[t money]

Originally Posted by Stan Weiss

Back in the early 70's I had a friends father who had a machine shop open up / clearance a set of SBC rods and ran them with no bushings. I turned that engine between 7500 and 8000 RPM and never had a problem.

Stan

I believe the boss 302 came from the factory like that and remember reading on a ford form that one of the guy raced his boss 302 27 years that way every refresh the pin is like new. I maybe wrong but the z28 302 is the same way

[Formulajones]

The 67 and 68 chevy 302's were press fit pins. In 69 they went full floating.

Speaking of these I-beam forged rods, when I rebuilt our 69 DZ 302 I went with a set of new forged I-beam rods that are full floating from Eagle. So I don't see why they don't offer them that way for Pontiac...er well, I can.

[phil400]

So is it worth replacing the 3/8 ARP bolts that come in the RPM 5140 rods with 7/16 or are the 3/8 ARP ok for most street builds?

Will the Eagle 5140 rods be available exclusively at Butler's?

Any word on the fit and finish of the new Eagle rod?

[Formulajones]

On mine we had to tweak the bushing on the floating end just a bit for more clearance. Machinist didn't like how tight they were.

He also checked the big ends and touched those as well. Can't remember if it was to get the bearing crush he wanted or roundness or...but there was something he didn't like about it.

We also switched out the ARP bolts for a different material ARP bolt, same size. I think it was 8740 to 2000

But that stuff seems to have always been pretty routine every time I've bought an aftermarket rod.

[Cliff R]

"On mine we had to tweak the bushing on the floating end just a bit for more clearance. Machinist didn't like how tight they were."

I have a ball hone set aside for that purpose and have used it on every single set of offshore "H" beam bushed rods that have came thru the shop as they are always a bit too tight for my liking. Even so it usually only takes about 25-30 strokes with a hand drill to get adequate clearance for most of them.

Having bushed rods is really not a performance "upgrade" as pressed pin rods are fine for high performance use even in severe applications. The biggest advantage is not having to heat the small end of the rods to push the pins thru them. Some piston designs also fair poorly when you find yourself having to press the pins out of the rods for some reason.

I drag raced a 292 CID small block Chevy for quite a few years. Shifted around 7000rpm's and went thru around 7500 with pressed pin factory rods and never had any issues with it other that having to change the valve springs couple of times a season.......Cliff

[track73]

Back in the 70's I took Chevy Pink rods and had the small end honed for full floating pins. I drilled an 1/8 inch hole at the top and chamfered it with a 1/4 drill to make sort of a funnel for lubrication. No bushings needed. I was told bushings made them weaker. It worked for 7000 rpm circle track engines,

[Formulajones]

Yeah this day and age, I didn't want to reuse the original full floating pink rods even though they were perfectly fine, they were still 50 years old and the cost to refurbish them was more than half the cost of a brand new stronger and lighter piece. And with the cost that these original blocks and crankshafts bring on the market these days it just made more sense. I wanted to have a little fun with it and buzz it to 7,000 on occasion without worrying about it so much.
These 5140 I-beam rods upgraded with better bolts was an inexpensive alternative and made the choice easier. Of course a lot of parts for the SBC are inexpensive when you compare to a Pontiac.

[mgarblik]

Originally Posted by phil400

So is it worth replacing the 3/8 ARP bolts that come in the RPM 5140 rods with 7/16 or are the 3/8 ARP ok for most street builds?

Will the Eagle 5140 rods be available exclusively at Butler's?

Any word on the fit and finish of the new Eagle rod?

You are locked in on the rod bolt size. You could possibly replace with a better material ARP fastener. They have several grades and tensile strengths. However, if you go to a stronger bolt, the torque clamp load will be higher, so now your into resizing the big ends because they will crush and egg shape when torqued. So IMO, plan on using them as they come. Like all new engine parts, they need to be checked and measured before use. My experience with Eagle components is they are improving every year in delivered quality. When we first started using them, every rod had to be broken down, cut and re-sized. None were even within the rather loose factory tolerance, let alone a race tolerance. Now a typical set of 8 may require 1 or 2 to have to be re-sized because they won't meet our +-.0002 tolerance. Seems the pin ends on floaters are a little tight as well, typically, .0002-.0003. So not bad in general.

[phil400]

Originally Posted by mgarblik

You are locked in on the rod bolt size. You could possibly replace with a better material ARP fastener. They have several grades and tensile strengths. However, if you go to a stronger bolt, the torque clamp load will be higher, so now your into resizing the big ends because they will crush and egg shape when torqued. So IMO, plan on using them as they come. Like all new engine parts, they need to be checked and measured before use. My experience with Eagle components is they are improving every year in delivered quality. When we first started using them, every rod had to be broken down, cut and re-sized. None were even within the rather loose factory tolerance, let alone a race tolerance. Now a typical set of 8 may require 1 or 2 to have to be re-sized because they won't meet our +-.0002 tolerance. Seems the pin ends on floaters are a little tight as well, typically, .0002-.0003. So not bad in general.

Ok thanks

[Will]

Isn't the whole point of the rods in question to be a reasonable cost stock replacement?

If you need a stronger rod or a full floater then just buy them. Trying to make these cheaper rods something they're not with stronger bolts or honing the small ends seems strange to me. By the time you're done you'll have as much in them as a better set of rods...

[Schurkey]

Originally Posted by mgarblik

My experience with Eagle components is they are improving every year in delivered quality. When we first started using them, every rod had to be broken down, cut and re-sized. None were even within the rather loose factory tolerance, let alone a race tolerance. Now a typical set of 8 may require 1 or 2 to have to be re-sized because they won't meet our +-.0002 tolerance. Seems the pin ends on floaters are a little tight as well, typically, .0002-.0003. So not bad in general.

Yeah. Who would expect Eagle to build them right, OR to be consistent.

[Formulajones]

It's just the way things are. You would never buy brand new parts without checking them first, at least I would hope not. Then there is the picky machinists who prefer their own clearances based off experience vs what these parts show up with. So they almost always need tweaked. That's just part of building an engine properly for those that care, even a street engine.

Since we were into the rods tweaking clearances, it made sense to upgrade the bolts on mine, for what I was doing and the application it was intended for. Not like your spending a ton of money. What's another $100 on a near $7,000 engine rebuild.... Doesn't matter if I bought a Crower rod that is 3 times the cost, I'm still going to check the clearances and tweak if necessary and most likely spend a little more money.

These aren't really considered stock replacements either, they are an upgrade from stock. Not really sure where that thought came from but a stock replacement rod it certainly is not. How can you go from a cast 3/8 bolt rod to a forged 7/16 piece and call it a stock replacement??? I don't grasp the logic on that one.

[72LuxuryLeMansLa.]

I was told by a machinist that the small ends on the rpm floating rods are manufactured slightly tight so that they can be accurately fit to the pins depending on the application. True or not? Just what I was told.

[Formulajones]

Originally Posted by 72LuxuryLeMansLa.

I was told by a machinist that the small ends on the rpm floating rods are manufactured slightly tight so that they can be accurately fit to the pins depending on the application. True or not? Just what I was told.

I don't know if it's done in manufacturing on purpose or not, but I seem to remember Paul telling me how they tweak the bushing end to a specific clearance depending on the application it's intended for. We got on that discussion over an engine that came back in for a freshen up, and one thing he looks for is how the pins are doing, and tweak as necessary.

Not his words exactly, he could explain it much better.

[ponyakr]

"...How can you go from a cast 3/8 bolt rod to a forged 7/16 piece and call it a stock replacement??? I don't grasp the logic on that one..."


I suppose words & phrases can mean different things to different people. In this particular application, to me, it means that it is one of the cheapest ways to replace the stock factory cast rods, in a Pontiac engine. No new cast rods are being made, as far as I know. So, the cheaper forged rods would be considered "stock replacements", while also being an upgrade.

But, I'd recommend spending a few more bucks for the RPM H-beams. Hey, lighter, stronger, & available in bushed or press pin version. To me, it's a no-brainer. But, what do I know.

http://www.racingpartsmaximum.com/sa...elhbeam-2.html

[JLMounce]

Originally Posted by ponyakr

"...How can you go from a cast 3/8 bolt rod to a forged 7/16 piece and call it a stock replacement??? I don't grasp the logic on that one..."


I suppose words & phrases can mean different things to different people. In this particular application, to me, it means that it is one of the cheapest ways to replace the stock factory cast rods, in a Pontiac engine. No new cast rods are being made, as far as I know. So, the cheaper forged rods would be considered "stock replacements", while also being an upgrade.

But, I'd recommend spending a few more bucks for the RPM H-beams. Hey, lighter, stronger, & available in bushed or press pin version. To me, it's a no-brainer. But, what do I know.

http://www.racingpartsmaximum.com/sa...elhbeam-2.html

This seems to be how Eagle themselves are billing them. Why pay the money to recondition 40+ year old factory rods, when for the same money you can purchase these new rods that are slightly stronger and lighter. They are listing the MSRP at around 450, but I see Butler is carrying them around $319.00

Eagles weights them in around 870g.

[ponyakr]

"...Butler is carrying them around $319.00..."


Yeah, & the shipping is probably $20-$30. So, if the total cost is $340, that means that you can have the lighter, stronger RPM H-beans for only $60 more.

Anybody here think the RPM H-beams are not worth $60 more ?

Price on their website is $400, & they ship free.

"...Standard Delivery - We pay the freight for UPS Ground anywhere if the Continental US. Please allow 3-7 days to receive..."

http://www.racingpartsmaximum.com/sa...elhbeam-2.html

[JLMounce]

That probably depends on the individual circumstance, I would think. Looking back to my economics study days, even modest cost increases can outprice would be buyers. For me, is that extra $60.00 for the RPM rod better? Yeah. For somebody else that isn't necessarily in need of a better rod, but is budget limited and wants his car on the road sooner, it may not be.

At the end of the day, any quality product coming to the market to help keep pontiac engines in pontiac cars, I'm good with it!

[ponyakr]

Originally Posted by JLMounce

That probably depends on the individual circumstance, I would think. Looking back to my economics study days, even modest cost increases can outprice would be buyers. For me, is that extra $60.00 for the RPM rod better? Yeah. For somebody else that isn't necessarily in need of a better rod, but is budget limited and wants his car on the road sooner, it may not be.

At the end of the day, any quality product coming to the market to help keep pontiac engines in pontiac cars, I'm good with it!

Yeah, I used stock, non-resized cast rods in most all my 455 bracket engines, because of a low budget. Even had cast factory pistons in my 1st 455. Never lost a rod or piston, street or strip. I suppose that for those on a REALLY low budget, cast resized rods will save a few bucks vs the $340 Eagle 5140's. Back when the RPM 5140 rods were barely over $200, everybody said they were cheaper than having cast rods resized, using ARP bolts. But, now that they are in the $300 range, which is cheaper ? Somebody who has recently had a set of cast rods resized, please post what you had to pay. Good cast rods are safe to 5500 rpm, in a 455. I'm sure of that, because of how many times my 455's hit the rev limiter, set on 5500.

For all the 455's I built, I did upgrade to TRW forged pistons. Were they ABSOLUTELY necessary ? Probably not. Lots of guys have used cast pistons in 455 engines, without piston problems. I consider the price difference between cast & SP forged pistons WELL worth it. Others here may not. Same for $340 5140 forged rods vs stronger, lighter $400 H-beams. I suppose for some, $60 would be a deal breaker. For others it would be a very wise use of $60.

[JLMounce]

Like you, I've had good luck with my factory rods. Topped with Speed Pro pistons, the engine sees 5700 rpm pretty much any time I take the car out. While I don't beat on the car, it gets driven hard and sometimes put away wet.

When it's time for an upgrade on my end, I've been leaning towards the Molnar's myself, but it's good to know more options are opening up.