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

Cam vs Head flow?

Thread Tools
 
Search this Thread
 
Old 11-20-2005, 04:44 PM
  #1  
TECH Resident
Thread Starter
iTrader: (25)
 
Ari G's Avatar
 
Join Date: Jul 2005
Location: Houston
Posts: 818
Likes: 0
Received 0 Likes on 0 Posts

Default Cam vs Head flow?

I´m going to put an agressive cam in my LT1 going 11 sec n/a but i need someone to back my ideas up.

The heads flow 270's at 0.525 lift on the intake side with oem valves,but i dont remember about the exhaust think 190's,what cam would be good with them

I´m thinking cc306,what other cam could be better?I´m allso checking out these cams and why do you think so?

310/310 duration
509/509 lift
246/246 duration @ .050"
108 lobe separation
2000-6000 rpm power range


292/292 duration
480/480 lift
230/230 duration @ .050"
109 lobe separation
2400-6000 rpm power range


RPM range 2500-6500
.501/.501 valve lift
Duration at .050" 244/244
Adv. duration 292/292

RPM range 3000-7000
.525/.525 valve lift
Duration at .050" 253/253
Adv. duration 305/305
Old 11-21-2005, 11:44 PM
  #2  
Launching!
 
2MuchNos93LT1's Avatar
 
Join Date: Feb 2005
Posts: 254
Likes: 0
Received 0 Likes on 0 Posts
Default

I would say this cam looks sweet

RPM range 3000-7000
.525/.525 valve lift
Duration at .050" 253/253
Adv. duration 305/305
Old 11-22-2005, 06:05 PM
  #3  
Staging Lane
iTrader: (2)
 
muraoka's Avatar
 
Join Date: Jan 2004
Location: spokane, wa.
Posts: 65
Likes: 0
Received 0 Likes on 0 Posts
Default

were do you find those cams? i'm looking for one as well.
thanks matt
Old 11-22-2005, 06:13 PM
  #4  
9 Second Club
iTrader: (14)
 
Dragframe's Avatar
 
Join Date: Oct 2005
Location: wyoming @ 12000 DA...
Posts: 2,333
Received 64 Likes on 54 Posts

Default

Originally Posted by Ari G

RPM range 2500-6500
.501/.501 valve lift
Duration at .050" 244/244
Adv. duration 292/292
sounds like the 292 magnum...
Old 11-22-2005, 06:24 PM
  #5  
TECH Addict
iTrader: (5)
 
DeltaT's Avatar
 
Join Date: Jun 2005
Posts: 2,404
Likes: 0
Received 1 Like on 1 Post
Default

Have you thought about a solid roller? I am running a custom Comp Cams Extreme Energy Street Roller in my LT4-block-based 383: 230/236, net lift .579/.584, with a short adv. duration of 268/274, LSA 112, 1.6 CC roller rockers. Remember that advertised duration is different for solid rollers - measured at .015" tappet lift. It makes their adv. duration seem really small.

Comp will grind it for you with the LT1 snout for around $300. Switch your lifter to the Endure-X Street Rollers that are .300" taller for our blocks, and the recommended springs/retainers and you are good to go.

My motor is blown with a Vortech. It will idle at 750rpm but pull to 6500 with about 8.5lbs of boost after the FMIC and throttle blades. I went pretty mild on the cam because it is a sleeper car (4DR 81 Malibu) and I didn't want an extreme idle.

John Lingenfelter's book recommends the newest generation of solid rollers. They don't need a lot of adjustment - like every 10K miles. To paraphrase him, "short duration and high lift is the way to go for a street motor". The Comp XS-R series can do all that. The lobes are a lot more intense than their older street rollers.

I would recommend you look at the CC Lobe Catalog, page 18:

http://www.compcams.com/Technical/Ca...obeCatalog.pdf

How do your heads flow at higher lift? If they flow well up to .600", you might as well use their capacity.

I discussed my 2 possible cam choices with the CC Tech Hotline and they recommended the smaller of the 2, and that's what I got. I am very happy with the cam and valvetrain.

Jim
Old 11-22-2005, 07:50 PM
  #6  
TECH Enthusiast
 
Jordan57's Avatar
 
Join Date: May 2004
Location: St. Peters, MO
Posts: 549
Likes: 0
Received 0 Likes on 0 Posts
Default

I concurr with DeltaT and furthermore think your camshafts are too small based on head flow #'s. IMO, the cam should be a tad more aggressive than the heads to maximize power (you sure arent going to lose any) as long as you can handle the revs. Sounds like a custom cam is in order, or GTP-6/GM847 with 1.6 rr's if the budget is smaller.
Old 11-22-2005, 08:06 PM
  #7  
11 Second Club
iTrader: (1)
 
96capricemgr's Avatar
 
Join Date: Sep 2004
Posts: 11,975
Likes: 0
Received 12 Likes on 12 Posts

Default

Why are you looking at single pattern low lift cams? IMO people go for far too much duration especially you f-body drivers and know someone who got rid of an f-body after CC306ing it and not appreciating the new "manners" yet still I would say that is the "best" one you mentioned.
Old 11-23-2005, 04:47 PM
  #8  
Registered User
 
PortPros1's Avatar
 
Join Date: Mar 2004
Location: Austin, Texas
Posts: 199
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Ari G
I´m going to put an agressive cam in my LT1 going 11 sec n/a but i need someone to back my ideas up.

The heads flow 270's at 0.525 lift on the intake side with oem valves,but i dont remember about the exhaust think 190's,what cam would be good with them

I´m thinking cc306,what other cam could be better?I´m allso checking out these cams and why do you think so?

310/310 duration
509/509 lift
246/246 duration @ .050"
108 lobe separation
2000-6000 rpm power range


292/292 duration
480/480 lift
230/230 duration @ .050"
109 lobe separation
2400-6000 rpm power range


RPM range 2500-6500
.501/.501 valve lift
Duration at .050" 244/244
Adv. duration 292/292

RPM range 3000-7000
.525/.525 valve lift
Duration at .050" 253/253
Adv. duration 305/305
I can design and grind a cam for you based on your engine combination. Going with a solid roller is a power gain over the hydraulic, something to think about. With the hydraulic you lose lift at the valve do to the preload on the lifter.
Be happy to help out, I can recommend a shelf cam or grind you one give me a call 512-257-0222, pm or e-mail. Advice is free. Ask for Harold
Old 11-23-2005, 08:10 PM
  #9  
Banned
iTrader: (2)
 
SStrokerAce's Avatar
 
Join Date: Mar 2002
Location: NY
Posts: 2,344
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Jordan57
I concurr with DeltaT and furthermore think your camshafts are too small based on head flow #'s. IMO, the cam should be a tad more aggressive than the heads to maximize power (you sure arent going to lose any) as long as you can handle the revs. Sounds like a custom cam is in order, or GTP-6/GM847 with 1.6 rr's if the budget is smaller.
Can't say I agree with that....

The better the heads are the less cam you need to make the power you want or run the same RPM band.

As for the Solid vs. Hyd... A Hyd can stay with a SR till 7500rpm if it's done right and can make more power to boot.

FWIW none of those cams look right to me.

Bret



Quick Reply: Cam vs Head flow?



All times are GMT -5. The time now is 10:12 AM.