Connecting Rod identfication and location

[james curl]

I purchased a set of new in the box NOS connecting rods for a 218 flat head plymouth from a fellow on the HAMB site. All six rods carry the same casting part number which is 954428 on one side and 14 on the other side of four of them and 13 on the other two. The rods in my existing engine carry a casting number of 954371 on one side, on the other side number one has a 11873#, #2 &5 have a 11862#, #3,4,&6 have a 11872#. How do the new rods go in the engine, would the two with the 13# on them be #2&5 and the rest be 1,34&6?

[Don Coatney]

James;

Can you see any physical differences in the rods?

[greg g]

Aren't the rods slightly offset to account for the difference between the cylinder bore centers and the crank throw centers??? I looked in the manual late last night and it gives a vague reference to maintaining matched pairs but doesn't go into detail.

I know it has been discussed that they can be installed incorrectly, but I don't think any one has ever detailed how to install new ones that haven't been previously refrenced as to which cylinder they came from.

I would imagine getting it right is very important, and would not proceed without that certain knowledge, and assurance.

[Don Coatney]

I also just read my Motors manual for rods on all Mopar flatheads. No reference found for new rod replacement. It only says replace all rods in the same holes they came out of.

[Jim Yergin]

Greg is correct, they are off-set. I know from recent experience that they can not be installed incorrectly. I installed 230 connecting rods in a 218 block. They were numbered as to cylinders when removed from the original block but I had a couple reversed from the correct orientation when I fitted the pistons to them.

Jim Yergin

[greg g]

perhaps the line in the manual that says to make sure the oil hole is oriented toward the cam side of the block is the clue that makes it understandable.

[blueskies]

James-

I don't recall any difference between the rods on my engine, aside from the offset and the oil hole that is supposed to face the cam side of the engine.

Maybe this pic will help you get them in the right order-

You can see numbers written on the rod and cap, from left to right 1-6. You can also see the offset faces each other on 1/2, 3/4, and 5/6.

Here's another pic-

These are the #5 and #6 rods. You can clearly see the offset on the #6 rod.

I think if you lined up all the oil holes, and then put the offsets in order like the first pic above, you should be good to go. The oil holes are facing away from the concrete wall in the pic above. Just make sure the oil holes are facing the cam side of the block when they go in. I don't think you can install the rod with the offset on the wrong side, it won't go on to the crank. But, you can get #1 and #2 reversed, and have the oil holes facing the wrong side of the engine.

Pete

[james curl]

Well I think i've been snookered, the rods do not have an offset to them. They are the same length as the 218 rods and the bearings seem to fit the big end and the piston pin fits in the bushed little end, but no offset. The rod bearing end is centered on the web. The person who sold them to me was probably told that they were for the 218 flathead engine. They are NOS in MoPar boxes. I hope someone has a book with the rod part numbers in it so that I can find out what they fit.

[PatS....]

I purchased a set of new in the box NOS connecting rods for a 218 flat head plymouth from a fellow on the HAMB site. All six rods carry the same casting part number which is 954428 on one side and 14 on the other side of four of them and 13 on the other two. The rods in my existing engine carry a casting number of 954371 on one side, on the other side number one has a 11873#, #2 &5 have a 11862#, #3,4,&6 have a 11872#. How do the new rods go in the engine, would the two with the 13# on them be #2&5 and the rest be 1,34&6?

According to my 1949 Chrysler Parts Book, Canadian P17, P18, D31, D32, D30, S13 and C45 use 6 rods of the same part # (954446)(1112764)(1112765)

The US built cars use one part # for 1,3,5. and a second part # for 2,4 and 6:

1,3,5 US built Part # 954376 are for D29 and D30

2,4,6 US built Part # 954377 are also for D29 and D30

1,3,5 US built Part # 1115901 are for P17 P18 D31 D32

2,4,6 US built Part # 1115902 are for P17 P18 D31 D32 as well

(Also, all of the 8 cylinder cars used two part numbers as well, 4 of part #954436 and 4 of part # 954437)

[blueskies]

James-

Here's another shot of my old 218 rods, clearly showing the offset...

Pete

I still have these rods, I'd be happy to send them your way if you want them...

They probably need to be reconditioned, they are straight out of my engine with 86,000 miles on them. I didn't re-use them because I swapped in 230 rods and crank.

Let me know.

Pete

[james curl]

Went out on the vintage powerwagon site and found that the 954428 rods fit the 251 engine and will be of no use to me. I bought them along with a set of .040 oversize pistons, and a set of used .060 pistons and rods. The package was sent from Calif.and damaged somewhere between there and Mesquite, Tx. Was returned to sender and determined that all six .060 piston and rod assemblies had been lost. So I got what was left. I really wanted the .060 pistons and rods and the .040 pistions, did not really need the rods I don't think. I paid $75.00 for each group or $225 for the whole package. Got the $75 back for the missing pistons and rods. Will be able to use the .040 pistons in my old engine or the 230 that I just got, so not all is lost.