AFR Heads....STILL getting the job done!
09-13-2008, 09:18 PM
#1
AFR Heads....STILL getting the job done! While the recent trend of some cheerleaders seems to have looked the other way (with no hard data actually warranting most of it), don't discount the tried and true....still the original aftermarket LS offering....and still arguably the best. Especially if your interested in enhancing your entire driving experience as well as looking for the obvious gains in peak power and torque. No other aftermarket head will boost the bottom of your curve like the AFR 205, and few can match it upstairs although now obviously you guys have a handful of other choices that will still produce excellent results (TF, ETP, etc.). However, the AFR is still the only one to offer a direct replacement bolt on (accepts stock rockers, has OEM valvetrain geometry, stock height valve cover rails etc.) and is CARB legal which is a nice perk depending on local emissions laws.
Whats got me fired up? Besides the last couple of months of opinions and posts I just have to grin and bear (knowing most of them stem from comparing advertised flow data which is a topic I would really like to split wide open one day), I just got back from the dyno last night....late last night I might add, and once again a simple combo with AFR 205's (that any of you could copy) has put up numbers that IMO exceed anything I have seen remotely comparable based on displacement and the sum of its parts. Sure its an optimized combo I personally picked most of the components (and built the engine in this case), but it still represents an effort that doesn't cost cubic dollars and performs like it does.
Check out this dyno gragh....off the same dyno I have personally used for my testing over the last two years or so (Mike Haddad Performance) so before you guys call BS, note my car has ran the number to back the dyno results and most of you guys have seen video which clearly shows how explosive that package was.
This is a 91 octane 383 that has a smallish cam (hydraulic roller 234/238) one of my ported 90/90's, about 11.35 to 1 CR, and a set of 205's that I also did some moderate porting work still retaining the 205 cc inlet port (most of the grinding was focused in the combustion chambers). The head "only" flowed a legit 304 CFM with exhaust flow in the 245 range. Big area under the curve and a tremendous amount of airspeed which most of you still just casually glance over (that is what packs the cylinder with more air/fuel).
Here is the curve....it exceeded the 525/500 mark I was hoping for rather nicely....look at the low RPM torque figures and how long it carries over 500 RWTQ
Also note it was approaching midnight last evening when we wrapped this up and this is NOT a set on kill tune....in fact there is probably a few more ft/lbs and 5-7 HP in it if I was really looking to punch a number. The A/F ratio is safe in the mid/high 12's and this pull only had 26' of timing. Every LS engine I have built has liked 28-29 for best peak numbers but seeing as this is for a customer and not for me personally, I will probably leave it very safe which is the graph you guys are looking at right now. This car is also his daily driver which is one of the reasons I chose such a mild cam.
BTW, peak torque is a staggering 508 ft/lbs (that's very good for an engine 20 CID larger and decent for a 427 for that matter) and peak HP came in at 535 on the dot. In spite of the small heads and the small cam this package still peaked nicely at 6500 RPM's and when we get finished tuning it I will likely post another graph showing the full curve to the 7000 RPM point I anticipate will make the best shiftpoint.
Whats also very cool about this test is the fact it is in a VERY similar driveline to my own....a C5 with a lightweight clutch/flywheel combo (an RPS dual friction single disc with an aluminum flywheel) and this car had a slight advantage over mine because it still has the factory 3.42 ring and pinion which tends to dyno a little better than an aftermarket unit with steeper gears. This package also benefited from a smaller header (the LG pro's which are known to make big torque) versus my larger (and shorter) 1.875 primaries, and obviously my former package was a solid roller with larger 225 heads, once again both moves aimed at bolstering the top numbers at the expense of some bottom. In actual size, when you account for the lash, my 242/248 solid acted and idled extremely similar to the hydraulic grind in this test, but the smaller head with its higher velocity charge would actually reduce some of the negatives associated with the overlap of a performance cam. I cant wait to drive this...it should actually feel alot more explosive than my former package from off idle to 5500 RPM or so and honestly it doesn't give up a whole lot to mine upstairs. Not to mention this package has zero maintenance due to the fact it has a hydraulic valvetrain versus a solid.
Next time Im at the dyno I will try and get data that compares some of the even lower RPM points where obviously the gains from the current package would gap up even more. Check out the actual overlay of both my former 383 and the new engine (built around my former shortblock freshened up)
More to come....I will try and fill you guy in on the rest of the details as the weekend continues to unfold.
BTW, I'm sure a few of you will point out the fact that I also ported the 205's and I don't discount that it was likely worth 5-10 ft/lbs and 10-15 HP, but when the smoke clears if I tune this car like any other shop would before posting to get it to punch a big number, even if you subtract those figures to simulate the same combo with out of the box 205's the numbers still rock for a mild mannered 91 octane pump gas 383....
Cheers,
Tony
PS....A BIG thanks to Mike Haddad and crew who stayed very late on a Friday night getting the car finished up and hooked up on the dyno. I even gave him an out saying I would come back on Saturday but the guys there were as psyched as I was to see what it would make. While I provided the complete rebuilt engine, the guys at Mike's shop did the entire install and tune as well as some exhaust work and a few other upgrades as well (injectors, fuel pump, etc.)
PSS...Another big thanks and congrats to the owner Rick Duncan.....
(NO Rick....my car is now in pieces and you cant have yours back anytime soon!)
Here is a pic of Rick's used 205 heads that I freshened and went thru as well as a shot of the 383 longblock shortly before delivering the complete engine to Mike
Whats got me fired up? Besides the last couple of months of opinions and posts I just have to grin and bear (knowing most of them stem from comparing advertised flow data which is a topic I would really like to split wide open one day), I just got back from the dyno last night....late last night I might add, and once again a simple combo with AFR 205's (that any of you could copy) has put up numbers that IMO exceed anything I have seen remotely comparable based on displacement and the sum of its parts. Sure its an optimized combo I personally picked most of the components (and built the engine in this case), but it still represents an effort that doesn't cost cubic dollars and performs like it does.
Check out this dyno gragh....off the same dyno I have personally used for my testing over the last two years or so (Mike Haddad Performance) so before you guys call BS, note my car has ran the number to back the dyno results and most of you guys have seen video which clearly shows how explosive that package was.
This is a 91 octane 383 that has a smallish cam (hydraulic roller 234/238) one of my ported 90/90's, about 11.35 to 1 CR, and a set of 205's that I also did some moderate porting work still retaining the 205 cc inlet port (most of the grinding was focused in the combustion chambers). The head "only" flowed a legit 304 CFM with exhaust flow in the 245 range. Big area under the curve and a tremendous amount of airspeed which most of you still just casually glance over (that is what packs the cylinder with more air/fuel).
Here is the curve....it exceeded the 525/500 mark I was hoping for rather nicely....look at the low RPM torque figures and how long it carries over 500 RWTQ
Also note it was approaching midnight last evening when we wrapped this up and this is NOT a set on kill tune....in fact there is probably a few more ft/lbs and 5-7 HP in it if I was really looking to punch a number. The A/F ratio is safe in the mid/high 12's and this pull only had 26' of timing. Every LS engine I have built has liked 28-29 for best peak numbers but seeing as this is for a customer and not for me personally, I will probably leave it very safe which is the graph you guys are looking at right now. This car is also his daily driver which is one of the reasons I chose such a mild cam.
BTW, peak torque is a staggering 508 ft/lbs (that's very good for an engine 20 CID larger and decent for a 427 for that matter) and peak HP came in at 535 on the dot. In spite of the small heads and the small cam this package still peaked nicely at 6500 RPM's and when we get finished tuning it I will likely post another graph showing the full curve to the 7000 RPM point I anticipate will make the best shiftpoint.
Whats also very cool about this test is the fact it is in a VERY similar driveline to my own....a C5 with a lightweight clutch/flywheel combo (an RPS dual friction single disc with an aluminum flywheel) and this car had a slight advantage over mine because it still has the factory 3.42 ring and pinion which tends to dyno a little better than an aftermarket unit with steeper gears. This package also benefited from a smaller header (the LG pro's which are known to make big torque) versus my larger (and shorter) 1.875 primaries, and obviously my former package was a solid roller with larger 225 heads, once again both moves aimed at bolstering the top numbers at the expense of some bottom. In actual size, when you account for the lash, my 242/248 solid acted and idled extremely similar to the hydraulic grind in this test, but the smaller head with its higher velocity charge would actually reduce some of the negatives associated with the overlap of a performance cam. I cant wait to drive this...it should actually feel alot more explosive than my former package from off idle to 5500 RPM or so and honestly it doesn't give up a whole lot to mine upstairs. Not to mention this package has zero maintenance due to the fact it has a hydraulic valvetrain versus a solid.
Next time Im at the dyno I will try and get data that compares some of the even lower RPM points where obviously the gains from the current package would gap up even more. Check out the actual overlay of both my former 383 and the new engine (built around my former shortblock freshened up)
More to come....I will try and fill you guy in on the rest of the details as the weekend continues to unfold.
BTW, I'm sure a few of you will point out the fact that I also ported the 205's and I don't discount that it was likely worth 5-10 ft/lbs and 10-15 HP, but when the smoke clears if I tune this car like any other shop would before posting to get it to punch a big number, even if you subtract those figures to simulate the same combo with out of the box 205's the numbers still rock for a mild mannered 91 octane pump gas 383....
Cheers,
Tony
PS....A BIG thanks to Mike Haddad and crew who stayed very late on a Friday night getting the car finished up and hooked up on the dyno. I even gave him an out saying I would come back on Saturday but the guys there were as psyched as I was to see what it would make. While I provided the complete rebuilt engine, the guys at Mike's shop did the entire install and tune as well as some exhaust work and a few other upgrades as well (injectors, fuel pump, etc.)
PSS...Another big thanks and congrats to the owner Rick Duncan.....
(NO Rick....my car is now in pieces and you cant have yours back anytime soon!)
Here is a pic of Rick's used 205 heads that I freshened and went thru as well as a shot of the 383 longblock shortly before delivering the complete engine to Mike
Last edited by Tony Mamo @ AFR; 09-13-2008 at 11:25 PM.
09-13-2008, 10:10 PM
#6
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Tony, I'm putting together a 383 and using my 205's from my camaro along with a T rex cam on a 110lsa, a victor jr/mighty demon 750cfm carb. The only accessories are an alternator. This will be mainly a drag car. I'm also using the YT ultra lites 1.7 adjustable as you recommended.
I'm expecting big results.
I'm expecting big results.
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09-13-2008, 10:21 PM
#9
Tony...as always, your post caught my attention. I always enjoy reading about your results, and hope that you are still in the game when it finally comes time for me to pull the trigger on the project I'm hoping to put together. Awesome results, and damn...those numbers remind me at first glance of a healthy 402/408 combo.
How is the 235 program coming along? That's what I'm really waiting to see...you can always ship the bits and pieces of your car to me and I'll put them together for you
at which point I'll be posting something to the effect of "Low Dyno Numbers...WHY?!?"
You sure those aren't engine dyno numbers?
How is the 235 program coming along? That's what I'm really waiting to see...you can always ship the bits and pieces of your car to me and I'll put them together for you
at which point I'll be posting something to the effect of "Low Dyno Numbers...WHY?!?"You sure those aren't engine dyno numbers?
09-13-2008, 10:46 PM
#10
LOL, sorry Tony. I'm on my laptop and it really isn't fun to type on
I admit it was a below par post...hehehehe
If typing was easier I would have gone into the setup you put together for me. As it was it was a shameless attempt to ride on your coat tails
09-14-2008, 07:39 AM
#19
Good work Tony. I'm putting together 2 combo's in the very near future and will be spec'ing them out with your heads. I'll be giving you a call in the coming weeks to talk over specifics. One combo will be a direct real world back to back comparison for everyone to see AFR's shine 
