Jason & Cstraub,

Ideally, that would be the best way to do it. Put them all on the engine dyno. Same set up. Set up typical to the LS1tech member.

I agree that flow bench isn't the began all - end all. Out of my pocket engine dynoing on my engine about 3 sets of heads is about all I'd be up for. As I said before I might be able to get engine dyno time for this sort of thing. If we had say 10 sets, I'd pick the top three (from the bench) and see what they do. Just one idea for doing this.

Everyone state their views of the right way to do this...let's see if we can get something set up.

Does Thunder have an engine dyno?

I really don't care what the format or test is as long as it's fair and objective. I think it's time for a lot of this to be put to the test and end the speculation.

 

Thunder has access to an engine dyno that we use frequently. We should have one in house within the next 8-10 months.

 

There is some good software out there and some of it works very well. My perspective and my way is a little different, but my "white box" cams have done very well over the years. If they didn't I could not pay my mortgage. I've seen a camshaft change make 100 HP of difference on a 410 sprint engine with a prototype set of $14K heads with all the airflow in the world. Hell if it don't come in and go out at the right times it doesn't matter how much air it flows. With that said I have cammed engines in the same class that the budget for 1 racer was 5X that of what another was in the class. One with an awsome set of heads the other with fair heads. Either way the engine builder matched the induction system with componets that worked together. Good heads less cam, bad heads more cam. . . just simplifying. . . and both combinations made very close power and ran up front. Is this fair, yes. The engine builder maximized power for both customers to give them the power they paid for. One guy spent more but that was his choice.

If you want a real test, then you have the shop, or the porter, or the engine builder supply heads and camshaft based on the parameters of using the stock intake and a specified short block. The power will be judged on an averaged in a specific RPM range. LS1 Tech's own engine builder challenge... Now you have something with merrit.
Now the down side, some sponsor on this board will be top dog and people like to be associated with winners so that guy's business will go through the roof. The 2nd guy and the rest may pull their sponsorship of the board and now the board has lost revenue. Decisions, Decisions. . .

I'm going back to working on this HAVA TAMPA profile for HVH and get ready for the PRI show and I look forward to meeting Terry Wilkes and seeing Rick and Tony again.

Chris Straub
Stef's Performance/B&B Performance
Sales Engineer

PS. And please call me Chris

 

I agree with 93Pony and Cstraub - flow is only a part of the story - and there are definitely places were less flow but more velocity will make more power.

Now you could get someone with a nice flowbench, flow the heads, CC the runners, measure the length of the shortside/longside radius's, and if possible probe for velocity in those places. A swirlmeter would also be interesting. Don't know if you would get a nice easy answer with all that data, since heads ported with different goals will have different characteristics.

The engine dyno would be a better solution, but then the camshaft question comes into play. Heads with different I/E, etc. will need a different camshaft to perform optimally - if you use the same camshaft for all the heads you are testing the heads, but are you measuring their performance, or just how well they match up to the camshaft (or both).

Ideally the best way to do it would be to test a "package". Set out certain requirements (idle rpm, torque peak range, hp peak range, average area, idle vacuum, etc. - whatever is felt to be pertinent) and then take a set of heads/camshaft ported to those specs and run them.

Not the cheapest thing to do, but that would definitely give you some verifiable numbers, etc.

 

Chris, Chris & Jason,

Excellent points!

LS1 Tech's own engine builder challenge sounds wonderful.

With the power curves, peak numbers and engine dyno data to work with we could classify winners for several catagories to avoid the winner takes all issue.

1. Best overall power curves
2. Most area under the curve for torque
3. Most area under the curve for horsepower
4. Peak rwhp
5. Peak rwtq
6. Best torque curve for a daily driver...ie most area under the curve between 2000rpm to 4000rpm

I doubt any one package would be able to meet all the objectives listed.

While this might hurt a few on the very bottom in all catagories, in the end it should help them realize what needs to be worked on and improved.

 

I really think thats the only way to do it. The average joe doesn't get a custom grind cam for his app., its mostly mixing different parts. This test should be conducted with the average joe in mind and not ***** to the wall or optimal performance. Same casting numbers for all the heads should be used as well.

There are hundreds of combinations that could be dreamt up but a single combination needs to be chosen and tested. Obviously certain heads are going to perform better with certain cams than others. You could even try testing a small, medium and larger camshaft. with all the heads but then the question of $$$$ comes to mind.

Who's going to foot the bill?

Who's going to step up to the plate and REALLY make this happen?

 

So what cam do you pick? Do you want the porters to port their head to that cam, even if their standard heads are ported differently. I still think specing out the cam and heads together is the only way to go - it's foolish to spend 1500-2000+ on heads, and not be willing to spend a few hundred more to get a matching cam - in my opinion or course. I realize there are people who do it differently, but I think to make the shootout "valid" you have to do the whole package.

 

From my understanding this is to test the standard port job, correct?

The underlying theme behind this is the consumer. So if the sponsors are going to put the max effort in a set of heads for a test, what is the consumer getting then? Isn't that what they are paying for?

Having different cams for different heads, if I am understanding you correctly, is only introducing another variable and BS flags are going to be raised all over the place .

I agree with you wholeheartidly though ChrisB, but thats a whole different arena with different variables.

 

I couldn't agree more....if the purpose here is to help people decide on which cylinder heads to buy, you have to just take a random sample of the vendors product otherwise you're allowing people to "stack the deck" by sneaking in a little additional work which wouldn't typically go into a "standard" production out the door package.

If the idea is to challenge each shop to come up with the best package, it should be qualified as such so that it's "no holes barred"...best man wins!

 

And this is why the Mustang world has never done a TW vs TEA vs AFR vs Edelbrock vs Brodix vs ....every other combo test.
Too many variables. I look at a motor as an entire package....heads, cam, intake, exhaust, displacement, etc. Everything must match correctly in order for the motor to scream.

What's happened is the Mustang comunity has let the real-world do the testing.....& that is precisely why Ed C. has so much buisness.

In the long run what I think is best for the LS1 aftermarket is a set of Race classes for...the LS1.
bolt-on class
bolt-on & cam class
Ported stock heads, bolt-ons & cam
Power adders....
etc, etc
Oh, & can't forget Drag Radial class.

But....for now I say keep it simple.
Do just cylinder heads on the same flowbench on the same day.
Gather as much un-biased data as possible from each head & post the results. (flow data with stub-pipe & intakes on various bores, AVG flow, Port volume, combustion chamber volume, etc) Let the Pro's decide what cam works best with what setup, & let the masses decide who & what they want to go with.
& to be fair I believe the Head porters should NOT know what head is being tested. Just one of their 'mass produced' units that the average Joe pickes up.

So far the best cylinder head test I've seen in mass-print is the MM&FF's Ultimate Guide To Cylinder Heads
I wish they had the articles online, but no such luck. You can however, pick up the latest MuscleMustang/FastFord at the grocery store & check out the articles for ideas. Part IV is currently on the stand I believe. Parts 1-3 all had good info.
Many were surprised to see the highest peak flowing heads didn't put out the most AVG flow, nor make the most power on their 'test' motors. Again, the camshaft was not ideal for a lot of the heads tested, but the raw data in the articles is worth a LOT to the informed gear head.

& it seems the LS1 comunity has a lot more informed gear heads then the Mustang comunity....

 

Well I can get flow bench testing done and get that data.

I might be able to work out testing the "top three" contenders on my engine when it's together. I could post up the all the data, we could have discussion and pick the top 3 for engine testing based on the data collected. Not perfect but it could be a starting point.

I'd rather get off the shelf heads to get what the average joe gets.

I don't have the $$$$ to buy 20 sets of heads.

However, people are build stuff all the time...I think I could get a set tested and returned in about a week. BTW only one head would really be needed.

We could easily do this ourselves. All it takes is sending a head to someone that flows it. Then the head can be returned. Members are building stuff all the time.

Let's work something out and at least get started on some basic consistant data collection.

 

What Chris, Chris, Jason, and Pony have said.

I don't have time to go searching, but someone has posted an example on this board of a lower flowing set of heads out performing a higher flowing set of heads. Bottom line? Head flow is not the right variable to base a head purchase decision on. The sad thing is that this is not generally understood and accepted.

Look at who is going fast and what they run. As already mentioned, that is a much better indicator than peak flow numbers.

 

I think most of us in this thread know the peak numbers are not all that important.

Head flow is by no means the sole factor in making power.

However, flow testing can help spot issues like ports that stall etc...so it does have it's place.

 

True, but wasn't the point of a flow-off to generate a report that the unwashed masses could use as a buying guide? The guys that know what is going on don't need the list.