I cant believe I'm doing this! When I first got my truck, before FTE and this forum. I was thinking get that old 292 and 4 speed granny gearned transmission out of it, and put in a nice 302 or 351 w\ auto trans. But since then, my Y-block applauded me and we bonded and I will never be the same. wait got something in my eye.

I just started the disassembly of the 312 I'm using for parts, crankshaft (will be machined for a 292), Heads (one ECZ-G and one ECZ-C, Wierd, I took them off, Looked like it was run that way), intake, rods, etc. I have another 312 available for parts with ECZ-C heads on it. I have a couple options on the 292 Block, one being the running but tired one in my truck now. I will look around for a second G head, But I think the C heads are fine too, and I have a pair of them. Seems I read about someone else that had the two different heads on his truck, and one was a G.

I have no questions...................Yet. I have read All the back threads I could find (Great Stuff!), and asked alot of questions. So I think I have a pretty good idea where Im going. But I have never done this before so If you all don't mind me just sharing whats going on, and pointing me in the right direction if I go astray (in between question) I would sure appreciate it.

Now that I started getting parts and started wrenching, Its starting to sink in, That I'm actually doing this. I'm thinking "OH Yaaa" & "OH No!". LOL
Larry

 

Sounds like fun!

I would suggest using the C heads for a few reasons.

With the 312 stroke and any overbore you will have higher compression than the stock 9.0 of a 56 312.

If you give the heads a cleanup shave and deck the block the CR is going up some more.

At about this point you have to ask yourself do I want it all but have to run 93 Octane or can I tone it down a bit and run on 89 or even 87 on a good day?

When I built the 292 for my F350 I decided 87 was plenty to pay for in a very thirsty setup (5.14 rear and 3 carbs) so I stole the C heads off a spare 56 312. I didnt even think twice about tossing the peanut valve heads that came on the 64 block but I didnt argue about using the forged crank either.

Ask away, thats what some of us are here for is to answer more dumb *** questions from fools that insist on playing with ancient technology
Gotta love them Y's.

If you want only 2 pedals in the cab consider a performance prepped C4. I'm going that route with the Altered next year.

 

Carl
A Fool maybe, A Dork for sure. And Dumb Questions there will be, Because I sure DO love my Y , and for whatever reason I am jumping in over my head and doing this, when I can't even convince myself it makes any sense.??????????? I do want the same things in my motor that you did, something strong but that will run good on lower octain fuel, so I am leaning towards the C heads.

Larry

 

That was me with the G head and the C1TE head on the same engine. It looked as if about .080" was milled off the small valve head to up the CR to match the G head.

I've decided to also go with the C heads I've done some reading on the Gand C heads in vintage hot rod mags and found the C heads to be better so long as the cam is stock to mild. The wilder the bump stick the better the G heads will do. They refer to the G heads as the valves being "pocketed" 3/64" below below the combustion chamber surface". So for the G heads to be effective there needs to be 3/64 of an inch more lift. Also the exhaust valve area is shrouded and thus only allowing nearly half of the valve area to be used effectively.

I feel with a clean up on the c heads and the use of the steel head gaskets my CR will about where I want it

Kevin Bigwin

 

Nice looking truck, Larry. I hope you don't mind that I named my truck Brutus, before I saw that you did also. Maybe I'll legally change his name to Brutass.

 

Bigwin Yeah that is wierd, two of us removing the same mismatched heads. I had in my notes, that I was hoping to come across some ECZ-G heads when I was gathering info, or a pair of C's as my second choice, (imagine my suprise when I got one of each on my parts motor). but unless another ECZ-G falls in my lap I think I'll go with the C's. I think a mild cam will be good also, these great old Y-Blocks have a natural Loping sound that I Love, and don't want to mess with.

Rebel Thanks. Brutus is a good name for a Tough old truck, I sure don't mind there being more than one.

 

Larry, as Carl said, you'll be just as well off with the C heads. If you bore that 292 out to a 312 bore, you can find pistons that are reasonably priced. I think John Mummert may have a line on hypereutectic pistons. You may need the 312 rods to make things work.

And look around for the ECG rockers. The ECG rocker ratio is 1.54 as compared to the 1.43 of all the other rockers. That's 25% more lift.

Zero deck to make the most of those heads. The ECZ-B intake fits Holley carbs.

 

Thank you everyone for your input. I am noticing that as I am getting more hands on now, that all the information thats bouncing around in my head is starting to make more and more sense all the time.

I didn't think I had to bore out my 292, to get it to 312. (I may anyway) I thought it benifited from the added stroke and compression, from the 312 crankshaft, rods and heads, and I thought I could use the pistons I had. I did not even noticed what rockers I had when I took them off the 312, (my father inlaw did point out they are they easyier to adjust ones). I will have to look tommorrow. But I am almost sure I had an ECZ-B intake on it, (big 4 barrel). I was at first just going to put it on my 292 before I decided on the rebuild. Y-Blocks rule

 

Larry, you can get 292 pistons up to .080" oversize. Once you get into the 312 bore prices go up. Rods are the same.
There are hypereutetic pistons available Ive been told but I havent used any on a Y Block. They should be ideal for a long life driver.

That B intake is very good but if you have some spare time clean up and match the ports to the heads.

The Y suffers from a pretty poor ignition plus it is a PITA to work on, go electronic. Get a new dizzy from Advance Auto, NAPA, etc, its not worth the time/$$ to mess with an old one. Plug in your module of choice. ALWAYS keep a complete points setup in the glove box tho, since Murphy enjoys electronic stuff.

 

Does anybody recall there being a problem with 312 cranks?? I have heard a few times from different sources that the 292 crank is a much better choice as the 312 cranks are somehow weaker or inferior. Just curious. John

 

Most 312 lower end problems are owner & shop induced by bad published data in Motors Manuals.
Wrong torque specs and mains bolts that are too long did most of the damage. So as a result, many bad 312 blocks show up.

Ive seen pictures of a broken crank, dont know if it was related to the above.

Ive also seen broken flathead cranks (no sign of a blown engine)and that isnt supposed to happen

 

Carl Thanks Sounds like good advice. Finished dismantling yesterday And everything looked so good, With my Father inlaw's advice I decided to Just Rebuild the 312. The pistons where standard, and so where the crankshaft bearings. Saving money helped me decide. I'm taking the block to be boiled out tommorow.

The intake is a 'B' , how do you match the port? Is it difficult?

I think I will go with electronic ign, any kind that works well with the Y-Block? Is there a specific type that can accept points in a pinch?

Oh yeah I I.D. the Crank its a ECZ 3.44 stroke. it has the the 1 Cresent/1Large Dot.

Larry

 

You got a virgin!

The main thing with the ports is to clean up any casting flash and roughness. You can also use gaskets to outline the port area and grind out at a smooth flowing angle to fill the gasket openings. Do the same on the heads.
An air die grinder does this well.

The above is not necessary on a stocker but it does offer a noticable improvement with a nice cam and higher rpm's.

The Pertronix seems to be a decent ignition as well as being very easy to go back to points on the side of the road

 

There is a Mallory electronic distributer for y-blocks on ebay right now! Good luck, John

 

My father in law kinda got excited when he saw the Block and Crank where "virgins" (He Said Standard). I got excited too, when he told me what it meant.

I am leaning towards a mild cam, (or rv cam), and I am really hoping that this 312 Y-Block, has a similar loping sound to it that I have really grown to Love in my 292 Y-Block. This is an important factor to me. I will stay stock if needed.

Thanks for all the great input, Larry