AWilson

AFR has a on-line thing where you enter in your build info and desires and they recommend heads. I did that and I just don't understand. AFR recommends 180 heads for my 383. Guess I need to call them but thought I would see what you guys think too.

When I look at the flow for 195 vs 180 the 195's flow better at all lifts. I believe a 383 with my cam lift can pull those flow values, so again why would someone, AFR, choose 180's for my build? I am not saying they are wrong. Who am i to say. But maybe you guys may say they made an error. I figure I either get validation which makes me more comfortable or I need to respectfully question them and explore, learn further.

use: My car is a 383 and I want a street warrior. I want it to scare me off the line! To make me feel foolish for doing such things at 52 years old. It may never see the strip.

HERE IS THEIR RESPONSE FOLLOWED BY THE INFO I GAVE THEM:
NOTE: Maybe I entered the cam info wrong. so I included a pic of the cam card.
Alan,
Based on the engine combination, vehicle weight and power range goal; you should look at our 180 Eliminator heads. Our 180 head delivers a significant upgrade without compromising the low-end/ mid-range performance. Although this is one of our smaller runner heads it produces superior airflow while maintaining velocity for overall performance specific to your power band.

You will need to special order your heads with our #8020 “spring exchange” to suit your hyd./flat tappet camshaft.

Our 180 Eliminator will promote excellent torque on your 383!

Hope this helps. Please call me if you require further product support or assistance with your order.

(name withheld)


Subject: New Quote Request - Alan 12-09-2014


CONTACT


PURPOSE
Purpose.......... Street Strip Street Only

INTEREST
Interest..........Chevy Small Block

ENGINE
Type Of Head..........big valve camel humps (current)
Displacement..........383
Bore..........4.030
Stroke..........3.750
Piston Type..........Flat
Piston CC..........0
Desired Compression Ratio..........9.5
Combustion Chamber Volume..........63-64
I really didn't understand the next 3 questions but did the best I could:
RMP Range Start..........Idle
RMP Range End..........5000
RPM Range Max..........5500

INDUCTION
Induction..........Carburetor

MANIFOLD
Manifold Brand..........Edelbrock
Manifold Manufacturer's Model..........RPM Performer
Manifold Type..........Dual Plane

POWER ADDERS
Power Adders..........No

CAMSHAFT Engle EP-22HYD (1022H)
Inatake Lift..........480
Intake Duration (adv)..........274
Intake Duration @0.050..........230
Exhaust Lift..........480
Exhaust Duration (adv)..........274
Exhaust Duration @0.050..........230
Camshaft..........Flat Tappet - Hydraulic



IGNITION
Ignition Manufacturer..........MSD 36 deg.
Digital Ignition Box..........Yes

EXHAUST
Head Pipe Diameter..........1-3/4 I think) (Stans Tri-Y 109-Y)
Muffler Type..........Street
Exhaust Type..........Long Tube Headers

DUEL TYPE
Fuel Type..........Pump Gas

VEHICLE
Vehicle Make..........Chevy
Vehicle Model..........Corvette
Vehicle Year..........68
Vehicle Weight..........3425

TRANSMISSION
Transmission..........M-21 close ratio
Rear End Gear Ratio..........3.7
Rear End Tire Diameter..........26.6
Number Of Gears..........4
Transmission Type..........Manual
Additional Comments..........This is 95% a weekend warrior car. I
want a decent idle. Not smooth just decent. A little of that lope as
they say is fine. BUT it needs to go when I floor it. I am looking for
low end power for off the line goofing around on the street. 0-60
numbers, not top end as much. Rotating assembly is all forged. Thanks
in advance for your input.

bluedawg

I'd go 180's with your cam shaft. If you really want a street beast, match the compression, gearing and stall to a larger hydraulic roller that would optimize the 195 ' s or 210's for that matter. A Flatt tappet camshaft that wasn't some were above .560" lift with the 195's wouldn't be the best match. Even with the 180's if the camshaft wasn't to aggressive 1.6 to 1 rockers would help take advantage of the head. Regardless afr are good heads and that's whatcha need to make decent power, but remember that matching "all" the components is what will produce the best results.

Oh I see you got a manual and 3.7 gears.
DO MA NEU!

cv67

Talk to Jeremy at AFR hes pretty straightforward
For a mild flat tappet 383 where you want the grunt way down low dont see anything wrong with a 180cc head dont get too wrapped up in flow #s.

hugie82

Velocity vs flow . Velocity gives you that off the line toque and all around midrange. That's why 180 is the better choice. Moving to a larger 406 or 427 will creat the same velocity with the bigger 190 heads..
Only an all out race engine uses the bottom of the page cam and heads due to it screaming 95% of it's time at max rpm.

63mako

Flow numbers are not the best indicator for street performance or all heads would be 220 CC. For peak HP the 195 will be better. You indicated you are looking for bottom end-midrange torque. Port velocity needs to be a factor. A 180 head will feed a 383 to about 5500- 6000 RPM. It will maintain good port velocity at the bottom end for better throttle response and bottom end torque. You will give up some peak hp for bottom end, midrange throttle response and torque your looking for. Your intake is designed for 1500-6500 RPM.
The 195 is the best all around head made in my opinion. If you look at the descriptions the 180 is designed for idle to 5500 RPM performance.
195 is designed for 2000 to 6500 RPM Performance.
Which matches the operating range of your cam better?
You need to subtract about 300 RPM from the cam's advertised operating range for 383 vs 350.
What RPM range more closely matches what you use the most? Idle to 5500 or 2000 to 6500? What is more important to you. Power idle to 4000 or power above 4000? Your gearing gives you a 8.14 to 1 first gear. The car is heavy. That needs bottom end torque. If your 1st gear was 10 to 1 I would recommend the 195 for sure. The gearing would allow you to get into the powerband quicker. I see why AFR made their recommendation. I also see need for a 195 head on a 383 with your intake. Either way 1.6 rockers will help make full use of the potential of the heads. You will have to determine what suits your use the best. Everything is a compromise.

Kevin BC

Very similar experience.
I have a similar 383 build, comparable cam, etc. and AFR also recommended the 180 heads. I was thinking the 195's but after doing some more research for my driving style and operating range of idle to 5500, it does look like the 180's are the right choice.
One difference is that I will be using a 2004R and 3.73 rear end.
63Mako's comments in this thread are a further confirmation for me on the 180's.

Kevin

AWilson

Mako you have been giving me good advice for years. So the smaller heads move the equal amount of air through faster which means better mixing with the fuel for a net gain. But that same restriction makes it a little too hard to pull it through at higher RPM's for a net loss. Can't have it all. Is this why they make 4 valves per cylinder in modern cars? To have more of it all?

Powerband on the cam is 1800-5800. minus 300 as you said is 1500-5500.
I don't think I have pushed the engine to 5000 ever, certainly not 5500.
So I want your referenced power to 4000 more importantly.

Intake Performer RPM 1500-6500 (Or would I be better off with the Performer:0-5500)
cam 1500-5500
180 heads 0-5500

I want the low end. So, 180 is the way to go I guess.

TedH

If you were running a bigger cam, I'd go 195cc. Also, with your target CR and RPM range, the 180cc will definitely give you rapid acceleration off the line.

My DART 180cc heads are close but not as good as the AFRs. I am running .502/.509 and the perf in my 350 is very snappy. Really great combo for a street engine.

63mako

CI tames the intake similar to the cam. If you already have the intake stick with the Performer RPM, ports fit better. If you still need to buy one get the performer, especially if you never go past 5000 RPM. The AFR 180 heads flow what most 200 CC heads made by anyone else flow with better velocity. Your cam should be fine in a flat tappet with your combination. Lift is your friend with the AFR heads.

AWilson

Don't have the intake yet so 180's with a Performer seems to be the decision. Turns out AFR also recommends the Performer, specifically the 3701.

Thanks much Mako and everyone else too!

terrys6t8roadster

The Performer 2101 fits under the stock hood. A personnel experience; performer RPM air gap according to specs is a 6500rpm manifold, a dart 195 headed Lunati cammed full roller started dropping off HP @ 5600RPM. Both my engine builder and dyno guys said my manifold is to small. Better for lower rpm power, in your situation 383 my opinion would be the Performer RPM. Eldebrock web site has all the specs on manifold heights for under the hood fitment, if your running a stock hood I don't know if the RPM fits. T

Postal123

Terry, I'm interested, but a little confused...? What was the combo that was falling off at 5600 RPM with the RPM Air Gap?

terrys6t8roadster

.040 350cid. Elde performer air gap, Dart 195 64c heads, Lunati .556 in .566 ex, 110 lobe separation, 231 in duration 237 ex. Crower roller rockers. Flat top Mahle pistons. 10 to 1 static comp. Harlan Scharps 1.5 to 1 rockers. Quick Fuel no choke 750 cfm dp df. It had 411rwhp at 5600. Doing an engine upgrade, been using a post called 'Molested6t8'. Looking to up my HP RPM range another 1k. Using AFR pt# 1036 195 75cc heads, Victor JR open plenum, Vortec V1. Working on cam specs, new specs are coming in about the same but have a 114 cam lobe separation. There is a lot to learn about cams, I'm going to rely on the grinders choice. T

TedH

2101 and 3701 are identical except 3701 has heat crossovers for EGR/emissions. Interesting that AFR makes this an emissions head.

If you are running stock height air cleaner and stock hood, 'safe' option is the 2101/3701. With your performance goal 0-5500, they both fit that bill very well.

If you go open-element air cleaner with drop base and choose an RPM or larger, I'd definitely verify clearance with clay or equivalent substance.

Postal123

Thanks for the details. That sounds like a stout 350/357, and it sounds like you're pulling out all the stops with your rebuild.

My question was for the sake of us all and simply because I wasn't sure if you were referring to the Performer Air Gap or the Performer RPM Air Gap. Thanks again!

Jason Staley

For a street engine, you are probably better off staying with the smaller heads. If anything, go with the ported versions and stay with the smaller size ports that maintain velocity. For street use velocity & lift are your friends.

Just for comparison sake, I'm running a 350 with a .545 lift roller hyd cam and ported GMZZ4 heads (165cc intakes). I'm pulling 325 RWHP (~385 HP net) and able to achieve 12.8 sec @ 108mph in the 1/4 mile. It's not blinding fast, but I've surprised quite a few people in it.

BlackC3vette

AWilson,

I have a 383 with Brodix 180 heads and about the same cam/lift specs.
Standard shift but for now, the stock 3.08 rear (or 3.07, I forgot). This thing has no problem spinning the tires, It also loves running right up to the top 5,500 rpm range. It's setup for the low end torque and I also questioned the engine builder for his 180 choice. If your looking to run a higher rpm, more top end speed, go with another more aggressive cam and the 195's. Sometimes I think I should of gone bigger, but I think some handcuffs may have gone along with that choice.

sumcollegekid

Remember, on a N/A engine it's about velocity almost as much as it is flow you need to strike a balance. The OEM will know best. If you go too big on the intake ports then the inlet velocity will drop and volumetric efficiency will be decreased.

I had a few friends in high school who went with HUGE intake manifolds for their 5.0L Mustangs and Camaros and the biggest intake ports that they could find for an N/A application. $3000 later their cars weren't even any faster!!

AWilson

So, OK 180 AFR's are the way to go. So what can I expect in increased performance from my current camelhump heads which have bigger valves installed.

sumcollegekid

Well... that's kind of a loaded question. The AFR's will be aluminum so it seems like you could run more timing on the same octane fuel (in combo with the right temp plugs) without detonation. Also since you will have aluminum heads you might be able to pump up your CR a bit with smaller chambers maybe target 10:1 static.