AFR 235 for the street! - Pro-Touring.com

Procharmo · #1 10-19-2009, 09:05 AM

Are the AFR 235's Ok for the street?
I'm looking to move up to the following combination:

Dart little M bore 4.155 (406 ci sbc)
Callies Magnum 3.750
JE inverse dish
pistons -28CC

Using my existing Procharger F1C, Airgap performer, AFR Competition Eliminator 195cc.
Comp Cams 12-560-4 Nitrous Blower cam, 268, 477/490 with 1.6 rockers.

Would I see any benefit in street manners or strip power at the same boost level if I were to change to AFR Competition 235's, Comp Cams CL12-568-4 Nitrous Blower cam, 284, 507/525 with 1.66 rockers and possibly a Super Vic?

I will consider a hydraulic roller cam to get me in the 650 lift range and modifying the existing dual plane to retain low end torque.

MonzaRacer · #2 10-22-2009, 10:59 PM

Talk to AFR, they are the experts.
Honestly those might be overkill unless your shooting for some 800-1000 hp range bottom end will suffer,and they wont like the dual plain without serious flow work,the intake will strangle them.
with 406 ci my thoughts would be one or 2 steps down(dont have catalogs in front of me),sat AFR220s full 100% port but try to have the heads kept on the smaller size to use the port velocity.
Also the 235s would better suited to longer stroked engine.
Just my 0.02.
And if you went with them your use of hyd roller would be a mistake but a call to Comp may prove me wrong.
Honestly unless you are looking for less street manners I just dont see that large a head working,215s would a more to my liking,, for a 406, 220s are a real limit as to port velocities.(think went boost is low)
Lee Abel
AFTERMARKET PERFORMANCE

Procharmo · #3 10-22-2009, 11:55 PM

MonzaRacer thanks for you advice. I did also think a ported SuperVictor would maybe needed if changing heads to the 235's but have seen many N/A internet combo's making 500hp+ on AFR 195's at less than 6500 rpm. As I'm looking to make in excess of 800hp with an F1C and have it reliable I thought an hydraulic roller at .600 lift after 1.6 rockers would suffice.

Are you saying even on a blown application the smaller heads will keep the velocity up and hence the torque?

I'll give AFR a call.

John Wright · #4 10-23-2009, 05:03 AM

Let us know what they say....I'm guessing the bottom end will be very soft with that large runner...I like your AFR 195's

notagn · #5 10-23-2009, 06:56 AM

I think you will find the 235's way to big I have a 421 withAFR 227s a cam around 280ish in duration and it rev's 7300 with out even thinking about it and you will have to buy a shaft rocker system for the street, or at least that's what they recomend.A good street setup with the 227's or 235's with cost as much as the heads.

MonzaRacer · #6 10-25-2009, 05:08 PM

Like he said, very serious heads on 235s.
For 800 think closer to 225s,,,, maybe, talk to AFR, they are the head experts I have used for a long time after having to redo several engines friends had done, and the old engines had Brodix box heads, and most were supposed to be 500-550 hp street engines and none would break 450, in fact best was 434 before tuning and 441 after,,,others just were not best mix of parts.
I always had to pull cams and re-spec them then shelve them as I have yet to see any of those engines even come close to 500hp with the Reed cam installed in all of them. Generally we went with bigger roller Comps to get actual 500+.

Procharmo · #7 10-28-2009, 01:36 PM

Thank you all for the feed back. I haven't called AFR yet, I'll do it from work (save on the phone bill).

I originally got the idea from reading Tom Nelson's build up of the F-bomb which has a 406 ci Dart SBC with Brodix 227's~(300cfm). Its a street car as well. In addition I thought boost would tame large heads whilst adding snap/torque at the bottom end.

Both AFR and Brodix now have 235 heads that flow ~350cfm with good low lift numbers (+300cfm at 0.500) which may have been used by some of the more serious builders if they were released earlier. (227's were the highest flowing available for the price). They are close to the legendary All Pro 23 deg heads or even many 18 deg heads.

I have one last question, If velocity and flow = torque. The Procharger at idle is always feeding more air than the motor can consume, meaning the velocity is always good???? When I snap the throttle wouldn't the motor rise from 2000rpm to 4000rpm in an instant thus negating the need for 500 lb/ft at 1500 rpm???

Thanks again, I hope I get to speak to Tony M himself!!!!!

slowcamaro · #8 10-28-2009, 02:51 PM

I've always heard it was much harder to have too large of a head on a boosted engine.

gkring · #9 10-28-2009, 04:01 PM

I might have missed it, but are we talking carb or FI on this motor? Fuel injection would be even less sensitive to the single vs dual plane question. I'd go with AFR recommendation on the heads as well.

turner69camaro · #10 10-28-2009, 06:26 PM

I had a set of 210 Eliminators on my 406 with 75cc heads. I was trying to run pump gas on a dome JE Nitrous pistons with a solid roller. Ended up I wasn't going to be able to run pump gas cause the compression was too hign so I pulled them and bought a set of milled 60cc 227 Eliminators with all the goodie. I figured if I had to run racing fuel why not go all out. The new 227 were the personal heads of Joe Facciano of Joe's Porting Service and he ported them himself and they flow 338 at 700. I haven't got to run the new combination yet but I believe its going to turn some great numbers.

I do still have the 210 Eliminators 75cc and have a total of 3 passes on them and are like new that I will let go of for $1350, I also have a set of 1.6 stainless roller rockers and stud girdles that I will do a package deal of $1500. I have a buddy that has these same heads on his 406 with a F2 procharger and he loves them.

MonzaRacer · #11 10-28-2009, 06:26 PM

I was trying to point out too large is just as bad as too small. Talk to AFR, get the real info from the makers. AFR has it over Brodix by may levels.
I have see nway to many huge and too many small heads from Brodix and never did any do what the parts ordered for do. They always disappointed, yet if I called AFR and asked a question and gave them all info they needed the parts in the box always did exactly what the customer wanted.
I just dont see street driving a head that I have yet to need to make larger horsepower, with a blower you negate needing a super high compression, and to this being super largerports yes you can make great numbers but I honestly feel it would get the engine ready for top end power but hamper bottomend.
Honestly I build for max fat torque curve rather than a mythical horsepower number. Make 500 lb/ft of torque and then make 500 hp,,then tell me which is better accelerating.
I have used AFR227s and the guy tried to drive it on the street, it now resides on an engine stand and another engine with 220s is atleast driveable and makes 680 hp,,,NA.
according to my numbers this engine (415) would be running around 840ish on 6 psi, but this is just estimate, so if you want bigger I wouldatleast stay in the 225/227 range, but I just have suspicions it will be lagging on lower rpms. Boost may help, wouldnt know till the boost and compression numbers get taken into account with actual flow numbers and I do believe your going to need bigger lift. But I live and learn let me know what comes from your call.

DeltaT · #12 10-30-2009, 11:20 AM

I am using them for a very similar build: 434ci, Vortech YSi blower, large FMIC (2048cfm), MPFI, 120lb/hr low impedance injectors squirting E85. Here are some pictures as they came out of the box. After talking with Tony Mamo at AFR, he assured me that my application would really benefit from the bigger heads. I'm not too worried about low-end power with 434ci!

I chose the largest chambers when I was planning a pump gas/meth injection setup. Since I started the build, they opened an E85 pump only 4 miles from my house, so I decided to go for an E85 build that would still support a lower boost gas tune for long highway trips. I'll probably mill these heads down to get the chambers closer to 75cc for a static CR of ~9.2:1:

The vane in the intake port is the biggest visible change over the 227's:

T&D shaft rockers, 1.7Intake, 1.8Exhaust will yield an actual 239/246@.050, net lifts .630"I, .674"E on a Comp Cams 242/248 solid roller cam:

To keep good pushrod alignment, I'm using .180" offset intake mechanical roller lifters:

World Motown Single Plane, ported by Dr. J, before conversion for EFI and embedded nitrous spraybar:

Plans are ~15# of boost with a target of 800rwhp.

More to come.

Jim

Procharmo · #13 11-04-2009, 11:01 AM

Delta T , that's a very desirable set up you have there. The heads look stunning. I think 800rwhp is conservative for that combination and should last 10's of thousands of miles if not longer. The motor is probably capable of 800hp n/a!!!!!

Well done!

I've still not called AFR yet as I'm still not convinced the Little M 406CI short block is for me. Perhaps a Iron Eagle 434ci or a Dart aluminium 406ci to keep with the Protouring handling theme?

DeltaT · #14 11-04-2009, 01:32 PM

I would have gone with the tall-deck Iron Eagle if I had known better. The price delta has narrowed for the whole package lately and you really need the extra space for an FI application to get a premium low-compression blower piston in there with a good rod length. But I'm still psyched to get this up and running ASAP!

Jim

Procharmo · #15 11-13-2009, 12:08 AM

Quote:

Originally Posted by DeltaT

I am using them for a very similar build: 434ci, Vortech YSi blower, large FMIC (2048cfm), MPFI, 120lb/hr low impedance injectors squirting E85. Here are some pictures as they came out of the box. After talking with Tony Mamo at AFR, he assured me that my application would really benefit from the bigger heads. I'm not too worried about low-end power with 434ci!

I chose the largest chambers when I was planning a pump gas/meth injection setup. Since I started the build, they opened an E85 pump only 4 miles from my house, so I decided to go for an E85 build that would still support a lower boost gas tune for long highway trips. I'll probably mill these heads down to get the chambers closer to 75cc for a static CR of ~9.2:1:

Plans are ~15# of boost with a target of 800rwhp.

More to come.

Jim

Jim,
I cant stop looking at your heads. They look great. I have one last question. Which pistons did you go with to clear the 2.125 valves with a 4.155 bore and -28cc dish?
Thanks,
David

DeltaT · #16 11-13-2009, 03:32 PM

No clearance problems so far (have only checked with one head on)with the KB forged stepped dish -26.5cc pistons.

Here I am checking the quench height and piston-to-valve clearances, then I got custom .027" Cometic gaskets to get it right where I wanted it at ~.044" quench.

The cam is small enough that the valves didn't even register on the clay in the eyebrows of the pistons.

Jim