Push Rod lenth??

[YoungGun]

Hey guys here with 1 more question. I have a stock 1994. I have Harland Sharp 1.7 Ratio Roller Rockers to install and I was wondering what lenth I needed? I have heard 7.5, 7.55, and 7.6. I really dont want to buy the wrong lenth! thanks for the help again!! -Seth

 

[J DAWG]

get the comp cams push rod length checker. I found one locally at a private engine parts warehouse. This wil take all the guesswork out of it for 20 bucks. Or you can order one from Summit which is in Ohio isnt it?


John

 

[YoungGun]

yeah I just looked one up on there site. 12 bucks. thanks alot I didnt even really know they made them!! thanks John oh yeah they are in ohio and fast shipping too!

 

[Joseph Dell]

definitely measure. guessing doesn't work. i have tried... trust me. BTW - Jdawg - i need to ship you your pushrod length checker back... sorry about the delay!

JD

 

[JiPi]

Which of the Summit's pushrod length checker would fit the VIPER?

 

[Joseph Dell]

annything that covers the 7.4 - 7.8 range. stock pushrods are 7.6x, and with rockers, you frequently need 7.70s. but some cars need 7.65s or 7.6 or even 7.5's...

JD

 

[JiPi]

Thanks JD.
With which roller rockers do you need to change the push rods? Why sometimes you don't need to change them like for the Crowers in the Illustrated Upgrades?
How do you remove the push rods, is it hard? Any precaution to take?

 

[99 R/T 10]

Thanks JD.
With which roller rockers do you need to change the push rods? Why sometimes you don't need to change them like for the Crowers in the Illustrated Upgrades?
How do you remove the push rods, is it hard? Any precaution to take?

If you have Crowers, I would suggest NOT using them. There have been problems and near tragedies

 

[J DAWG]

Thanks JD.
With which roller rockers do you need to change the push rods? Why sometimes you don't need to change them like for the Crowers in the Illustrated Upgrades?
How do you remove the push rods, is it hard? Any precaution to take?

anytime you start changing the geometry of the vavle train then you need to consider every part involved. Take nothing for granted and check everything several times.

Too long of a pushrod with too much preload and you can tap a piston especially if you are running stock vavle springs. Regardless of the brand it is so easy and inexpensive to take the extra minute it takes to check the length. Take a look at the Jesels or T&D/Mopars 1.7 roller rockers.

this is a nice beginners project to do on your Viper.

John

 

[Marv S]

3/8" or 7/16"?

 

[Purdue_Boiler_Viper]

Assuming you mean pushrod diameter, this is from Roe:

High performance 5/16" x .083 pushrods for Vipers and Ram SRT10. Complete set of 20. We keep the two most popular lengths for Vipers in stock, but can order any length for special head & valve train applications.
From the Manufacturer:
T&D Machine Products now offers the highest quality pushrods available for every application. Our standard one-piece forged pushrods are made from Mil-Spec .083" wall seamless D.O.M. 4130 chromoly tubing and are 100% Zyglo tested for material defects. T&D pushrods feature centerless-ground shafts, while the critical ball end of the pushrod is CNC profiled to provide a more accurate ball radius and finish, thereby assuring superior compatibility with adjuster screw and lifter mating surfaces.

 

[J DAWG]

3/8" or 7/16"?

I have only seen 5/16 and 3/8 sizes in a Viper. I dont know if there is enuf room along side the head gasket to get a 7/16 in there. 3/8 is plenty strong and most just use 5/16 which I had to do since Comp cams didnt make a 3/8 in a 7.4 length.

 

[Marv S]

Yeah, I need to correct that to 5/16" or 3/8".

Question being, stock size is 5/16" but if modifying the head with higher springs will the push rod deflect and should the larger 3/8" be used?

 

[J DAWG]

I would and did plan on using the 3/8 but unfortunately Comp Cams does not make on for my 7.4 length in a 3/8.


I would agree it would be ideal to go with the 3/8 if possible especially when doing head work. Most I believe just slap a set of rockers on the stock springs and use the 5/16 and never think a thing about it........and I havent heard of any failures or problems related to the 5/16 rod.


John