I had my engine rebuilt 3 years ago. I was promised chevy stage 2 rods capable of handling up to 450hp. Consequenlty, the crankshaft had a flaw in the snout and snapped with the additional force of teh blower pulley I need to know if the rods I have are capable of my needs? I had 290rwhp with 6psi and now I have 9psi and plan on using a 50-75shot of NO2. Will these rods be sufficient?

Thanks!!!!!!!

 

another

 

Yet, one more. Just want to see if I did infact get the Chevy stage 2 rods??????

Your help's, well:hail: :hail:

 

They look exactly like the ones that came from the factory in my 350 Vortec engine, which would make them "nothing out of the ordinary." And the fact that they have factory rod bolts doesn't make the outlook any better...

 

Yea, I knew they did not have arp bolts, however, I did see some other rod's that looked like they were the same thickness one each side. The one's posted have one side thicker than the other???

 

You mean the bolts? Yes, on my factory rods, the side that goes through the rod itself is thicker and has a crosshatch design etched in it. I still say factory rod bolts, or OEM replacements at least.

Or do you mean on the connecting rod itself on the "I beam" part? In which case, they still look like my Vortec rods.

 

¿¿Stage 2?? Never heard of any such, from the factory anyway.

They look like pretty ordinary rods to me; maybe the builder's "Stage 2" is the level of prep applied to them. In that case, I don't believe I'd want any Stage 1s, that's for sure. Mayeb not even any Stage 3s.

Put some better hardware than those stock bolts in them, they should be OK for that little bit of power.

 

whew. I was hoping I wasn't the only one not hearing of a stage II rod from GM. I know Summit offers a "stage II" rod which is basically an I beam with good bolts. They are rated at 450. Keep in mind though, rod ratings are usually given at the crank (where the rod is, incidentally) and you give rwhp numbers. Also, I'm not really sure how to go about putting faith in "hp ratings" for rods. I more or less think its a stress factor like RPMs and sudden changes in applied force (i.e. nitrous at a lower engine speed) that breaks or twists a rod. Not saying there isn't a point where sheer power will trash a rod, because I know there is. That's just me, though.

Take them to a shop, get some ARP bolts (I'm a fan of the Wav-loc series) and have them resized.

 

Yea, I was told GM had a stage 1 and 2 rod. The stage 1 =350hp, stage 2=450hp??? Anyway, I am hoping that I can keep these rods with hopes of achieving 375rwhp? What are your thoughts? IF I do keep these rods, they will have the arp wave bolts!

 

I'd say 375rwhp is pushing it on stock rods. Sure people have done it, but its all about risk. What are the plans for the engine? How much do you have to spend? I wouldn't use those with nitrous or forced induction. Take a look at the Eagle rods they are goods rods for a fair price.

 

they look like gm "pm" rods they are suppose to hold in excess of 450 horsepower.. most of your zz crate motors came with these too

 

How can you tell the difference between gm pm rods and standard gm rods? The only thing I was able to tell is the I beam structure is thicker on one side that the other side? I thought the PM rods had a pink circle near where the rod meets the crank?
The first two pic's are of the thick side of the rod. The Third pic is the thin side of the I beam........

so 400rwhp, They OK, or not OK?

 

They do look like PM rods, they don't have balance pads.

 

huh? Balance pads? How can I tell which rod I have???

 

Look at them, take a bolt out and look at it. Does it look factory?

Stage II heads = factory resized rods with better bolts and may be alittle smoothing or stress relief.

 

yea, they look factory. but could the balance pad have been ground off since the engine was balanced? Just a thought, never seen a balance pad.

 

Do all the rods look like that. PM rods are very uniform and are balanced as cast. They don't have a big bump of iron sitting there to grind and balance the rod.

 

yes, they all look exactly like that one. Do you think these rods will sustain up to 400rwhp? Or is it time for new ones (that I can't' afford)

 

They will if you have some good ARP bolts put in. PM rods are really strong. All of the rod making companies are starting to switch over to PM technolody because they are better all around. The new Hemi uses them, Japanese automakers and GM has used them for 10 years now they also use them in the LS1 varients.

The most stressed part is the rod bolts, they will break way before the rods will. Rods only break because the bolts break and stuff goes crash bang boom in the engine. Those rods should take plenty, but the bolt won't.

 

OK, next delema. IF I take the rods and get them checked and new arp bolts put in, will they need to be resized? They were balanced, the only new part is the eagle 4340 crank. OR can the machine shop just put the new arp bolts in and simply check the rods?

Thanks again!!!

 

Any time you get new bolts, they need resized as seen fit.

The cap sits just a tiiiiny bit differently with new hardware so the rod needs to be brought back to round again.

 

I am doing a rebuild on my 305 HO but I am going stock on most except little larger cam and 1.94 intake valves and headers. Will the stock bolts be ok. I really am running out of money on this rebuild.

 

If they're pressed fit pins, and it looks like they are, they'll have to be taken to a shop and pressed off the piston. After that the rod bolts can be pressed out and replaced. When all's done the rods bottom end will have to be resized.
I'm having the same thing done to a set of my own rods this wk. because as I was assembling my bottom end, I felt some of the used factory rod bolts stretch quite a bit.
It will cost about $150- $175 and it hurts, but if I don't do it, I'll be cringing every time I punch it.

Yeah, those look an awful lot like PM rods to me.
Stage II ???
Maybe that means their first stage of life was in the original engine, now they're on their 2nd stage.
If it makes you feel more comfortable there are guys with 11sec N/A cars using PM rods.


Oh... Also,
If you decide to take those in and have them pressed off the pistons for a new set of ARPs, be sure the shop you're taking it to has the right type of press for the task.
Some shops use a press that just uses the piston for support as the pin is pressed through. And that can wreck a piston.
Just be sure to make it clear that you want to re use the piston again when you order the work.

 

A LOT of engines are assembled with used factory rod hardware.
If this is your engines first rebuild, the rod bolts probabaly haven't been over stretched, and they will work out.
The engine I'm building is +.060 that has a set of stock rods that are of questionable origin.
It's always reassuring to know the origin of a set of rods, if they're used ones. If they came from a stock 305 that's on it's first rebore, chances are they haven't taken too much punishment.
I'd say use the factory hardware if you're in a $$ bind.

 

Then it's time to wait and save up a bit more, or earn some more somehow, or something....

Ask yourself: how will your money situation be if you build it, and you're driving down the street, and a rod bolt lets go?

Factory hardware is great for factory motors, put together at the factory under factory conditions including being brand-new, and used as a factory motor is intended by the factory to be used. If you're just rebuilding a stock motor in a mostly stock way with the typical myriad of tiny downgrades that go with a typical maintenance-or repair-oriented rebuild, then you can "get away with" re-using the stock hardware, probably. If on the other hand you're trying to get more out of the motor than the factory did, especially if you intend to run it at any higher RPM than they intended, then their hardware is inadequate in its specs when new, and already weakened from prior use besides. It's one of the wisest places to use your limited funds; as opposed to chrome timing or valve covers or "noisy" gear drives, for example.

 

Well, It is going to cost me 50 bucks to have them resized and another 50 for arp bolts to be pressed in. I purchased a set of scat 4340 rods for 300 bucks. Now, I may just put another 400 on hte visa for a set of forged pistons. The hyperutetic pistions I have are in excellent shape and I really can't affort the forged now, but man, I don't wanna do this project again! Been thinking of selling hte rods and pistions on ebay, but not sure if it's even worth it?

Thanks for all of your help and input!:hail:

 

thats what i was thinking buy new rods.for what new ones are worth you may as well.get the forged pistons you dont want to do it again. i cheaped my last engine only lasted 3000 miles before it flew to pieces

 

Yes... When it comes to shop labor, it gets to the point where a new set of replacement rods can be less expensive.

Naturally there are differing opinions on this. And I'm not really debating, but "clarifying"

What it ends up boiling down to is this:
The likelyhood of failure of a given part under certain conditions.
And a builders willingness to pay, to reduce that likelyhood.

It's like buying insurance, if you want more coverage, you pay more $$.

Countless engines have been rebuilt, using stock bolts, that put out more power than your 305 will.
I'm not sure of the percentage of those that held together or failed.
I'm certain though, that if you compared that with the failure or success rate of engines built with new ARP bolts, the failure rate would be much lower with the ARPs.

As I mentioned, there are a lot of successful rebuilds using stock hardware.
There are also cases of rod bolt failure in stock engines as they sat idling in the driveway.

It's true that the rod bolts are the most critical fastener in an engine.

With rod bolts you can feel if it reaches the yield point before it gets to the specified torque setting as you're tightening it. That can be very helpful to know, when using used hardware.
You know bolt is junk, when it stays at 45 lb/ft for 1/2 turn and the torque spec is 50 lb/ft.

Or you can spend more $$ and be sure.

 

I am selling the pistions with the rods. I took the rods and pistons to a machine shop and they said they were pm rods, but since I anticipate using the blower and nitrous, I am going all forged. I hate to spend the cash but like I said, don't wanna do this project agian! so my .020 over hyperutectic pistions with the rods (which have been balanced to each other) are for sale. If I was not going to use the additional 150 shot of NOS on top of my 10psi of boost, I would keep the hyper's.

 

All SBC rods are forged even the PM.

 

Don't mean to pick and nag, but the bolts look exactly like my ARP waveloc bolts in my GM "X" rods. (which most engine builders think are stronger than pink rods, but whatever).

IROCBlueZ28: If the bolts say "ARP" on the top, then just have the rods checked.

If they don't have ARP bolts, just throw them away.. Eagle I beams can be had under 200 bux.

-- Joe

 

I spoke with Craiger..Raiden and he gave me his connection and I got a set of Eagle forged rods for about 210$ I plan on selling these on ebay. I did find that they were infact the chevy PM rods and capable to withstand 450hp max. Now, I know my set up will sustain at least 600hp I got 4340 crank, forged rods, westco pistons/rings and 1000 miles on her, she's running great!

Thanks for the advise.

 

Was that the H beam or I beam eagles?

-- Joe

 

It was the I beams 3irc with the arp wave loc bolts

 

Ahh Ok thats what I thought., Yeah I see those for about $180 - 190 now.

I'm gonna get some H beams for my new rig.

-- Joe