I am putting the 847 in my stock lt1 here next week and was wondering if anyone had experience with Rhoades or any other variable duration/high intensity lifters. I know they will make a little noise but can't be worse than a solid lifter. Also what would I have to change in the Program to compensate, or can Madwolf or PCMFORLESS tune it? I have PCMFORLESS now but I ended up pretty much tuning myself and just using his tranny program. Any input is appreciated.

Troy

 

It's been a long time, but I had them in a block Vette I owned and was very disappointed in them as yes…… they were noisier than solid lifters.

You can never ever beat tuning a particular car as each car regardless of similar mods seems to have individual personalities. If you have the capability to tune a car and access to a wideband 02 sensor, it’s really not very hard.

 

I'm not to wooried about the noise or tuning the fuel I was more concernd with the knock sensor pulling timing, would I have to just disable it? If so how would I go about setting the timng? Did you notice any increased bottom end or drivability?

 

Anybody?

 

I had the complete engine redone so I have no baseline to tell if it picked up on the bottom end or not. Based upon the noise, I frankly don't care if it did or not as it sounded like you needed to adjust your lifters all the time.

This was a while ago and in a big block, so they may have improved or act somewhat differently now.

 

I had stock lifters on 847 and stock heads. You couldnt hear them at all, yet it was still enough to throw the knock sensor off the charts. I kept lessening its sensitivity, and yet it kept pulling timing. I finally just disabled it completely and relied on dyno tuning and listening for pinging. With a noisier lifter, its only going to get worse.

 

So is the general consinsous that the problems out weigh the gains? This car is my daily driver so I want as much bottom end as I can get out of the 847. I know I will have to live with the idle and some drivabilty but just wanted to "help" it as much as I could.

 

My assumption as to why so few have responded is the lifters you mention are very old technology and the 847 cam is a proven performer. Most of the bad habits can be resolved by tuning.