Eagle 135mm Forged H-Beam Connecting Rods?

[E30-TourZing]

Now that I have figured out my crank and rods are from a M50, I am in need of new parts. I will do my best to find a m52 locally for very little money, but if I cannot put together the package then I will have to buy some new rods.

Does anyone have any input on on the 'eagle 135mm forged H-Beam rods?'

I found some local in Canada which means it would save me a lot of money considering duty and shipping.

Any advice would be very helpful.

Thank you!

[digger]

get some OE 135mm rods, the m52 crank will probably come with them

[E30-TourZing]

Thank you for your input digger. You just feel the OE ones are good enough considering the cost of the eagles? or is it more related to the quality?

[digger]

OE quality will be good, eagle you have to check them. i'd get Molnar rods if i wanted an affordable aftermaket H-beam set with good quality.

[Northern]

I think Eagle are the same as a few others(K1, Max peeding rods, etc.), but they are more popular among the turbo 24v crowd. Maybe the QC is better than the others - I think I heard at least one case where the maxpeedingrods ones were out of tolerance.
If you aren't aiming for more than like 600whp, IMO it's better to go with stock m52 rods for QC and cost reasons. I don't think there's any weight savings to be had with the H-beam stuff over m52 or s52 rods anyway.

[pazi88]

I think Eagle are the same as a few others(K1, Max peeding rods, etc.), but they are more popular among the turbo 24v crowd. Maybe the QC is better than the others - I think I heard at least one case where the maxpeedingrods ones were out of tolerance.
If you aren't aiming for more than like 600whp, IMO it's better to go with stock m52 rods for QC and cost reasons. I don't think there's any weight savings to be had with the H-beam stuff over m52 or s52 rods anyway.

For turbo use the m52 stock connecting rods aren't good enough. We have managed to bend those even with 370 crank HP. M50 connecting rods are much more capable and in my engine, 560 crank hp wasn't problem for those. But those maxspeeding rods etc. aren't that expensive to get for turbo build. And the H-beam connecting rods are quite a bit heavier than stock m52 connecting rods. NA build would be much better with the stock rods.

[digger]

is this for turbo engine?

[whodwho]

...
And the H-beam connecting rods are quite a bit heavier than stock m52 connecting rods. NA build would be much better with the stock rods.

I have to challenge this, from notes I have these weights:

Rods
 M20B27 130mm - 617g
 M20B25 135mm - 640g
 M50B25 135mm - 600g
 M52B28 135mm - 575g
 S5x US 135mm - 540g
 M50tu 140mm - 675g
 Pauter 140mm - 510g
 Eagle 135mm - 549g

[ForcedFirebird]

The stock rods vary slightly in weight, but the sets will match about +/-3g across a set when from the same engine (A1-9, and B1-139 stamped on the bottom of rod cap). I have two "B3" and one "B6" 130mm rods sitting on my desk here and they are 601g, 603g and 610g respectively.

Splitting hairs, I know, but have had to replace a single rod on our race motor a couple times, and is always easiest to grab on that was factory matched to begin with, otherwise I end up shaving a ton off the cap weights for matching (typically get can them +/-.2g per end when building race motors).

Now that I have figured out my crank and rods are from a M50, I am in need of new parts. I will do my best to find a m52 locally for very little money, but if I cannot put together the package then I will have to buy some new rods.

Does anyone have any input on on the 'eagle 135mm forged H-Beam rods?'

I found some local in Canada which means it would save me a lot of money considering duty and shipping.

Any advice would be very helpful.

Thank you!

Using custom pistons for the 135mm rods? The 130mm m50nv and m20 rods are quite strong and fairly available, the 135mm m20 rods are everywhere and also very strong.

As others have said, the more budget-friendly aftermarket rods need to be checked, and often times machined. Since that's the case, might as well use factory rods and just have them reconditioned, if even necessary.

[ForcedFirebird]

For turbo use the m52 stock connecting rods aren't good enough. We have managed to bend those even with 370 crank HP. M50 connecting rods are much more capable and in my engine, 560 crank hp wasn't problem for those. But those maxspeeding rods etc. aren't that expensive to get for turbo build. And the H-beam connecting rods are quite a bit heavier than stock m52 connecting rods. NA build would be much better with the stock rods.

Be glad those aren't powder forged like the m54+ engines. They just break off, and won't bend like earlier rods.

[Northern]

For turbo use the m52 stock connecting rods aren't good enough. We have managed to bend those even with 370 crank HP. M50 connecting rods are much more capable and in my engine, 560 crank hp wasn't problem for those. But those maxspeeding rods etc. aren't that expensive to get for turbo build. And the H-beam connecting rods are quite a bit heavier than stock m52 connecting rods. NA build would be much better with the stock rods.

I've seen your results, but loads of people in the US are running stock M52 bottom ends up to 450~550 ftlb without issues for some time now, which is ~600whp.

You're right though, if you want to be 100% sure you don't have an issue with a turbo build, then yes, buy something aftermarket or chunky M50NV rods.


I looked at OP's other threads and it looks like this is for an 86x84mm NA M20 build, so I'd say definitely go M52 or S52 rods just for QC and cost reasons. No point in spending a bunch of money here for what you're doing

[Northern]

@ Keith, what do those weights include? bolts/bearings/pins wise?

[E30-TourZing]

Thank you for your responses everyone! This is all a big help

is this for turbo engine?

No, this is for a NA motor. I am building the 3000 Sport/Rally motor from metric mechanic. I hope to make somewhere around the 200 WHP range. I am getting notion that I would be potentially wasting my money on cheap aftermarket rods. I will stick with M52 135mm Rods.


Currently I have 140mm M52B25 rods. Unfortunately I think they will be a few millimetres to long with the 84mm crank. At-least I am under the impression 3000 S/R pistons are not designed to deal with that length of rod.

I also have some 135mm M20 rods, but I would like to keep the internals as light as possible. Jim from M/M has been super adamant on the phone, telling me to keep everything as light as they can be for performance and reliability.

[E30-TourZing]

This is a picture of the piston going into the motor -



P1011349 by Jan Willem Wilderom, on Flickr



These are the 140mm rods -


P1011528 by Jan Willem Wilderom, on Flickr

[digger]

Thank you for your responses everyone! This is all a big help


No, this is for a NA motor. I am building the 3000 Sport/Rally motor from metric mechanic. I hope to make somewhere around the 200 WHP range. I am getting notion that I would be potentially wasting my money on cheap aftermarket rods. I will stick with M52 135mm Rods.


Currently I have 140mm M52B25 rods. Unfortunately I think they will be a few millimetres to long with the 84mm crank. At-least I am under the impression 3000 S/R pistons are not designed to deal with that length of rod.

I also have some 135mm M20 rods, but I would like to keep the internals as light as possible. Jim from M/M has been super adamant on the phone, telling me to keep everything as light as they can be for performance and reliability.

so the OE rods still applies. Molnar/K1 are the H-beam you want if you need an economy aftermarket for NA as they are light strong and compact.

the MM sport pistons are probably designed for 135 mm OE rods.

light is good except when you go too far.