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View Poll Results: Is the side machining and oil wiper critical???
Both side machining and oil wiper is important. 1 33.33%
Neither side maching or oil wipers are important. 1 33.33%
Side maching is important, but oil wiper isnt. 1 33.33%
Oil wiper is important, but side maching isnt. 0 0%
Voters: 3. You may not vote on this poll

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Old 10-27-2017, 07:09 PM   #1
Bram
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Default Turbo Tuff - No oil wiper slot or side machining.

Hello.

So I just purchased a set of Manley I beam Turbo Tuffs (+2mm with +625s). And right away i notice there is no machined side face of the big end, and no oil wiper groove cut either. Im talking about the side edges of the big end area. Not the bearing contact faces. The side of the manley rods are the raw un-machined rough surface from the forging process. It looks like a bead blasted surface. Very rough finish.

2017-10-29_09-54-47 by bram biesiekierski, on Flickr

I was speaking with a local engine builder here and he refuses to use those rods, and had even purchased and returned a set for his own engine. I remember he actually warned me about this before i purchased, but it washed over.

The way he explained it, is the rod is basically floating in the crank and piston pin. The machined side faces are basically there as thrust faces against the crank if the rod moves back or forwards. The oil wiper slot is just that, it is a slot that alows oil to be wiped across the crank and lubricte the side face of the rod as it rotates.

Now this is just one persons opinion. So I am asking how important are these 2 features for a rod? (Please dont get off topic, about how so and so uses these rods and blah blah. I want to know specifically what is the concensus on these 2 features. Im sure the rods will physically work. But what i want to know is if its better with the smooth face and wiper slot. I dont want to hear from 1000 fan boys who soley base thier opinion on the fact they have an engine with them inside.)



I notice OEM rods have the sides machined, amd they have an oil wiper slot aswell. So to Subaru at least, this was an important step.


I Notice Manleys own H beam also has sides machined and oil wipers.
2017-10-28_07-00-16 by bram biesiekierski, on Flickr


This is an Argo rod that the engine builder in question used on his own build to replace the Turbo Tuff. As you can see it has the machined side, and oil wiper slot.
2017-10-28_06-47-21 by bram biesiekierski, on Flickr


And get this, in the box that came with the Turbo Tuff, there is a little pamphlet with a picture of a turbo tuff rod, and it shows 2 oil wiper slots machined in the rod. The rods i recieved dont have the wiper slots like whats pictured in Manleys own promotional material. So they have even done it on some rods. So why isnt it done on the ones i have recieved?
2017-10-28_06-36-52 by bram biesiekierski, on Flickr


So I got to browsing google image search looking at as many Subaru specific con rod pictures as i could find. And virtually all of them have the machined side faces. BUT not all of them have the wiper slot. So as a general consnsus, most manufacturers consider the side machining nessisary, but not all consider the wiper slot nessisary. I did find one picture of Tomie Subaru rods and it looks like possibly they havent mavhined the side faces either. (No shine to the side) But it is too low a quality picture to say 100%.

2017-10-28_06-56-47 by bram biesiekierski, on Flickr

rod by bram biesiekierski, on Flickr

2017-10-28_06-56-54 by bram biesiekierski, on Flickr

I did conside that the machined side is done to get a thicker forging down to the correct width. And perhaps the machining on the Manley turbo tuff is not done because they are forged at the right width to begin with. I used a micrometer to measure the side face of a rod and it was 0.8419" / 21.38mm wide.

Thankyou
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Last edited by Bram; 10-29-2017 at 05:40 AM.
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Old 10-28-2017, 09:19 PM   #2
Bram
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Bump. No one has any discussion about the raw un-machined sides of the Manley turbo Tuffs?
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Old 10-28-2017, 10:00 PM   #3
Bram
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This is what im talking about.

This is an OEM rod, in a OEM crank. There is approx 0.0095" clearance between the 2 machined surfaces. But those surfaces are what stops the front back float of the con rod on the crank pin. The surface of the crank is machined flat, and it sits proud. The corresponding side surface of the rod big end is machined flat and sits against the crank surface.
2017-10-29_09-45-34 by bram biesiekierski, on Flickr

If you look at this close up of my Manley Turbo Tuff, you can see its raw. Does anyone else think this may be an issue???
2017-10-29_09-54-47 by bram biesiekierski, on Flickr

I only have access to OEM, manley H-beam and Manley I-beam currently. But it is clear that the I beam is the odd one out with the lack of cut surface on the side. And also lack of any oil wiper notch.
2017-10-29_09-50-24 by bram biesiekierski, on Flickr

Thoughts?
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Old 10-28-2017, 10:53 PM   #4
Bram
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If you look closely at the used OEM rod in the above picture you can even see the wear marks on the side of the big end where it meets the crankshaft. So clearly these surfaces are contact surfaces. I am really concerned with these manley rods not having a smooth face.
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Old 10-29-2017, 09:16 AM   #5
Homemade WRX
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Yeah, those 'oil wipers' as you call them, are our oil piston squirters. You'll want them.

By side machining, I'm guessing you're asking about the thrust clearance? Sorry, scanned briefly.

Last edited by Homemade WRX; 10-30-2017 at 08:12 PM.
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Old 10-29-2017, 09:28 AM   #6
Bram
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Quote:
Originally Posted by Homemade WRX View Post
Yeah, those 'oil wipers' as you call them, are out oil piston squirters. You'll want them.

By side machining, I'm guessing you're asking about the thrust clearance? Sorry, scanned briefly.
Yes and yes.

The sides of the big end are raw and un-machined. These are the thrust surfaces that run against the crank shaft. They stop the rod floating for or aft on the crank pin.

And yes, the slots at the base of the rod, on the sides of the big end that face towards the piston.

These Manley I beams have neither.
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Old 10-29-2017, 09:51 AM   #7
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Have you called turbo ruff and asked them?
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Old 10-29-2017, 05:34 PM   #8
Bram
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Quote:
Originally Posted by carlos.danger View Post
Have you called turbo ruff and asked them?
Im in australia. So havent called. But i have emailed the retailer i purchased them through. Will wait for the reply.
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Old 10-29-2017, 06:16 PM   #9
Pro60modman
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The oil rails machined into the rod are not necessary for street or drag applications. If you are building an engine that will see significant circuit course time then the oil rail slots are recommended. Check your side clearance and if it's tight enough then machine the sides, otherwise don't use them.
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Old 10-29-2017, 09:52 PM   #10
Bram
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Quote:
Originally Posted by Pro60modman View Post
The oil rails machined into the rod are not necessary for street or drag applications. If you are building an engine that will see significant circuit course time then the oil rail slots are recommended. Check your side clearance and if it's tight enough then machine the sides, otherwise don't use them.
Engine is specifically being built for circuit/targa racing. Car is technically still street registered, but is never actually driven on the street. And it is always trailered to/from race meets and such. The car is far too modified to be practically driven on the street.

What would be the maximum acceptable side rod clearance if I were to have the sides ground/machined smooth? Obviously machining them smooth would take a significant amount off the sides, therefore increasing the side clearance.

For what its worth. I also purchased a Manley 75mm crank in the exact same order. And it is machined smooth on the corresponding surfaces that the rod sides would face up against. So im still confused why manley would not machine the rods smooth, yet clearly they know that side surface is important, otherwise thier own cranks wouldnt have the additional side machining done during the manufacture.
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Old 12-11-2017, 02:48 PM   #11
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From My understanding, The H-Beams start with a lager forging. So they cut down the big end width. Shot Peen the rods. Then touch the faces slightly again. The TT IBeam forging is rather spot on to the size from the get go. 0.840" big end width. So they require very little machining to square up the big end width. Then they Shot Peen the rods after final machining. Though the surface looks rough, is not as rough as some might think. Ive never seen a issue with using them personally.

I currently have 4 sets of TurboTuffs and 3 sets of H-Tuffs bnib if anyone wants measurements of consistency etc.

Im on the fence, but might pick up a set of +2mm Tri-Beams soon for a personal build.

Ian,
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Old 08-14-2020, 12:30 PM   #12
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Old, but perhaps it needs a ribbon on it?
The texture on the rod shown is made by shot peening. It is not "bead blasting". Technically, very different processes!
Peening can be done with different sizes of shot and different materials for the shot and it can be applied gently or more forcefully and it can be applied for a few seconds or for many seconds. It is a stress relieving process that helps remove stress risers and it generally work hardens the surface down a few thousandths of an inch or deeper. In the steels we are focusing on, it is not very deep.
However, the surface finish on the rod shown looks relatively coarse. From reading, and looking at the many sets I have from various manufacturers, the finishes vary and some do post peening operations. The range of thrust clearance is fairly large. If the texture concerns you/anyone they can be hand lapped to reduce the roughness. You might keep in mind the nominal .005" clearance Subaru specifies and the fact that their rods have oil squirter channels. As the thrust gap grows the squirter's effectiveness lessens.
If you consider the forces, there is really none exerted on the sides of the rod!
I would think an oil film, any oil film, would be able to prevent wear. Prove me wrong...
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