AFR recommended 195 heads for my 350
02-07-2010, 12:25 PM
#1
Race Director
Thread Starter
AFR recommended 195 heads for my 350
I'm putting together a nice 350 to take the place of my original engine. The car is a '71 with a 4-speed and 3.36 rear end. For the engine, I'm using forged pistons, a GM forged crank, 4 bolt main block bored .030, Crane roller cam with .284/.292 duration, 112° LSA, and ,509/.528 lift. AFR recommended that I used their 195 heads, which surprised me. For 350s, it seems like everyone goes with the AFR 180. So, I'll get the 195, but I was wondering if anyone else with a 350 is using the 195s and how do you like them?
02-07-2010, 01:27 PM
#2
Race Director
There are a lot of guys 4 or 5 years back that would recommend nothing but 200 cc or bigger heads on a 350. (you actually have a 355) AFR kind of changed that perception. They flow big numbers for the port size. Runner size will determine port velocity. The 180 will have better port velocity. But those heads with 200 cc runners ran great 5 years ago with higher peak hp and little or no midrange power loss and they still will today. The new AFR 195 flow better at over .500 lift. That is probably where AFR's recomendation came from. A high performance 350 could run either. if your cam lift is under .500 like most a 180 is fine. You are on the borderline of 180 or 195. Driving style will determine which would be best for you. Either way choosing AFR is a good move. The 180 competition ported flow like the 195 with a 180 port. They are the best of both worlds but they are pricey.
02-07-2010, 05:55 PM
#3
Race Director
I'm kinda surprised they are recommending heads that flow ~280+ cfm for a mild 350. The heads I had on my 406ci flowed about the same and made 550HP something is not adding up and I am a big head guy so I am not sure what it is yet. Could be they made 10x as many 195's.
But if it was me I would be building a solid roller 355ci with 11:1cr and 240ish duration @ .050". and put the 195's on it. It would make near 500 ponies but I would be concerned about a soggy bottom end. I don't know anymore, they threw a monkey wrench into the works with flow numbers on these smaller heads
What are the 180's for stock cam and compression L48's ?
What is your compression ratio and what are the .050" duration specs on the cam
But if it was me I would be building a solid roller 355ci with 11:1cr and 240ish duration @ .050". and put the 195's on it. It would make near 500 ponies but I would be concerned about a soggy bottom end. I don't know anymore, they threw a monkey wrench into the works with flow numbers on these smaller heads
What are the 180's for stock cam and compression L48's ?
What is your compression ratio and what are the .050" duration specs on the cam
Last edited by MotorHead; 02-07-2010 at 06:03 PM.
02-07-2010, 06:31 PM
#4
Race Director
Thread Starter
Compression ratio will be 10.2:1, duration at .050" is 222°/230°. I'm just building a nice strong street engine. It's a convertible without a roll bar so the local safety gurus won't even let me on a track.
02-07-2010, 08:33 PM
#5
Team Owner
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St. Jude Donor '05
180. 195 may give you more up top/carry the power further.
Personally Id use the smaller head but to each their own. I think youd be real happy either way.
Personally Id use the smaller head but to each their own. I think youd be real happy either way.
02-07-2010, 11:22 PM
#7
Racer
AFRs are great,but if you are wanting to save some coin...I have some Brodix IK180s over in the parts for sale section.They have less than 900 miles on them since being rebuilt with new valves,retainers,keeps,etc.They are ready to bolt on,and go!They are 64 cc,180 runners,and 202/1.60s valves.They come with 1.6 Harland Sharp gold roller rockers,the extended poly locks,and a stud girdle.I will give you your choice of tall edelbrock elite valve covers,or some tall roundie round valve covers.750.00 for the heads,and the parts,and 75.00 to put them on your door step.If you arn't interested in the stud girdle setup,then 700.00 for the heads with another set of the harland Sharp gold roller rockers with the poly locks,but the ones that will fit under your valve covers.
Kevin
Kevin
02-08-2010, 12:06 AM
#9
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I'm putting together a nice 350 to take the place of my original engine. The car is a '71 with a 4-speed and 3.36 rear end. For the engine, I'm using forged pistons, a GM forged crank, 4 bolt main block bored .030, Crane roller cam with .284/.292 duration, 112° LSA, and ,509/.528 lift. AFR recommended that I used their 195 heads, which surprised me. For 350s, it seems like everyone goes with the AFR 180. So, I'll get the 195, but I was wondering if anyone else with a 350 is using the 195s and how do you like them?
02-08-2010, 03:24 AM
#10
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I used AFR 195's (see my build) after a couple years with cast heads on my 383. While I gained top end HP and some torque, I lost some of the low-end crispness it used to have. Around town I like the old heads better! So my recommendation would be the 180's on your engine especially since it is not a stroker.
My Crane is not a wild one and I chose one with lobe sep. that would idle well on a small block with an automatic. I also used a 2500+ stall convertor.
I gotta say though, the 195's really woke my engine up at freeway speeds. From 65 or so up to 115 (fastest I've driven it) my torque is terrific and it really sounds healthy. I'm actually thinking of putting a larger cam in it now, to get the best use out of those heads.
My Crane is not a wild one and I chose one with lobe sep. that would idle well on a small block with an automatic. I also used a 2500+ stall convertor.
I gotta say though, the 195's really woke my engine up at freeway speeds. From 65 or so up to 115 (fastest I've driven it) my torque is terrific and it really sounds healthy. I'm actually thinking of putting a larger cam in it now, to get the best use out of those heads.
02-08-2010, 04:11 PM
#11
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I am building a 383 stroker with roller cam. All forged bottom end 10.5-1 compression. Cam 242/248 duration at .050 lift. I am am going to purchase the AFR 195's also for my setup. My question is are the 195 competion heads worth the extra 500 bucks over the eliminators? The guy at AFR told me if I have the money to spend it but I dont know if that is him just being a business man. He claims I would gain 18 more hp over the eliminators, that tru?
02-08-2010, 04:29 PM
#12
Team Owner
I am building a 383 stroker with roller cam. All forged bottom end 10.5-1 compression. Cam 242/248 duration at .050 lift. I am am going to purchase the AFR 195's also for my setup. My question is are the 195 competion heads worth the extra 500 bucks over the eliminators? The guy at AFR told me if I have the money to spend it but I dont know if that is him just being a business man. He claims I would gain 18 more hp over the eliminators, that tru?
You can look up HP potential VS intake CFM and in an ideal world the extra CFM of the comp. ported heads with raise the hp. Or you can use a higher lift cam and or lobe profile that keeps the valve flowing the max CFM for the longest time possible and accomplish the same thing.
IMO - poster: changing the head port size 20 - 30 cc is such a minor thing. You have to measure the total cc of the whole port including the intake manifold to compare dead air that goes from stopped to near the speed of sound when the valve opens.
02-08-2010, 04:52 PM
#13
Race Director
Thread Starter
Here's the bulk of the e-mail AFR sent to me. Whichever way I go, if I don't like them, I can always sell them to one of you and get the other set.
I would recommend a set of our 195cc Eliminators. Your specific
combination would be able to harness the power potential of these heads.
They flow remarkably well while retaining a relatively small intake
runner volume. This increases the velocity of the intake charge
resulting in not only a peak horsepower gain but also an increase in
bottom end power. If you take the time to compare our heads with our
competitors, pay attention to not only the peak flow numbers but also
with flow ratings throughout the valve lift.
If you are looking for even more overall power and torque
throughout the RPM range, along with a little better throttle response,
then you may want to consider our Competition version of the 195cc
Eliminators. These heads improve upon already phenomenal statistics.
Extra time is taken during machining in order to hold tighter
tolerances. We spend hundreds of hours in research and development
making small changes in order to achieve maximum power and this extra
time taken during machining allows us to produce a closer replica of
those prototypes.
combination would be able to harness the power potential of these heads.
They flow remarkably well while retaining a relatively small intake
runner volume. This increases the velocity of the intake charge
resulting in not only a peak horsepower gain but also an increase in
bottom end power. If you take the time to compare our heads with our
competitors, pay attention to not only the peak flow numbers but also
with flow ratings throughout the valve lift.
If you are looking for even more overall power and torque
throughout the RPM range, along with a little better throttle response,
then you may want to consider our Competition version of the 195cc
Eliminators. These heads improve upon already phenomenal statistics.
Extra time is taken during machining in order to hold tighter
tolerances. We spend hundreds of hours in research and development
making small changes in order to achieve maximum power and this extra
time taken during machining allows us to produce a closer replica of
those prototypes.
02-08-2010, 07:56 PM
#14
Safety Car
I am building a 383 stroker with roller cam. All forged bottom end 10.5-1 compression. Cam 242/248 duration at .050 lift. I am am going to purchase the AFR 195's also for my setup. My question is are the 195 competion heads worth the extra 500 bucks over the eliminators? The guy at AFR told me if I have the money to spend it but I dont know if that is him just being a business man. He claims I would gain 18 more hp over the eliminators, that tru?
According to AFR website info, at .550 lift, the street versions intake flow is 280 cfm; the comp version flows 294 @ .550 lift.
This link shows a calculator for horsepower supported per head flow cfm: http://users.erols.com/srweiss/calcafhp.htm
280 into this formula yields 575 hp......294 will yield 604. (a 29 hp gain).
AFR info.....http://www.airflowresearch.com/index.php?cPath=24_29
02-08-2010, 08:18 PM
#15
Race Director
Basically you multiply the CFM X 2 = HP the heads will support, I have used this formula for many many years and just found some pretty interesting data that seems to back it up.
Start with Chevy chart first, it is pretty amazing when you look at the intake flow and the HP how close the HP is double the intake CFM
http://users.erols.com/srweiss/tablehdc.htm
Start with Chevy chart first, it is pretty amazing when you look at the intake flow and the HP how close the HP is double the intake CFM
http://users.erols.com/srweiss/tablehdc.htm
02-08-2010, 10:11 PM
#16
Le Mans Master
Basically you multiply the CFM X 2 = HP the heads will support, I have used this formula for many many years and just found some pretty interesting data that seems to back it up.
Start with Chevy chart first, it is pretty amazing when you look at the intake flow and the HP how close the HP is double the intake CFM
http://users.erols.com/srweiss/tablehdc.htm
Start with Chevy chart first, it is pretty amazing when you look at the intake flow and the HP how close the HP is double the intake CFM
http://users.erols.com/srweiss/tablehdc.htm
Man thats crazy....good info. My heads flow in the the 320(bad port) to 323(good port)..... Double that would be 646hp....Mine actually dynoed 657-662hp depending on the dyno(I dynoed it twice).... your 2x formula was pretty damn close on mine....
Although my builder(also is the head porter) said he makes 700hp with these same heads but with more compression and solid roller...they are relatively small ports though for a BB...(270-280cc).
Neat info...
02-08-2010, 11:39 PM
#17
Race Director
02-09-2010, 05:55 AM
#18
Melting Slicks
i would think unless your goal is BIG HP #'s, you'll be happier with the 180's.
Velocity = TORQUE in the lower RPM ranges where most street engines spend their time.
You also don't mention what intake you're planning on using
Velocity = TORQUE in the lower RPM ranges where most street engines spend their time.
You also don't mention what intake you're planning on using
02-09-2010, 06:28 AM
#19
Team Owner
The real truth is that you will not be excited about 355 ci power within a month or two of driving it and you will be planning your next upgrade. So you should probably buy at least the 210 cc which are needed for your stroker engine build.
4 speeds can handle much more than an auto tranny even with 3500+ stalls
4 speeds can handle much more than an auto tranny even with 3500+ stalls
02-09-2010, 07:25 AM
#20
Racer
I was reading through the posts this morning, and thought....I used to run AFR 190's on a 350, 292 comp magnum, and 9.5 compression. (4spd, 3.36's) Never thought soggy bottom end, and yep it pulled awesome at the top end. When I gead GKull's last comment, I smiled because it was like he read my mind. Most likely, the more power addiction will over take you, and you'll wish you had the 195's if not bigger. Of the two choices, I recommend the 195's. It sounds like a nice motor.