Topic: anyone here ever welded cast iron?

[Ichiban 4]

Hmm..

Well..I'm old school as far as welding is concerned (meaning before MIG..and certainly TIG were commonly used)..but first off..no crank shaft I've ever seen is cast iron..they've always been FORGED steel.  Which means..the concern about welding cast seems superfluous.

[although some of the recommendations here for actually welding cast iron seemed pretty good to me (mainly have to preheat it..can weld with either cast rod..or BRAZE it..with either nickel or just plain brass rod).  If you don't preheat cast..it will crack/fracture.  Ditto for cooling slowly afterwards.]

ANYWAY..with forged..from which most cranks are actually made..you can simply weld with a regular arc welder..or I suppose more efficiently..with MIG and/or TIG. [BTW: we used to arc weld directly on the counter weights themselves when balancing cranks]

Just another perspective on the subject Fuzzy.

Al / Ichi

[mark]

sorry Ichi.... forged Ford cranks are pretty rare.

[Markcb750]

Forging and casting

Crankshafts can be forged from a steel bar usually through roll forging or cast in ductile steel. Today more and more manufacturers tend to favor the use of forged crankshafts due to their lighter weight, more compact dimensions and better inherent dampening. With forged crankshafts, vanadium microalloyed steels are mostly used as these steels can be air cooled after reaching high strengths without additional heat treatment, with exception to the surface hardening of the bearing surfaces. The low alloy content also makes the material cheaper than high alloy steels. Carbon steels are also used, but these require additional heat treatment to reach the desired properties. Iron crankshafts are today mostly found in cheaper production engines (such as those found in the ford focus diesel engines) where the loads are lower. Some engines also use cast iron crankshafts for low output versions while the more expensive high output version use forged steel.


Just confirming what I thought I knew... Wikipedia

[754]

Yup there certainly used to gobs of cast cranks on US made engines, and forged were harder to come by and you paid dearly for them, on a lot of models.

I have been told my 74 Chev( wanted to pull the 350 out and save it), will not have a steel crank, not in a pickup...

Still I think, bolting or sleeving the crank would be as quick or quicker, for this project...

[mark]

if I had myself a situation where I was going to stick a mailbox on an old balancer on the end of an old cast crank, and then stick another cast crank to the end of the first, and all I had was a wire welder...... I would round up a handfull of the flywheel bolts, screw a few into each flange, and then weld the steel bolts together.

[Ichiban 4]

Just a little addition: Ford has been making FORGED vanadium steel cranks since the Model T's.  Don't know about the Focuses..but certainly through most production till today. 

How in the world could cast iron stand up to the forces on a crankshaft?  It's the weakest form of iron there is.  That's why they started making things out of steel after the Industrial Revolution. Even connecting rods are all made out of FORGED iron or steel (or alumimum alloy and/or machined billets)..and they take no less force than a crankshaft.

As said in my previous post: we used to always add stick welds at room temperature to crank counterbalances when balancing engines.  You cannot do that on cast iron..or it will become brittle and/or crack.

I'm all eyes to see what documention there is (facts please..not opinions) that establishes that straight cast iron is ever used for automobile engine crankshafts (particularly Fords).  Perhaps a Briggs & Stratton industrial engine would use a cast crank..but still bet it's been forged afterwards.   Now..if CAST STEEL billets are being used to start with rather than rolled steel..which is still FORGED afterwards..then perhaps that's what the confusion about something being CAST..is about. [If you read Markcb's post carefully..it says that most cranks are FORGED..and from steel]

But again..it's been over 30 years since I studied metallurgy in University..so maybe I'm forgetting something here.  Please enlighten me..(facts, data please).

Domo,

Ichi

[mark]

...... Today more and more manufacturers tend to favor the use of forged crankshafts due to their lighter weight, more compact dimensions and better inherent dampening. ...... Iron crankshafts are today mostly found in cheaper production engines (such as those found in the ford focus diesel engines) where the loads are lower. Some engines also use cast iron crankshafts for low output versions while the more expensive high output version use forged steel.


Just confirming what I thought I knew... Wikipedia

the key word here is "today".



......... now back to yesterday's engines........

.......a trashed 428 balancer, on 2 FE motor cranks, a 428 and a 406

Ford 406 1959-63..... 428 1966-70.

http://www.fordification.com/FEcrankshaft_casting-numbers.htm

Forged cranks found in HD truck and rare hi-perf passenger(read factory racer) applications.

406 - all cast. 428 - all cast - even the Super Cobra Jet!


edit: smallblock Ford - all cast except Boss 302

Chevy was a little more generous with forgings but note that most are truck and exotic '68-69 Camaro Z/83 302' passenger stuff.



Happy trails.

[Markcb750]

...... Today more and more manufacturers tend to favor the use of forged crankshafts due to their lighter weight, more compact dimensions and better inherent dampening. ...... Iron crankshafts are today mostly found in cheaper production engines (such as those found in the ford focus diesel engines) where the loads are lower. Some engines also use cast iron crankshafts for low output versions while the more expensive high output version use forged steel.


Just confirming what I thought I knew... Wikipedia

the key word here is "today".



......... now back to yesterday's engines........

.......a trashed 428 balancer, on 2 FE motor cranks, a 428 and a 406

Ford 406 1959-63..... 428 1966-70.

http://www.fordification.com/FEcrankshaft_casting-numbers.htm

Forged cranks found in HD truck and rare hi-perf passenger(read factory racer) applications.

406 - all cast. 428 - all cast - even the Super Cobra Jet!


edit: smallblock Ford - all cast except Boss 302

Chevy was a little more generous with forgings but note that most are truck and exotic '68-69 Camaro Z/83 302' passenger stuff.



Happy trails.

Do not know the statistics, but remember the metallurgy.

Every crankshaft i ever held in my hands was either a steel forging or a cast high quality iron such as ductile iron. Both of these are very weldable materials, with a little care, even with a 110v TIG. 

If you drill into the shaft you will note the chips come out like little cornflakes, not the spiral seen when you drill into a plate of SAE 1020, but good sized solid chips. The cast iron which is a little difficult to weld will come out a drill hole in powder sized chips, and small chips you can crush in your fingers.


It is brittleness that makes welding low grade CI difficult. Thermal gradients induce cracks which lead to failure.  This is why pre-heating the parent material helps.


Anyone here, besides me, seen a crankshaft forging operation? Noisiest place I have ever been in, even the noise of a F4 pales in relation to the hammering in those press rooms. Although a thumbtack press operation is pretty damned annoying also.


All this is secondary to the simple fact that in the time it took me to type this up Fuzzybutt, I could have welded your cranks together, and no baseball bat wielding hoodlum could break iit off, but I do type really slow.

[fuzzybutt]

well, the son in law will be over on monday to help me cart my creation out to the corner of the driveway. i dropped thr cranks onto the garage floor. the floor cracked and had a little chunk come out. my welds held though. i'm pleased with the results. bet the damn kids cant break this off with a 2x4 

[754]

If I remember correctly Nodular and ductile iron are the same, and of much higher strength, plus possess some ductility.

That is why they use nodular iron for the strong Ford 9 inch.

You got to remember that a crank has  a lot of rigidity supported by the mains, but does not has to be as strong for passenger vehicles as it does in a racecar with higher stress and rpms..

 And yes, you will see the differences in the chips drilling it.

 Bottom line, crank is different cast iron than  your house drain pipe..