How to select main bearing and connecting rod shell sizes

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I don't remember as well? The mains are actually very forgiving anyway but you can verify the colors to the numbers from the crank and block.

Sean
 
Hi,

Concerning the rod shells:
I opened up all four connecting rod caps to find No. 1 and 2 having black and number 3 and 4 something between red and brown. I already had seen the color for no.4 before but hadn't mentioned it because it was not really clear.

On the crankshaft, I saw the numbers 21 meaning No.1 and 2 have size number 2 and No. 3 and 4 have size number 1.

The equation for rod shell size is:
Rod size - Crank size = Shell size.
Or:
Crank size + Shell size = Rod size.

Leading for No. 1 and 2:
2+2 (black)=4

And for No. 3 and 4:
1+3 (brown)= 4
or
1+7 (red) = 8

So when filling in the brown color (3) I get the same rod size as for 1 and 2. When trying red I get something way out there.

@Sean, have you even seen rod sizes differ from 4 to 8 or are they as I assume normally matching?

As stated before I will be checking with plastigage but do not want to order a whole set of the wrong shells if not necessary.
 
Hi,

Made some progress again today and inspected the crank bearing shells again. After some time I did find one bearing still had _some_ ink left and found it to be green. This means that in my case, (numbers on the flywheel side) the numbers are read from lest to right for J1 to J4. If the numbers should been read the other way around the shell would have had the Yellow color. So that sorts out the bearing shells for now.

The rods are a different story. All ink is gone but using a flashlight I found out the numbers were still visible on some rods.... And yes, it were 6`s. So that means where I have black shells (ink on this one was still just fine) I should have found a green one....

Can't wait for the Plastigage to arrive......
 
Hi,

Got the Plastigage in today and measured three of the four connecting rods and they turned out to be way out of spec. They should be between 0.021 and 0.043 and found them to be at something like 0.045, 0.055 and 0.070 (!). So at least I know that what`s in now is crap. I`ve ordered all shells as calculated, will fit them and then recheck.

Small question: The rod cap bolds need to be at 36Nm but do I need to add some locktite?

Thanks again!
 
I normally don't use locktite. BUT, keep in mind the rods can be egg shaped and the best way to verify that is to measure in a couple of different directions. I can't remember what the clearance is in metric compared to inches. I know it's max .0018 though I see no problem with a little more then that.

Sean
 
I normally don't use locktite. BUT, keep in mind the rods can be egg shaped and the best way to verify that is to measure in a couple of different directions. I can't remember what the clearance is in metric compared to inches. I know it's max .0018 though I see no problem with a little more then that.

Sean

The 0.070mm one is actually 0.0027 inch. So that`s actually 1,5 times the maximum value. That can't be good i guess :rofl_200:
 
It's a bit big. .002 is still acceptable. Looser like that can make power but lower oil pressure.

Sean
 
Well that was fun... Got the shells in today and started with the rods.

First did cylinder 1 with the Green shell, which resulted in a gap of 0.070. Tried the same cylinder with the Yellow one, same result.

Then tried cylinder 3 which had a gap of 0.070 to start with and got the same result with the Yellow shell...

So that didn't work out as calculated did it :damn angry:.

You would think that the higher the number the thicker the shells are. The strange thing is that cylinder one had a black shell (size two) that is actually thicker then the green one (size four).

The conclusion is that I have to order new shells again.... Can anyone tell me the difference in thicknes between the numbers? So if I go from size 4 to 7, how much difference would that make?

Thanks!
 
The numbers on my block were on the opposite side of where my manual said I would find them. Good Luck!
 
The numbers on my block were on the opposite side of where my manual said I would find them. Good Luck!

If they are on the opposite side then they are also in the opposite order, see further into this thread for details that Rampage and Sean clarified for us. I think one of the manual supplements shows them in the alternate location and clarifies how they are in a different order as well.
 
Well, got the final verdict

Crank bearing shells: 3 out of 4 were fine, the fourth was changed from green to blue. So that`s 3 grades thicker. That resulted in the oil clearance going from 0.070mm to 0.050 mm with 0.044 being the max clearance allowed it is close but not actually within spec.

Rods: Calcualated as 2x green and 2x yellow. Well they all needed to be blue. All now 0.045mm with 0.043 being the max.... so that`s close.

Balancer shaft: Calculated as green and brown. Needed to be brown and blue, bringing them to 0.044 and 0.050 with 0.048 being max.

So of ten shells, three were as calculated..... Thankfully I did check this with plastigage.

Sean, is that normal? Or does it indicate the 50K on the odometer could easily be 150K KM?


Thank you!
 
AS they wear they get more clearance and is also why they make more power. I do use plasti to verify but also use a micrometer and hole mic to validate the bearings (since plastic can "lie" to you on occasion).

Sean
 
(since plastiguage can "lie" to you on occasion).

Sean

I've wondered about that on the mains, i.e., the weight of the crank making the "down side" of the main have less clearance and the top side have more clearance since the crank might not be centered in the "clearance hole"

Wouldn't think the others would be mnuch affected by this tho"

Thoughts:ummm:
 
Theoretically that is possible. Don't sweat the mains much though as they rarely ever spin. I've only seen one engine that did that actually.
 
Theoretically that is possible. Don't sweat the mains much though as they rarely ever spin. I've only seen one engine that did that actually.

I know, I over analyze everything huh???:biglaugh:

Just need to put this bitch together and go!!!:punk:
 
Well I`l just leave the shells like this. They are all at the outer spec of clearance, so it shouldn't be a problem if the clearance is actually a little less.

One other question: I wanted to check my balancer shaft to see if it`s timing was right but I could only find a punchmark on the balancer shaft, not on the crankshaft. It seems the balancer shaft needs to be in sync with the weights on the crankshaft so I checked it using the following method:

- Rotate the crank untill the two cylinders on the right hand side (from normal upright position) are at their lowest position and symmetrical. That way I know the crank journal for those two cylinders is at it`s lowest point (from normal upright position). After that I engaged the balancer shafts`cogs with those of the crank while aligning the punchmark with the upper crankcase half. This way, the weights on the balancer shaft and crankshaft on each side of the engine are facing the same direction.

Is this a valid method or is there a better way of doing this without the punchmark on the crank?
 
I have alignment pics on the facebook site (Engine section I believe). Also, there should be a dot of white paint that you align the stamped dot with.

Sean
 
I have alignment pics on the facebook site (Engine section I believe). Also, there should be a dot of white paint that you align the stamped dot with.

Sean

Well, as with everything else in this build, it`s not that easy.... The paint is gone so I cannot check that anymore. Can you confirm that in this pic:

282227_10150262199718679_282702488678_7420123_5630670_n.jpg


the rod journal in the front is in it`s top position? Because this is what it looks like in my setup too (minus the white paint)

Thank you!
 

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