AFR Cylinder Head Update
#1
AFR Cylinder Head Update
Hello Everyone,
Seems there has been a lot of rumors flying around of late regarding our new cylinder heads and I wanted to personally take the time to address AFR’s more recent developments and progress regarding the launch of our new product.
First off, I would like to say that AFR is as excited as all of you to get our new LS “X” cylinder heads into production and sitting between the fenderwells of all of you that have been patiently awaiting their release. As most of you already know, there have been delays along the way, some of which were internal, some of which were beyond our control, but the bottom line is that AFR won’t ship a single pair until they meet or exceed our expectations. The good news is we are getting close and their looking real good! Any of you that had the chance to see even our first prototypes at PRI should be able to vouch for that. We have refined them even further over the last few months.
I have seen a few posts requesting flow data utilizing a 3.910 bore fixture. I’m not going to go over every lift point at this point in time as the numbers might even get better prior to launching production, but suffice to say that right now the intake port is flowing low-mid 280’s @ .500, mid 290’s @ .550, and low 300’s @ .600. These numbers jump quite a bit when placed on say a 4.125 bore, but this head was specifically designed to be optimized on the standard bore diameter. The exhaust flow data at .500 averages 226 CFM and climbs to the mid-high 230’s by .600. All of the exhaust data I will quote now and in the future will be utilizing a 1.875” flow tube curved much like any production header on the market. Before you all jump up and down about a 1.75’ pipe, due to the fact the 1.75 pipe still easily clears the entire exhaust port exit, the flow difference between the two would be negligible at best. I wouldn’t be surprised to even see the numbers higher as it is a better “fit” with the outlet of the new AFR exhaust port. All of this flow data is subject to improve prior to production as we are still refining and improving the final product. Keep in mind the much smaller cross-sectional area the AFR heads are equipped with. Both the 205 and the upcoming 225 were both designed from a clean sheet of paper from the combustion chamber on up….as a manufacturer our hands were not “tied” as they would be with anyone attempting to port a factory GM casting. Anyone that is familiar with any of our product line can also attest to the “overbuilt” quality of all our castings. Our new LS “X” line of cylinder heads will be no different and be much better at handling the higher power levels we are all striving to build.
Lastly, as many of you know already, we have had some brief time on the dyno with the first pair of our 205 cylinder heads. The main objective of that testing was to quantify and sought out some different valve spring options that we are considering for our new heads. Over the next few weeks, we will be doing the same kind of spring testing with a “cammed” motor as well to see if what we learned recently will play out the same way on that particular combination as well. We were hoping to do a stock head swap at the end of the day to see the power gains the AFR headed stock motor provided, but unfortunately, we ran out of time and couldn’t do a baseline comparison the same day with the exact same equipment. Westech (the testing facility we use) is extremely busy and we are not scheduled to be back on the dyno until early March. We were very pleased with the numbers so far and look forward to really waking things up with the addition of a few aftermarket performance cams. I will not be posting any numbers until AFR has all the facts and documentation to back up that data. I know all of you have been patient already, but it will only be a few more weeks until we can paint a truly comprehensive picture of some preliminary test results from our 205’s. Certainly there will be many other combinations which might provide different results, but at least we will be able to provide you with some data reflecting a portion of the potential gains our cylinder heads are capable of.
Once again, all of us at AFR appreciate the interest in our upcoming new product, and look forward to hopefully launching production shortly. I will be back in touch in a few weeks when AFR lets me out of R&D for a brief while (they slide food under my door from time to time) and we get to do some additional dyno testing.
Regards to all,
Tony Mamo
AFR Sales / Product Design
Seems there has been a lot of rumors flying around of late regarding our new cylinder heads and I wanted to personally take the time to address AFR’s more recent developments and progress regarding the launch of our new product.
First off, I would like to say that AFR is as excited as all of you to get our new LS “X” cylinder heads into production and sitting between the fenderwells of all of you that have been patiently awaiting their release. As most of you already know, there have been delays along the way, some of which were internal, some of which were beyond our control, but the bottom line is that AFR won’t ship a single pair until they meet or exceed our expectations. The good news is we are getting close and their looking real good! Any of you that had the chance to see even our first prototypes at PRI should be able to vouch for that. We have refined them even further over the last few months.
I have seen a few posts requesting flow data utilizing a 3.910 bore fixture. I’m not going to go over every lift point at this point in time as the numbers might even get better prior to launching production, but suffice to say that right now the intake port is flowing low-mid 280’s @ .500, mid 290’s @ .550, and low 300’s @ .600. These numbers jump quite a bit when placed on say a 4.125 bore, but this head was specifically designed to be optimized on the standard bore diameter. The exhaust flow data at .500 averages 226 CFM and climbs to the mid-high 230’s by .600. All of the exhaust data I will quote now and in the future will be utilizing a 1.875” flow tube curved much like any production header on the market. Before you all jump up and down about a 1.75’ pipe, due to the fact the 1.75 pipe still easily clears the entire exhaust port exit, the flow difference between the two would be negligible at best. I wouldn’t be surprised to even see the numbers higher as it is a better “fit” with the outlet of the new AFR exhaust port. All of this flow data is subject to improve prior to production as we are still refining and improving the final product. Keep in mind the much smaller cross-sectional area the AFR heads are equipped with. Both the 205 and the upcoming 225 were both designed from a clean sheet of paper from the combustion chamber on up….as a manufacturer our hands were not “tied” as they would be with anyone attempting to port a factory GM casting. Anyone that is familiar with any of our product line can also attest to the “overbuilt” quality of all our castings. Our new LS “X” line of cylinder heads will be no different and be much better at handling the higher power levels we are all striving to build.
Lastly, as many of you know already, we have had some brief time on the dyno with the first pair of our 205 cylinder heads. The main objective of that testing was to quantify and sought out some different valve spring options that we are considering for our new heads. Over the next few weeks, we will be doing the same kind of spring testing with a “cammed” motor as well to see if what we learned recently will play out the same way on that particular combination as well. We were hoping to do a stock head swap at the end of the day to see the power gains the AFR headed stock motor provided, but unfortunately, we ran out of time and couldn’t do a baseline comparison the same day with the exact same equipment. Westech (the testing facility we use) is extremely busy and we are not scheduled to be back on the dyno until early March. We were very pleased with the numbers so far and look forward to really waking things up with the addition of a few aftermarket performance cams. I will not be posting any numbers until AFR has all the facts and documentation to back up that data. I know all of you have been patient already, but it will only be a few more weeks until we can paint a truly comprehensive picture of some preliminary test results from our 205’s. Certainly there will be many other combinations which might provide different results, but at least we will be able to provide you with some data reflecting a portion of the potential gains our cylinder heads are capable of.
Once again, all of us at AFR appreciate the interest in our upcoming new product, and look forward to hopefully launching production shortly. I will be back in touch in a few weeks when AFR lets me out of R&D for a brief while (they slide food under my door from time to time) and we get to do some additional dyno testing.
Regards to all,
Tony Mamo
AFR Sales / Product Design
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#10
Man, this is great. Getting the info straight from the manufacturer. Completely unlike the recent FAST intake mess. Nothing but rumors, guesses, third hand info, etc... about that product.
#12
It'd be interesting to see what they flow ported. Those flow #'s are about the same as my ported stock castings. Starting at a higher level with porting should yield interesting results.
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