Nah bud, these were the pushrods that combination motorsports used to offer with their cam kits. As we know, combo is no more.. or at least, bought out by someone else...

After the day I'm sure to have today... I'll need about 5 beer:30's

 

well sence we are talking pushrods, and im going to step up to chromoly, how long should they be, I have a 383 cc306 +1.6rr 0 deck block with stock heads that are shaved .005 and .039 head gaskets, im useing 7.195 now should, and they look good but sit high on the studs should i go shorter? the chromoly ones im looking at are 7.200 will they be ok?

 

You should get an adjustable pushrod length checker that's within the appropriate range (6.8-7.4 or so) and check them. It depends on how the rocker is moving on the valve tip.

 

Just because something is "hardened" doesn't make it any stronger than a stock pushrod. It means the outer surface is a higher rockwell number (the engineering standard for hardness) so it can take metal to metal contact without wear. Cheap "hardened" pushrods are usually a lower quality metal, normally a carbon steel (1018-1026 tubing most times) not a alloy steel like a 4130 pushrod, and the lower qualty tubing that the stock ones are made of has a much thinner wall thickness than the seemless high quality tubing you use in good pushrods. THAT'S WHY THEY COST MORE!!!

The "hardened" pushrod is "case hardened" so the outer few thousands are hard enough to take rubing against a guideplate, THAT'S ALL. This doesn't improve the strength of the pushrod at all, in fact the 1/2"-9/16 tapped Nextel Cup and Pro Stock Pushrods aren't even "hardened" at all, they don't have to be THEY DON'T HAVE GUIDEPLATES, they have shaft mount rockers that don't need them and if they rub something they rub aluminum which is not harder than The big deal is the wall thickness and consistency of the wall thickness, and how the load is applied. This is called Column Theory.

To quote Terry/Knoll Manton of Manton Pushrods

So... What is Column Theory?

Column Theory
Because a pushrod is an eccentrically loaded column due to angularity load and arc motion within the engines atmosphere, whenever possible, it is most proper to use either a single taper or offset dual taper design pushrod. It is also very important to use the largest diameter pushrod that you can fit in the engine. This will help lessen deflection in the pushrod by putting the major diameter and mass where it is needed the most. The greater the angularity, the greater the arc motion. As the pushrod encounters this, the high load area on the tube moves closer to the energy source. The energy source being the lifter, as it travels up the ramp of the camshaft. It makes it even more important to use these tapered designs when using large roller bearing diameters, increased valve lash, very high engine speeds, high rocker ratios, rapid valve train acceleration and high spring pressure. These tapered designs make it easier for the pushrod to do its job properly, and will enhance the performance of all the other valve train components, which will enable the engine to produce the maximum possible horsepower. The tapered designs and large diameters will also reduce valvetrain harmonics. Do not be over concerned about pushrod weight. The difference between a stock 5/16 diameter pushrod in a small block Chevrolet and a 7/16 to 3/8 tapered pushrod, represents a difference of approximately 2.5% of effective weight. This is because the pushrod is on the slow moving side of the valve train. The effective increase in weight between the two pushrods may be small but provides a huge increase in valve train stability. Remember the valve side of this valve train is the critical side where any weight savings will make marked improvements. No matter what we change, valve train stability is the goal.
Important Special Instructions & Suggestions

Hell I should go out in the dumpster and find a stock pushrod cut it up and measure the wall thickness and compare it to the good .060" and .080" wall thick stuff I use, but who cares if your smart you understand this stuff if not you just live in ignorant bliss.

Bret

 

"It is also very important to use the largest diameter pushrod that you can fit in the engine."

I have seen this from other builders as well. That's why I went with the Manton 3/8" number 4 pushrod in my buildup.

 

how many of you had to change your push rods leanght?

 

I did, milled heads, thinner gasket, zero decked block... running 7.05" pushrods.

 

Mine, stock shortblock, heads milled .010. Impy head gaskets = 7.15 lenght pushrods for my set-up.

 

I did same as Javier and use 7.1", 7.05" worked slightly better for intake, but I didn't want to buy two sets. RR and cam can also affect PR length.

 

Yeah... i didn't even get on that train yet. Getting proper pushrod length is worth dividends if you don't want your guides to wear out from crazy side loading. Again it's down to money, spend it now or spend more later.

Bret

 

If there would have been a big difference, I would have definitely spent the extra money to get the two different sizes, but it was minimal going from 7.1 to 7.05.

I went with the Manley chromemoly pushrods. You use those, Bret?

 

How do the thunder racing pushrods compare to the comp's? I'm probably gonna need shorter pushrods since my heads are going to be milled and I'm going to be using a thinnder gasket. They are $30 cheaper, but if they aren't as good as teh comp's I'll just go with the comps again.

 

I was told they're all made by the same two or three companies.

 

Yeah pretty much everyone uses, Trend, Manley etc.... just don't use junk ones and get the right length. I've always had good luck with the Comps, they are consistent.

Bret

 

I knew you couldn't live w/out getting in a cheap jab. LOL... You can preach on all you want. The FACT OF THE MATTER is I have supplied a link to hardened pushrods that WORK for mild applications such as the 211 cam or hotcam. It's not an opinion. It's a fact. Sorry you have such a complex that you can't get over this and move on.
Thanks for your efforts, but you will not convince me otherwise from what has worked for me for 8+ years.