440 Connecting Rods, DF & Balancing ?

[1970FuryConv]

I have a 1971 440 long block that I bought without connecting rods and pistons. I recently purchased 8 rods through the mail
· casting number: 1851535 LY on all 8 rods
· on the opposite side of the rods, the DF numbers varied.
· Stroke: all had the same stroke, but some had more metal above the piston pin than others.
· The DF numbers probably mean different runs and different years, although it would be interesting to know what DF stands for. The rods are numbered 1 through 8 at the rods and caps, but with the difference in height above the piston pin, how hard are they going to be to balance when I rebuild the 1971 440? THANKS!

 

[413]

They won’t be hard to balance at all. It’s good that they have never Been balanced yet.

The stroke of an engine is sent by the length of the crank jourmanls from center. The rods don’t set the stroke.
Its not a long block if it doesn’t have rods and pistons,

 

[CBODY67]

A block with just pistons, in the OEM realm of things is termed "fitted block". Just as a block without the rotating assembly is a "bare block". "Short block" has the entire rotating assembly installed in it. "Long block" is a short block with the cylinder heads installed. FWIW

The "pads" on the pin end and also on the rod caps are the "balance pads", which is where the rod's weight is adjusted during the balancing operation. Factory production rods usually have smaller/shorter balance pads than a single rod which was purchased from the parts department, by observation. The trick is getting the rods and the crank they were originally with. Which then leaves just the pistons to worry about balancing. Which is what my machine shop operative did, he'd call his brother that was in the engine core business and order up a matching crank/rod set when he was building a motor that needed a crank and such.

Tracking the casting number should reveal the original application of the rods.

Just some thoughts,
CBODY67

 

[Davea Lux]

If you do not have the crank these rods came from, you are probably going to need a balance job anyway, the pads will likely be re-cut as part of that process. I would be inclined to invest in a set of the modern hi tensile replacement rods. These weigh the same as a stock rod but are a good deal stronger and already come with the heavier rod bolts. That way you are starting fresh with a better rod that has not been resized or stressed from use. The LY rod 1851535 is the stock rod used with the steel crank.

Dave

 

[Gerald Morris]

If you do not have the crank these rods came from, you are probably going to need a balance job anyway, the pads will likely be re-cut as part of that process. I would be inclined to invest in a set of the modern hi tensile replacement rods. These weigh the same as a stock rod but are a good deal stronger and already come with the heavier rod bolts. That way you are starting fresh with a better rod that has not been resized or stressed from use. The LY rod 1851535 is the stock rod used with the steel crank.

Dave

So, in a case where one switched from a cast iron to a steel forged crank, it would be best to get the replacement rods too then? I have a 383 with pistons and rods, and a 400, which I plan to transplant that forged 383 crank into. I planned to use the rods from the 383 along w the crank, though seeing that Iron Cross on the 400 block indicates I probably will want to shave .010 off the crank main bearing journals, so some machine work will be needed regardless.

To wit, are modern connecting rods always the most cost effective investment for rebuilding an engine? As always, I thank folks for sharing their experience here, in order that I may sometimes learn something of use to myself.

 

[1970FuryConv]

So, in a case where one switched from a cast iron to a steel forged crank, it would be best to get the replacement rods too then? I have a 383 with pistons and rods, and a 400, which I plan to transplant that forged 383 crank into. I planned to use the rods from the 383 along w the crank, though seeing that Iron Cross on the 400 block indicates I probably will want to shave .010 off the crank main bearing journals, so some machine work will be needed regardless.

My crank is a forged steel crank that came with the engine.
Casting 1851535 is the stock 440 light duty connecting rod that came on 440 engines 1966 to 1978, regardless of forged or cast crank.
I think your 383 rods will work fine unless your are building some super high HP race motor. For a street cruiser with HP increased a few ponies by added compression, aluminum heads, bigger cam, etc., stock rods have always worked fine for me.

 

[CBODY67]

You can always get them "crack checked", checked for straightness, and ensure the rod bearing and pin areas are of the correct size, before use, for extra insurance. The srraighrness issue might have some clues as to the wear patterns on the pin hole and the rod bearings. Wear not uniform across the bearing surfaces, for example.

The 400 pistons are slightly heavier than the 383s. Which is why the 400 balancer is a different part number than the 383. As I recall, the 400 balancer had a little differenrt shape to it, for the steel crank, (beveled and with notches every 90 degrees, as I recall from the ones I got from the Chrysler parts closeout sales years ago), than the '66 383's traditional shape?

Enjoy!
CBODY67

 

[twostick]

are modern connecting rods always the most cost effective investment

The short answer in my opinion is yes.

By the time you have those LY rods magnafluxed, resized, new rod bolts installed and have their weights adjusted and equalized, you will have spent a large portion of the price of a set of H-beam rods on 50 year old rods that will weigh about 100 grams per rod more than the new ones.

Kevin

 

[CBODY67]

Is that weight difference in a more efficient design or in a less-heavy pin?

 

[1970FuryConv]

The short answer in my opinion is yes.
By the time you have those LY rods magnafluxed, resized, new rod bolts installed and have their weights adjusted and equalized, you will have spent a large portion of the price of a set of H-beam rods on 50 year old rods that will weigh about 100 grams per rod more than the new ones. Kevin

I hear you Kevin. There's just a part of me that distrusts things that are new and wants to save and reuse things that are old. It's like new=junk, old=quality. It's a hard mindset to break.
In a weird way, I'm talking to the OEM part, saying, "You've been in that box a long time, waiting and collecting dust. But you're going into an engine now. You're going to be used for what you were made for. I know you can do it."

 

[Gerald Morris]

Is that weight difference in a more efficient design or in a less-heavy pin?

Valid concern! Research needed here. for sure. Stands to reason 400 pistons weigh more than 383 pistons, as they have a greater volume to work in, all other dimensions than top surface area being equal. Here too, modern stuff weighs less, but the Question arises: does decreased mass in modern engine components come from more efficient MECHANICAL design, or more efficient BEANCOUNTING? I know how asiatic crap resolves this dilemma as a rule, and, sad to say, how 1970s Detroit accountants overruled zealous engineers in a similar fashion.

Be that ugly scenario as it may, there ARE better alloys, more clever designs et al in some modern components. I suppose my final determinant will come from where I hire shop time, if that course looks compellingly worthwhile, or not. I too HATE TO THROW THINGS AWAY unless they're clearly irreparable. I CAN do a fair bit of grunt work, even with my rugrats running amok, and my favorite local shop has cut me due slack on basic stuff like control arm jobs, rear axle stuff because I did a decent job at home. Mind you,I REALIZE rotating assembly work gets more involved and is more critical than suspension and rear end stuff so care will be exercised.

 

[Gerald Morris]

I hear you Kevin. There's just a part of me that distrusts things that are new and wants to save and reuse things that are old. It's like new=junk, old=quality. It's a hard mindset to break.
In a weird way, I'm talking to the OEM part, saying, "You've been in that box a long time, waiting and collecting dust. But you're going into an engine now. You're going to be used for what you were made for. I know you can do it."

I'm STRONGLY inclined the same way. I too often recite:

All that is gold does not glitter.
Not all those who wander are lost
The Old that is Strong does not wither.
Deep roots are not reached by the frost....

My young Babushka loves this poem too!

 

[Davea Lux]

So, in a case where one switched from a cast iron to a steel forged crank, it would be best to get the replacement rods too then? I have a 383 with pistons and rods, and a 400, which I plan to transplant that forged 383 crank into. I planned to use the rods from the 383 along w the crank, though seeing that Iron Cross on the 400 block indicates I probably will want to shave .010 off the crank main bearing journals, so some machine work will be needed regardless.

To wit, are modern connecting rods always the most cost effective investment for rebuilding an engine? As always, I thank folks for sharing their experience here, in order that I may sometimes learn something of use to myself.

You will be into about $135 just to install the heavier rod bolts and resize the rods before your do any balance work. The 383 and 400 can interchange rods with the steel crank without any issues. I usually go with improved components on any kind of a build, but a street engine that is not pumping a lot of extra horses will do fine with stock rods.

Dave

 

[Gerald Morris]

You will be into about $135 just to install the heavier rod bolts and resize the rods before your do any balance work. The 383 and 400 can interchange rods with the steel crank without any issues. I usually go with improved components on any kind of a build, but a street engine that is not pumping a lot of extra horses will do fine with stock rods.

Dave

Much obliged Dave! Since I've got a plethora of parts from these motors, I likely WILL recycle as much as is reasonable. Of course if the bores need cutting beyond just knocking the glaze off and clean-up, then new pistons MIGHT become desirable, as one can only do so much with oversize rings. Damn! I'm starting to itch to build that 400 now! Reckon I better shake down the local Demo congress-thing and convince it to front me some kilodollars for Progress, Peace and Happy Horseshit! So long as I don't have to praise chineseum.....

 

[twostick]

Is that weight difference in a more efficient design or in a less-heavy pin?

I suspect both.

Kevin

 

[1970FuryConv]

Much obliged Dave! Since I've got a plethora of parts from these motors, I likely WILL recycle as much as is reasonable. Of course if the bores need cutting beyond just knocking the glaze off and clean-up, then new pistons MIGHT become desirable, as one can only do so much with oversize rings. Damn! I'm starting to itch to build that 400 now! Reckon I better shake down the local Demo congress-thing and convince it to front me some kilodollars for Progress, Peace and Happy Horseshit! So long as I don't have to praise chineseum.....

Hi Gerald
I used .030 over Keith Black Hypereutectic pistons in my last 440 street build. They come with pins and teflon skirts. I believe they were made in Mexico.
Weights: Keith Black piston and piston pin: All weights within one gram of the others. Range 1002.7g to 1003.7g
My results were excellent. Great power. Ben

 

[volksworld]

through the years my main problem has been trying to find a source of properly rebuilt rods...normal sunnen rod resizing machines at your local machine shop hone the rod journal and pin end(most of those i deal with have pin bushings) to an accurate diameter but not parallel to the crank centerline or each other and not to the exact same length as that varies with how much you grind off the parting face...the trw rebuilt ones i just pulled out of my 440 if you turned them over the rod bolts fell out...i would rather re-use a junk rod out of a running engine than a rebuilt one....the price of new rods is less than properly rebuilding them...if anyone knows of a rod rebuilder that bores and hones them parallel on a cnc machine like manufacturing a new one i might be willing to try them ...i see some commercial rebuilders claim they do them like this for their own use but they dont sell them separately

 

[1970FuryConv]

through the years my main problem has been trying to find a source of properly rebuilt rods...normal sunnen rod resizing machines at your local machine shop hone the rod journal and pin end(most of those i deal with have pin bushings) to an accurate diameter but not parallel to the crank centerline or each other and not to the exact same length as that varies with how much you grind off the parting face...the trw rebuilt ones i just pulled out of my 440 if you turned them over the rod bolts fell out...i would rather re-use a junk rod out of a running engine than a rebuilt one....the price of new rods is less than properly rebuilding them...if anyone knows of a rod rebuilder that bores and hones them parallel on a cnc machine like manufacturing a new one i might be willing to try them ...i see some commercial rebuilders claim they do them like this for their own use but they dont sell them separately

The rods I bought are a gamble. If the rebuilder says they won't work, into recycling they go. It's hard to get a set of matching stock rods unless you find someone building a stroker.

 

[blue88]

Who makes and sells good aftermarket (not chineseium) rods to replace our stock rods?

 

[twostick]

Who makes and sells good aftermarket (not chineseium) rods to replace our stock rods?

Lots of people if you wish to pay thou$and$.

Crower, Oliver and Carillo come to mind.

Nothing wrong with Scat, K1, Molnar or 440Source for anything most of us mere mortals will ever build.

Kevin