LT1-LT4 Modifications 1993-97 Gen II Small Block V8

GM847 cam only

Thread Tools
 
Search this Thread
 
Old 08-10-2012, 09:37 PM
  #1  
TECH Enthusiast
Thread Starter
 
93Euphoria's Avatar
 
Join Date: Feb 2012
Location: Orlando
Posts: 631
Likes: 0
Received 0 Likes on 0 Posts
Default GM847 cam only

so im taking my first step into fixing up the LT1. have about $1500. With a good tune how much power you think ill be putting out with the GM847 and how risky is it with the stock bottom end with new bearings and new rod bolts? or forged pistons are a must? My first step would be cam with bolt ons then, port the heads when i get a little more cash and maybe stroke it or boost it. Whats the best i can get out of a gm847 cam only A4? I know there are tons of threads on this but I would like to know from personal experience with Gm847 with stock bottom end.
Old 08-11-2012, 04:56 AM
  #2  
TECH Fanatic
iTrader: (1)
 
nascarnate326's Avatar
 
Join Date: Sep 2009
Location: Michigan
Posts: 1,574
Likes: 0
Received 1 Like on 1 Post
Default

When you say Cam Only, do you really mean cam only?

Id think some rockers, better pushrods etc would be in order for that cam.

A stall converter would be need too.

Dont do a cam only install, it makes the LT community look bad.

If your going to pick a bad *** cam like the 847 put some of required goodies with it.
Old 08-11-2012, 06:55 AM
  #3  
On The Tree
iTrader: (2)
 
HarleyZ28's Avatar
 
Join Date: Oct 2011
Posts: 171
Likes: 0
Received 0 Likes on 0 Posts
Default

That cam wont be good for more than anything than the sound on a stock bottom end. You could get a smaller cam that will perform much better on the stock bottom end, and still have that awesome sound. The GM 847 cam loves high rpms which a stock bottom end doesn't like as much.
Old 08-11-2012, 08:22 AM
  #4  
TECH Fanatic
iTrader: (1)
 
Rob94hawk's Avatar
 
Join Date: Aug 2010
Posts: 1,662
Received 24 Likes on 13 Posts

Default

What are the specs on the 847?
Old 08-11-2012, 08:32 AM
  #5  
TECH Veteran
iTrader: (17)
 
Puck's Avatar
 
Join Date: Oct 2006
Posts: 4,152
Likes: 0
Received 6 Likes on 6 Posts

Default

Originally Posted by Rob94hawk
What are the specs on the 847?
234/242 .576/.595 112 LSA on old magnum lobes. Too big for stock heads and will want more RPM then a stock shortblock will want. Figure around 6700.

If he is rebuilding the shortblock, porting his heads, and doesn't mind revving it high then its not the worse choice possible...but I wouldn't run it on a 350, and definitely wouldn't run it with boost. A modern cam ~226int will make similar top end, more down low, and be just as fast or faster while being easier to tune with better street manners.
Old 08-11-2012, 08:37 AM
  #6  
11 Second Club
iTrader: (35)
 
SmokedOutZ28's Avatar
 
Join Date: Dec 2004
Location: NW Chicago burbs
Posts: 2,163
Likes: 0
Received 0 Likes on 0 Posts

Default

GM847 cam on a SBE LT1 out of my camaro. This was 2006 I believe Car had LT's, CAI, Catback, Tune & Supporting mods for the cam like Springs & pushrods.




Power was nice and ran low 12's @ 113 in the 1/4, Idle was rowdy and a real head turning, After the tune adjustment from Ion (madz28) car drove flawlessly. Depending on what you want to do with the car this might not be the right cam there are plenty of cam's that can give you better power in a more streetable rpm band! as I have learned with the LS motor I have bigger is not always better. But it's your choice good luck! BTW: My motor bent rod #5 NA with that cam it was the last time I had a LT1 in the car!
Old 08-11-2012, 08:42 AM
  #7  
TECH Fanatic
iTrader: (1)
 
Rob94hawk's Avatar
 
Join Date: Aug 2010
Posts: 1,662
Received 24 Likes on 13 Posts

Default

What rpm where you shifting at?
Old 08-11-2012, 03:38 PM
  #8  
11 Second Club
iTrader: (35)
 
SmokedOutZ28's Avatar
 
Join Date: Dec 2004
Location: NW Chicago burbs
Posts: 2,163
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by Rob94hawk
What rpm where you shifting at?
6600 RPM is where the shift light was set at.
Old 08-11-2012, 04:41 PM
  #9  
TECH Enthusiast
Thread Starter
 
93Euphoria's Avatar
 
Join Date: Feb 2012
Location: Orlando
Posts: 631
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by nascarnate326
When you say Cam Only, do you really mean cam only?

Id think some rockers, better pushrods etc would be in order for that cam.

A stall converter would be need too.

Dont do a cam only install, it makes the LT community look bad.

If your going to pick a bad *** cam like the 847 put some of required goodies with it.
Yes obviously haha. That would be a bad idea to put a cam only without the supporting mods. Thatll just make things worse then already. Maybe starting out solid roller. How well are solid rollers and there manners on the street?
Old 08-11-2012, 04:45 PM
  #10  
TECH Enthusiast
Thread Starter
 
93Euphoria's Avatar
 
Join Date: Feb 2012
Location: Orlando
Posts: 631
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by SmokedOutZ28
GM847 cam on a SBE LT1 out of my camaro. This was 2006 I believe Car had LT's, CAI, Catback, Tune & Supporting mods for the cam like Springs & pushrods.




Power was nice and ran low 12's @ 113 in the 1/4, Idle was rowdy and a real head turning, After the tune adjustment from Ion (madz28) car drove flawlessly. Depending on what you want to do with the car this might not be the right cam there are plenty of cam's that can give you better power in a more streetable rpm band! as I have learned with the LS motor I have bigger is not always better. But it's your choice good luck! BTW: My motor bent rod #5 NA with that cam it was the last time I had a LT1 in the car!
Bent rod?! detonation? bad tuning? Im assuming you were on stock bottom end. Dang now i feel bad because you left the LTX community behind because of a bent rod ohwell it happens.
Old 08-11-2012, 05:26 PM
  #11  
TECH Fanatic
iTrader: (2)
 
nitrous2fast's Avatar
 
Join Date: Dec 2010
Location: Oklahoma
Posts: 1,084
Likes: 0
Received 0 Likes on 0 Posts
Default

The 847, with new bearings and upgraded rod bolts in the short block, would do decently well. I would run 1.6rr on the intake and 1.5 on the exhaust with that cam to keep the low rpm cylinder pressures up(with stock heads of course).



Quick Reply: GM847 cam only



All times are GMT -5. The time now is 09:47 AM.