LT1 383 Cam Selection
Thread Starter
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
LT1 383 Cam Selection
I need some help here guys.... heres a few quick specs on the build
10.84 Compression Ratio
Eagle 383 Rotating Assembly
Ported and Polished Stock Heads
Port Matched intake
Stock TB
Long Tube Hooker Headers
Stock Converter
Stock Gears
I am looking to get the most out of this setup with retaining stock like driveability. I know I wont be able to go as big as I want because of the stock converter but hopefully big enough. Any suggestions would be great!
10.84 Compression Ratio
Eagle 383 Rotating Assembly
Ported and Polished Stock Heads
Port Matched intake
Stock TB
Long Tube Hooker Headers
Stock Converter
Stock Gears
I am looking to get the most out of this setup with retaining stock like driveability. I know I wont be able to go as big as I want because of the stock converter but hopefully big enough. Any suggestions would be great!
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Because of the stock converter, don't go higher than 224/230 in duration @ .050. One along the same lines as the GM HotCam, but with more aggressive ramps and higher valve lift would be an excellent choice. Something like 218/224 @ .050 in duration.So, in that duration range, 218/224 to 224/230 - there are several excellent options available.
I'm a die-hard CompCams guy, so, as you might expect, my recommendations would be one of theirs. I like their XFI profiles but, even better would be to have one custom ground using their CRC lobe profiles. Look for their 3100 series lobes.
Their off the shelf cams and lobe profiles are on Comp's website and in their catalog.
I've seen the XFI offerings priced at $265 and the custom grinds at $303. You'll need good valve springs too.
Contrary to what some choose, I would definitely keep the Lobe Separation Angle at 112 to 113. Nothing tighter than 112 in order to keep the idle less raunchy, esier to tune and to broaden the power band.
You'll need to have your PCM tuned and, in order to get the best tune, you need to either put the car on the dyno or have all the specs of your engine - especially the head flow numbers - and have Bryan at PCMFORLESS.com re-program it for you.
Full, non-self aligning, roller rockers, 1.6s or 1.7s, are pretty much a no-brainer. Those, along with one-piece, hardened, .080 wall, 5/16" pushrods are in order.
Remember, it's the total combination of parts that makes all the difference. In my experience, many guys over-cam their engines. I guess most of them fall into the "bigger is better" trap.
Jake
West Point ROCKS!
I'm a die-hard CompCams guy, so, as you might expect, my recommendations would be one of theirs. I like their XFI profiles but, even better would be to have one custom ground using their CRC lobe profiles. Look for their 3100 series lobes.
Their off the shelf cams and lobe profiles are on Comp's website and in their catalog.
I've seen the XFI offerings priced at $265 and the custom grinds at $303. You'll need good valve springs too.
Contrary to what some choose, I would definitely keep the Lobe Separation Angle at 112 to 113. Nothing tighter than 112 in order to keep the idle less raunchy, esier to tune and to broaden the power band.
You'll need to have your PCM tuned and, in order to get the best tune, you need to either put the car on the dyno or have all the specs of your engine - especially the head flow numbers - and have Bryan at PCMFORLESS.com re-program it for you.
Full, non-self aligning, roller rockers, 1.6s or 1.7s, are pretty much a no-brainer. Those, along with one-piece, hardened, .080 wall, 5/16" pushrods are in order.
Remember, it's the total combination of parts that makes all the difference. In my experience, many guys over-cam their engines. I guess most of them fall into the "bigger is better" trap.
Jake
West Point ROCKS!
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Remember you posted ". . . retaining stock like driveability".
As a rule of thumb, each 6 degrees of duration difference in cams is a one step change. A change in .050 from 218 to 224 is a one step larger (longer duration) change; 224 to 230 is another.
So with the new converter you can go to 230 intake 236 exhaust but remember to keep the Lobe Separation Angle at 112 to 113. With a 230/236 I'd go with a 113 LSA.
113 LSA will help smooth the idle, keep the vacuum up so you won't have a power brake vacuum problem and help keep the power band broad as opposed to peaky. I suspect your average HP, from just off idle to redline, will he higher too.
Just my views, of course there will be others who have their own preferences.
Jake
West Point ROCKS!
As a rule of thumb, each 6 degrees of duration difference in cams is a one step change. A change in .050 from 218 to 224 is a one step larger (longer duration) change; 224 to 230 is another.
So with the new converter you can go to 230 intake 236 exhaust but remember to keep the Lobe Separation Angle at 112 to 113. With a 230/236 I'd go with a 113 LSA.
113 LSA will help smooth the idle, keep the vacuum up so you won't have a power brake vacuum problem and help keep the power band broad as opposed to peaky. I suspect your average HP, from just off idle to redline, will he higher too.
Just my views, of course there will be others who have their own preferences.
Jake
West Point ROCKS!
Drifting
Joined: Mar 2015
Posts: 1,276
Likes: 387
From: West Fargo ND
Confirmed. Billy Boat long tube headers will not bolt directly to the stock ZO6 H/X pipe for years 2012 and 2013 as advertised at multiple vendors. An aftermarket x-pipe or fabricated piece is needed for those years.
