Cold spring breakage questions.
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From: Central, MA
Cold spring breakage questions. I know I'm in the off season for this question here, but, I'm looking for a cam and spring setup I can run in my daily driven truck all year round, with little side effects in the winter months.
It can get as cold as -10*F here in Massachusetts, nevermind if I head North for a weekend at the mountains.
I some somewhat conflicting opinions on when it's okay to drive the vehicle when it's been sitting in cold weather. Some say not move the gear selector out of Park unless your fully up to temp, others just say don't try to lift the wheels off the ground unless you're fully up to temp.
I don't know about others, but I DON'T want to sit around for half an hour while my motor idles there, getting all the way up to temp. Normall on the really cold mornings, it takes 10-15 minutes before the temp gauge starts to creep up off the bottom. When the temp gauge comes up a notch or two, to an indicated 160+, then I start to drive. Always very easily, until fully warm.
What is it that makes cold spring breakage a problem with aftermarket cams? Is it the spring rate, or is it the amount of lift? Both?
I'm looking at durations under 220/220, and lift in the low to midrange side of things. .525 to .560. I don't have a whole lot of desire to spin past 6K - I want a stump puller. Are there any configs I can go with to help minimize winter driving habbit changes?
Thanks
It can get as cold as -10*F here in Massachusetts, nevermind if I head North for a weekend at the mountains.
I some somewhat conflicting opinions on when it's okay to drive the vehicle when it's been sitting in cold weather. Some say not move the gear selector out of Park unless your fully up to temp, others just say don't try to lift the wheels off the ground unless you're fully up to temp.
I don't know about others, but I DON'T want to sit around for half an hour while my motor idles there, getting all the way up to temp. Normall on the really cold mornings, it takes 10-15 minutes before the temp gauge starts to creep up off the bottom. When the temp gauge comes up a notch or two, to an indicated 160+, then I start to drive. Always very easily, until fully warm.
What is it that makes cold spring breakage a problem with aftermarket cams? Is it the spring rate, or is it the amount of lift? Both?
I'm looking at durations under 220/220, and lift in the low to midrange side of things. .525 to .560. I don't have a whole lot of desire to spin past 6K - I want a stump puller. Are there any configs I can go with to help minimize winter driving habbit changes?
Thanks
ls6 cam wouldnt be too bad for winter...i could see the asa cam being ok because the lift isnt horribly out of control...its partly the ramp rates partly the lift that really would put alot of stress on those springs especially when cold.
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From: Central, MA
Ramp rates... I forgot about that too.
I hear that smaller duration cams with quicker ramp rates like the popular cams run today, are harder on springs than cams with similar lobes with more duration. The lobe turns into "too sharp of a spike" or something to that effect.
I'd like to stick close to durations 212/218 with LSA's of 112-114. That would include the old low-lift Comp 212/218, the high-lift version custom ground with a tightened up LSA, and a 210/218 Vinci cam. (Vinci cams are available with lobes available ranging from .530, .551, and up to .600" lift.) I might even go with the tiny Comp 206/212.
I hear that smaller duration cams with quicker ramp rates like the popular cams run today, are harder on springs than cams with similar lobes with more duration. The lobe turns into "too sharp of a spike" or something to that effect.
I'd like to stick close to durations 212/218 with LSA's of 112-114. That would include the old low-lift Comp 212/218, the high-lift version custom ground with a tightened up LSA, and a 210/218 Vinci cam. (Vinci cams are available with lobes available ranging from .530, .551, and up to .600" lift.) I might even go with the tiny Comp 206/212.
Launching!
Joined: Jan 2004
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From: Trois-Rivières (Québec / Canada)
To have an idea of the ramp rate, you have to substract the duration at .050 from the duration at .006 (advertised duration). The lower the number, the more aggressive the ramp rate.
Ex: Lunati 55003 (218/221 .526/.534 116)
282 (in@.006) - 218 (in@.050) = 64
287 (ex@.006) - 221 (ex@.050) = 66
Ex: Comp cam 54-412-11 (212/218 .522/.529 114)
265 (in@.006) - 212 (in@.050) = 53
271 (ex@.006) - 218 (ex@.050) = 53
So, even if the comp cam have a lower duration than the Lunati cam, it's ramp rate it much more aggressive and harder on springs.
--
Eric D.
99 Firehawk M6
Ex: Lunati 55003 (218/221 .526/.534 116)
282 (in@.006) - 218 (in@.050) = 64
287 (ex@.006) - 221 (ex@.050) = 66
Ex: Comp cam 54-412-11 (212/218 .522/.529 114)
265 (in@.006) - 212 (in@.050) = 53
271 (ex@.006) - 218 (ex@.050) = 53
So, even if the comp cam have a lower duration than the Lunati cam, it's ramp rate it much more aggressive and harder on springs.
--
Eric D.
99 Firehawk M6
I live in MA. I've been running a T1 for years (221/221 .558 112lsa) and I've never really believed that crap about cold springs. I do NOT beat on the car until it is fully warm (at least 150* temps) but normal driving is fine (I keep it under 2500 until it's warmed up). Been using the same 918s for...3 years?
Dope
Dope
I run an XE-R cam in MI and I've started it up in -10F weather this last year. I just let the motor idle for about a min (usually while I scrape the windows LOL) and then drive conservatively until the oil is warm. No issues so far.
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Thread Starter
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From: Central, MA
Thanks a lot, guys.
Blue Hawk, That's really interesting that the little Comp cam has more agressive lobes than the bigger Lunati. Just glancing at the specs, I'd assume they were very similar with lift vs durations. Looks like I have some more specs to hash out.
I see VHP is measuring advertised duration at .004 rather than .006. Is it that much of a difference? A.D. looks to be rather high for the smallish looking at .050 lobes... and the lobes are supposed to have quicker ramp rates. VHP cams are here.
Blue Hawk, That's really interesting that the little Comp cam has more agressive lobes than the bigger Lunati. Just glancing at the specs, I'd assume they were very similar with lift vs durations. Looks like I have some more specs to hash out.
I see VHP is measuring advertised duration at .004 rather than .006. Is it that much of a difference? A.D. looks to be rather high for the smallish looking at .050 lobes... and the lobes are supposed to have quicker ramp rates. VHP cams are here.
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Originally Posted by Blue Hawk
The lower the number, the more aggressive the ramp rate
Ex: Lunati 55003 (218/221 .526/.534 116)
282 (in@.006) - 218 (in@.050) = 64
287 (ex@.006) - 221 (ex@.050) = 66
Ex: Comp cam 54-412-11 (212/218 .522/.529 114)
265 (in@.006) - 212 (in@.050) = 53
271 (ex@.006) - 218 (ex@.050) = 53
So, even if the comp cam have a lower duration than the Lunati cam, it's ramp rate it much more aggressive and harder on springs.
Ex: Lunati 55003 (218/221 .526/.534 116)
282 (in@.006) - 218 (in@.050) = 64
287 (ex@.006) - 221 (ex@.050) = 66
Ex: Comp cam 54-412-11 (212/218 .522/.529 114)
265 (in@.006) - 212 (in@.050) = 53
271 (ex@.006) - 218 (ex@.050) = 53
So, even if the comp cam have a lower duration than the Lunati cam, it's ramp rate it much more aggressive and harder on springs.
and more overlap the cam has
Originally Posted by HumpinSS
The higher the number, the more aggressive the ramp rate
and more overlap the cam has
and more overlap the cam has
As for the VHP cams, from what I see, the lobes are not nearly as aggressive as Comp XE-R ones are.
The exact reason why I like TRs cam lobes. Especially the 220 and 224. Decent .555ish lift with fairly aggressive lobes. Remember, more aggressive ramp rates make the engine more responsive down low and also idle better. My buddy has been running a TR220 114 in his 5.3L silverado for a year now and has had great results, so dont be afraid to get an aggressive cam. If I were you, i'd get a TR224 114 or a TR220 112 cam, especially since you have a bigger motor.
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Ahh, I talked to you about your friends 5.3 truck over the winter... I forgot about that.
Yeah, I'm definitely considering a TR220. I'm just more or less looking for a cam to come alive and be real healthy at 2K. If it comes down to it, I'd rather feel a big increase in the lowned and midrange than I would with the top end... which is why I was planning on keeping duration on the low side.
Yeah, I'm definitely considering a TR220. I'm just more or less looking for a cam to come alive and be real healthy at 2K. If it comes down to it, I'd rather feel a big increase in the lowned and midrange than I would with the top end... which is why I was planning on keeping duration on the low side.
Originally Posted by marc_w
Ahh, I talked to you about your friends 5.3 truck over the winter... I forgot about that.
Yeah, I'm definitely considering a TR220. I'm just more or less looking for a cam to come alive and be real healthy at 2K. If it comes down to it, I'd rather feel a big increase in the lowned and midrange than I would with the top end... which is why I was planning on keeping duration on the low side.
Yeah, I'm definitely considering a TR220. I'm just more or less looking for a cam to come alive and be real healthy at 2K. If it comes down to it, I'd rather feel a big increase in the lowned and midrange than I would with the top end... which is why I was planning on keeping duration on the low side.
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From: Central, MA
The reason I worry about lowend, is when the stock converter locks up... RPM's and speeds anywhere from 1,100 rpm at 36mph to 1,500 rpm at 50-55mph.
I can tune my way around it nice and easy, but I'd rather just have some lowend snap.
EDIT: Putting serious thought into it, I don't think any aftermarket cam will help in the 1,100-1,500rpm range. I'll set my "healthy running cutoff point" to 1,500.
I can tune my way around it nice and easy, but I'd rather just have some lowend snap.
EDIT: Putting serious thought into it, I don't think any aftermarket cam will help in the 1,100-1,500rpm range. I'll set my "healthy running cutoff point" to 1,500.
Last edited by marc_w; Jun 17, 2004 at 02:58 PM.
Launching!
Joined: Jan 2004
Posts: 273
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From: Trois-Rivières (Québec / Canada)
Originally Posted by HumpinSS
The higher the number, the more aggressive the ramp rate
and more overlap the cam has
and more overlap the cam has
For a same duration at .050, the longer the advertised duration will be, the softer the ramp will be.
Here's a little graph that show it:
--
Eric D.
99 Firehawk M6
