Phil99vette

iTrader: (11)

I can't wait to get my hands on a set of 225s with the 62cc chambers and mill them suckas to a nice lil 55-56cc. I'm really interested to see how they compare to my current head which makes pretty good power.
Phil

Tony Mamo @ AFR

iTrader: (13)

Yes...Because it's painfully obvious that we don't know what we are doing.

(FYI....some of the heads on the list are AFR castings done by some of the "good" guys....shhhhhhhhhh.....don't tell anyone).

We have worked extremely hard at maximizing the flow curves you see our heads deliver at the current volume's that we offer them....for most applications the two heads we currently sell should work extremely well....especially for a street/strip driver type. Down the road we will also produce our version of a "big" head (245 cc) with the same dedication to maximizing the entire flow curve and keeping the airspeed up, however, it will really be sold as a max effort cylinder head requiring at least a 4.000 bore to fully utilize it and preferably 400 CID or larger engine. Also, it will benefit from ported higher flowing intake manifolds and more aggressive cam profiles with higher lifts etc.....preferably a solid roller set-up. For an aggressive street set-up, its still going to be tough to beat the 225, but for a more aggressive larger cubic inch application, the proposed 245 will be a good choice.

By the way. it's at LEAST 6 months away....we will hopefully have it finished in time for SEMA and PRI. I will of course keep you posted.

Tony M.

Classic....hope you dont mind I "quoted" you. I have just seen that same type of statement time and time again, and while what we offer right now might not fit EVERY application, if your looking for anything close to the volumes we offer, you will be hardpressed to find a higher flowing head in the sizes we produce....especially if you consider the entire flow curve, not just the peak flow. Granted, this opinion is from someone totally tainted who might have inhaled too much grinding dust in the last ten years!

Bo White

iTrader: (59)

I would like to see the flow #s of the 205 head as cast

Visceral

iTrader: (1)

Has anyone got a copy of the June Hot Rod around? (I think it has a pic of the 07 Shelby GT500 on the cover) In it they compare a set of TPiS 22X cc LS6 portings against the 225 AFRs on a motor. They both flow within a few cfm of each other...

And they both make within a few hp of each other too, from what i recall.

It sort of messes up that whole "The whole AFR port design is radically superior" thing and again leaves it to the "Yeah its nice to have such a thick deck for non-NA play" thing.

It would be nice if someone has that around and can post the details. Comparing apples to apples is rather difficult here, and few are anywhere close (myself included). The Hot Rod test seemed to be very apple-to-apple.

Tony Mamo @ AFR

iTrader: (13)

No such animal Bo....the 205, the 225, and the future 245 all start life as a casting designated "CNC" which would pour somewhere in the 175-180 cc range if you were to check it. The bigger heads get a roughing program before we actually finish port them or we would be busting expensive porting tools left and right.

Tony Mamo @ AFR

iTrader: (13)

You might want to take a closer look at the area under the curve numbers while also taking into consideration the fact that the AFR headed motor was still at a half a ratio lower in compression (should be worth about an additional 1.5-2% increase, roughly another 10 ft/lbs and 10 HP or so), and the fact this was a total "ringer" head with titanium valves (which also usually make a little more power due to perfect valve control from their lighter weight). I spoke with Myron personally about the test and he said that there was tons of time invested in those heads and that's why he was so interested in the results. All things considered, I think the out of the box 225's did quite well.
This test was a far cry from an apples to apples by the way, but close enough to at least learn something.

Also Visceral, I dont ever remember posting that our heads were "radically superior"....we work extremely hard to manufacture a good product that produces consistent results. I try to only post factual information I have personally documented and explain some of the benefits our cylinder heads may offer you. If your a fan of AFR (and use our products), you might have already experienced some of these benefits, if your considering AFR you probably don't mind reading about it, and if your a fan of another product thats OK too....competition is what pushes all the manufacturers to make a better product....ultimately all of us benefit from that type of situation in the long run. My C5 WAS a rolling testament to that statement....LOL

Tony M.


EDIT: I just took the liberty of adding all the numbers (of the TPIS test)....
First off, there were some RPM points where the AFR headed engine made over 10 more ft/lbs while still having a significant disadvantage in CR....a half a point of compression is worth at least 10 ft/lbs in a 600+ HP engine. The peak "delta" in torque was 18 ft/lbs @ 4500 RPM's.

The average gain over the entire sweep (4100-6500 RPM's) was 6 ft/lbs and 6 HP in favor of the AFR (583/565 versus 577/559). If you even up the score with higher CR it would have looked more significant at say 16 ft/lbs and 16 HP, again, NOT taking into account a similar engine with Ti valves will usually produce a little more power (especially upstairs) due to the lighter weight and perfect valve control the titanium valves provide. The AFR heads were fitted with our standard steel valves.

2c5s

iTrader: (11)

Those were $4,500 heads from TPIS. Hell, for $4,500, I would expect more power, not less... -3ft. lb's less in Tq and -2 less in H.P.

Bo White

iTrader: (59)

I understood that they all are from the same casting, I was just wondering how the casting stood as cast. I was just wondering also how well they were "shaped" from the cast as well, looks like they are born to be ported

Visceral

iTrader: (1)

I'm sorry... where did anyone read that TPiS was any good at porting LSx heads? What about those $4500 heads was un-reproducable by TEA, AS, PP, etc?

As far as the compression ratio and Ti valve thing... I do enjoy your willingness, Tony, to point to CR when it helps you, and dismiss it when it doesnt. Also, the engine only spun to 6500 rpm. Are you saying that titanium valves are worth any significant power at or under the peak power of these dyno tests? Any more than, say, 5 hp?

Net-out here... There is a 225-ish port of an LS6 head that can come damn close to a 225 AFR head in power and flow.

Since they were looking at a large bore and ci motor, a LQ9 head would have been within a millimeter... no sense in using an expensive LS6 casting. A properly CNC'd, then hand ported, non-titanium valve, LQ9 head could be within a HP or two of the example heads... for ... well.... not alot of money.

I have a set of <$2200 TEA LQ9 heads that I just had independently flowed. And Im willing to go toe to toe with *any* AFR head available for up to $300 more than what I paid (core included)[lets say <$2470], on a NA 4.125 bore motor. What AFR heads can I buy from whom, ready to go, for that money?

Taking a "random" sample of Stage 3 heads and showing your superiority would be a relatively easy excercise. Ive seen, owned, and installed, several phenomenally crappy Stage 3 heads. Stage 3 seems to be where companies have the most opportunities to screw up...

Classic

iTrader: (3)

Tony, no problem quoting me And I certainly didn't mean to imply that you guys don' know what you are doing Also, when I was refering to the "good" porters I wasn't necesarily talking specifically about anyone on this board -- yet I still imagine that any porter won't be able to come up with flow numbers at your port volume (using your castings) for some time as you guys have a head start on everyone

I do have a quick question for you though. Some CNC based porting companies just use the same port (designed for X valve), then when someone wants those heads for a bigger motor they just place a larger valve in the same port, or vice versa for a smaller application -- therefore the cross sectional areas are off, and the port isn't developed to those valve sizes, etc. resulting in a poor cylinder head (especially when considering smaller valves in the larger port volumes ) Just curious to see what your opinion is on that topic?

gollum

iTrader: (1)

[QUOTE=Tony Mamo @ AFR]Down the road we will also produce our version of a "big" head (245 cc) with the same dedication to maximizing the entire flow curve and keeping the airspeed up, however, it will really be sold as a max effort cylinder head requiring at least a 4.000 bore to fully utilize it and preferably 400 CID or larger engine. Also, it will benefit from ported higher flowing intake manifolds and more aggressive cam profiles with higher lifts etc.....preferably a solid roller set-up. For an aggressive street set-up, its still going to be tough to beat the 225, but for a more aggressive larger cubic inch application, the proposed 245 will be a good choice.

By the way. it's at LEAST 6 months away....we will hopefully have it finished in time for SEMA and PRI. I will of course keep you posted.

Tony M.

QUOTE]

Will the new AFR 245cc heads be a complete new casting based on the factory racing C5R and LS7 427 head?

Will the C5R head design be the new trend in High Performance street cylinder heads? Small and large bore versions with 225cc, 245cc ports sound cool.

Is this just the beginning of the end of the cathedral type LS1 head? GM really threw everyone a curve ball with this new LS7 engine. I am waiting and scratching my head on this one.

J-Rod

I'd like to expand on that just a bit...

David Reher had this to say also.

We have also learned that low-lift flow (meaning anything below .400-inch valve lift in a Pro Stock engine with a .900-inch lift camshaft) is relatively unimportant. Think about the valve events in a racing engine: From the point when the valve first moves off its seat until it reaches mid-lift, the piston is either going the wrong way (that is, it is rising in the cylinder) or it's parked near TDC. The piston doesn't begin to move away from the combustion chamber with enough velocity to lower the pressure in the cylinder until the valve is nearly halfway open. Consequently it is high-lift flow that really matters in a drag racing engine. (We're not talking a street motor, but I wanted you to see what he big boys have to say about this).

Now guys, don't get to stuck on this. Keep in mind this is referring to a PS motor with +.900 lift. So mid lift there is a bit more than mid lift on our motors. Also keep in mind they are talking about a motor with a narrow high speed operating window (with WAY more than 100% volumetric eff....)


I agree a port with good veloicity helps get the air moving sooner. Just keep in mind when the cylinder is actually going to pull air, and where the piston and the valve are going to be in relation to that event....

In addition, this is what Tony, Ed, C Straub,Bret Bauer, Erik K., and a whole host of others have been trying to help some of you guys understand. Its not all about peak flow numbers. I mean they are important, but, there are other factors which are a key part of it. The big deal is to get tha column of air moving as quickly as you can, and to effectively fill that cylinder as much as possible. As RPM increases, time decreases which is why we go up on duration. But on the low speed side that slows the air down, and you end up having overlap and low speed airflow issues ( that cool chop chop on a big cam).

This has been the point of the cam thread, the cylinder head threads, and the ignition timing threads. Bigger isn't always better. Efficency (which the AFR has in spades) is the name of the game. This is why the LS1 is such a good motor. Small, light, and efficient....

I'll take a smaller more effiecnt head witha better overall curve over a big head with peak numbers and no velocity any day....

zforme

Great discussion! I have learned a lot from this, in my quest for making broad consistant power.

SStrokerAce

iTrader: (2)

Brent.... you might want to look at Dynamic Quench.... You can run a Al block with a tighter quench then a Iron one...

https://ls1tech.com/forums/showpost....25&postcount=4

Static Compression requirements depend on a lot of things... One is Octane..

Dynamic Compression, Coolant Type, Chamber Design, and Volumetric Efficency all have a big play in if detonation will show up or not.

Bret

SStrokerAce

iTrader: (2)

J-Rod.... From what I have heard PS is over 1.000" lift and sometimes 1.100" and really tight to the coil bind on the springs they run. There are RPM ranges when the whole port is moving air but with the durations that they run there is time when the piston is moving the wrong way in the cylinder.... The problem is the pressure in the port is not just effected by the motion of the cylinder, you also have resonant tuining in there that can add 5-7psi into the intake charge... All depending on the runner lengths and cross section related to the cubes and RPM of the motor, and the main reason the LS1 is so strong compared to classic OEM small blocks. Ain't just the head flow, but it is the total cylinder filling.

One thing that I think is interesting on the AFR is that it is SO small... I'd like to see what the effective port cross section is in the head with a velocity probe. That's a big thing to look at in a LS1 head, that whole cross section isin't moving air in that port, it's actually one of those head designs that isin't very sensitive to port size nearly as much as traditional heads. IMHO it has to do with the tall and narrow port shape.

BTW I just looked at a cam I'm doing for a motor now.... Hyd Roller over .600 lift (.630 range) medium sized duration, sub 7500rpm and a "street motor"

.000-.100 68 degs 22%
.100-.200 40 degs 13%
.200-.300 26 degs 8.5%
.300-.400 34 degs 11%
.400-.500 32 degs 10.5%
.500-.600 60 degs 20%
.600 + 44 degs 14.5%

Now making a change in that motors flow curve from .200-.400" lift of 4.4% nets less than a 1% loss in max power and about .4% in average power. Now if you changed the flow at the top end .600+ 4.4% you would see a 1% loss in average power. This is with big changes in flow of 15-20cfm at the top end. That's 150% more loss in average power.

To add a little more to this the lowest pressures seen in the port (highest vacuum) at the max VE occur between .420-.520" lobe lift (opening) and the highest pressures occur between .150-.020" lift (closing), from lowest vacuum to highest pressure there is roughly a 15psi change in pressures. The highest average velocities occured for 84 degs at lifts over .500". The more flow you have in that lift area will raise the amount of duration that the motor pulls that high of a velocity given the same sized port.

So you can see the time when the port is filling the motor the fastest is around max lift, and the time it's filling it with the most pressure is around valve closing while the piston is coming up the bore.

Bret

Visceral

iTrader: (1)

Never mind... you fixed your decimal points and now what you are saying is clear and doesnt fly in the face of my conventional thinking... unlike the unedited stuff...

SStrokerAce

iTrader: (2)

Yeah once I reread it I was like WTF... sometimes in typing you get decilexiphobia....

Bret

BrentB@TEA

I know ..missed my point. Outside temp and conditions play a major role in detonation.

SStrokerAce

iTrader: (2)

Oh yeah.... throw some more compression at a high altitude high DA motor, hell say someone in Alaska. Then take that thing down to No Problem in the summer with the same octane gas and you can expect problems if you were pushing it before.

Bret

SSBRONCS

SO WHICH HEAD SHOULD I BUY?????? TEA OR AFR?????
YOU BE THE JUDGE!!!!!! what is going to make more USABLE power and what is going to get me down the track quicker...... also which is going to leave my wallet FATTER at the end??????????????????????????????