Rise of the Phoenix

iTrader: (27)

My thoughts exactly. You should be able to sell them for $450.00 all day long and twice on Sunday.

kinglt-1

iTrader: (26)

a set of low mileage LS6 243's will sell for more then 400.00. I am guessing you could get 5-600.00 or possibly more if you hold on to them. Those heads are not easy to come by. sure plenty of 799 or 243's with standard valves, but not the hollow/sodium units.

cali_bear2003

iTrader: (7)

[QUOTE=kinglt-1;18995368]a set of low mileage LS6 243's will sell for more then 400.00. I am guessing you could get 5-600.00 or possibly more if you hold on to them. Those heads are not easy to come by. sure plenty of 799 or 243's with standard valves, but not the hollow/sodium units.[/QUOTE
I do plan on just holding on to the heads. I would not sell them for $600 as I could not go out and replace them for that price. Hot Rodding is expensive lol...

J-Rod

A ported set of LS6 heads may be considered a cost effective modification to a vehicle depending on what your criteria for success is.

So, you asked who the "best" person was to port your heads. The best is a subjective term, the cost to pay a top tier guy to port your stock castings makes buying a set of aftermarket heads probably very attractive. Also consider the time it would take to get your heads back. I know of some porters who in some cases take over a year to deliver a set of heads back to you.

Yes, you could send your heads off to some of the vendors on this site who have a CNC program designed to work on the stock casting. Again, you are working with in the limits of a stock casting. If you go back and look Tony Mamo did a really extensive test of a lot of ported stock castings years ago. So, you can see what most ported heads will do.

Unfortunately in this game shops that "fudge" the numbers a bit sell products. So, in many cases, it drives the whole market to "fudge" just a little. In fact I've seen the results of flow testing of most of the heads out there. All I can say is most of the talk of small volume ls6 heads making big flow number is all hype. If you aren't modifying the runner, then all that leaves you is the bowl and the short turn. So, short of epoxying up the bowl you can't add material back in, you have to take it out... Thus the volume has to get bigger in a ported ls6... So, once you port them, they start to get very large in cross section and volume just to get "decent" flow numbers. This effects throttle response and again, the size and specs of camshaft selection. Well ok, it should anyway. But many folks ignore that and just blindly pick cams out of a catalog (but thats another topic).



I'll give you my own personal example...
The heads on the H/C I drive were "supposed" to flow around 330-335 according to Jay @ Absolute Speed, and were supposed to be around 220-225 cc's. At the time (2002-2003), these were recognized as some of the best heads you could buy for an LS. AFR 205s (first aftermarket head) didn't hit the market until 2004-2005.

In reality my 225s ports were 237cc's, and they flowed as follows:

Intake side
….200….300….400….500….550….600
….146….208….264….301….314….323

On the exhaust side they were a bit soft, and we had Greg Good touch up the exhaust side. Thus we picked up some exhaust volume. They poured at 90CC which is pretty big for an ls6 port on a 346.

Exhaust side
...200….300….400….500….600
….114….155….214….238….252

So, a relatively decent ported Ls6 head.

With these heads, a stock ls6 shortblock, FAST90, and a LGM G5X3 package we made ~503RWHP. Its pretty well known what the car ran, and where it ran it at. So, we'll just leave that as it is...

We've tested a Nick William Throttle Body (one of the first ones he ever built), a TPIS throttle Body, and a GM 90. The GM cost us peak HP (5-8HP), but the low speed drivability was much better with it in place. Since we street drive the car, we took that hit.

So, that gets us to when we swapped the car to AFR... We had planned on using an AFR 225 on the car to see how it might fare against the ported ls6 heads that were on there. See, my belief is that velocity makes power.

But, the AFR 225 wasn't available at that time, so we decided to try an AFR 205 head. For those who aren't up on what AFR quoted on the 205 heads.

….200….300….400….500….550….600
….145….210….257….290….301….308


So, lets compare that with my ported ls6 heads

….200….300….400….500….550….600
….145….210….257….290….301….308
….146….208….264….301….314….323
....-1.....-2.....+7....+9....+13...+15

Wow, just going on flow numbers alone it looks like clearly the AFR heads are just simply inferior to the ported Ls6 heads. In fact our AFR numbers may have even been a bit worse as I milled the heads, and shrouded up the chamber a bit more than most. But, I think this is pretty close to what we can consider accurate. Keep in mind our ported LS6s were probably one of the better sets you are going to find on anyone's car out there.

But, like peak dyno numbers, peak flow numbers are only one point in the curve. Again, you have to look at things like velocity, cross section area, etc... when taking flow numbers into consideration.

Anyhow, we decided to do an A to B test of the AFR heads vs our Ls6 heads on our current combo at that time.

It should be noted that the combination was an custom cam from Flowtech induction 244/248 111 +0 on LSK lobes. Also, we had moved to a forged 347 after dropping a seat on the Ls6 heads. The additional reciprocating mass of the 347 cost us a few Hp over the much lighter cast piston 346. The 347 is still a flat top motor, so we aren't doing anything creative with super high compression. Its basically as close to duplicating a stock 346 as we could with a set of forged pistons. This combination dyno'd around 503 RWHP after it was put together. This was done with an Exedy dual disc. After that dyno test we switched to a Textralia single disc.

The problem was, something was up with the car. Having changed nothing on the car we were down on power from our previous dyno runs. The best the car would pull was 452.7. Obviously that is quite a bit down from the 490-500RWHP numbers we were expecting as a baseline that we had seen before.

Before the question is asked, all my dynos were done at an independant 3rd party location who has no vested interest in either side, and no agenda to promote.

After spending two day sorting the car out. We were still in the 450's. So, it was decided to go ahead with the swap and see where we were at. We were quite happy to see the car find its lost power. With final tuning on the car completed we had recorded a best of 492 RWHP with the AFR heads in place. But that test was only to ~6800-7000 and the car was designed to make peak power at 7400-7500.

The one thing that was really noticeable with the AFR 205's was the drivability. The part throttle response is much better, the low speed drivability is much better. In other words for a street head, to me it is a much better choice.

Having had a bunch of other obligations we really had no time this past year to make it to the track and make many runs in the car. So, we wanted to get a chance to run the car in decent air before the summer heat and super positive DA's skewed our results too bad. On the car's first pass it sheared 9 teeth off the ring gear, and destroyed the pinion. The new clutch hits much harder than the clutch it replaced. In the next 3 attempts to race the car we shattered 3 built rear ends on the starting line. The car went 10.90's @129 in +1100 DA with traction issues. If we could have kept the rear together I would have expected 10.30 - 10.40's in good weather.

As a side note, the car was re-tuned by Pat G after we made 492. The car pulled cleanly to 7400-7500 and in that testing the car made 515-520 RWHP.

96capricemgr

iTrader: (1)

People keep comparing the cost of as cast aftermarket heads to ported stockers without talking about the performance of each without talking about the fact ported stockers will outperform as cast aftermarket. Ported aftermarket should outperform ported GM but by the time you pay for porting, PM guides or roller rockers etc you have added a LOT of cost, likely close to double but not double the HP gains.

There certainly comes a time when you need to go there when looking for big numbers but many advertising swayed folks are too quick to jump on that bandwagon.

A ported 243/799 head still in production and more easily found today than ever before can easily be ported to support more power than useable on street tires at legal speeds. Yes there are those who want more than that but that is sufficient for most of us who aren't in a rush to put a rollbar and all in our cars.

3.8TransAM

J-Rod and 96caprice both make valid points.

The best thing to do is to be honest about yourself with the build. If it lives on a trailer and only goes to the strip will be far different than if you drive it 40 miles to work everyday. Don't lie to yourself and pretend otherwise.

Same goes for budget, what can you actually spend versus what you really end up spending are two different things. If you have $4k to devote to an engine, your choices will be far different from someone who has $8k or $12k.

Be honest with what you want and what you can afford and investigate the people and cars that are doing something similar to your own end goal.

Well though out "cheap" builds usually end up being better than "expensive" builds that were not thought out.

J-Rod

Sorry, been too busy to come back and reply to this.

What "as cast" aftermarket heads are you referring to? Most if not all aftermarket heads are cast and the CNC ported. By your logic why port a set of factory heads at all?

The rest of your argument is subjective at best. Again, why even port heads if we stick with your logic? Per NHRA rules my car already needs a roll bar and it the car is 100% stock. Lets just tell everyone on Ls1tech to stop modifying their cars...

Again, your objectives might be suitable to you, but its subjective at best. If you want to believe that ported stockers are the best option, by all means. Feel free to, doesn't make it correct though.

I'll go back lastly to what I've said countless times before define your objectives, your criteria for success, your budget, and then go from there.

axe murderer

iTrader: (3)

Aftermarket heads also have better valve angles.
The cathedral as cast will out perform the popular CNCed heads & it looks like the Dart as cast LS3s might do the same.

Public Enemy

i have seen the as cast tfs 220 outperform ported 243 on stock ls1 and ls2 shortblocks a number of times, so i am unsure where you got this data from.

FYI, i had 2 cars make over 500whp on stock shortblock ls2, automatic vehicles with tq converter with the as cast tfs 220. Show me one ported stockers which was able to come close to that. The TFS also comes with PM guides and uses stock rockers

96capricemgr

iTrader: (1)

People still acting like ported=ported, one guy can wreck a pair of castings and the next can make them great.

So where do we find Trickflows with PM guides? And what do they cost?

KCS

iTrader: (20)

There was at least one "cam only" LS2 that made a tick over 500whp on a Mustang dyno. Pretty sure it was a stick car, but the heads weren't ported. It's one of the first links that come up if you search cam only LS2.

KCS

iTrader: (20)

Agreed. I think what a lot of people don't realize is that aftermarket castings allow you to do things that can't be done with the stock heads or cost more to be able to do with stock heads. I wanted a big intake valve in a cathedral head, and after I added it all up, it was more financially sensible to start with the TFS 220 head than to machine a stock casting to accept a big valve. Then there are other advantages like the lower valve angle that you've mentioned, as well as more structural support around the rocker stands and more meat around the ports for larger cross sectional area. When you actually utilize the features of the aftermarket casting, you will usually see just how inferior an OEM casting is.

J-Rod

There are just limits on the stock casting of initial port size and wall thickness in several parts of the casting.

I'll also note that Tony Mamo who spent a considerable amount of time developing and aftermarket LS casting for AFR has now left AFR and does hand porting for those who want ported stock castings. You might solicit his input on what he can do on a ported stock casting vs an aftermarket casting that he designed. He can probably speak authoritatively on the pros and cons of each.

https://ls1tech.com/forums/generatio...l#post18660802

Brian Tooley Racing

iTrader: (13)

I've seen CNC 243 heads make over 500 rwhp on a stock LS6 shortblock, which is great bang for the buck in my opinion.

We sell a lot of the TFS As Cast 220 heads because we've had many sets make over 500 rwhp on LS2 setups.

The attention to detail in the port matching and additional hand work makes the difference.

JakeFusion

iTrader: (7)

Brian, have you done much with the TFS LS3 or LS7 heads? A bit off topic for sure, but just curious if you've seen anything with those heads? I know you've made a ton with TFS 245s and like cathedrals, but was wondering if you had an opinion on something like the 255s or 260s from TFS. They flow well with relatively sane port volumes but have larger valves (which is an important factor for thinking about heads).

Brian Tooley Racing

iTrader: (13)

We've had mixed results. We had some of the TFS LS3 heads make a good bit more than the stock LS3 heads, but we had a set of TFS LS7's make around 20 rwhp less than a set of CNC Advanced Induction GM LS7 heads, back to back.

For most hydraulic roller combinations up to 427 cubic inches turning under 7,000 rpm a very good set of cathedral port heads are still going to do as well or better compared to square port heads.

When you think about the 440 testing we did while I was still at TFS, a box stock set of LS7 heads that flowed 370 cfm on our bench made 20 hp less than a set of TFS 235 heads with a port matched Fast 90. Once you get a handle on WHY this is possible it makes cylinder head choices make a lot more sense.

J-Rod

Agreed, but those combinations are typically max effort setups (as I outlined above). It also depends if all you are looking for is peak HP.

So the question becomes a question of cost vs benefit. So, the "best" is dependent on perspective.

What defines "best"

• Is it best peak power
• Is it best power under the curve
• Is it lowest cost to reach X peak flow number
• Is it highest flow with lowest port volume and cross sectional area
• Is it hand ported vs cnc
• Is it aftermarket castings vs stock castings

So, I would say there are some general assumptions:

• If someone already have a set of stock heads, it may be more cost effective to have the stock heads ported.
  
• There may be trade-offs (drivability, performance, etc..) vs using an aftermarket head, but those trade-offs may not be offset by the increased cost of aftermarket heads.
  
• Someone may be able to hit whatever goals they have set for themselves with ported stock castings.
  
• A set of aftermarket heads have greater potential for power production over a stock casting.
  
• The end user must decide what criteria they define for success, and plan accordingly.

Brian Tooley Racing

iTrader: (13)

If you're looking for 500 rwhp out of a 5.7 liter engine, you should already know that's a max effort setup... lol

This car runs low 10's on motor... guides weren't replaced, customer had less than $1900 in all parts and labor.

I agree that aftermarket is generally better, that's the direction I push most people. This customer wanted to use stock castings that came on the car (C5 Z06).

J-Rod

So those are certainly impressive numbers, can you share the details?

Typically if you are in search of max effort setup, you are looking for peak HP and Tq. All things being equal how much power are you leaving by going with ported stock castings vs an aftermarket head?

Again,if they made their power goals with ported stock castings, thats great how much more would they have made with a better head?

Conversely they could have skipped porting the heads altogether and gone cam only and thrown a kit on the car and made more power for less money. But its all about requirements/objectives. My point above was that defining the criteria for success and requirements will drive out what "best" is for a combination.

In a purely theoretical world aftermarket heads are pretty much always going to be better than a ported stock casting for power production. But I agree that someone may be able to meet their goals without the need to move to an aftermarket casting. Again, it goes back to requirements.

HP is a matter of money, so how much HP can you afford to make?