AFR cylinder heads

[RPM427]

I am planning on installing a set of AFR 185 (with 2.02 intake valves) cylinder heads for my 91 GT. I also have a Holley systemax intake along with 3:73’s, 255 in tank fuel pump, MSD ignition.

My question is what cam you suggest I run. I was looking into comp cams xtreme line up. I would like to not modify the short block if possible (i.e. notch pistons). What is the highest amount of lift and duration I can run with 1.6 ratio rockers without notching the pistons? I’ve been told I can go as high as .555 by some, and some tell me I need to notch the pistons regardless of lift due to the larger valve size. Your help will be appreciated.

[RPM427]

can anyone help me?

[lx mike]

Why the 185's?? the afr 165 heads are enough unless you want to turn your engine over 6000 rpm's or have a stroker. as for the cam i think with the 185 that you have to notch the pistons anyways to run those heads but i'm not 100% sure there.

[USMC302]

I am running the TFS twisted Wedge heads withthe 2.02 valves and am running in the park of 512 lift with 1.6 rocker now. It is a custom grind cam but I was told I cannot go much more or I would need to notch. Even with 1.7's I would have to notch. Not sure, don't quote me, ask someone else, ignore me, but I was under the impression we could run up to .525 lift max then boom.

[91GTturbo]

The TW heads were designed to run 2.02 valves on a stock mustang without having to flycut the pistons, only new rods are needed because the length changes. If you've got AFR 185's, your going to have to cut your pistons even with the stock cam and 1.6 rr.

[HDD95SAYLEN]

Why go with the 185's. Go with the the 165's if you are not moving up to a stroker or blower. Keep the velocity high and port volumes low for a NA 302. They will actually make the same power on a 302 with mild cam and long runner intake than their big brother and without the trouble of fly cutting the pistons. Yes it is manditory with the 185's.

[Brian88]

it is not mandatory. i have the afr 185s with 1.6 motorsport rockers and b cam.

[HDD95SAYLEN]

Every combo is different. According to AFR the 185's requirer Fly cutting the piston to use on a Stock short block. But hell what do they know. The only way to be sure is to check the piston to valve clearance.

[RPM427]

I just got a response from joe at mustang magic:

"Ryan; sorry to say you can't run 2.02 intake valve with stock pistons unless you use Twisted Wedge heads. The valve relieves are not wide enough for a 2.02 intake. Joe @ Mustang Magic"

I wanted to go with the 185's cause i'm probably going to get a 396 short block in a when its time for a new engine. I will probably go with the 185's then.

Does anyone know how much lift/duration i can go with the 165's with the smaller valves using 1.6 rocker?

[RPM427]

anyone?

[Stroked408]

RPM,
with the AFR 165 I would talk to Ed Curtis at Flow Tech Induction,he is the master at getting stock block 302-310 motors to run like crazy,he can probably suggest a custom grind for you with your combo,on the matter of Twisted Wedge heads and max lift this is straight out of the mouth of TFS .540 max lift as long as duration is under 290 degrees and many engine builders i talk to say the same thing,just remember this do not get hung up on the bigger is better theme unless you are talking displacement but in the end it all depends on combination,to answer your question with AFR 165 heads 1.90/1.60 valves the max safety lift you should run is .480 to be on the safe side,always check the piston to valve clearance no matter who you talk to

[ballistic_331LX]

hey whats up....Well, I am sure that the afr are the same cumbustion chamber location as the original dart II's and a buddy of mine ran the dart II's on a stock 89 block with .544 lift and it buzzed to 7000 R's and ran 12.88 with noticible traction loss out of the hole. i have the tfs stage 1 cam on my 185's and i love it...it pulls all the way to the rev limiter and never misses a beat.....it is a 331 but was on the stock block with 185's and was really really nice.......try that new lunati cam that i seen.....its .512/.512 220 @ .050 duration.....i would love that cam with 1.7s......anyways good luck......hey USMC302...i go to the track tomorrow to get times for the 331 (frye)

[Old Guy with 87 GT]

rpm427......one of my best friends was running afr 185s ,e-cam ,1.7 rr .......no clearance problems ,he was running them on a stock short block 92 moter (forged pistons with factory valve reliefs)

i've heard peaple say that the 185s are a little big for a 302 but if your going to upgrade later ,then get the 185s ....even with the lower velocity they still work just as good if not better then the 165s.........

my friends car was turning mid 7s in the eighth and dynoed at 320 hp at the wheels with that combo (naturaly asperated )........he was running stock short block,e cam ,afr 185s, 1.7rr ,systemax intake, 70mm tb, 24lb injectors, full lenth headers, 355s and t-5 man trans..........

i'm don't have the specs for an e cam handy ,but i know with that combo(e cam and 1.7s) his valves were pretty close so before finale essembly it might be wise to clay the engine ,but you should be allright with 1.6 rockers ..........

only problem my friend had --->for quite a while he was making that power(320 rwhp) with the stock block and stock computer ,but he eventually got a custom chip and was turning his moter up to 7,000 ,.....he soon discovered that if you turn a stock moter to 7,000 rpms with that much power ,the stock block doesn't like it ........he cracked his block .......the stock moter is'nt balanced to handle the high rpms ......he recently built another 306 short block balanced to 7500 with the same combo adding a custom cam ,fly cut pistons ,and 10 to 1 compression ....he hasn't had it at the track yet but initial dyno numbers are like 340rwhp and a much better torgue curve .....he's still tuning but i can update you on progress as he gets it tuned ,just pm me if you want more info

[1BAD89]

Screw the 165's & 185's go with the AFR 205's! They flow 314cfm. Heh. For the people that are going to reply to that, I'm j/k so save your fingers. I'd personally go with the 185's if I had to pick between 165's & the 185's, but that's just me. You always want to look down the road when you mod.

[RPM427]

In the future I want to get a 408 with AFR 225's. But for now i have decided to go with the Trickflow twisted wedge. They flow as much as the 165's and are $300 cheaper. They also allow 2.02 vaves with a larger cam becuase the valve locations are changed.

[Killercanary]

I run the AFR 165's on my stock bottom end. I also run an Ed Curtis (FTI) cam. It was close, but I am safely running .546" lift with 224 duration on the intake at 500. I am running a thin .035 compressed gasket though which makes it even closer, with a standard gasket, I would have plenty of room. The only heads that do not require piston notching with 2.02 valves are the TW due to their valve positioning, and the "new" holley systemax heads... the valves are recessed quite a bit and work fine. now as it was said, all motors are different and its obvious from the post above that some are getting away with it. Just make sure to check the piston to valve clearance with checker springs in the heads, if you don't the heavier springs in the heads will bleed the lifters off and give you false readings. Hope this helps.

[RPM427]

I am def going to check the PTVC when I am assebling my engine. I am going to use a solid roller the same size as the hydrolic one to make sure I get an accurate reading. Thanks for the advice