storm5.3

iTrader: (1)

Or can I run the stockers and get away w/ it. Comp 222/224 .566 .568 112 LSA. Plan on running up to about 64-6500 rpm...Zed

Nate_Taufer

iTrader: (1)

even though it's an auto, just spend the extra 100 bucks and be done with it...spend a little now or a lot more later. You're not gonna wanna tear back into the motor for something as trivial as a pushrod once you get it back together.

Nate

Nittany_marine

iTrader: (7)

Get the pushrods. Better safe than sorry. It's cheap insurance, if you think about it.

2MuchRiceMakesMeSick

What exactly is going to cost more?

If it was a M6 (and not a all out race motor) and you miss a shift. A push rod is a hell of a lot easier to replace then a lifter. I understand you want strength but why not make the push rods the weakest link for "cheap insurance". Just a thought...whats wrong with that idea?

PREDATOR-Z

What is wrong is where is it written that the p-rods are a fusible link??
If they bend, that means they flex, if they flex they are robbing you power and induce valve float.
Darn, I wish poeple quit refering to the stock p-rods as a fuse
Also stock p-rods are 7.38 in length and aftermarket cams are .03 smaller in base circle, so unless you have adjustable rockers, you're valvetrain geometry is out of whack by .03, and that my friend makes a noisy valvetrain and again a loss of power and worse if your lifts are pretty decent.
Sorry but please QUIT referring to stock p-rods as a good fuse.

Flareside

Are sure SURE about your facts? I'm not sure you should be "rolling eyes" at everyone that doesn't have the same internet engine building knowledge that you have.

Fact 1: Aftermarket cams are not all ground on a .030 base circle. They are ground on whatever circle is necessary to get the specified lift. I have a Comp 224 XER that's .045 smaller, an LPE that's .050 smaller, and an LS6 that's .025 smaller than a stock 1.55" LS1. Lobe height is limited by the height of the cam journals, so the only place they can change is the base circle.

Fact 2: An 03 LS1 (mine), came from Chevy with 7.400" pushrods. I measured them twice...

Fact 3: I'm running .040 less preload than stock (I'm @ .030"), and the valvetrain is as quiet as stock with AFR springs installed.

If you overrev an LS1, something is going to break. You're either going to bend a pushrod, kiss a valve, etc. I'd rather bend a pushrod, and not have to run overkill springs.

How much extra valvetrain weight are you adding with heavy pushrods, and how much are you increasing spring pressure and wear to accomodate them? Just another question that you should be thinking about.

Cal

iTrader: (1)

I have to agree. Designing an engine to fail is lunacy. There is no such thing as a "good fuse" for an engine. If the valves hit the pistons, your looking at a rebuild no mater what push rods you have. Better to prevent it with strong push rods than to plan for it with the weak stock ones.

PREDATOR-Z

.03 is an average, yes I know different cams may have different BC. thank You

Damn "my stock p-rods are smaller than yours" LOL

As for the internet motor building comment, well

Flareside

It's just frustrating to read all the bad information that's taken as gospel on this forum and continually regurgitated by people who haven't tested it. If you've never even measured a stock pushrod or an aftermarket cam, you can't know what's best for this guy's engine?

You increase pushrod strength and weight when spring pressure dictates it, not before. The parts replacement recommendations that you read here would lead you to believe that a stock LS6 with stock pushrods and beehive springs could never run at or near the rev limiter all day long on the track, but it does.

jimmyblue

iTrader: (11)

What about the inertial loads as you raise RPM? Your
pushrod load is spring + (rocker, spring, valve) inertial
on the way up. You tend to go to higher springs as you
build for higher RPM but that's (spring rate) not the whole
story.

Thing about pushrod-as-safety-valve is, I don't think there
is any good info on a pushrod fail-point vs any of the other
mechanisms and also using it as a crumple-zone for valve-
to-piston collisions is kind of too late, I expect. If you get
enough force to bend a pushrod out of that contact I don't
think anything else is trustworthy, after that.

I guess the question is, other than the hundred bucks,
"why wouldn't you?". Presuming that the stiffness and
toughness are there without a mass penalty.

PREDATOR-Z

Now bear with me while I'm following your gospel.
Comp 222/224 .566 .568 112 LSA. Plan on running up to about 64-6500.
That is the cam he is planning to run.That cam is an XE cam part# 54-426-11, XR275HR.
This cam is recommended with 26918 springs, Seat load 130 @ 1.80, open load 318@1.200 & coil bind 1.085.
Now please tell me these are the same specs than a stock 5.3L truck motor?? or an LS6 for that matter.
Can you assure me that stock GM p-rods will not flex under the load of this XE lobe and against those stiffer springs?
If it is better to bend the p-rods, can you also assure me that no other damage will result in the valvetrain (guides, valves ?)
I think not!!! Then WTF is YOUR gospel supporting??

Ben R

Valvetrain geometry is much more complicated than pushrod length. A pushrod length that is off by .003 will almost never affect your geometry by .003.

SiL3NtXWS6

iTrader: (17)

My stock pushrods after a mishift

Needless to say, they got replaced with strong ones. But i'm sure it could happen again, just not this bad.

Flareside

Geez, get over the pushrods already. As I said, pushrod strength has to go up WHEN/IF SPRING PRESSURE SIGNIFICANTLY GOES UP. Take from that what you will...

You posted the "rolling eyes" comment,implying that anyone who would question pushrods is an idiot, then proceeded to post a bunch of bad information that has spread through this forum like a virus. It's obviously wrong, so I pointed it out.

PREDATOR-Z

Why did you not replace with stock ones?

storm5.3

iTrader: (1)

This springs recommended on Comp Cams website for this cam are the 26915's but the "PREMIUM CHOICE" are the 26918's. Not trying to start a war here but my question still has not been answered clearly. I know of one person (slowprocess) that runs a TR224 w/ stock pushrods and he hasn't had any problems yet but this is in a 6.0 and I was just wondering if I could do the same. But some do have a point to go ahead and run the hardened rods to have peice of mind...Zed

PREDATOR-Z

YES you can but it is not recomended, you can take a poll if you do not believe
and best of luck

1madss

iTrader: (10)

The main reason I would not consider stock as a replacement is that the last time I priced them (about 4 years ago when I was running SI) they were $18 each. WAAYY more than a good set of aftermarkets.

PREDATOR-Z

.003 would be compensated and absorbed by lifter. But could we say the same about .03>.05 with non adjustable rockers. If so why such a small margin on different p-rod length? 7.35/7.40/7.45
Comp even has a 7.375 now.
Just wondering

PREDATOR-Z

Ok so you decision was based on price.
So 18x16= $288 stock replacements
or $ 109> $129 aftermarket

But if the stock ones could potentially protect a $5000 motor by being a "Fuse", shouldn't this warrant the "extra" expense??

The reason most of us do change to aftermarket is the same principle for insurance AND performance.