312 connecting rods length ????

[Ecode70D]

Back to the cracked main webs in the 312 blocks.  I have only found cracks in '56 blocks.  In '56 Ford specified 130 ft. lbs. torque for the mains.   When having Y Block cranks reground, insist that the shop maintain the radii at the ends of the main and rod journals.  I have found many reground cranks where the radius has been eliminated, and have found that is where the cracks start.  Crank grinders are reluctant to dress a radius on their grinding wheels.   John

     John... Thanks for that reminder about the 312 main web area.   I have no intention of taking my car on the track,  but really was  a little worried about that area.  I feel a little better now.    Now I have to email Guenter and see if his crank main radii on his crank are OK.   I didn't  check it that closely when it got delivered to my shop before it got shipped to Austria.  .  Jay 

[djfordmanjack]

Thank you John for sharing your first hand experience. I see what you mean be weakening the crankshaft by decreasing the overlap of mains to rod journals and that is a good thought in racing application. I had read before about the extensive torque specs in the 56 312s and is easy to understand where that additional stress would help cracking the block.
I just checked my crank and it has nice little radii in the turned down areas. a sharp corner could increase the stress factor x2, that is true.
Again, I will not be racing my wagon and I think that engine should easily cope with my driving habits. I just want a solid 292 with maybe that little extra 312 torque added.
I am a little worried though that my engine will be built from at least 4-6 different ones and I will check and recheck everything many times. I want to put the rotating assembly in the block with all caps torqued and without piston rings so I make sure it spins freely and will check all the bearings afterwards. there is a million mistakes to be made when you are changing nearly everything in an engine.
Like Jay said I have no choice. I bought 3 292s and none of them was good. from uneven decking to frozen pistons and mixed rods to a freeze cracked block and cracked heads and damaged rocker assemblies. I have about 2 tons of Y block scrap iron in my place.....haha....
Yes Rich, now you got me. I've been sent over here to bring some light to the blind -er- English to the German speaking...haha
Honestly that is flattering, but I know how my English is still limited. ask Jay, most times when we talk he doesn't really understand me and insists in talking German....hahaha....
I owe it all to my brilliant English teachers, one of them had been studying in NY in the 1940s and 1950s.

[djfordmanjack]

Want to thank all you guys this has been real informative. Portland Swap Meet is just around the corner so will search for heads, oil pan and pickup

Zap-

ZAP there is a later head out there called the 113. it also has the big intake valves. be sure to use those heads in matching pairs because some of them have a different chamber size (ie F code for less compression or later HD heads)

[lalessi1]

Guenter, assembling an engine out of a bunch of different ones has always worked for me when I have done it. After all, new engines were built from parts from different suppliers. One thing that I have figured out for myself is that things are simpler than I make them out to be.... keep the faith.   

[hiball3985]

Guenter, my current engine is made from a conglomeration of different parts from different years. Runs like a dream.. It started from a 272 EDB Dearborn block.

[Hoosier Hurricane]

Guys:

For street use, the lack of a radius on the journals probably won't make any difference as far as cracking.  I have only seen cracking starting on cranks that have hundreds of 1/4 mile runs on them.  I have broken one crankshaft into 9 pieces, I put one too many runs on it without magging the crank.  It was a regrind without radii.

John

[Ecode70D]

Guys:

For street use, the lack of a radius on the journals probably won't make any difference as far as cracking.  I have only seen cracking starting on cranks that have hundreds of 1/4 mile runs on them.  I have broken one crankshaft into 9 pieces, I put one too many runs on it without magging the crank.  It was a regrind without radii.

John

John...      Since I'm not going to be doing any racing, that's a very comforting thought.   I'm thinking that there was there wasn't much  at all that you could have salvaged from the engine after the crank busted up  into pieces.   
Guenter...  I suppose that means when you make your frequent trips to Germany, that you will be OK driving the 57 on the Autobahn without any speed limit.   Well maybe just enough to get the old gas out of the carburetor..  HAHA

[djfordmanjack]

Jay, who knows what the speed limit will be when I finish with the 57...haha...in 2025 or something like that....
My driving habits are so that I rarely go beyond 3k. that's exactly where the 34 does about 90mph and she loves those rpms.
The 57 will have pretty much the same cui displacement and axle gearing ( but with OD). maybe it's a little heavier, but I think I will rarely get the 312 over 3k for long. except getting rid of stale gas of course.....hahaha....
It's still good to learn about John's racing experience. it helps eliminating mistakes before making them.
@Lynn and Jim. I like your attitude and will build my engine with faith. Still a little checking here and there won't hurt either.

[racton]

 :unitedstates:Is there a difference between the Ford and Merc.312 engines.My 272 is running on a gas can and new plugs.The cap looks fairly new as does the rotor.I have a miss,we think its a wire.Im waiting for the sending unit to be restored,it was probably done today but I didnt check.My tank is back from renew,and I picked up 4 205 75r 14 s today .Now im taking my favorite lady to the corner for dinner and a beer.. Isnt Life great........Racton

[Ecode70D]

Racton
   I don't think that there is much difference between the Merc. and the Ford 312 but someone will let you know.  It seems to me that someone said that 205 75 R14 is  the correct size radial tires.   Those are what I'm getting ready to put on my car very shortly. 

[Zapato]

Radius corners. ... from my almost 40 years of work as a machinist a radius corner is always the prefered result. During my Navy days repaired  many a pump shaft  everyone that failed was at a shoulder. Often it was impossible to tell whether the it was radiused or not. My personal observation was that on some was that whoever had machined the shaft when facing off the shoulders for lengh had actually undercut the adjoining diameter. My early training was to always radius shoulders. Maybe it was a bit of overkill on some parts but if it's my parts radius would be my choice.

Can truly understand why a grinder operator wouldn't  want to radius shoulders as he would loose a bit of wheel diameter. My thinking just adjust price to cover wheel wear.

Zap-

[SkylinerRon]

ECZ-G Heads are the ones to use. They are good for 20+ hp. The hi-lift rockers are cheap power also.
Be sure to use a 57 up distributor.
You will need a pass car (front sump) oil pan, pick-up tube and the frt cover is slightly different but,
you my not need to change it.
57 up exhaust manifolds are better too.

Goodluck,

Ron.

[Zapato]

How does one identify the high lift rockers? Or is there a source  for them?

Zap-

[hiball3985]

How does one identify the high lift rockers? Or is there a source  for them?

Zap-

Casting numbers are different. I always check this measurement.

[djfordmanjack]

Great pic, Jim, just saved it in my files. shows how the rocker with the higher ratio is the shorter one in dimensions.( since the valve side arm has the same length, so the pushrod side has to be shorter for higher ratio).