niphilli

Hey Guys,
Just wanted to get the general consensis on Hardened pushrods. Seems like everyone is using them. Just wondering if they are really nessisary. I am looking at getting a T1 cam and I am wondering if the lobes are really aggressive enough to cause a stock pushrod to bend under normal conditions (no missed shifts)? I have always been under the impression that I would rather bend a pushrod than a valve, but it would be a pain if the stockers bend under normal driving conditions.

TIA,

niphilli

Anyone have any input??

TTT

JoSeY

VERY VERY NECESSARY especially on a Manual...doesn't take but an hour to swap'em out if you've already had the coils off and only used one or 2 bolts again to put'em back on, but if it's ur 1st time to have coils off...look out that's a pain. LOL...

100 bux is good insurance for a relativaly easly replaced fragile internal part.

99 Black Bird T/A

iTrader: (4)

Last Katech had a bullient of their website, that mentioned stock push rods flex under load more than stiff push rods do. The stock push rod flexing makes it harder to control the valve train. IMO this was enough to make me want to get rid of the stock push rods. I didn't save a copy of the article but I wish I had. Trick Flow has an LS1 harden/stiff pushrod that should cost ~$90

Based on the Katech article I think the "weak stock pushrods are a fuse" line is pure crap. When the stock push rod flexs it makes it harder for the spring to control. Problems can occur when the valve train gets out of control. In other words, flexing pushrods make problems more likely to occur.

pimpmaro

I've always heard that the stock pushrods are the weakest link in the ls1 valvetrain...

niphilli

I definately have also, but I have also seen people bend pushrods & valves at the same time.

I guess the real point of my question is: Do the stockers flex enough with a small ish cam (MTI-T1) and a stock limiter or limiter 200 RPM higher to need a replacement??

I like the idea of having the pushrods as the weak link, but not if they are going to cause other problems under normal driving conditions.

99 Black Bird T/A

iTrader: (4)

Under normal driving, I don't think the stock pushrods are much of an issue. I think of normal driving as being under 4000rpm. My guess is if the stock rods do not flex until in the higher rpm range. At high rpm I don't won't to worry about flexing stock pushrods contributing to beating up the valve train or the valve job.

Dave Carney

I'm just not buying any of this flex crap. I'll be using stock push rods with my cam (225/223, .580,.564) and crane doubles. There are hundreds of guys using the stockers with aftermarket cams and no problems. Push rods can bend on a missed shift or whatever but I'm just not seeing this flex, then flex back to straight stuff.

1999_SS_M6

Thats just crazy to say that. Deflection is a reality, and with ramp rates as aggressive as some of the grinds running in these cars, it's definitely happening. I mean, if there are forces in the valvetrain sufficient to cause deflection in the rocker arm itself, how in the hell can you think the isn't enough force to cause deflection in a scrawny pushrod?

niphilli

I think of "normal driving" as pulling the car to redline in 1st and 2nd about 60% of the time I am in the car and not missing shifts . My rev-limiter will be kept stock for a while and I *may* bump it up 200 RPM at a later date.

4thGENRETARD

As said above, while replacing the cam, why not go all the way?? It's called insurance.

Why do poeple change the Timming chain? insurance.
Why do poeple change the oil pump? insurance .

Get my drift.

U can buy a complete valve Kit with Titanium retainers, springs, chain, P-rods and have a peace of mind. Maybe you don't beat on your ride, but the one day you will, you will be confident.
Have No Fear is necessary in any race. Why take the risk?

MyLS1Hauls

iTrader: (2)

I ran stock pushrods on my Comp 216 cam w/out any problems and reved it to 6500 rpm consistently. My buddy now has my TR 220 cam in his truck and is using stock pushrods w/ 918 springs and no problems. I did upgrade to the chromoly rods because they were only $80. I wouldnt want to use the stockers with an XE-R lobe personally, but they would probably be fine with a T1.

niphilli

No, the point I am trying to make is that GM made the Pushrods weak for a reason. If I can get away with using the stock (softer) pushrods without any problems and I do happen to miss a shift then I will most likely bend a pushrod instead of a valve (if it does not over-rev by alot). If you replace a factory pushrod with a pushrod whose yield strength is higher than your valves and you miss a shift then something has to give and it is probably going to be a valve.

Dave Carney

What are you insuring against by replacing the push rods? What is the risk that you refer to? IF the pushrod was to deflect (big "if") then what tragedy to think will befall us? .020 less lift? This isn't the same thing at all as replacing a timing chain or oil pump. The motor ain't gonna pop from a little less lift (again assuming this deflection is even possible)

CAT3

iTrader: (9)

Insurance my ***. How many people changed their timing sets n oil pumps and outta those how many HAVENT had problems? Not enough in my books.

I changed my cam and springs and prods, but not the chain and oil pump... I havent had any problems since, and dont expect to for many many many miles.

I do get the soft Prod, weakest link, or sacrificial lamb, idea..if something has to give on a miss shift/overrev...Why not make it the prods that cam be changed in an hour and be done with it.

JoSeY

i changed pushrods cause their easy and cheap...theres NO excuse not to change those guys out.

Go FasTA

You guys seem to forget that the reason that push rods and valves get bent/damaged when over-reving in a stock setup, is that the springs are too weak and allow for valve float. If you're installing an aftermarket cam, then you're replacing the stock springs with some that are much more capable of controlling valve float. Keeping the stock pushrods in this scenario is of no insurance. In fact, I would guess that odds are higher that the aggressive cam patterns will cause the pushrods to bend or even break which could lead to even worse problems.

Also, I don't buy for a minute that GM designed the stock pushrods to be the weak link for a reason. I think they simply put in as much as the car needed under normal conditions.

Smoke_Ford

Definetly do it if you do a cam, nice sig by the way, i wish my garage looked like that

Mike K.

Shoot who's to say that you wouldn't bend a valve and a pushrod? Also people have bent the stock prods on stock cars from overrevving. Chances are one day you will probably miss a shift and you just might bend a stock prod, I have hardened prods and have missed a few shifts and do not have any valve damage with my 224 and I think the t1 is a tad smaller so you may as well replace them just in case. Also I think the damage that occurs is from a mechanical overev like accidentally shifting from the top of 2nd to first not from a bump on the rev limiter in which case the chances are even less that you will cause damage cause it is even harder to mechanically overev. Plus say you do bend a valve it could be a justification to get new heads

dug

iTrader: (10)

Id run the stock p/r and see how the engine runs. You can always change them later without too much work.