ok guys ive been wondering for a while....alot you yall run or have ran afr 205 heads, why not run the afr 225....more horsepower right?? or is there someting wrong with these heads , i know the 225 are for stroker HIGH HP engines but isnt the afr 205 about the same as a 225? im just wondering , for future refernece.... eddie
what do you want to do with your motor? street torque or race piece? Velocity is the key, and the 205's keep it moving. Now if you got a 408, 418, 427, 440, etc, then those 225's work real nice...
no im just thinking out loud...my engine is already together....i was just thinking in 2 or 3 years build a bad ass windsor or bottle fed 302 stroker...not sure i just seen everybody doing 205s i was just wondering
i got 185s on my 392 FMS in my cobra. They are great with an RPM Air Gap. I could see maybe stepping up to 205's but no need for 225's. It a 500+ hp setup. http://airflowresearch.com/articles/article024/A24-P1.htm
I know of someone who swapped from 205s to 225s and only picked up 1 mph and .05 ET in the 1/8 mile. Not much of a gain for $2100, IMO. BTW, his combo is very similar to mine...408", alcohol carb, super victor....spins 7100 at the stripe shift at 7000. I'm looking at the victors myself. They kick the snot out of the 225's any day of the week!
One of the drag racers here has a 347 with 205s. He posted in another AFR thread in the drag forum about how he turns very high rpm and still doesn't get the full effect of the 205s. I have done a lot of studying of the aftermarket heads and have narrowed the 205s down to being the best. Unless they have some new Victors out, or some Nascar sponsored special editions with weird valve angles and stuff, I have found that on published flow bench tests the AFRs are better. So my studies, along with the real world drag guys using them, I think the 205s are the most someone would ever want on an engine that does not run 100% strip. The 205s step up to the really good exhaust ports, unlike the 185s, but don't lose as much velocity on the intake side as the 225s. If the car was not a professional drag car, IMO, 225s just don't belong, and 205s should probably go on at least a 393w for best results. Even though some folks like them okay on smaller engines. My .02 Dave
I’m running the AFR 185s seem ok for my 393.... its not a problem getting air in as it is getting it out .... I did not go with the 205s rise ports …changes the angle of the header …I did not want any more issues with header fitment then I already had ….then there’s the headers primaries would be to small to take advantage of the 205 heads…when I ordered mine from AFR they told me they could do some stuff to the 185s to make them fit my combo better ..so that’s what I did
Ed, let me point out something that you can go see for yourself. First the 205 are even to big for the street on a 302. Here's why. The average cam valve lift is close to.500 +/- a bit for small block Fords. Go and look at the airflow at that lift on both the heads and you will see no great difference that would lead to great HP increases. These are race heads meant to flow air at hi valve lifts and much higher RPM that you simply don't run on the street. They tell you that these heads are to be used on a 331 or larger from 3500 to 8000. Surely you don't run on the street at those rpm levels very much of the time. If throttle response means anything then these heads won't cut it unless you use a ridiculas rear gear like 4.56 etc to keep engine rpm high that you would not normally be happy with on the street. Another way too look at this is that a 302 at 6000 rpm will pump only 500 cfm of air so you can put to big a head on the engine and lose flow speed and have poor throttle rsponse. It's much the same as using to big a carb for many of the same reasons. Lastly, the cam duration would have to be lengthened to admit more air the heads can use making the motor manners on the street very poor. Does this all make sense to you?
Now...to add to my previous post (felt it necessary....sorry). The AFR225 vs. Victor Sr: the 225's are great heads, don't get me wrong. But, if you're like me and like to watch every penny, we can't afford to spend $2200 on a set of heads and turn around & do it again later on! I'm still "thinking" about replacing my Victor Jrs with something else...and looking at the Sr's. The Sr's are expensive by the time you get all the right stuff, though. Shaft rockers, different pistons (to work with the 15 degree valve angle...std. angle is 20 deg), a short block to handle the RPM & HP they're capable of, etc. All said & done I was quoted almost $3700 For the heads only (with valves, springs, rockers, porting and ready for action). BUT what do you get for that? The person who quoted me that price says that they will flow enough air to support 850+ HP on a small block. Naturally aspirated. I guess I could go with a turbo & put down 1500 or so with the same heads if I wanted to. He gave me examples of different combinations that have put down serious power numbers. Several were in excess of 900 NA, many of them were 750-850, and a turbo application made 1570. Let's see a set of 225's flow the appropriate amount of air to get you up to 900 HP. I guess it could be done, but they'd end up about the same price...probably more to be honest. The Sr's ARE better (relatively speaking) than the 225s, in the sense of what I'm doing (fast bracket car), but they are not a bolt-in-and-go type deal. Ports are seriously raised (both intake & exhaust) which make header & intake fitment a biotch if you're not prepared. As mentioned, the valve angles are different....might work with a lower lift cam (under .700") with just a little duration (probably under ~250 @ .050"), but be prepared to notch the pistons just in case. So where are the AFR's better? The ports aren't raised nearly as much, the valve angles are stock or near stock, and basically the intake lines up just as a factory intake would. Other than that, the Sr's have them beat hands down. If you want real flow #'s, how about over 400 CFM at 28" of water? From a numbers standpoint, the 225's are no better than the 205's are...at least not much better, IMO. Would I put a set of ported Sr's on a little 347? Heck no! Not unless I had the shortblock capable of making power up to and over 9000 RPM. They are meant for larger displacement applications. Another tidbit of information; it seems that AFR likes to focus on keeping the intake port size down to the smallest possible, yet still provide good numbers. Fine & dandy...but for a race car, you really want a large(r) cross section and lots of port CC, ESPECIALLY for someone like me running alcohol, nitromethane, or nitrous. There will be more fuel in the intake tract, which means you can get away with more intake port and still work fine. Back to the ol' debate of which is better, it realy depends on what you're doing and how much trouble you're willing to go through to make it all work together. Keep in mind that both the 225's and the Srs are great heads, and are capable of flowing enough to split any factory block. If you're looking at these types of offerings, whether it be the Srs, TFS R, TFS hi-port, Neal, FRPP "yates", 225's, etc, you should also be budgeting in a few other things as well...like aftermarket blocks, steel cranks, GOOD rods, scattershields, stuff like that. All of those heads are meant for SERIOUS race cars, and NOT for street cars unless you want a blubbering pig on the low end and a TON of top end power. So what do I have? An OLD set of Victor Jr's. They work great, for what I'm doing, and they just might stay on there. Im guessing probably close to 600 HP with them and honestly I don't know if I want to go much faster than I am now, at least, not in this car. It's already a handful on a marginal surface. When you start going faster & faster, the price doubles. Trust me. Tires get more expensive, GOOD parts to SAFELY go faster get more expensive, cages, 'chutes, blocks, pistons, trans parts, rear ends, on and on.
People really get caught up on airflow numbers of a bench, and the old addage if "if big is good, then bigger must be better" gets applied. I am using Performer RPMs on a 393 and the torque and throttle response is outstanding. Ports size, velocity and tumble have a lot of effect on drivability and USABLE horsepower. 225s are pretty much race heads. 185s and 205s are about as big as you want to go on the street. Flow numbers indicate that the performer RPM heads flow about the same as 165s, and dyno tests have shown that a 351w with the RPM package nets 400hp at the flywheel. That gives you an idea how good the 165s are, and how big and unnecessary the 225s are.
