Solid roller lobe selection for power or durability
#1161492
01/20/12 05:50 PM
01/20/12 05:50 PM
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Joined: Aug 2005
Posts: 762 Southington Ct.
turbobitt
OP
super stock
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OP
super stock
Joined: Aug 2005
Posts: 762
Southington Ct.
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After reading through the valve spring selection thread, I thought I would start this thread to get some insight to thoughts on cam lobe selection. Based on my own most recent quest for selecting lobes, I found a few actual profiles that would fit my constraints.
For my own example, I was looking for a lobe that had at over .400 lobe lift with about 242 duration @ .050. This limited me to only a few lobe profiles that would fit those constraints(Comp Cams RT,TK, High tech 420).
So, for a given engine, RB,SB,Hemi, does anyone have a prefered profile to use as a good ballance for power and valve train durability ? More specifically limited street driving ?
Allan G.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Re: Solid roller lobe selection for power or durability
[Re: turbobitt]
#1161493
01/20/12 06:37 PM
01/20/12 06:37 PM
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Joined: Oct 2003
Posts: 3,698 NE Oklahoma
Von
master
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master
Joined: Oct 2003
Posts: 3,698
NE Oklahoma
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I had a RT lobe grind for awhile. There seems to be mixed opinions on the durability issue with valvetrain parts with the RT lobe. One guy at Comp told me it was OK to use on the street, the consenus among others is that it will be a parts breaker in a street/high mileage ap.....By the specs I would think its fairly gnarly and probably not the easiest on parts. I know Smothers had a RT lobe in a stock appearing Bee that ran very hard...but he said it wasnt useable on the street...due to being a parts beater. I was told (not by Comp, but somebody way more knowledgeable) the HT 420 lobes are supposed to be easy on parts... Give Porter a call...He knows the Comp lobes.
Last edited by Von; 01/20/12 06:59 PM.
72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72.
Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.
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Re: Solid roller lobe selection for power or durability
[Re: turbobitt]
#1161497
01/20/12 09:18 PM
01/20/12 09:18 PM
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Joined: Jan 2003
Posts: 5,486 SoCal
Brian Hafliger
master
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master
Joined: Jan 2003
Posts: 5,486
SoCal
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Quote:
After reading through the valve spring selection thread, I thought I would start this thread to get some insight to thoughts on cam lobe selection. Based on my own most recent quest for selecting lobes, I found a few actual profiles that would fit my constraints.
For my own example, I was looking for a lobe that had at over .400 lobe lift with about 242 duration @ .050. This limited me to only a few lobe profiles that would fit those constraints(Comp Cams RT,TK, High tech 420).
So, for a given engine, RB,SB,Hemi, does anyone have a prefered profile to use as a good ballance for power and valve train durability ? More specifically limited street driving ?
Allan G.
You can't sum up all those engines under one catagory. Just going from a non offset rocker to an offset rocker in a sb can cause problems so it would help to know exactly what engine your working with, rocker ratio, rpm range, valve sizes or weights, and the rest of the engine build including the car and intended purpose.
Brian
Brian Hafliger
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Re: Solid roller lobe selection for power or durability
[Re: Brian Hafliger]
#1161498
01/20/12 10:17 PM
01/20/12 10:17 PM
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Joined: Aug 2005
Posts: 762 Southington Ct.
turbobitt
OP
super stock
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OP
super stock
Joined: Aug 2005
Posts: 762
Southington Ct.
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Quote:
Quote:
After reading through the valve spring selection thread, I thought I would start this thread to get some insight to thoughts on cam lobe selection. Based on my own most recent quest for selecting lobes, I found a few actual profiles that would fit my constraints.
For my own example, I was looking for a lobe that had at over .400 lobe lift with about 242 duration @ .050. This limited me to only a few lobe profiles that would fit those constraints(Comp Cams RT,TK, High tech 420).
So, for a given engine, RB,SB,Hemi, does anyone have a prefered profile to use as a good ballance for power and valve train durability ? More specifically limited street driving ?
Allan G.
You can't sum up all those engines under one catagory. Just going from a non offset rocker to an offset rocker in a sb can cause problems so it would help to know exactly what engine your working with, rocker ratio, rpm range, valve sizes or weights, and the rest of the engine build including the car and intended purpose.
Brian
My intent was to have general discussion over cam lobe selection and actual experience with lobe selection vs. durability.
Allan G.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Re: Solid roller lobe selection for power or durability
[Re: turbobitt]
#1161499
01/20/12 11:13 PM
01/20/12 11:13 PM
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Joined: Jan 2003
Posts: 5,486 SoCal
Brian Hafliger
master
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master
Joined: Jan 2003
Posts: 5,486
SoCal
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That's the problem. A certain lobe may work well in a sb with no offset 1.6 rockers, then put it in a BB with offset rockers and it hurts springs. That's what I've seen. Comp does a pretty good job of listing their lobes with descriptions that for the most part are accurate but I would always work with an engine builder because they see those lobes work in many different arenas.
Going along with the theme of this thread, I will say that on Turbo apps not needing much cam to make sick power, if you don't plan on turning too much rpm...quick intake lobes work fantastic!
I've been using Comp's new hybrid hyd/solid roller lobes and as along as you plan out the valvetrain they are as good as TK's but more reliable on easier on springs up to a point. They are smaller lobes so if you run them past their happy place you'll know it! TK's and HiTQ 440 lobes can be run higher than the hybrids but not much so I prefer the hybrids.
I also like NC lobes alot and have used them in many different engines and they always seem to make good HP and TQ without killing springs. They don't mind 1.7/1.8 ratios either.
Brian Hafliger
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Re: Solid roller lobe selection for power or durability
[Re: Brian Hafliger]
#1161500
01/21/12 02:36 AM
01/21/12 02:36 AM
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Joined: Aug 2005
Posts: 762 Southington Ct.
turbobitt
OP
super stock
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OP
super stock
Joined: Aug 2005
Posts: 762
Southington Ct.
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Quote:
That's the problem. A certain lobe may work well in a sb with no offset 1.6 rockers, then put it in a BB with offset rockers and it hurts springs. That's what I've seen. Comp does a pretty good job of listing their lobes with descriptions that for the most part are accurate but I would always work with an engine builder because they see those lobes work in many different arenas.
Going along with the theme of this thread, I will say that on Turbo apps not needing much cam to make sick power, if you don't plan on turning too much rpm...quick intake lobes work fantastic!
I've been using Comp's new hybrid hyd/solid roller lobes and as along as you plan out the valvetrain they are as good as TK's but more reliable on easier on springs up to a point. They are smaller lobes so if you run them past their happy place you'll know it! TK's and HiTQ 440 lobes can be run higher than the hybrids but not much so I prefer the hybrids.
I also like NC lobes alot and have used them in many different engines and they always seem to make good HP and TQ without killing springs. They don't mind 1.7/1.8 ratios either.
Good info about the offset rockers. My Super Stock racing buddies tell me that pushrod selection will also effect spring durability.
Allan G.
Last edited by turbobitt; 01/21/12 03:43 PM.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Re: Solid roller lobe selection for power or durability
[Re: turbobitt]
#1161501
01/21/12 04:30 AM
01/21/12 04:30 AM
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Joined: Jan 2011
Posts: 4,785 Utah and Alaska
astjp2
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master
Joined: Jan 2011
Posts: 4,785
Utah and Alaska
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I am running a crane roller in my hemi that has 248@.050 and a .400 lift, also using it with pushrod oiling. Tim
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