Poor Man's RB26 Stroker....

[Danno]

What makes you think CAT manufacturers Tomei's rods? They say the material is (SAE?) 4340 - equivalent to SNCM 439, which is the same as Tomei's, but how does their quality control compare to others? Is it real SAE 4340, or "4340?" Think about the McDonald's "100% beef" brand patties, that aren't actually 100% beef.

4g variance is quite a bit for high performance rods. Check out what Carillo, Pauter, Crower, Cosworth do for their specs and tollerances. That alone should be enough to ward you away from those Ebay rods. If you're not a machinist, you also should factor in the time/cost of labour for your machinist to make the roundness of those Ebay rods within spec, and then balancing and anything else they might need.

I would have more faith in the stock rods than those Ebay ones. Avoiding paying for overpriced parts is one thing, but saving money by buying junk is another.

If you're feeling brave, go for them. If you can build a "poor man's stroker kit" for under 5k and make it last as long as Tomei's kit for example, power to you. Someone needs to be the guinea pig I guess.

[Terrh]

What makes you think CAT manufacturers Tomei's rods? They say the material is (SAE?) 4340 - equivalent to SNCM 439, which is the same as Tomei's, but how does their quality control compare to others? Is it real SAE 4340, or "4340?" Think about the McDonald's "100% beef" brand patties, that aren't actually 100% beef.

4g variance is quite a bit for high performance rods. Check out what Carillo, Pauter, Crower, Cosworth do for their specs and tollerances. That alone should be enough to ward you away from those Ebay rods. If you're not a machinist, you also should factor in the time/cost of labour for your machinist to make the roundness of those Ebay rods within spec, and then balancing and anything else they might need.

I would have more faith in the stock rods than those Ebay ones. Avoiding paying for overpriced parts is one thing, but saving money by buying junk is another.

If you're feeling brave, go for them. If you can build a "poor man's stroker kit" for under 5k and make it last as long as Tomei's kit for example, power to you. Someone needs to be the guinea pig I guess.

You should ALWAYS balance aftermarket rods, I don't care who makes them.

as a side note, I still don't think ebay manufactures parts. If I buy carillo rods from ebay, what makes them weaker than carillo rods I buy from the local engine shop at double the price?

I have "ebay" Eagle rods in my car. They were all within spec and balanced very tightly. I believe there was less than a gram difference between the heaviest and lightest rods, it may have even been less than that. It was closer than my stock rods were.


idk how good they are or not, I have around 17,000KM on my motor and it hasn't blown up yet.

[mcfly]

Every set of carrillos have showed up on my door step within .01g of each other. clearances have been within .00001 of that they specified too.

Being that, the only rod i have seen actually break in a rb26 without oil failure was an eagle. People have twisted jun and carr rods when they lost their pump but never break.

for the average engine i wouldn't think twice about someone using them. Doesn't mean I would, i'd prefer a stock rod over the eagle.

[GTR-Dad]

I think you're going to find that some guys are willing to spend more to get 'name brands' believing that the risk of rod failure goes down as price goes up.

There will be another more budget minded group that says 'show me the data'. I won't believe there's a problem until someone proves it to me.

I understand both perspectives! I'm personally in the first group based on the following logic...

1 - Consequence of rod failure is high.
2 - Rod-related failures can be triggered by material defects, forging geometry flaws, finish machining flaws, and probably some others I can't think of.
3 - Low cost manufacturers are highly motivated to maximize efficiency.

While their processes may be more efficient, QC and QA activities are also on the table. The easiest way to pass QA is to specify the widest tolerances you can justify and still achive the design intent. (This is just good engineering.) The magic is in determining what's critical, what the tolerance limits are to achieve the design intent, measuring what matters, and catching bad ones before they get into your engine.

Leaning only on manufacturing experience and logic, my concern with installing low cost rods would be with wider than 'ideal' tolerances, (Get more 'good' parts), and undetected non-conformances. (Material flaws, missed non-conforming dimensions)

It all boils down to risk tolerance. All too often people want a black and white answer and it's just not that clear. Your job is to sort out how much of the concern is real risk and how much is internet rumour and (wrong) perception.

To do a really good job of this, you need statistical failure data. Even if you could find it, interpretation would be very difficult. (Guys willing to shell out for expensive rods might tune more carefully and/or conservatively. Ergo, fewer failures for the same real risk.)

Just remember that one happy story about low cost performance parts doesn't mean every part is good. (Says Dan, thereby revealing his bias!)

Hope this helps.

Dan

[JD74]

..... I still don't think ebay manufactures parts..

I don't know about that......

I have literally spent about $5,000 on Ebay buying parts in the last month or 2...and I can honestly say something is fishy.

Here's what I think:
-------------------
EBAY maintains a slave-labour or child-labour factory somewhere in a destitue province of China where everything is manufacturered....most likely bordering North Korea in the North East somewhere.....
The people that are forced to work there are Parent's that can not afford to pay the $50 USD fine for having a second child, so they agree to 5 years of forced labour in lieu of cash payment.

The parts are manufactured (or, knock-off/copied, or what ever it is they do) by disgruntled factory workers...then the parts are branded with the manufaturer's logo of choice (for a realism effect)....then prepared for Export to North America (for all us suckers out there), where they are SOME HOW shipped TO the 'Manufacturer' of who's Logo the parts bear (that's the tricky part)......then THAT Company somehow unknowingly drop ships the parts directly to me, after I pay another retailer of said products, who places the order for it...SUPPOSEDELY, directly to that manufacturer for the purpose of Drop Ship sales in an attempt to further trick me into thinking I am getting REAL parts somehow.......

That, my friend, is some tricky stuff.

To top it off, no company is immune to it, as I have received MOST of my items drop shipped directly from the 'manufacturer'.

For example, I believe that somehow, there has been a security breach at Greddy USA, more specifically, in their shipping department, because all of the 'Ebay Parts' that I have ordered that bear a Greddy Logo, seemed to have come drop shipped directly from Greddy USA....in California.

This problem goes deeper than we all once thought.

Not only are the Ebay people able to 'knock-off' Greddy parts, they have also found a way to forge Shipping and Customs Documentation as well as online Tracking capabilities (hence why I think N.Korea is involved somehow as well......some SCARY stuff).

I used Greddy, as simple an example, as I have received quite a few things bearing that logo.....but I am sure that other name brands that I have ordered might be subject to the same 'conspiracy'......ESPECIALLY the 'dop shipped' items that come directly from the 'manufacturer'.

I will not rest untill I get to the bottom of this, as this continues to hurt the JDM marketplace more and more every day......and I don't want to be the one to tell JDM suppliers that 125% markups might not be possible if this trend continues......and a standard "wholesale + 30-50%" markup that other people in the industry use, may just become common place.

I will keep fighting the good fight for everyone out there that needs a $150,000 'Benz to drive to work in, while I drive my 20 year old GT-R

God Bless us....everyone !
Allan

[sidewayz32]

WOW. you should cut back on the kronic and use the internet for something usefull..................like porn or naked women lol.

[JD74]

WOW. you should cut back on the kronic and use the internet for something usefull..................like porn or naked women lol.

Please tell me that your comment is the result of atleast a High School education ?.......(I hear STUPID is 'catchy')....

[Shadao]

Please tell me that your comment is the result of atleast a High School education ?.......(I hear STUPID is 'catchy')....

you did go off the deep end there you know...

ya N.korea is trying to take over the world with ebay ooo ahhhh scary stuff...

i dont think you are smokin kronic, i think you are smoking straight up pure CRACK

and do you know how easy it is to fake a freakin waybill and customs documents... its easier than making fake parts using disgruntled child laborers

[JD74]

and do you know how easy it is to fake a freakin waybill and customs documents... its easier than making fake parts using disgruntled child laborers

In that case, I will need one of your Tinfoil hats.......as I am all out.

[JD74]

The SAD SAD part is, that because of the lack of READING skills that has become appearant to me, some are unable to even distinguish between sarcasm and reality.

Are you kidding me ? I support Ebay. Read the post again, hit yourself with a hammer.....then bring something back to the table, moreso than something I might find acceptable and expect from my neighbours 7 year old kid.

...god I hate the uneducated world we live in.

Reading is fun....try it. If the words are too big, I can help by using smaller ones next time.

[Shadao]

well you should note that scarcasm doesnt tranfer well to print.... the next time you go off on a rant like that...

[JD74]

well you should note that scarcasm doesnt tranfer well to print.... the next time you go off on a rant like that...

Fair enough......my appologies.

This was just a poor attempt by ME to put the 'Ebay Critics' to bed once and for all........and again, it blew up in my face ......lol