Are These Rods Good?

[stanhayward]

http://www.ebay.ca/itm/BMW-M20-325e-...vxp=mtr&_uhb=1

Does anyone have experience with these? Balanced to within a gram (apparently) and ARP 2000 bolts? Seems like a killer deal if they're actually well made...

[nando]

are you sure you want 130mm rods?

[stanhayward]

Yup, I am putting together a budget stroker with an M52 crank, 130mm rods and stock i pistons and 0.5mm decked off the block. I know the rod length is too short for the best performance, but for right now this is all I need.

[Cayoncrusier93]

I have NOT used them but from reading the description, "made from 2 separate Pieces for stronger strength" what is that suppose to mean? Seems weird, i would think they are cast in one piece?

[stanhayward]

I have NOT used them but from reading the description, "made from 2 separate Pieces for stronger strength" what is that suppose to mean? Seems weird, i would think they are cast in one piece?

It seems too good to be true honestly, especially with a lifetime warranty too... I may just have the stock b27 rods I have balanced and but some ARP rod bolts for them....

[TobyB]

Seems like they spend more time marketting the bolts than the rods-
I'd find some decent OEM rods, buy the good bolts, and be done.

Because BMW did NOT use Chinese made rods of unknown quality back then...

t

[digger]

the issue will be a big end / pin size accuracy on a low hp application. the material wont be the limiting factor. eta rods are alot cheaper and go with the budget theme

[redlightpete]

the issue will be a big end / pin size accuracy on a low hp application. the material wont be the limiting factor. eta rods are alot cheaper and go with the budget theme

Try to get some with good pin bushings to avoid having to get replacemant ones sized.

[EatsHondas]

Balanced within a gram? Is that supposed to be impressive? A blind kid could do that with a whetstone. Precision internals are supposed to be measured to within .0001 (ten-thousandths) of an inch and at least hundredths of a gram if not smaller. I would stay away from these rods.

[digger]

Balanced within a gram? Is that supposed to be impressive? A blind kid could do that with a whetstone. Precision internals are supposed to be measured to within .0001 (ten-thousandths) of an inch and at least hundredths of a gram if not smaller. I would stay away from these rods.

hundredths of a gram lol

[EatsHondas]

hundredths of a gram lol

Am I wrong?

[digger]

Am I wrong?

a tenth of a gram is more than enough, any less than that and i think people are exaggerating the accuracy of the scale in a 500g part.

1 tenth is 0.1g, so this in 500g is 1 part in 5,000 or 0.02%
1 hundredth 0.01g, so this in 500g is 1 part in 50,000 or 0.002%

[LJ851]

Precision internals are supposed to be measured to within .0001 (ten-thousandths) of an inch

LOL, one ten thousandth.

[nando]

.0001, you can't even measure that accuratley. Thermal growth from holding the mic in your hand is probably more than that.

Aircraft parts are often to .001 or maybe .0005 at most...

[SkiFree]

and to understand the weight of a gram in practical terms...... it's about the weight of a single sheet of copy paper.

And for the record, these rods are not balanced even close to the advertised amount. As all China parts, it's always hit or miss to start with. The only saving grace is the diligence of the middle man (I wouldn't say a ebay store middle-man is all that diligent). It took 3-4 sets to put together a decently "balanced" set.