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Brodix dragonslayer 320cc

21K views 62 replies 16 participants last post by  BillyGman 
#1 ·
Does anyone have any experience with these heads? Any actual impressions of there "as cast" they seem very cheap and wondering if anyone has any first hand experience with them?
I truly appreciate your knowledge
 
#3 ·
Looks like complete heads start at $934.20 each ($1868.40 per pair) and go up to $1310.85 each. That's not exactly cheap considering some of the offshore heads available. Sorry but I have no experience with these heads.

Best you talk to Mike Lewis (wolfplace), Mark Jones (VortecPro) or Chris Straub (cstraub). Any one of them will be able to answer your questions and give you sound advice based on your build requirements and intended use.
 
#4 ·
#7 ·
Out of the box????? I have my doubts.
Have you flowed an as delivered ProMaxx 317 assembled head?
Don't get me wrong, I know that once you rework the heads they are good to go but just how good are they if a person were to buy a complete assembly?
 
#10 ·
Maybe I'm a little slow here, but you're joking, right? Offshore? Not according to brodix. They claim that they're made right across the street from thier office. That's what their salesmen say anyway.

I was considering their BBC dragon slayer 365cc heads for my 632cid engine. One thing that surprised me was their salesman told me, (I've spoken to three of them so far) that on their assembled heads, they don't install valve seals on the exhaust valves. Only on the intake. He claimed they've been doing it that way for 20 years since it helps keep the exhaust guides and valves lubricated and cool during use at the drag strip. IDK enough about that topic to say if that's bad or good.
 
#13 ·
The dragon slayer heads are a fairly new offering from Brodix, and the main point of the savings with them is that they're taken from a full CNC ported BB-2x Brodix head, and were casted from that CNC model, and are supposed to offer the flow characteristics of the BB-2X CNC does, but without the xtra CNC machine work that would add an additional cost to the customer. That's the main benefit of the BBC Dragon slayer head. You're getting a better flowing head than there other as cast heads flow, but at the same price as an out of the box as cast head, along with better flow numbers. Supposed to be the best of both worlds in that sense.

Another thing that some of their saleman didn't even know until today: (long story) is that the Dragon Slayer is now their only BBC 26 degree head that comes standard with their upgraded Manganese/bronze valve guides. All thier other BBC 26 and 24 deg heads have the phospherous/bronze guides, and require a special order to be upgraded to the Manganese/bronze
 
#26 ·
So now that you have,(or had) brodix heads, what do you think about their practice to deliberately leave out valve seals on the exhaust side, and only install them on the intake valves? Did you buy brodix heads complete or bare? if they were assembled by brodix, then my question applies. does your engine smoke when it's cold? Brodix told me that they've been leaving out the exhaust valve seals for the past 20 years now. So that's why i ask you that.
 
#36 ·
You could probably call Brodix and ask them, my receipt had every thing listed but I don't remember it saying anything about that, CNC chamber, gasket match ports, machine to 115 cc chamber, CompCams guide plates ect., edit: my "063" heads when I had the valve job done correctly at the 2nd shop they installed all new guides and machined for umbrella "or viton I can't remember" seals
 
#39 ·
Yeah Rick, I'm gonna call them about that. Hopefully the salesman I get will actualy know the answer. Some of these guys are real ham & eggers. They're helpful at times, and are polite and patient too. But like most aftermarket companies, they can be a little uninformed about the products they sell.

I was the one last week responsible for teaching two of the brodix salesman that their Dragon Slayer heads come standard with the manganese/bronze guides. One of them adamently insisted over the telephone that I was wrong and that the manganese/bronze guides require a custom order and is an upgrade which comes with an extra charge. I pushed back and stayed on him and it was then he placed me on hold and got back to me sayig that i was correct and that he wasn't aware of that since it only applies to their Dragon Slayers because every other head that brodix sells requires a special order for the managanese/bronze guides to be included, and that the rest of them come standard with the phoserporous/bronze guides.

Anyway, those seals you have in that pic are not the umbrella ones. I installed Umbrella seals on a SBC engine I had years ago, and they are shaped just like an umbrella, ( and probably don't seal as well as the ones you have either). Another thing in the mix is that i have a hi-volume oil pump in my engine. It's an aftermarket block with a "priority main oiling" design which allegedly directs more pressure and oil volume to the main bearing than a factory block does. However to my knowledge, my engine doesn't have any oil restrictors that I believe some engine buiders use with hi-volume oil pumps to prevent too much of the oil from being up in the heads during high volume.

So here again, where does this leave me with this exhaust valve seats vs. no exhaust valve seats question? There sre so many variables my head is spinning with all this crap. LOL :D I can say one thing: when I first start up my engine, the oil presure gauge goes right to 79 PSI and stays there until it's warmed up good. IDK if that's bad or good. But is any of this a factor in choosing to run exhaust valve seals or to leave them out? I really don't know. Then there's the fact that I have a solid roller cam with .700+" lift at the valves with the stock 1.7:1 rocker ratio. So what's that have to do with the price of eggs you say? Maybe nothing. IDK. But I've often wondered if the use of solid roller lifters with a healthy dose of lift from the cam can reduce the volume of oil or the rate of the flow from getting to the heads. Can the use of high lift solid roller cams and lifters be the original reason forthe development and need for roller rocker arms, due to less oil volume or a slower rate of oil going to the cylinder heads with solid roller lifters starving stamped steel rocker arms enough that they binded up and gailled surfaces and bit the dust? Or is it more due to the higher lifts achieved with roller cams which the stamped steel rocker arms cannot accomodate? Or both? Just a hunch on my part. but if so, then would that offset the effects of the high volume oil pump being used without oil resrictors installed in the block?

Yeah yeah.. I know I'm just a crazy analyst. I can see Scott sitting back and shaking his head. But I have to do my own homework. I can't just tell myself, "well that's what this pro told me or what that pro said so that's what i did". have to know why I made the choices i did when it's all said and done.
 
#37 ·
Billy
You are spending way to much time overthinking a simple deal,,,
When it comes to seals
Brodix is primarily a drag race company so it errs on the safer side of wide open throttle operation
If this is what you do not having seals on the exhaust is usually a good thing

In street usage as Jason stated earlier in this thread if you are cruising at say 3000rpm under no or light load conditions you will likely want exhaust seals

The reason is both simple & intuitive if you give it some thought,,,

Under these conditions you have both low pressure & a "siphon" effect in the exhaust port
Ever use a siphon gun to clean something?
What happens when the air passes an orifice with a liquid in it at a fairly steep or right angle?
Same thing happens at cruise to the exhaust guide... if you develop a low pressure area under the guide the oil is going to head there unless something controls it
Enter the exhaust seal :)

To another question Brodix usually uses the exact same metal encapsulated Viton seal I have been using for longer than I can remember
See Rick's picture above, excellent shot of the seals,,,,,,,,
With the exception of extreme lift or less than normal installed spring height (shorter valves) They do not need any machining to install on any aftermarket head I know of, they have an interference fit to the guide (this means they are tight around the guide)
 
#46 ·
Mike, I didnt notice your post until now. Let me say that I'll admit thatwith some things I have enough knowledge to get myself in trouble, and somtimes no more than that. :D

Please be patient with me. I don't do this stuff for a living like you and Scott do. ;) The question for me really has to do with my application. My car will NOT just be street driven only. It is a street/strip build. And while I'm just a test N tune type of drag racer, and I've never been competitive like you were and a number of guys like Jason and others here are, I've raced other cars I've had in the past at the strip too. To give you a better idea of this build and my intention for it, It has a TH400 with full manual reverse shift pattern valvebody with a transbrake and a ratchet shifter along with a dana 60 rear that I'll be running with a spool. I'll run 30" tall Hoosier bias-ply slicks at the track, and 30" tall hoosier "DOT" drag radials and/or 30" tall Mickey Thompson Drag radials on the street.

None of that might sound impressive, and that's ok because I'm not trying to impress anyone here. I'm just trying to give you an idea of what my intended use and application will be.It's a pump gas engine sure, but with a spool transbrake, and 1050cfm Dominator carburetor too. So although I have 3.73 rear gears and a 30" tall tire, and will be using it on the highway a little, it won't be for interstate travel by any means, and it sure won't be a daily driver either. My fuel cell is a 20 gallon deal, but with a 5 or 6 MPG consumption rate, how much will I really be street driving with it? Like I said, maybe one day out of the week, and even if that day includes bringing it to work, I only reside 7 miles away from my work place anyway.

So the whole point to all of this is that I'm kinda smack dab in the middle with this car of what Jason has, and what a daily commuter or even a mild built Chevelle is. I cannot even be quick to claim that it will be more street than strip, or vice versa. But I sure don't want any valve guide wear issues a year from now nor even two years from now because I chose to run exhaust valve seals with manganese/bronze valve guides, because unlike a more serious drag racer like Jason, I am not in the practice of digging into the engine every spring before race season starts, nor do I want to be. I don't have the time for that nor the $$. Which is just one reason why I'm just a test N tuner at best, and one of the less hardcore ones at that. That's why I'm up in the air with this. This car will kind be a jack of all trades, and perhaps also a master of none.
 
#45 ·
#47 ·
My apology to the OP for stealing his thread. Maybe some things I've brought up here apply to him. But if not, I sure hope he knows since it is his thread, he sure doesn't need to be shy about chiming in here to get us back on track, if everythig hasn't already been answered for him concerning the brodix Dragon Slayer heads.
 
#48 ·
Again this is really simple for YOUR APPLICATION
My recommendation for your deal,,, & you can take it or leave it
There is no reason I can think of not to use an exhaust seal for your combo
Were I setting up your heads I would use the standard Viton seal that Brodix comes with & I would remove the little spring that surrounds the upper part on the exhaust seal only

That said if you do not have a problem with a little exhaust smoke after deceleration, coming of a hill & accelerating or on start-up................ leave the seals off of the exhaust side
 
#50 ·
I use seals with springs, seals without springs, and no seals but it completely depends on the application and customer. Extreme builds can benefit from more ex valve guide oiling and some will get no seals at all, especially blower builds but if you have a customer who can't keep a decent tune or is new to the game, more oil in the combustion chamber is NOT a good idea. He gets seals with no springs whewre maybe a professional racer who knows what he's doing will get no seals. 99% of the heads that go out of here, however, get seals just like they come out of the box. It just all depends on the application. I would never tell a street customer to run no seals. Even with the spring, the guide is not wiped 100% clean and there is still a film thickness of oil. More than enough for 99% of applications.
 
#51 ·
Scott, thank you for taking the time to comment. And what you explained compliments and brings into focus a comment that Jason previously made about "detonation prone" applications not being good candidates for extra oil being added to the mix from the lack of a valve seal. Puting both your comments and Jason's together helps me understand the bigger picture. :thumbsup:
 
#52 ·
BB-2+ on my junk has no seals anywhere- they came with them on the intake only but on a race only engine, I’ll take them off. Last set of Race Rites I tore down had seals on intake and exhaust. Never had problems with oil smoke or any sign of oil on plugs, just an occasional puff of smoke on startup (just means it still has a little oil in it haha)
 
#54 ·
I truly appreciate the info and have no problem with you stealing the thread man I learned a ton and now I know allot more about seals.

This is for a 496ci application. I was nervous with the big runner's it would be "doogish" on a street car without a radical cam. But I have the opportunity to get a set cheap. Cheaper than 1600 assembled. At that price for an american casting with a name like brodix could I really lose? Is this runner to big? It has a large combustion chamber of 119cc. This will be on 91 octane so 10.5 to 1 I'm thinking would be great any ideas for pistons? Around a 25cc dome? But my real question is will I sacrifice allot with a large runner and rectangular ports?
Hoping to make 700hp at 6500rpms. With a solid roller cam.
 
#55 · (Edited)
A lot of pro engine builders will tell you that the shape of the ports and the contours inside of them have just as much to do with how the flow and more importantly, how the air/fuel velocity will be effected as the port volume does, (if not more).

So in light of that, I don't believe that anyone can give you a valid and applicable blanket statement that a 320cc intake port volume is too big for any 496cid engine combination. Furthermore, I don't know if you're ever going to find very many pro engine builders who have a whole lot of experience with the BBC Dragon Slayer heads, simply due to the fact that they're a fairly new offering. So they just haven't been around enough yet for someone to be an expert on them and on what applications they're best suited for. And I don't believe the brodix salesmen will be able to give you specific nor definitive answers on that either.

What I'm saying is, a 320cc port volume from one head manufacture might work differently on your particular engine/vehicle combination and application than another 320cc port volume head will especially if the shapes and contoured angles inside the ports of the heads in question were different from each other. That's just a guess on my part, but it's a somewhat educated guess. I'm no expert. But if I were in your place, given the great price you say that you can get on those heads, I would go for it and experiment. I for one sure cannot garantee you that it will work great. I just wouldn't be quick to tell you that it won't, nor would I be real quick to believe anyone else who would be quick to tell you that it won't, unless they were able to elaborate and share some specifics that I am not currently aware of.

What cam specs will you be working with, and how high are you looking for your RPM peak to be? And what rear gear ratio are you using? As faras your static compression ratio target, or what it should be for pump gas use, that will depend greatly on your camshaft choice. How high up on the RPM scale do you want to spin this 496 of yours?
 
#56 ·
Transmission is tremec 6 speed, and the rear gear is a 3.90 as of right now. (Might change now that I have a 6 speed) I dont have a cam in mind yet and but I'd love to see peak at 6500 and I am confident of spinning it up to 7000 or even 7500. Also gotta figure out what carb will fit under a cowl 71 hood but that's another thread I havnt looked for yet. I appreciate your option I think I will take a chance on them I just hope it's not sluggish with the large runners.
 
#57 ·
You can also make fun of me but I hear everyone say slow numbers ain't ****. But these ones look impressive, but is it the runner size that's bad? It doesnt say anything about a down pipe for comparison. Does brodix fudge flow numbers? And is a 320cc runner to big for a 496 street only full weight car
 

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#59 ·
We would recommend a head that large for a 496 street car. Several members on here have very good running combinations. Blue66 has a 305 headed pump gas 496. At 3600# Brian's car run's 9.80's. Run that through Wallace's calc and it makes north of 700HP.

You have to keep in mind, you want a cross section that works for the average rpm the car will be in most of its life. A 320 might be fine at 7000, its worthless running down the road at 3000 rpm and punching it.

It cost less to do it right the first time.
 
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