I just installed the 7.4s that LGM supplied w/ my kit, stock are actually 7.38X. All is well on my end, but if I ever pull the heads I'll be installing the caddy lifters and measuring for correct pushrod length.
7.425 pushrods
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
7.425 pushrods
Anyone switched to 7.425 pushrods after installing the Cadillac Racing Lifters? If so did this lenght pushrod help quiet the valve traing down? Thanks,
SLPRC5
SLPRC5
Last edited by SLPRC5; Jun 21, 2007 at 12:46 AM.
Racer
Joined: Mar 2007
Posts: 471
Likes: 2
From: Hillsboro MO
from what i have seen, the caddy lifters do like a little longer pushrod. I used a 7.425 once and it did quiet the valvetrain down. did you mill the heads any when you had them off? It seems that taking about .010" off the head (if it hasnt been milled yet) helps a lot too
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
from what i have seen, the caddy lifters do like a little longer pushrod. I used a 7.425 once and it did quiet the valvetrain down. did you mill the heads any when you had them off? It seems that taking about .010" off the head (if it hasnt been milled yet) helps a lot too
The heads are Patriots 243s and had the cc mill from 64cc to 62cc.
Well I don't plan to remove the heads. So I'm going with the 7.425 push rods to quiet down the VT more than it is now...everyone was saying how the Caddy lifters made the VT quieter, but no one mentioned the push rod lenghts..
Thanks Quick
SLPRC5
Melting Slicks
Joined: May 2005
Posts: 3,394
Likes: 12
From: Leon Iowa
St. Jude Donor '06-'07-'08-'09
The longer pushrods will quiet it down no matter what lifters you have. I just don't understand why so many people still say to use the stock length pushrods when a bigger can is used. After I seen for myself that the the aftermarket cams have a smaller base circle it just made total sense that a longer pushrod needs to be used to get back to the correct preload. Deno, I bet you will be happy with the way it will sound after you get the pushrods in. Like i said if you need any help just call me.
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
The longer pushrods will quiet it down no matter what lifters you have. I just don't understand why so many people still say to use the stock length pushrods when a bigger can is used. After I seen for myself that the the aftermarket cams have a smaller base circle it just made total sense that a longer pushrod needs to be used to get back to the correct preload. Deno, I bet you will be happy with the way it will sound after you get the pushrods in. Like i said if you need any help just call me.
I'll let you know how it works out and make a sound clip on the new push rods
Thanks Buddy,
Deno
Former Vendor
Joined: Feb 2004
Posts: 10,876
Likes: 8
From: Las Vegas NV
St. Jude Donor '06 & '12
Cause not ALL aftermarket cams run a smaller base circle.. Also, there is no set base circle size. Some companies run different sizes. You need to know the measurements in order to properly determine what you need.
The reason people "Chase" valvetrain noise is because they dont want to spend 20 bucks to buy the proper tool necessary in order to verify the size requirements.
The reason people "Chase" valvetrain noise is because they dont want to spend 20 bucks to buy the proper tool necessary in order to verify the size requirements.
I just don't understand why so many people still say to use the stock length pushrods when a bigger can is used. After I seen for myself that the the aftermarket cams have a smaller base circle it just made total sense that a longer pushrod needs to be used to get back to the correct preload. .
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Melting Slicks
Joined: May 2005
Posts: 3,394
Likes: 12
From: Leon Iowa
St. Jude Donor '06-'07-'08-'09
Cause not ALL aftermarket cams run a smaller base circle.. Also, there is no set base circle size. Some companies run different sizes. You need to know the measurements in order to properly determine what you need.
The reason people "Chase" valvetrain noise is because they dont want to spend 20 bucks to buy the proper tool necessary in order to verify the size requirements.
The reason people "Chase" valvetrain noise is because they dont want to spend 20 bucks to buy the proper tool necessary in order to verify the size requirements.
Pro
Joined: Jul 2006
Posts: 688
Likes: 12
From: Detroit - Buffalo - Houston
Pro
Joined: Jul 2006
Posts: 688
Likes: 12
From: Detroit - Buffalo - Houston
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
I have the Comp Cam 224/224 .567/.567 on a LSA114.
I have cadillac racing lifters and at present 7.400 PR, so I have the 7.425 ordered and like others have said this should quieten it down, if not I'll have to live with it because the engine is all together now.
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
you are right. There is no way though that you can get it exact when pushrod sizes are in .025 increments. Example on mine is that I need a 7.440 to get me back the the stock preload. I have to run the 7.425 because the next size up is the 7.450. I believe that too much preload will do more damage than not enough. So in reality there is no way to get it perfect but you can get it close as long as you know the measurements of your cam.
Le Mans Master
Joined: Nov 2005
Posts: 5,451
Likes: 2
From: East Peoria Illinois
You may have the same problem I'm having with the sewing machine sound.
I have the Comp Cam 224/224 .567/.567 on a LSA114.
I have cadillac racing lifters and at present 7.400 PR, so I have the 7.425 ordered and like others have said this should quieten it down, if not I'll have to live with it because the engine is all together now.
I have the Comp Cam 224/224 .567/.567 on a LSA114.
I have cadillac racing lifters and at present 7.400 PR, so I have the 7.425 ordered and like others have said this should quieten it down, if not I'll have to live with it because the engine is all together now.
still some work to do
Thread Starter
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Thanks,
Sleeper
Last edited by SLPRC5; Jun 27, 2007 at 02:36 AM.
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
^ I have yella terras... they're the newer lightened design. They work great. There is valvetrain noise when the oil is not, but nothing worse than stock when hot. Click the link in my sig for an idle video. I don't run fuel rail covers and I have a vented hood so that actually increases the noise.
Here's some pics:
Here's some pics:
Drifting
Joined: Nov 2003
Posts: 1,898
Likes: 6
From: Sahuarita AZ
Are you sure about the stock length you're quoting? I measured mine with a caliper and they were 7.400" stock.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
6.800 + 10.5 X 0.050 = 7.325"
However, now you must add in your lifter preload to set the plunger in the lifter. If you want the preload to be 0.100", you would add that on and end up with 7.425" pushrods.
Hope this all makes sense.