Rod bearing alignment issue

[DeNoZZo]

I have a set of 6 bolt rods with arps that have been machined to fit my seven bolt crank. I went to install the rods tonight and noticed when putting in the rod bearings that the ends of the two bearings do not line up perfectly with the cap on. The cap is aligned perfect as I cannot feel the crossover from one bearing half to the other. I have king bearings for a 7 bolt crank.

(Bearing doesn't line up left/right wise in the picture on that side or the other)

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*Heres a pic of the other side

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[BogusSVO]

did you check the part number on the bearings to make sure you have the proper set?

were the rods resized?
are the rods the proper width for the crank?

 

[DeNoZZo]

did you check the part number on the bearings to make sure you have the proper set?

were the rods resized?
are the rods the proper width for the crank?

The part number for the bearing is what it is supposed to be. I even matched it up with my old 7 bolt bearings and they are identical (but my kings are thicker because they are undersize)

The rods were not resized, but honed.

They should be the proper width for the crank as they are sold as "ready for 7 bolt crank".

These are the rods I have
DSM Graveyard - Your #1 Source for DSM Parts!

Thanks for helping me out!

 

[donniekak]

Looks like an even amount of material wasn't removed from both sides of the rod, and cap when they were narrowed. For a little more than the cost of all the machine work done to fit stock parts, that don't fit, you could have had brand new forged rods and pistons.

 

[DeNoZZo]

Looks like an even amount of material wasn't removed from both sides of the rod, and cap when they were narrowed. For a little more than the cost of all the machine work done to fit stock parts, that don't fit, you could have had brand new forged rods and pistons.

I don't understand how that would affect the inner part of the rod where the bearing sits, even if that was the case?



My rods were bought for $200 total. The 6 bolt rods with arp's have been proven to hold 500hp when properly set up. That's plenty for my goals and budget. My pistons where the about $180 for oem cast pistons. Which are also perfect for a daily driven year round street car.

 

[donniekak]

I don't understand how that would affect the inner part of the rod where the bearing sits, even if that was the case?



My rods were bought for $200 total. The 6 bolt rods with arp's have been proven to hold 500hp when properly set up. That's plenty for my goals and budget. My pistons where the about $180 for oem cast pistons. Which are also perfect for a daily driven year round street car.

If an even amount of material isn't removed from the rod and cap, the bearing location tabs won't line up.

 

[DeNoZZo]

If an even amount of material isn't removed from the rod and cap, the bearing location tabs won't line up.

I have a set of 6 bolt rods with arps that have been machined to fit my seven bolt crank. I went to install the rods tonight and noticed when putting in the rod bearings that the ends of the two bearings do not line up perfectly with the cap on. The cap is aligned perfect as I cannot feel the crossover from one bearing half to the other. I have king bearings for a 7 bolt crank.

No matter what is machined off the rod, the location of the tabs isn' going to change? I don't think?

 

[90tsiPA]

I'm nearly positive you need to run a 6 bolt bearing. Some aftermarket evo rods use 6 bolt rod bearings on evo 7-bolt cranks. After machining the 6 bolt rod with fit flush with the 6 bolt bearing instead of sitting in from the outsides of the rod.

 

[TurboAnything]

I thought the tangs went on opposite sides of the rod journal?

 

[BogusSVO]

honed is resized...

and are the tabs of the bearings in the groove of the rods?

to me... but the bearings look way to narrow in the rod....

 

[90tsiPA]

Thats why he needs 6 bolt rod bearings. The bearings will fit flush with the outside of the machined rods

 

[DeNoZZo]

Thats why he needs 6 bolt rod bearings. The bearings will fit flush with the outside of the machined rods

It says on dsm graveyards website to use 7 bolt bearings?
DSM Graveyard - Your #1 Source for DSM Parts!

Go down and click on tips

honed is resized...

and are the tabs of the bearings in the groove of the rods?

to me... but the bearings look way to narrow in the rod....

Yes the little tabs on the ends of the bearings are in the notches on the cap and rod

 

[RamenPride]

Thats why he needs 6 bolt rod bearings. The bearings will fit flush with the outside of the machined rods

this is what I'm thinking also

 

[donniekak]

No matter what is machined off the rod, the location of the tabs isn' going to change? I don't think?

They will change in relation to each other.

 

[JacksonAuto]

Are the tangs on the bearing shells the same width as the grooves in the rod? If they are narrower and fit sloppy you will need the 6 bolt bearings. I'm willing to bet, though, that the 7 bolt bearings are what you'll need since they started out life as 7 bolt rods. The only way you could use an early bearing would be if DSM Graveyard machined the rod to accept the wider tang of the 6 bolt bearing shell. Most aftermarket rods use the early bearings because they're wider and offer more support.

The tangs should both be on the same side of the rod. It doesn't matter if the rod was resized or not.

 

[TurboAnything]

The bearing looks to be too narrow and the tangs are holding the bearing out away from the rod journal. They need to sit in the grooves to lay flat.

 

[DeNoZZo]

Are the tangs on the bearing shells the same width as the grooves in the rod? If they are narrower and fit sloppy you will need the 6 bolt bearings. I'm willing to bet, though, that the 7 bolt bearings are what you'll need since they started out life as 7 bolt rods. The only way you could use an early bearing would be if DSM Graveyard machined the rod to accept the wider tang of the 6 bolt bearing shell. Most aftermarket rods use the early bearings because they're wider and offer more support.

The tangs should both be on the same side of the rod. It doesn't matter if the rod was resized or not.

I understand what your saying and agree that I might have the wrong bearings, but they started life as a 6 bolt rod and are being put in a 7 bolt block.

 

[Tanro]

I dont think the tangs are meant to line up. Non of mine do. I have the rods setting right and cant get them to line up in any way.

 

[MidShipCivic]

Those look exactly like a 7 bolt bearing in a 6 bolt rod as it is now it won't seat centered because the bearing surface is wider.

To clarify, tangs do not line up they sit on opposite ends of the bearing edge (left right).

Left 6 bolt rod and right 7 bolt rod with bearing which sits centered.

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7 bolt bearing on center .

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Also honing a rod is not resizing. The honing process corrects the distortion from tighter clamping fasteners. The above picture is a honed 7 bolt rod with std bearing.

 

[defrag010]

That looks fine... build it and forget it. A little misalignment won't hurt a thing, and that bearing is more than wide enough to work fine. If you were to use the 6 bolt bearings, they would need to be narrowed anyways. Narrower bearing = less friction, this is an extremely common mod in many racing engines... some 2bbl circle track engines have bearings that are just wide enough to cover up the oil hole on the crank!! The sole purpose of bearing tangs is to locate the bearing, the crush is what keeps the bearing in place. Alot of new OEM engines today don't even come with bearing tangs. If you want to be OCD about it, you can just grind the tangs off from the backside and stick the bearings where you want them.

 

[DeNoZZo]

That looks fine... build it and forget it. A little misalignment won't hurt a thing, and that bearing is more than wide enough to work fine. If you were to use the 6 bolt bearings, they would need to be narrowed anyways. Narrower bearing = less friction, this is an extremely common mod in many racing engines... some 2bbl circle track engines have bearings that are just wide enough to cover up the oil hole on the crank!! The sole purpose of bearing tangs is to locate the bearing, the crush is what keeps the bearing in place. Alot of new OEM engines today don't even come with bearing tangs. If you want to be OCD about it, you can just grind the tangs off from the backside and stick the bearings where you want them.

I'd like to go ahead and do so, but your going against the grain here dude. Everyone else is questioning it. What you said makes sense, but can anyone else chime in?

 

[90tsiPA]

Have you contacted dsm graveyard directly?

 

[MidShipCivic]

I'd like to go ahead and do so, but your going against the grain here dude. Everyone else is questioning it. What you said makes sense, but can anyone else chime in?

You have enough info already go buy the right bearing you already tried a 7 bold bearing and it fit perfect so what info do you need? None use the tang, and I've never seen a rod with out a tang it'll be bad if that bearing were to walk out some way some how.

 

[DeNoZZo]

Have you contacted dsm graveyard directly?

Yes, called them earlier today and they confirmed my 7 bolt bearings will not be perfectly centered but they will be close enough and should work perfectly.

You have enough info already go buy the right bearing you already tried a 7 bold bearing and it fit perfect so what info do you need? None use the tang, and I've never seen a rod with out a tang it'll be bad if that bearing were to walk out some way some how.

what?

 

[MidShipCivic]

Gah sometimes I forget double check my typing