NewbVetteGuy

Can any of you engine geeks help me make sense of what I'm seeing?

-I'm comparing the Profiler 195cc head to the Profiler 210cc head. (The Jegs version of the Profilers are on an INSANE sale right now -$200 off per head; so I want to pull the trigger.)

The standard advice we all know is that going with a larger intake port in a head you are trading low-end torque / air velocity for more high end rpm and more airflow especially at high lift.

Looking at the published air flow #'s for the 195cc and 210cc Profiler's, it's interesting that the CFM anyway doesn't give anything up on the low lifts, and there is a lot to be gained at 0.500" and up and they don't stop flowing more air until higher lifts. -no real shocks there.

195cc Profiler CFM #'s
Lift Intake CFM Exh CFM % Exh/Int
0.200 145 110 76%
0.300 209 145 69%
0.400 254 180 71%
0.500 273 206 75%
0.600 274 213 78%
0.700 276 216 78%
0.800 276 218 79%


210cc Profiler CFM #'s
Lift Intake CFM Exh CFM % Exh/Int
0.200 145 110 76%
0.300 207 145 70%
0.400 258 180 70%
0.500 283 206 73%
0.600 285 213 75%
0.700 291 216 74%
0.800 297 218 73%



Here's where stuff gets weird:
I am using the formula to calculate the air velocity at various lifts for each head; Chad Spier measured the min CSA for the 195cc and 210cc heads for me and came up with 2.15" for the 195cc heads and 2.19" for the 210cc heads.

The simple air velocity formula is: FPS = (CFM * 2.4) / CSA.

When I apply the min CSA of each head to the flow #'s this is what I get:

195cc Profiler Velocity #'s at various lifts
FPS@ 0.600" lift = (274 * 2.4) / 2.15 = 305.8605
FPS@ 0.400" lift = (254 * 2.4) / 2.15 = 283.5349
FPS@ 0.200" lift = (145 * 2.4) / 2.15 = 161.8605

210cc Profiler Velocity #'s at various lifts
FPS@ 0.600" lift = (285 * 2.4) / 2.19 = 312.3288
FPS@ 0.400" lift = (258 * 2.4) / 2.19 = 282.7397
FPS@ 0.200" lift = (145 * 2.4) / 2.19 = 158.9041


This is the crazy thing: The velocity of the 210cc Profiler head at 0.200" lift is only a TINY bit slower than the 195cc head; at 0.400" they're even and at 0.600" the 210cc head has a HIGHER velocity than the 195cc head...


Is the 210cc head just this good that it has the same air speed and torque as the 195cc head but more flow at mid and higher lift and much more capacity for making more power at higher RPMs?

-I thought this wasn't supposed to be possible.... What am I missing? What's going on here?
My best guess is that either the 210cc Profiler is really something special, or there was something wrong with Chad's #'s; it seems hard to believe that with only a 0.04" increase in the CSA at the pinch point that the 210cc could flow 21CFM more than the 195cc head.

If these #'s pan out, I'm thinking that I'm going to go with the 210ccs despite the common wisdom being that this is going to be too big for a torquey 350 build... -But I don't see how they can pan out...


Thanks!
Adam

76strokervette

The numbers are accurate. The bigger issue imop is the 1206 gasket for the 210 head. You will not find a dual plane intake that will match the ports of the 210 runner. I had to remove a lot of material to get the Victor Jr intake to match the Pro-Filer 210 head.I have a build thread that is a couple of years old showing the finished part. That thread will be completed after I get the 12 bolt conversion completed. A dual plane intake with the smaller ports will probably cost at least 20 hp. There are threads on the Nova site showing this with a dyno test.

Crimson Thunder

Go with the 195's unless you are running more than 400 cubic inches.

gkull

I use the AFR 210 heads on my 383 with a 5 speed manual. single plane Team G and 1/2 inch 4 hole wood spacer. 2 X 14 inch K&N with the filter lid top. 830 cfm race demon. The exhaust ports also require bigger headers. I ground out 1 3/4 inch super comp and left a bottom lip on the aluminum head for anti-reversion

210cc Street Head Flow Chart
.200 .300 .400 .500 .550 .600 .650
Int 145 199 255 292 301 309 311
Exh 110 158 192 210 214 220 222

NewbVetteGuy

Yep. And the Profiler 195 is also the 1206 gasket.


Adam

REELAV8R

If you can get an intake to match it, it would work given that the intake is not going to choke the combo. Single plane team G can match a 195 AFR I believe. I don't know of a dual plane that will match the intake port of a 210 and still fit under the hood or not kill the potential of the head. Even a 195 with a dual plane is potentially limiting. Maybe with your proposed fuel injection set up you can find one.
If you put a hole in the hood then then you got many more options.

cv67

use the 195 for your FIRST TPI 350 you wont gain anything from going bigger esp if youre maxing out at 5500-6k tops. Even a 383 I think that 195 will be fine based on your posts of what you want to do.

Now go burn up your VISA youre thinking too much

lionelhutz

If you are still using the FIRST TPI, then the 210 heads wouldn't match with it.

You always have to consider the whole combination.

NewbVetteGuy

you'll be happy to know the 210cc Profilers were not available through Jegs so I started burning my Visa yesterday and bought the 195cc heads with.600" max lift springs.


Adam

REELAV8R

Good choice. It's what I would have on my engine if it were a sea level build or a 383 or 406 displacement.
Despite the greater flow of the larger valve openings on the 210 you have to consider the intake manifold involved as well. It needs to be able to feed the head and also keep the velocity up. An intake that could feed a 210 head would likely not have good velocity on a 350 engine below peak torque. And peak torque would move up the RPM range due to the low velocity.

resdoggie

Newby, what is your goal? I seriously doubt you're gonna build an engine that will be 100% full tq/hp with nothing left to be squeezed out. Professional racecar builders try but they can't do it either which is seen in all the r&d they do to keep squeezing a little more out of it. As I said in a previous thread, you should get to at least 90% of the engines potential with the available resources and parts. Trying to squeeze more will require cams changes, different heads, head porting, carbs, timing curves, piston changes, etc, etc, etc. You have enough knowledge now to design and build your engine with an expectation of 90%+. Getting all wrapped up in the velocities, flow rates, port sizes, etc is not necessary for a street build with occasional track use. I would go with a Team G if you plan on getting above 5K rpm and AFR 195's heads as they are already to go straight out of the box and no port matching required. I don't do stoplight-stoplight because of the risks and consequences so I don't care if I lose a few lbs of tq at low rpm. Anyway, my combo worked well with the help of the guys in here. Just bought the parts and assembled. No screwing around with any after purchase mods to make things fit.

MotorHead

I tis not only possible but it is a fact. The ol wive's tales I have been trying to debunk for years, the bigger heads make more power, period. And in doing so they make more Torque and HP across the board.

Too many people rely on books and the internet for their knowlege, I build the engines and I see first hand what the outcome is.

Why do you think the 210's are sold out ?

NewbVetteGuy

I honestly wanted to go with the 210cc version, but I got the 195cc heads for $998 including tax and shipping, so I just couldn't justify the added cost.

All the things I've seen so far indicate that head intake port size is maybe the 5th or 6th important factor for low end torque vs internet lore which focuses on it as #1 or #2.


LS heads have huge intake port volumes; you don't hear people complaining about low end torque.

Air velocity and quantity in the cylinder is king; if you improve airflow faster than the min CSA increases, you're increasing velocity, which seems to mean increasing cylinder pressures with an appropriately matched cam and therefore more torque.

Adam

resdoggie

May I ask what the difference in HP/TQ will be between the two heads you you selected?

gkull

When you are talking about apples, you can not use apples and oranges examples. low lift port velocity is the initiation of getting still air to begin filling the cylinder. A smaller cc port has less volume to get moving. Gen I heads "nearly" make a 90 degree angle from the manifold to the cylinder.

Head porters learned how to raise the roof of the port to get a straighter shot at the valve and cylinder with a decreasing cross sectional area all the way to the valve. The LS heads are a very tall narrow width port with as straight a shot as practical to the valve.

A more correct statement might be that 210 is only @ 7.5 % larger or 15 cc is the difference of about a table spoon filled with water in difference. In reality you have to consider the whole intake track to the plenum and if it is a tuned port or just some long restriction.

cv67

This!!
On lack of low end hell yes my 5.3 has all the throttle response of a basketball, its gutless below 3500 and thats with stock with 3.73 gears.
What gkull posted is the only way they can get away with sheer port volume + long intake manifold runner they finally figured itout.

Bigger isnt always better depends on a lot of things.

stuck what was advertised as a 200cc head (found later it poured over 215) on a hot rodded 350 it wasnt any faster than the stock 462s. Too big

REELAV8R

Grumpy has this to say about 210cc heads.

http://garage.grumpysperformance.com...-and-area.333/

So if this is true then your 195's would be the better choice of the two.

I ran some Dart 180's that had a true volume of 195+ cc's. With my 9.9CR and at 4000 feet I was not satisfied with those results. It ran good and all, but I felt that the throttle response could be better and that the peak torque and HP occurred too late for my combo.
I changed to a set of 180cc AFR's that actually cc'd out to 180cc's and had better flow than the darts. That combined with a compression bump and the difference is very noticeable. Much better throttle response peak power occurring prior to 6000 RPM as I wanted. The car is just quicker and more responsive than it was before.
Peak HP....maybe a bit more, maybe not, have not hit the dyno yet. However I can say with some confidence that peak torque is earlier as is peak HP.
This combo will also loose less performance from density altitude changes vs the previous one giving me better overall performance through the summer months. Still just running 88 Octane with 10.6:1 CR. So CR could still be upped. That would probably require a larger port min CSA head though to prevent choke.

NewbVetteGuy

Thanks folks for these last few posts. Helps set me straight; I know I probably got lucky on going with the 195cc version, but I'll take it! ;-)

Adam

gkull

Grumpy has a very fair assessment my first heads we're about to 2 27 cc on a 383 when I lowered it 210 cc afr with the same cam it ran better

It was always kind of a high end thing so it doesn't count to any body with out 3800 stall or 5 speed manual transmission

I have 11.2 cr and sr cam

Sky65

I'm using Profiler 185s on a mild 355. Howards hyd roller cam 225/225 .525/.525 108 LSA, 3x2 intake with Rochesters and it runs great. I am very happy with the 185 heads. I am not an engineer but I think the piece you may be missing is the capacity of the pump used calculating CFM and velocity. I believe the max numbers given are pulled from a pump that is capable of pulling more than more CFM and therefore velocity than measured. I don't know how to calculate it but is your 350 capable of pulling more than measured specs? If not you will not get the CFM or velocity listed. Did I explain that right? I think that is where the flow numbers and head size must be matched to the engine. JMHO

Tom