847 Cam and stock heads
Thread Starter
Teching In
Joined: Sep 2004
Posts: 15
Likes: 0
From: Olathe, KS
847 Cam and stock heads I will be installing the GM847 cam in my 97 WS6 and I wanted to use my stock heads until I'm ready to upgrade. I want to replace the stock rocker arms with 1.6 Crane Gold rockers. Should I get self-aligning or non self-aligning? The rocker also specifies which size stud it will work with. Does this mean the size of the push rod? Should I replace them too? If so what size do I need to get (3/8 or 7/16)? I know I need to upgrade my springs while I'm at it. I see that some of the guys running 847's recommend K-motion 800 springs w/titanium retainers. Is this all I need to do to keep the valvetrain from falling apart? I only have 29K on the car, do I need to replace the timing chain too? 
Staging Lane
Joined: Oct 2004
Posts: 95
Likes: 1
I would go with Comp Mag Rollers. The rocker stud is no relation to the push rod. Stock rocker stud is 3/8". Run with those.
When replacing the cam you should do the follwoing
1.Timing Chain LT4 ED or equal
2.Chromemoloy pushrods-stock lenght
3.lifters
4. rockers arm will get the lift out of the cam your looking for.
5.Springs/retainers
6.tuning
That cam is pretty big for stock heads and you will need a good tune for it to run right.
Good Luck
Chris
When replacing the cam you should do the follwoing
1.Timing Chain LT4 ED or equal
2.Chromemoloy pushrods-stock lenght
3.lifters
4. rockers arm will get the lift out of the cam your looking for.
5.Springs/retainers
6.tuning
That cam is pretty big for stock heads and you will need a good tune for it to run right.
Good Luck
Chris
Thread Starter
Teching In
Joined: Sep 2004
Posts: 15
Likes: 0
From: Olathe, KS
Thanks for the input. Anyone else have an opinion? Do I have to get a stall converter right away? I forgot to mention I have an A4. What would happen if I don't get a converter? What stall should I get when I do finally buy one?
The tune will help the cam a lot, replace the timing chain as insurance. I disagree on changing the lifters with a car with such low miles. Easy to do when its all out, but you should be able to reuse your stock lifters, perhaps change them down the line if you wanted when you did the heads. Check them for any wear, but at 30K miles they should still be in great shape.
I would NEVER even think of running the 847 without a stall and gears, and you need some SERIOUS tuning time with it to get it running right, but it is very possible, just going to take some know how.
Again i suggest the comp pro mag rockers. Non self aligning. You need guideplates with that setup too, and hardened pushrods. Also i would spend another 35 bucks or whatever it is and upgrade to 7/16 studs (3/8 is stock, you need to remove them anyways if you are going non slef aligning rockers). Cheap insurance.
Also a new timing chain. Personal preference is cloyes double roller with electric h20 conversion. That is a cheaper alternative than the lt4 HD, and will give you more HP b/c of the h20 pump, and its also a better chain.
Stock lifters will be fine, i ran mine on the setup above for 15k miles without any issues, and my car had 70k on it at time of install.
For the bigger cams, good parts are needed, more spring pressures, more rpms etc. You really cant skimp like you could on a hotcam or smaller cammed car and expect to get away with it.
Again i suggest the comp pro mag rockers. Non self aligning. You need guideplates with that setup too, and hardened pushrods. Also i would spend another 35 bucks or whatever it is and upgrade to 7/16 studs (3/8 is stock, you need to remove them anyways if you are going non slef aligning rockers). Cheap insurance.
Also a new timing chain. Personal preference is cloyes double roller with electric h20 conversion. That is a cheaper alternative than the lt4 HD, and will give you more HP b/c of the h20 pump, and its also a better chain.
Stock lifters will be fine, i ran mine on the setup above for 15k miles without any issues, and my car had 70k on it at time of install.
For the bigger cams, good parts are needed, more spring pressures, more rpms etc. You really cant skimp like you could on a hotcam or smaller cammed car and expect to get away with it.
