Camshafts, idle quality, driveability and LSA-REAL WORLD EXP and OPINION

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mopowers said:
I'm just glad I'm not the only one who feels this way. These camshaft know-it-alls sure make me feel good about leaving my camshaft decisions to a professional.
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Hope your're not including me in that list. I clearly stated in the OP that these are my observations based on my experience. I have my ways which are based on my experiences. I am no cam guru or expert but if I am asked an honest question then all I can offer is an honest answer--which will be based on my experience. J.Rob
 
RAMM said:
Im kinda surprised that no one has really mentioned the driveability aspect and how LSA effects it--not even me and its in the thread title--LOL. B3Re has touched on it a bit--Tight LSA's lend themselves well to power delivery that hits like a sledgehammer and while impressive is not always satisfying or the fastest way from A - B (traction). Tight LSA's are total crap at part throttle or just off idle. Tight LSA's are a nightmare with stock converters and highway geared rear ends. Tight LSA's on the street require a hot plug in order to burn off all the crap the builds up on them too but you can run into pre-ignition and detonation due to the higher than normal cylinder pressure @ and below peak torque. Look I build a few circle track deals and tight LSA's are employed here and its almost the tighter the better too. They have their place just not in my street car. J.Rob
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OMG, did you actually read the link? If you can't hook your power that's on you.


Who, in their right mind is going to use a stock converter and highway gears with a cam like we are talking?

It's stupid. If you want to run 3.08 gears and a stock converter that is a whole different discussion. You professional forum guys make **** up for the purpose of discussion.

So, if you are going to start a thread and then make all the discussion a moving target, change the parameters, or not lay them out maybe you should have went to law school.
 
RAMM said:
I should be more clear. Cams: LSA trumps duration when considering things like vacuum- vacuum equals = part throttle tip in, mileage, ease of tuning, part throttle torque under peak torque, and a much wider and user friendly power band.
Also again:Increasing LSA has a much greater impact than reducing duration in order to achieve a certain idle/power curve/drivability.

Corollary : Narrow LSA will negatively impact idle vacuum, narrow/abrupt power curve and make driveability/tuning difficult--To a MUCH GREATER DEGREE than a wider LSA will.

Look all of this is in countless publications and all over the place. All I am saying is what I said in post #1----Cam 2 cam and duration 2 duration the cam with the wider LSA will be the better choice for the street bound crowd. Also given the choice I would prefer to widen the LSA than reduce duration to target a given HP goal AND retain any kind of manners. J.Rob
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So, in the link that IQ posted did that power curve negatively affect driving? If so, how? The tight LSA made more power from the start of the pull, all the way up and was 5 HP down and max RPM. It's in black and white. Not my numbers. In fact, I said the LSA was to narrow. In fact, that cam should have been on a 108 LSA with 10 LESS degrees on the exhaust. That would have killed the 110 LSA all over.




Let's face it...this isn't about making power. Some of you guys were born to drive Hondas.
 
318willrun said:
Silly?... Only if you keep assuming things. :) I know, you have repeated all about the events, functions and LSA and all this, that, and the other in multiple threads. I've stayed out of all the arguements. I haven't needed help in picking a cam in 20+ years. I picked that question because of a private PM I received from another member. That's ok, isn't it? Or did I break a forum rule.... :D
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You didn't break any rules. You all like a moving target.

When you have something to post, let us know. I'd like to hear it. I've posted my experiences. Someone else posted dyno results that show exactly what I have said is correct, then you move the target.

Grade school bullshit.
 
yellow rose said:
You didn't break any rules. You all like a moving target.

When you have something to post, let us know. I'd like to hear it. I've posted my experiences. Someone else posted dyno results that show exactly what I have said is correct, then you move the target.

Grade school bullshit.
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LOL..... teasing ya...relax. You weren't even in my mind when I asked that question. You made yourself a moving target.... :D Didn't say anything about you being wrong.
Not grade school at all, and there is a reason why I asked that particular individual. But you jumping all over my post without knowing kind of reminded me of a 3rd grade girl.... LOL
There is nothing that I have to add to these discussions that will make a hill of beans difference on those engaged.
 
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yellow rose said:
Why use a 104 LSA on a SBC? That head is good enough to use a 107-108 LSA.

But the test still supports what you're saying. The 110 did really well.

Second, the 104 LSA kicked the **** out of the other two for low end grunt, without giving up top end power. I thought that's what all you guys wanted...low end grunt.

Not necessarily. I like a broad flat power band with really good idle manners. That 104 didn't offer either.

Third, no where in that entire article is it said where each cam was installed. That is total bullshit. I'd have taken the 104 LSA and shoved it in at 100, or even 98*'s so 4-6* ahead. That would have helped the idle, because it shuts the INTAKE valve earlier and it would have moved peak torqu down a bit.

Shot in the dark here, since they didn't mention it, I'm going to guess they were either installed straight up or installed per manufacturers recommendation. Now talk about changing the test and a moving target. Lets be fair. If you get into playing around with installing cams other than factory specs you kind of negate the purpose of this test. We can also say that installing 4-6 degrees advanced will not come without consequence. It will change the dyno outcome as well as the idle and off idle manners. The same can be said of the consequence of changing the LSA. It's not without consequence. There is no free lunch here.

And yet and still, the 104 kicked ***.
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The test wasn't to prove anything. The 104 did kick ***. So did the other 2. All for different desires and purposes. The thing that I didn't like is a number I love to look at. Average HP and Average tq.

yellow rose said:
We'll see.

The article that IQ52 posted actually verified what I have been saying the whole time.
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Yes and no. Yes in the way that typically less LSA will outperform more as far as gross HP and torque. NO in the way that the idle and low speed suffered.

yellow rose said:
Who, in their right mind is going to use a stock converter and highway gears with a cam like we are talking?
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Just an FYI, you do realize there are some dumb cement heads out there that try to do exactly that.

Edit: make sure you click "expand"
 
318willrun said:
LOL..... teasing ya...relax. You weren't even in my mind when I asked that question. You made yourself a moving target.... :D Didn't say anything about you being wrong.
Not grade school at all, and there is a reason why I asked that particular individual. But you jumping all over my post without knowing kind of reminded me of a 3rd grade girl.... LOL
There is nothing that I have to add to these discussions that will make a hill of beans difference on those engaged.
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My bad. I apologize.
 
roccodart440 said:
The test wasn't to prove anything. The 104 did kick ***. So did the other 2. All for different desires and purposes. The thing that I didn't like is a number I love to look at. Average HP and Average tq.



Yes and no. Yes in the way that typically less LSA will outperform more as far as gross HP and torque. NO in the way that the idle and low speed suffered.



Just an FYI, you do realize there are some dumb cement heads out there that try to do exactly that.

Edit: make sure you click "expand"
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How did you see that average power was down with the 104 LSA? I didn't see that. From 3500 on up on the test they posted the 104 was much better than both.

When you are talking low speed, what does that mean? Are you talking lowest possible RPM or the lowest RPM the engine will see under load? They are two entirely different things and the former is a rediculous expectation.

The text says that Chase Knight says that the narrower LSA would affect torque from 500-1200 RPM. Was he guessing or did they do testing to show it?

The other thing is what I have already posted. There is no way any even reasonable ninth grader would ever use those heads with a 104 LSA. Just like the same normal ninth grader would NEVER consider a 114 LSA as even remotely acceptable.

That engine should have had a 107-108 LSA with a 105-106 ICL. Then you could run 242-245* duration in a single pattern cam and you would gain the vacuum back, clean up the idle a bit and make more power yet.

I realize some people want a Honda idle and 500 HP. It's impossible. There is a difference in an engine that idles at 900 RPM and will run power brakes and still makes 500 HP and one that idles at 1500 and makes 210.
 
Okay I have a question, throwing another factor into LSA and cam choice. I'm building 2 408 Cu In 360 Magnum based engines for a boat with water cooled exhaust so I also have to worry about water reversion. My engines are running ported Enginequest heads with 2.02 I and 1.62 E valves and 9.4 to one compression Icon pistons with a .040 quench. The cams I have selected are as follows:
3658d26c-4b39-46d9-bae9-0922b6c1248f_zpskywdfkft.jpg


Will these cams give me a decent idle around the docks? Max RPM for my application will be maybe 6000 RPM. From what I have learned the 114 LSA should help fight off the reversion and keep decent low RPM characteristics. Am I on the right track, or am I missing the boat completely? (LOL) SHould I install them at 110, or advance or retard them? I plan on Dynoing them this spring, but Looking for a baseline. As for induction I have Performer RPM air gap intakes with Eddy marine 750 carbs, but am considering moving to the Eddy Victor EFI manifolds with ported Magnum throttle bodies on adapters and some tuned OBDII Mopar controllers and sensors
 
Depends on the boat.


Boats are a horse of a different feather.

I'd call some other grinders besides Hughes (that looks like a Hughes lobe) because I'm thinking 115-116 installed at 110 may be better.

But that's just me.
 
Also, you may want to get a bit more exhaust duration of the manifolds you are going to use look like a typical boat deal.
 
It's a 27' Magnum Marine 24 degree deep V off shore hull. Old school 7000 Lbs of wave cutting fun. The exhaust is 1986 Chrysler Marine center rise iron manifolds that internally resemble passenger side 340 HO manifolds upside down with 3" risers and 4" thru hull pipes. It is a Hughes lobe.
 
murfman said:
Okay I have a question, throwing another factor into LSA and cam choice. I'm building 2 408 Cu In 360 Magnum based engines for a boat with water cooled exhaust so I also have to worry about water reversion. My engines are running ported Enginequest heads with 2.02 I and 1.62 E valves and 9.4 to one compression Icon pistons with a .040 quench. The cams I have selected are as follows:
View attachment 1714998460

Will these cams give me a decent idle around the docks? Max RPM for my application will be maybe 6000 RPM. From what I have learned the 114 LSA should help fight off the reversion and keep decent low RPM characteristics. Am I on the right track, or am I missing the boat completely? (LOL) SHould I install them at 110, or advance or retard them? I plan on Dynoing them this spring, but Looking for a baseline. As for induction I have Performer RPM air gap intakes with Eddy marine 750 carbs, but am considering moving to the Eddy Victor EFI manifolds with ported Magnum throttle bodies on adapters and some tuned OBDII Mopar controllers and sensors
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Your camshaft choice will be very satisfying. Put them in straight up, your static comp maybe a touch high for a boat and the available fuel on the water. I'd bet your idle vacuum to be somewhere around 16-17" without much difficulty, idling around the docks and outdrive shifting should be a non-issue with a low RPM idle speed you will use. Keep us updated when you dyno them. J.Rob
 
Hey Jesse, give me your definition of "straight up" on a camshaft. Just so's I can better understand where you are coming from. 'Cause if you told me straight up I would install it with a 114 ICL
 
That cam should idle very nice around the docks. Unless the manufacturer specs and install of 110 I'd go 2 degrees to start. If it idles decent maybe 114 would really suit you better. Is this going on a dyno first?
 
yellow rose said:
How did you see that average power was down with the 104 LSA? I didn't see that. From 3500 on up on the test they posted the 104 was much better than both.

The 104 just didn't make peak hp was all I meant. Not down on power at all.

When you are talking low speed, what does that mean? Are you talking lowest possible RPM or the lowest RPM the engine will see under load? They are two entirely different things and the former is a rediculous expectation.

Low speed to me is idle to 2-3k RPM. Street RPMs.

The text says that Chase Knight says that the narrower LSA would affect torque from 500-1200 RPM. Was he guessing or did they do testing to show it?

Since it wasn't dyno'd at that RPM, I'm guessing he is basing that on the crappy idle.

That engine should have had a 107-108 LSA with a 105-106 ICL. Then you could run 242-245* duration in a single pattern cam and you would gain the vacuum back, clean up the idle a bit and make more power yet.

I realize some people want a Honda idle and 500 HP. It's impossible. There is a difference in an engine that idles at 900 RPM and will run power brakes and still makes 500 HP and one that idles at 1500 and makes 210.
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It would seem like they weren't trying to be optimal. More so pick tight LSA, then a high LSA and one that fell in the middle. This is interesting because that falls 109LCA. They went 110, you'd go 108 and play with the installed ICL.

Really, no test out there is without flaws. This one IMO had come decent value to it. It wasn't trying to sell you a part at the end.
 
IQ52 said:
Hey Jesse, give me your definition of "straight up" on a camshaft. Just so's I can better understand where you are coming from. 'Cause if you told me straight up I would install it with a 114 ICL
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I know where you're coming from Jim. Yes truly straight up would have you retarding the cam a little to show a 114 when using the intake centerline method. I actually meant put them in as they were intended and make sure it checks @ 110 on the ICL method. I actually hate that most cam grinders just grind them in a +4 position--just makes it confusing. So in laymens terms when I think of straight up I think "As intended". I actually just check ICL but set the cam in position by looking at Intake opening and closing to see if it all makes sense. J.Rob
 
So we better all make clear what we are talking about and state LSA and ICL when we talk about straight up, advance or retard. The one that confuses me the most is the dot-to-dot. If I want to advance a dot-to-dot do I undot the top gear or undot the bottom gear? And do I undot to the left or right or do I undot clockwise or counter-clockwise. How many degrees is 1/4 dot, 1/2 dot and if I advance 3/4 dot do I have a 3/4 race cam?
 
IQ52 said:
So we better all make clear what we are talking about and state LSA and ICL when we talk about straight up, advance or retard. The one that confuses me the most is the dot-to-dot. If I want to advance a dot-to-dot do I undot the top gear or undot the bottom gear? And do I undot to the left or right or do I undot clockwise or counter-clockwise. How many degrees is 1/4 dot, 1/2 dot and if I advance 3/4 dot do I have a 3/4 race cam?
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:rofl:
 
318willrun said:
Straight up to me means dot-to-dot
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Not necessarily. I have seen variances in timing sets by as much as 3 degrees. That's why I degree everything I do, even stock rebuilds. I also once had a fellow bring me a cheap gear drive to install in his good running 454 because he liked the sound and when I installed it dot-dot and degreed it it was off 15 degrees (retarded). It would have ran like a pig
 
Interesting thread. I have spent hours trying to decide on my 325hp or so 360.... so much decision...
 
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