hand knowledge and some distant college classes, there is a "casting mark" on it either way, it's just more clearly defined in a casting than a forging. You have to use a "mold" in either process but in a casting you add more heat to get the metal to go where you want it in the mold (liquid form) and in forging you use pressure instead. Both ways leave a place where the 2 pieces of the mold/form fit together.

edit: Google to my rescue... :D Check the second page of this article. http://www.carcraft.com/techarticles/116_0308_crankshafts_how_to/

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #8 – June 07, 2007, 02:15:39 PM

Guess that answers that question.
You are Spot ON Doodaa

Thanks for the link

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #9 – June 07, 2007, 02:44:42 PM

Excellent article, doodaa, and thanks for the answers everyone. I kinda figured it was a cast crank, but was kinda hoping that since it was a heavy duty application (long wheelbase E-350 van) that it may have been cast steel or nodular iron instead of just plain cast iron. I do have some casting numbers:

That says "3J2Q" or "3J20", and:

That says "WGS" to the left of the journal and "14" to the right

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #10 – June 08, 2007, 12:58:15 AM

i can tell its not steel,, just not smooth enough compared to steel cranks ive see here and there. All the steel ones im seeing are bout as smooth as a counter top (close but good nuff)

that casting,, its bugging me cause for some reason i wanna say 400. not sure why but something sounds familiar about the 383 combo. you sure that rod length is standard 351 length?

piston height?

what does the crank say on the other end,, should say Ford, and then something on the other side

what year van?
what year block
is the dipstick in the block? or in the pan?

since its in that good of shape,, do the heads look like they have been under a UFO recently , i guess thats what they call it up there,, (where you see the large orbital cut / milling marks on the bottom of the head since it was machined)

run a couple layers of electrical tap over all the oil ports except for the first and last one,, then put some air down that crank just to make sure its breathing / not clogged. i know the bearings look good but since you got er out,, might as well.
id do the same on the block.

my wifes 351 timing chain is doubled up like that to,, not sure how relevent that is since its EFI. Prob stock configuration but not sure what block you have. we do know its poked,,,

it would be fun to do a spec sheet on it,, deck height, rod lenght, head milled or not, ect.

Dove a little deeper into the 351 today, more pleasant surprises (now with pics)

Reply #11 – June 08, 2007, 08:39:04 AM

It was a '94 van with a '94 roller block (F4 casting). The dipstick hole is in the block. It does have the Ford logo on the other end, but nothing on the other side (I took pics of the only numbers present, they are above). I don't know the piston pin height or rod length but I've no reason to believe they aren't stock