Hey all,

Just looking for a little feedback on people's opinions and experiences with Brodix M2 T1 227cc CNC heads vs. the AFR 227cc CNC heads? The flow charts for both are nearly identical with Brodix having a slight advantage on intake and AFR having a slight advantage in exhaust... I suppose what it will come down to in my choice is personal experience from some people. Which one do you think is likely to deliver the most power, be the most reliable, and be the easiest to match up with good .040" cometic gaskets? Bearing in mind the manifold will be a Vic. Jr. CNC and the cam a very agressive roller, compression ration of just around 10.75:1.

Just from looking strictly at empirical data it would appear the Brodix heads are the slightly superior ones, but any input is highly appreciated.

 

How many ci and how many rpm is your red line going to be? My last motor with Dart 227's was 11.2 c/r and SR cammed. Nearly everyday I drove it it hit the 7500 rev limiter and it was only 383 ci.

In retrospect it was over cammed and they heads were probably on the large size for street driving. Dart was kind of right when they said 400+ ci and 7000+ rpm. I used crutches like 3500 stall convertor and 4.11 gears to prop it up. I never really liked driving it around town in stop light traffic. Open roads and race tracks were where it liked to be. Although you could put it in lockup up overdrive at 45 mph and go WOT and it would start moving out. by the time you hit 85 mph and 3000 rpm it was starting to make power. Anything over 4000 rpm and 120 mph - I never met a car that could keep up. It would just leave Z06's

 

Sry the engine is a 434 rat with a theoretical red line of roughly 7000. It has a 4 speed right now but when the engine is built a Richmond 6 or a T56 is going into it.

See thing is Im not looking for just high end power, I also want a deadly low end as well, Im not sure if the heads can do that. The Brodix jobbers have better intake and exhaust flow at the low end, so hopefully that would help. This car will have 4.11 gearing as well. I wanted more of a 1/4 mile setup than a full on 7000rpm racer. any thoughts?

 

If your engine's a rat, why do you want mouse heads?

 

HUH? 227cc heads are about as big as you can get in standard 23 degree configuration... both the Brodix and the AFR flow at over 300cfm at .700. Whats mouse about those heads?

Im still looking for some ideas on heads here guys... Ive been thinking about all sorts of things lately with the engine, quench, piston top shape, perhaps a dished design with dimples and a flat portion to increase the amount of swirrel and exhaust scavenging.

Heads are my main concern right now, any thoughts on the 2? I know A LOT of you guys run AFR, but I dont see many Brodix guys, why is that?

 

That's because they are huge heads that wiill support over 600HP and they also have 60/40 valve spacing which may or may not be a problem. You want to build a killer motor for 7000RPM then be prepared to pay over $3000CND for those heads and the rest of the motor had better be all stout ( read expensive ) pieces too. I wish I had deep pockets like you because that is going tt cost more than a half decent C3. Make sure you plan every part out carefully with a machinist that knows what he is doing. I would go with the Brodix heads

 

This above statement and "very agressive roller." are not consistant.

With a steep ramp roller cam you should not even care what the low lift numbers are because the valve passes through them in an instant of time. You should only worry about the .600 lift numbers and use a cam lift and rocker ratio to keep the valve at the highest CFM of flow for the longest time. That is why I use 1.65 ratio rockers to have Net valve lifts of the .620 range.

I'm now driving around a 427 ci Motown small block in my lite 79 Vette.

I was trying to figure out how to explain it. Unless you have driven an honest 600 HP car you just wouldn't understand.

You better get these items:

1. The best tires availiable. The 345/18 on 12X18 rims on the rear.
2. The best 1/2 shafts, U-joints, and Yokes.
3. HD trailing arms and spindles - Have them set to "Zero toe" on the rear. So you don't create bending thrust.
4. You need @420 inch pound rear spring, good shocks and sway bar.
5. Tom's $700 posi unit - I used to break posi cases about annually. This Toms unit has last me 4 years.
6. I have 1/2 inch wheel studs torqued to 105#
7. Upgrade and hoop the drive line.

a 427-434 ci 600 hp motor is dangerous. Every time I broke something over the years I bought better than original parts. That's why i went to a full roll cage. Your life is on the line if you have major mechanical failure at high speed of any driveline or suspension piece.

 

I had a set of Brodix - 11 down port nozzle heads off a race car. They are also @23 degree. But more like 255 cc and 2.15 intakes. I determined that high port intake, custom pistons, and custom spread port 2 inch primary headers made them not a wise choice.

These 227cc heads really require shaft rockers. That is a thousand more than steel rockers and stud girdle like I run.

 

Oh I know Im getting myself in VERY deep here, but money isnt an option with this build up. I plan on using the VERY best components from gaskets to rods to rockers to a bloody oil filter...

Im trying my best to learn here, Ive DRIVEN over 600hp cars before but I have never built one, and I certianly have never built one that I can drive every weekend for several years.

As far as suspension, brakes, rims, driveline components, all of this has been thought out, Im using at least 1380 spiver U joints, carbon fiber halfs, carbon fiber drive, Im converting the rear end to a Guldstrand 5 link setup, the front will be totally rebuilt with the hipo kit from Ecklers. Rims will be 18x10.5 at the moment, but with the mods to the back I am confident I can do 11s.

I am taking the model of Shafiroff Racing's 434, using most if not all the same parts. It makes 625hp in the SS version, Im looking for a few more to around 650. Hence the thoughts of the higher flowing Brodix heads.

It would appear youre suggesting I use 1.65 ratio rockers, thats fine with me as long as the clearence is there. The heads wont be spread exhaust, I like my side pipes and plan on keeping them.

I plan on doing this once, and only once, Im going to dish out major money ONCE so I dont have to dink around for the next 5 years breaking parts to get the right combo, hense me asking so many annoying questions. Im sorry if I come off a little harsh, Im just trying to milk all of you for your experience so I DONT have any blow ups or manjor screw ups . Anyhow, the advise so far has been really good and I DO thouroughly appreciate it

 

This is the base that Im using to create the engine with, Im just sort of going through part by part to replace the weaker or less efficient and productive parts. Any guide here would be appreciated:

ENGINE BLOCK: Motown 9.025” deck height 4-bolt main
CRANKSHAFT: Eagle 4340 nitride crank 4.00” stroke
CONNECTING RODS: Eagle 4340 6.00" H-Beam 3D Rods w/L19 Rod Bolts
PISTONS: JE Pro Series 11-1 Forged Aluminum Pistons
COMPRESSION RATIO: 11 to 1
PISTON RINGS: C&A ZGS Ring Set
BEARINGS: Clevite 77 H series
CAMSHAFT: Comp Cams 12-773-8 MECHANICAL ROLLER duration @ .50: 254/260 intake valve lift .582 exhaust valve lift .588 separation @ 110 degrees. ORRRR Custom Small Base Circle Steel Billet Roller Cam 255/255 .590/.600@ 110 degrees.
LIFTERS: Crane rollers
CYLINDER HEADS: Dart PRO-1 SBC 227cc fully CNC ported, OR the M2 T1 Brodix 227cc CNC
VALVES: Dart 2.080 Intake, 1.600 Exhaust Valves
VALVETRAIN: Stud girdle, 1.550 Competition Roller Springs and titanium retainers
ROCKER ARMS: Offset 1.6:1 roller rockers (Aluminum heads utilize a .150 offset rocker)
INTAKE MANIFOLD: Edelbrock Victor Jr.
CARBURETOR: 950cfm BG Mighty Demon Carb
IGNITION: MSD Digital 6 Plus MSD-6520, MSD Pro-Billet tach-drive distributor MSD- 8570, MSD HVC Blaster II coil MSD-8253, MSD 8mm ignition wire, Accel spark plugs (416 for aluminum heads) gapped @ .035
BALANCE: Internally balanced, SFI Hardcore CNC Balancer
TIMING CHAIN: True Roller Timing Chain w/Torrington Bearing
LUBRICATION: Moroso Street/Strip Oil Pan, Oil Pump & Pick Up
ASSEMBLY COMPONENTS: Fel-Pro, ARP and Manley
ACCESSORIES: Polished Cast Aluminum Valve Covers
IGNITION TIMING: 36” total @ 3000 to 3200 rpm
VALVE ADJUSTMENT: Valve lash adjustment is .028 Intake & .030 Exhaust
REDLINE: 7000 rpm

 

Do you plan on drag racing alot??? Those heads are a bit much for the street...even AFR doesn't recommend running those heads on street driving.

 

Yea but "reccomendations" are just those, Bill Mitchell and Scott Shafiroff both use heads exactly like that on street engines that are drivable on pump gas... I unno... I might just give up trying to do this myself and contract out an engine builder to do it as he sees fit.

 

If you are looking for the "very best componentes" ditch the Eagle rods and crank. If you want to stay with steel rods the best would be billet from Oliver, Crower, Lunati, or Carrillo. Best cranks would also be billet from Sonny Bryant, Windberg, Scat, etc.

 

Nice stuff other than the comp cam. That is unless you can talk to a manager and not one of the phone morons. I've got hoosed by them.

You really need a cam with a base circle of .950 or less and it should have a sleeved dist gear so you can run the standard dist. gear. Comp cams claims to make small base circle and then when it arrives on your door step it's 1.030 inches and then you end up having to grind and polish every rod. My Crane cams were always .930 B.C.

I've been very happy with my Dart heads. I have the 2.08/1.625 .100 over length. In retrospect I would talk to Dart and see if you can just get the 2.10/1.6 valves. I also use the 7/16th ARP tall studs because of the .700 or so max lift springs. This required using .200 longer 5/16th push rods. The reason was my steel rockers were contacting the retainers.

As far as a cam duration. I went with 242/248 110. The bigger the head flow the less cam you need.

Your pistons need to be @20 cc dished to get 10.7 compression

Dart heads make the most power at @32-34 degrees max timing. With 64 cc heads and @.040 quench

 

Talk to Corkvet or Ski_dwn_it, they both built 434's for their C4's using the Brodix heads and I think they run low 10's.

 

thanks again guys, Im keeping note of everything here, its good info to be certain.

Gkull: Ive already talked to comp once and they assured me they do small base circles, but Ill definitely double check that with someone higher up.

69 N.O.X: I was already thinking about changing up the rods to crower, as well as the lifters, they seem to have a really good repor with engine builders and racers. I was thinking of a scat crank too, I mean the crank is the last place you want to take a shortcut if you want a high rev.

 

I believe the LAST place would be the valve train.

 

I was just giving you a hard time. You called your 434 small block a 'rat' motor. That term is normally reserved for big block engines. Small blocks are usually referred to as mouse motors. But you probably know that??

 

Just my oppinion, but if your going to use crower rods anyway why not use their crank also? I'm not a fan of Scat or Eagle myself, they may be alright I just couldn't make myself take a chance when money is no object.

 

Yea thats a good call too. I like homogeny among my parts anyhow, crower parts probably work well with their own kind best.

What do you guys think about pistons though? To get the 10.7:1 comp I need 20cc dished, but has anyone here seen or used dished pistons with a dimpled or flat portion to increase swirel in the chamber? apparentally there is a decent going in power by combining those type of pistons with a tight quench.