Looking at several pics, It appears the ls1 swirl dam area near the valve guide is completely removed on the higher flowing heads.

Are there any negative effects of removing this area in the port ?

 

Does SAM sell heads or plan on selling any?

 

""Does SAM sell heads or plan on selling any?""

You can email the school but it's mostly just that, a school, and not set up to do a lot of customers work anymore. I think Judson does stuff for his friends every once in a while but there's not enough time to do all the work he's offered in any given week. Sometimes he gets several calls a day to do whole engines and heads etc., with all the heads up success we've had against the other guys on the same tracks on the same days etc. You can give it a try but I wouldn't expect anything fast or cheap either. It takes a lot of time, effort and labor going back and forth to the bench on every port to get a set of heads that run like our current ones do. Of course a set of street type heads would be less I'm sure.

 

[quote]Originally posted by SpeedDemon:
<strong>
What's happening John? I can't tell you if these heads were flowed on a 3.900" bore, but don't you think that would be kinda silly considering they are not going on a 3.900" bore??? For a typical Stage I, II, III head that is going on a stock bottom, yes, the bore needs to be 3.900" but if it is going on a 4.00" or better, it needs to be flowed on that size bore. Who cares what the heads flow except on the bore that they are actually going on. <img src="images/icons/smile.gif" border="0"> <img src="images/icons/smile.gif" border="0"> </strong><hr></blockquote>

Hey Chris! hows life?
Now on to the tech. Chris, if we are comparing heads and their ability to flow. We need to compare them with the same bore. Most of us are using heads on a 3.9" bore and that is the info that we have. Telling a fella that you have heads that flow 350cfm and then he goes and installs them on a 3.9" bore motor (stock0 and they only flow 315, he is going to be pissed.

For the sake of argument...heck for just a little continuity we should compare apples to apples. Not some head that was flowed on a 4.125 bore to a head that was flowed on a 3.9 inch bore. Whats the point?

Yes, if the head was to be installed on a 4.125 bore the head should be tested on that bore. But to go and tout that heads flow number dominance over other heads that were flowed on a 3.9 inch bore and not mention the fact that it was flowed on a larger than 3.9" bore is at the very least...misleading. (intentional or not)

I guess we can agree to disagree. <img src="images/icons/smile.gif" border="0">
You take care Chris.

Raugahmmer
<img src="images/icons/cool.gif" border="0">

 

Flow #'s go up when you flow heads for example on a 4.000 bore.

 

And they go up even more when the bore is larger than 4".

JC

 

Even more so than is the case with dynos, it's hard to compare flow numbers from different shops, bores, and lifts.

Yes, the bore size on which a set of heads was tested matters alot when comparing flow numbers. You could take a STOCK set of heads, flow them on a large bore and show some higher numbers than on a 3.9" bore.

I agree, peak flow numbers don't tell the whole tale.

I think best thing to do is look at who is making the MPH. Still alot of variables in making that MPH of course, so you have to try to take everything into consideration.

 

Flow numbers don't mean much, SAE dyno numbers and trap speed really tell the hp tale.

 

reply to swirl dam...

i saw the more perf. heads had it completely removed.. but my are s2's have almost all of it intact.

 

[quote]Originally posted by Raughammer:
<strong>

Hey Chris! hows life?
Now on to the tech. Chris, if we are comparing heads and their ability to flow. We need to compare them with the same bore. Most of us are using heads on a 3.9" bore and that is the info that we have. Telling a fella that you have heads that flow 350cfm and then he goes and installs them on a 3.9" bore motor (stock0 and they only flow 315, he is going to be pissed.

For the sake of argument...heck for just a little continuity we should compare apples to apples. Not some head that was flowed on a 4.125 bore to a head that was flowed on a 3.9 inch bore. Whats the point?

Yes, if the head was to be installed on a 4.125 bore the head should be tested on that bore. But to go and tout that heads flow number dominance over other heads that were flowed on a 3.9 inch bore and not mention the fact that it was flowed on a larger than 3.9" bore is at the very least...misleading. (intentional or not)

I guess we can agree to disagree. <img src="images/icons/smile.gif" border="0">
You take care Chris.

Raugahmmer
<img src="images/icons/cool.gif" border="0"> </strong><hr></blockquote>

John, if we are building a set of heads for a large bore motor, we flow them on a large bore. I am not hiding ANYTHING?!?! I can't believe that you are insinuating that I am lying?!?! <img src="images/icons/shocked.gif" border="0">
All of our heads for our heads and cam packages are flowed on a 3.900" bore. Also, there is a heck of a lot more that can change flow numbers that just bore size! There are 100 ways to cheat. We are one of the ONLY shops that use ALL of the standards. We have talked to other shops that admit when they flow exhaust, they use tube on it(cheating), different bore sizes, orafices sizes, temps, depressions, etc.

Sorry if in any way I was misleading. You just don't flow a set of heads that were built for a certain bore on a different bore. That would be kinda dumb as flow characteristics change...

The funny thing is, you even said it yourself. A head built for a large bore should be tested on a large bore?!?! <img src="images/icons/confused.gif" border="0">

BTW, I am not sure, but I am going to take a guess that the SAM heads were not flowed on a 3.900 bore either. Why would they be?

Chris

 

[quote]Originally posted by just me:
<strong>Looking at several pics, It appears the ls1 swirl dam area near the valve guide is completely removed on the higher flowing heads.

Are there any negative effects of removing this area in the port ?</strong><hr></blockquote>

It is my educated opinion that if you remove the swirl vane, you will reduce swirl and tumble. This will in effect make your engine more prone to detonation. So you will need to run less total ignition timing or higher octane 'racing' fuel.

 

well I was talking to Wenzler heads of Pontiac fame a while back and was told that really, swirl and tumble just go out the window and flow is really the important thing on a race head.
But I suppose every porter has their own thoughts on some issues.

Speeddemon, it looks as if you guys also knock it out from the pic on your website?
I have never seen such a thing like the swirl dam in the ls1 heads on any other head.
On my first porting of these heads I left it in.
I am supercharged now and I really don't see the need for the thing as mixture motion is handled pretty well by the pressureized intake.
I think I am going to grind it out of my heads and run a normal type race port.
I am just going to concentrate on all out flow.
Steve
www.tech-ls1.com

 

First off, thanks for all the help. I was wondering this beacusae I plan to get heads soon. I will be running them as a heads & cam combo first and then on to a larger displacement(hence the flow #'s question). What would be the optimium valve size for a for a stock displacement motor running a large cam. For example,I don't wan't to spend extra on 2.08 valve when I will make more power with 2.02.

Again any help would be appreciated,
Marty

 

[quote]Originally posted by SpeedDemon:
<strong>
I can't believe that you are insinuating that I am lying?!?! <img src="images/icons/shocked.gif" border="0"> Sorry if in any way I was misleading. You just don't flow a set of heads that were built for a certain bore on a different bore. That would be kinda dumb as flow characteristics change...

Chris</strong><hr></blockquote>

Jeez, chris, take a chill pill. first off my posts have been about SAM ...NOT YOU. i dont know why you persist in thinking you or your shop are being talked about.
I started my first post off with "Pat,...."
That is not at you, about you or had anything to do with you.

But.. I must reiterate. When posting flow numbers that were not flowed on a 3.9" bore...that fact should be mentioned so someone is not mislead be AWESOME but not attainable flow numbers on thier 3.9" bored head.

(sigh)... again. I never meant to insinuate that you (chris) were lying, hiding anything or anything of that matter. Again... you were not the target of my query at all. I was merely asking if SAM's 350 cfm was flowed on a 3.9" bore. And if they were'nt. What bore are those fantastic numbers from? what do they flow on a 3.9" bore? I would like to know... because I found them AWESOME.

Campbell

 

He He, Sorry. I guess having to deal with Electircians, plumbing, phones, etc. over the last week setting up our new shop has left a bad taste in my mouth. <img src="images/icons/smile.gif" border="0">
Sorry for jumping on you John. I think we are pretty much in agreement in the end. Flow the heads on the same bore that the heads will go on. <img src="images/icons/smile.gif" border="0">
I'll buy you a track dog next time I see you at the track. <img src="images/icons/smile.gif" border="0">

 

[quote]Originally posted by just me:
<strong>
Speeddemon, it looks as if you guys also knock it out from the pic on your website?
I have never seen such a thing like the swirl dam in the ls1 heads on any other head.
On my first porting of these heads I left it in.
I am supercharged now and I really don't see the need for the thing as mixture motion is handled pretty well by the pressureized intake.
I think I am going to grind it out of my heads and run a normal type race port.
I am just going to concentrate on all out flow.
Steve
www.tech-ls1.com</strong><hr></blockquote>
Steve. We do not take the swirl out of the head at all! That is not the correct way to get power out of a set of heads. <img src="images/icons/smile.gif" border="0">

 

I agree heads should be flowed on a 3.9 bore, but from a business standpoint why would one porter advertise his 3.9 bore flow numbers against everyone else's 4.0 bore numbers? To most stupid buyers they won't notice or understand the differences. Also, I think we're stressing flow numbers way too much. #s will vary between benches and the people that flow them. I'm seen the exact same head flowed by 2 different shops and there was a ~20 cfm difference. I sure wish my heads were flowed on that other bench, then my heads would have flowed nearly 320 cfm at .500. <img src="images/icons/rolleyes.gif" border="0"> lol!

Peak flow numbers don't mean squat! My heads never broke 300 cfm, but the mid range was killer. As TEA's Brian Tooley says, "Peak flow numbers sell heads, mid range numbers make power."

As for the swirl dam, I talked to Brian for a long time on this one. He had been taking it completely out. He'd never seen where extra swirl actually made more power. Yes, it could decrease emissions and increase fuel economy, but not power. But he was curious about leaving it in also. The last car with their heads had some detonation around peak torque and we wondered if this might be the cause. My heads have a partial dam and I didn't have this detonation. He also learned the dam hurt peak flow a little.

Matt

 

[quote]Originally posted by just me:
<strong>well I was talking to Wenzler heads of Pontiac fame a while back and was told that really, swirl and tumble just go out the window and flow is really the important thing on a race head.
But I suppose every porter has their own thoughts on some issues.

</strong><hr></blockquote>

Steve, that is exactly true for a head ported for a race car. You will the highest flow numbers and hp by removing the swirl vane. But, on a street car, is this smart?

Is the extra 5-10 fwhp worth the detonation, and the need to reduce your timing or run race gas on the street?

Personally, I don't think so. The GM engineers are pretty sharp and I will be leaving the swirl vane in if I ever port my heads.

 

[quote]Originally posted by Sporadic:
<strong>
As for the swirl dam, I talked to Brian for a long time on this one. He had been taking it completely out. He'd never seen where extra swirl actually made more power. Yes, it could decrease emissions and increase fuel economy, but not power. But he was curious about leaving it in also. The last car with their heads had some detonation around peak torque and we wondered if this might be the cause. My heads have a partial dam and I didn't have this detonation. He also learned the dam hurt peak flow a little.

Matt</strong><hr></blockquote>

Matt, you are right on the money about people being too concerned about peak flow numbers on a set of street car heads. Mid lift flows are where the power is found on a street car. I think you did the smart thing by getting the aluminum 6 liter truck heads and leaving the swirl vane in. Very nice street/strip heads.

 

[quote]Originally posted by Sporadic:
<strong>I agree heads should be flowed on a 3.9 bore, but from a business standpoint why would one porter advertise his 3.9 bore flow numbers against everyone else's 4.0 bore numbers? To most stupid buyers they won't notice or understand the differences. Matt</strong><hr></blockquote>

Only one reason. I would rather be honest. I woudl hate to have to explain what kind of tactics I used to sell a customer to that customer once he wised up. I guess I am just honest like that... <img src="images/icons/smile.gif" border="0">