Now that you guys have talked me into a 555/565 motor I'll need a bigger head than the old 310 Canfield.

What do you guys think of the Brodix 3X head on a 555, 13.5-14:1 motor trapping at 7200-7500 RPM's? These heads seem to make a lot of power in the 6600-7200RPM range,(at least on paper) which is what I need. If they are a bit lazy in the lower RPM's it is okay with the limited tire that we run.

I'm just not sure that the 363cc ports may be a little too big to get this heavy car down the track.

Also any cam suggestions would be a big help also.

Car specifics: 3500 lbs, 400 turbo w 6000 stall 8" converter, 28X11 Goodyear slicks, 433 gears.

We've been going 9.90's at 135 at 7200RPM on the old 454 with a small shot starting at the 330' mark. Hoping to go a little faster with a new motor without spray. Add the spray and hold on!

 

A forum member here has a set of the CNC 3X's. We flowed them on two different benches. They out did the CNC AFR 357's he had previously. Still had to do a little clean up work in the ex ports (same on the AFR's) to get them to flow right.

He used them on a pump gas 632. Using only a .685 (at the valve) lift solid roller it made 780 ft lbs/878HP I think. We will be back soon and it will break 900+ for sure with no issues. It was having some major mechanical issues during the first dyno test (his engine builder sorta forgot to size lifter bores..they stuck bad!!)

For an out of the box head, they are very nice.

I have Brodix 2Xtra's on mine. They start with a 365cc port. I ran them two years before pulling them to port and found they still outflowed what Brodix claimed even with a 2 year old valvejob! Mine are now 377cc....yes pretty big....but they pull like a **** on the big end!!

Smaller will help midrange some I'm sure..but you have juice for that!!

Check with 69NOXRat....he has some recent info on some N20 dudes using smaller heads by design and somehow it's working out better. Still sounds strange to me.....hoping to hear more.

I'd also look closely at the newer Dart and Brodix super big ovals with the rollover valve angles.....14* and 16*. Also check the BMF CNC ported Canfields. Really good flowing stuff.


But I still think Brodix has the best casting in the industry.

If you're interested, shoot me an e-mail and I can give you some of the flow numbers we've been accumulating in real life...not advertised.


JIM

 

I am the guy Jim is referring to in the post. I orginally ran the Aluminum GM signature series Rectangle port heads on my 540. These heads barely flowed 300cfm on the intake. I then had them ported and picked up 60 RWHP along with a cam change. I then purchased the AFR 357s. They didn't flow nearly what AFR claimed on the exhaust side, but were fairly close on the intake. The exhaust clean up didn't take much effort to pick up over 20 cfm.

For the 632 I bought the Brodix BB3 Xtra's. As Jim mentioned these heads had the same issue on the exhaust as the AFR's ... (Gee I wonder how that could have happened ). The Brodix heads are a very nice casting. They didn't CC as much as Brodix claimed, they were closer to a 355 CC rather than a 363CC.

There are so many head choices available now it is almost overwhelming. I have heard some very good things about the CFE-BMF heads. Edelbrock is supposed to be coming out with some new killer BBC head soon.

As far as Casting quality, I didn't have any problems with any of the heads I purchased, but I did notice the Brodix appeared to be a bit heavier than the AFR's. Brodix definitely throws more meat around the stud bosses than anyone else. If you are running a shaft rocker system, then this isn't much of a concern, but if you are running studs and girdle, with big spring pressures, then it might be a definite plus in favor of Brodix.

Another thing I have noticed at just about every major drag event I have attended is that 95% to 99% of the BBC engines were running Brodix. I guess they are still doing something right.

 

I assume you want to make 900+ hp on the motor ? How much nitrous on top of that?

Is there a budget involved? are 18* heads out of the question?

If there are major budget concerns the Pro-Action heads at 1800.00 per set are supposed to be really nice heads. Dart makes a good head at a reasonable deal also. ReherMorrison used dart 355's CNC on their Super Series 540-555's. They make around 950 hp. You could duplicate one of their motors, they sell the cams also. Lots of R and D in those motors.

Check out their web site and you might get some ideas on heads and cam shafts. Their in house oiling system is a very nice wet sump set up. Those guys are known for building reliable motors with just a little sacrifice in power. Just what guys like us who pay our own bills want.

 

Jim - What is Steve up in Puyallup Washington using for heads on his N20 monster?

In my experience of beating motors to death with rpm/high compression/methanol injection. I should also add limited budget. That your better off just going with a quality big blower. The cost per HP and how long the blower motors lasts is phenominal. I'm also very pro methanol fuel. It's so nice to drive up to the stagging lanes on a 90 degree day and wonder if your going to get enough heat in the motor. No tow vehicles, no pushing, and driving back to the pits.

Big ci aftermarket blocks and 1000 hp is not even stressing the motor with a blower. Once your up in the 1000+ hp range N/A your looking at short term motors. One of the local friends has AA/gas altered 632 injected, dyno at something like 1370 hp and it's had lots of problems and he bought the motor for something like $50K

 

They got bought by Comp Cams and are sold under the RHS name now.

 

The RHS big block heads aren't available yet. I talked to the guy there about 10 days ago and he wasn't sure when they'd have 'em. There are still a few Pro Action heads available but they're getting harder to come by. I think you can get a set bare on ebay for about $1250. The 320's have decks that are about .600 thick while the 360's are closer to .400. If you plan to spray it hard, I'd get the smaller ones and have your local porter work 'em over a bit, they'll probably out-torque the 360's. Our local race shop is using Brodix 3-xtras, mostly CNC'd on their 555 - 598 engines. Power is up about 5% over the 2-xtra. You can even get 'em oval, they actually make a few more ponies and ft/lbs.

 

When I was looking for heads my first choice was the 3X but I couldn't get them complete with valves. The heads came bare, that ment I had to buy the valves, no big deal but I also then had to have the guides honed. That meant one of the local jobbers and I would rather have had Brodix do that.
I ended up with the 2X with the 340 cc intakes and ended up opening them up to about 360.
I really openned up the exhuast, I left the D shape or left the floor alone but really raised the roof by about 1/4 inch.
Brodix also claims very little exhaust flow difference between the 340 and the 360 heads and being blown that is what I wanted.
I also agree with George if you are looking for big horespower a blower motor is the way to go. Lots and lots of torque without stressing the motor with super high rpm.

 

When I was looking for heads my first choice was the 3X but I couldn't get them complete with valves. The heads came bare, that ment I had to buy the valves, no big deal but I also then had to have the guides honed. That meant one of the local jobbers and I would rather have had Brodix do that.
I ended up with the 2X with the 340 cc intakes and ended up opening them up to about 360.
I really openned up the exhuast, I left the D shape or left the floor alone but really raised the roof by about 1/4 inch.
Brodix also claims very little exhaust flow difference between the 340 and the 360 heads and being blown that is what I wanted.
I also agree with George if you are looking for big horespower a blower motor is the way to go. Lots and lots of torque without stressing the motor with super high rpm.

 

Blower motors can make lots of power. Blown alcohol is what I would do if I were building a roots blown race motor. That being said, I do not think a roots blown motor would be the best combination for a small tire stock suspension car.

I did not know that the RHS head were not available yet. I would be willing to bet they will be a very good head. Comp Cams has a lot of exposure to high end racing and while their tech lines are manned by knuckleheads for the most part; they guys in R and D are smart fellars.

The -3 heads are excellent. I would also look at the ovals port option. If I remember right the exhaust is a little weaker on those. However be careful about getting too caught up in exhaust numbers, modern pro stock heads have a very poor exhaust port in terms of I / E ratio.

 

Steve has an older (10+ years) set of Dart Big Chiefs on his. They were brand new and sitting in his garage from another project,,,he just finally used them. They don't have all the newest features and stuff,,but they still bump up in the 1150-1200 hp range in *street mode* without the juice!!

Dukes and Chiefs are typically worth 90-100 or so HP over a nice set of regular heads. But they come with a lot of extra stuff you have to do too. Pistons, headers, rockers etc etc.

5% is a LOT of power when you are already in the 900-1000 hp range. Makes the 3xtra's look even better for a big motor deal.


JIM

 

I've been looking at the BMF/CFE line for awhile now. Per the recommendations made here i called them today. I talked to their sales/tech person and told him our combination. He said their 385 head would work the best on the motor using a big shot of nitrous, but since we don't intend to use the bottle on a regular basis he said the 350 head would be the best compromise.

In talking to him, (Larry) asked just how fast we wanted to go. I told him that the goal would be around 145 MPH in the quarter. He kind of snickered and said "that should be no problem, we have customers going much faster than that, N/A, in 3500-3600 lb. cars with less cubic inch motors."

Now I am getting excited!!

Needless to say I ordered the 350cc CFE/BMF head.

Now my only problem is how to mount a parachute to a C3 Corvette. Any suggestions?

 

Good choice, great heads.

What are the plans for the rest of motor ?? Carb, intake, cam, compression, shaft rockers? etc, etc !!

 

Going to try and get this thing in and running before the end of this season. The local tracks up here close after Holloween. Heads are on national back order, but they should be shipped by the third week of Sept. With a little luck we may get in a few tuning passes before Nov.

Going to use a Merlin III block 4.560 bore, Callies DragonSlayer 4.250 stroke crank,Oliver 6.385 billet rods, Wiseco Nitrous 38cc hollow dome pistons (approx 13.5:1) with .043 Manganese top rings, Demon Race RS 1050 carb, Brodix 2000 manifold already plumbed with NOS Pro Shot Fogger, Canton 8 qt power pan, Isky Red Zone lifters, Comp roller rockers.
Going to think about the cam and probably get a recommendation from CamMotion on a good grind for this combo (Any suggestions on a cam would be appreciated).

Some things may not be optimum like the 4150 carb, but I already have it, and it will get us up and running. This winter will be a good time to work on the top part of the induction system.

I am also going to have to contact TCI to see of my 8" race converter is going to need to be modified.

 

You made an excellent choice going with the CFE/BMF heads. Great products that works very well. From what I've seen, they are the best conventional head out there for the bbc.

I do wonder why your old 454 combination didn't run better though.

My last seasons 454 combination ran a best of 9.99 @ 132.8 mph with a 1.38 60' at 3515 lbs. This was a .030" 454 with GM 781 large oval heads (just bowl blended & large valves), .697" lift, 262/272 Bullet solid roller and 13.1 to 1 compression. This was run normally aspirated with typical times being in the 10.0's to 10.20's...on 275/60-25 M/T Et Street radial DOT tires.

Over the winter I swapped out the 781 large oval iron heads for a pair of the CFE/BMF 310 cc heads. The compression went up to 13.4 to 1 due to a 114cc chamber vs the previous 116cc chamber.The only other change was a slight cam tweak with lift being .738"/.710", duration @ .050 is 269/276. Best time out this season (still not done tuning) is a 9.62 @ 138.8 mph with a 1.32 60', again, all motor - no power adders, 3450 lbs race weight. This was done on a 325/50-15 M/T Et Street Radial DOT tire and through mufflers. With cool fall air coming, I know the car will see 9.50's and am hopeful it may squeek into the 9.40's with more tuning and perfect air/track conditions.

I would have liked to see your old 454 combination tuned & tweaked as I'm sure you had a ton left on the table. But I also don't blame you for going bigger although I like running as quick or quicker than many of the guys I race with that run 509's and 540's .

Good luck with the new bigger bullet.

 

If any of you guys want to sell one of those old roller cams, something in the 265-275 range @ .050 I would be interested.

 

Please tell us more! 1.32 60' with radials. WOW!

What trans, converter, rear, gears, etc are you running?

I think that our times and MPH were down somewhat because we were blowing thru the 8" race converter.

 

I talked to the guys at my local race shop last week and they said that the 3-xtra ovals are worth a few hp and ft lbs over the rectangle ports. Call Tracy or Jamin at Sunset Racecraft, they generally have the best prices on those heads. (806) 747-2700

 

Basic hi-perf rebuild th400 with ATI reverse manual valve body (no t-brake), 8" ATI Treemaster converter flashing 5900 rpm, 4.10 gears. The 325/50 radials measure approx 27.5" tall and have 11 3/4" of tread (13" section width on a 9.5" rim).

Car is launched off the footbrake at 2500-3000 rpm, shifts made at 7400 rpm and the engine see's 7300-7400 at the stripe. Converter slippage is 5.8%.

Recently installed a RPM Performance data logger with a wide band O2 which is helping a bunch seeing what's going on with the converter flash, slippage, driving hitting or missing shifts, etc. lol.

If you need any other info, feel free to ask.

I could only dream of a 500+ ci monster...oh well, will make due with this little rat.

 

A data logger is on my want list. Which one did you get? How do you like it?

I've never seen a C-3 Vette sixty foot like your car. How do you do it?
Please give your suspension setup.

We've tried everything from 5000 RPM on the trans brake to 1500 RPM on foot brake. Experimented with different spring rates, adjustable shock settings and different tires. The best 60' we've had is 1.44. Granted the track prep here is not all that great here but I don't see how low 1.30's is possible with the IRS suspension and a 3500# car.

Thanks