BBM CNC Program?????

[ArtZarateJr]

I'm still not sure what to say. At $4,500 for the pair.....

[My427stang]

What are you unhappy with? 

Did they provide a flow sheet?  The price is high indeed

[pbf777]

        I'm assuming that the O.P. is just not impressed with the sum of material removed in the "CNC Porting" presenting the sums of as cast surfaces remaining? 

        The take from this, as from the manufacture's point of view, I am of the impression that they don't seem to be demonstrating very much confidence in the accuracy of the casting work and are afraid that anything more aggressive in the way of porting work might lead to an unacceptable sum of trashed heads?  But even if one isn't impressed with the results of this CNC work, if one were to want to go farther in the porting endeavor there is significant value in the location references that the scrubbing does provide, just not sure of the monetary value?   

        Of course, it could be that they consider the port to be as nearly 'perfect' as cast, and the "CNC Porting" is being addressed as just an extra charge window dressing option for those whom demand it?   


        Scott.

[My427stang]

I assume you are right, but asked just to be sure

It doesn't take much sometimes to gain even up to 40 cfm without changing a port shape, but would be interested in the numbers to see if it did well on these heads

[Jb427]

I think Blair Patrick is doing all BBM heads now there was a post not that long ago that Blair said he is doing BBM's cnc program and preping of bbm heads. I am not sure if Blair did my heads it was a few years ago now but mine look the same and flowed 350cfm @.700 on a 4.250 bore I got my heads flowed in Australia

[1968galaxie]

I certainly would trust Blair with anything he did to the heads.
He has more experience with race winning FE's than most.

JMO

[CaptCobrajet]

The heads are cast with throat sizes that will accept 2.09 and 1.600 minimum valve sizes.  I have different programs for various valve sizes.  We run the cnc through all intake ports, on every head that is sold, just to touch up the port and keep the product consistent.  There is no worry of “core shift” when we do that.  There are areas that do not need to get any bigger, or be shaped any different.  Making the hole bigger isn’t necessarily better.  All of the transitions from cast to milled are blended nicely.  The places that need to be bigger, are such.  A lot of testing went into the port shape and design.  The cnc work that is done is done with results in mind. Making it bigger just so the program cleaned up completely would actually hurt more than help.  The poster might want to put those heads on an engine and test them before he gets too bent out of shape.  Might be surprised by the results if the rest of the engine is up to it.  He failed to mention that the valve job is perfect, and the blending from the seat insert to the cnc milling is also blended perfectly. 

To the poster:  If you are not happy, and you want to return the heads directly to me, I will refund your money in full, provided they are unscathed.  You will not be able to buy a better head for the price paid with better quality hardware, with a Medium Riser port location, than the head you just received.  I’ve been doing this a long time, with some modest success here and there.  That is high quality stuff you have there, whether it is obvious to you or not.  There is $800 worth of tool steel retainers, machined 10 degree locks, PAC solid roller springs, locators, blue Viton seals, shims, etc. included in that price you referenced. Again, if you want to return them, get in touch with me directly.

BP

[1968galaxie]

Thank you Blair!

I have seen similar comments from heads that my brother ported. The customer complains that all areas of a port are not "finished".
Many do not realize that some as cast ports are already too big in certain areas - hence not being touched.

[ArtZarateJr]

The heads are cast with throat sizes that will accept 2.09 and 1.600 minimum valve sizes.  I have different programs for various valve sizes.  We run the cnc through all intake ports, on every head that is sold, just to touch up the port and keep the product consistent.  There is no worry of “core shift” when we do that.  There are areas that do not need to get any bigger, or be shaped any different.  Making the hole bigger isn’t necessarily better.  All of the transitions from cast to milled are blended nicely.  The places that need to be bigger, are such.  A lot of testing went into the port shape and design.  The cnc work that is done is done with results in mind. Making it bigger just so the program cleaned up completely would actually hurt more than help.  The poster might want to put those heads on an engine and test them before he gets too bent out of shape.  Might be surprised by the results if the rest of the engine is up to it.  He failed to mention that the valve job is perfect, and the blending from the seat insert to the cnc milling is also blended perfectly. 

To the poster:  If you are not happy, and you want to return the heads directly to me, I will refund your money in full, provided they are unscathed.  You will not be able to buy a better head for the price paid with better quality hardware, with a Medium Riser port location, than the head you just received.  I’ve been doing this a long time, with some modest success here and there.  That is high quality stuff you have there, whether it is obvious to you or not.  There is $800 worth of tool steel retainers, machined 10 degree locks, PAC solid roller springs, locators, blue Viton seals, shims, etc. included in that price you referenced. Again, if you want to return them, get in touch with me directly.

BP

Thank you for chiming in. I appreciate that.

First I apologize for being absent. There's a lot of work to do around here.

Second I agree with the blending of the valve job. Very nice work indeed.

Third....my ignorance is partly to blame here. I should have spoken with you directly. I feel that I would've received what I asked and paid for.

I'll have to pick this back up a little later, but I'll leave you with this.

Why does your head detach at 0.600? 298 at 0.500 is screaming in there and 329 at .600 wow and done.....flying over the short side and beating right into long side wall. What's the fuel gonna do??? 😬

I'll touch on some more later, and relax. I'll keep the head I was sent, but I would've liked what I asked for. I'm not building the engine I want to anymore....I'm building what I have to. The supply and demand is a factor. The salesman.....smh.

[CaptCobrajet]

You must be flowing the head with some sort of radius entry just right against the intake flange.  You will not get the whole picture that way.  The intake port on the FEis very short, and on a couple of angles at the flange.  All other heads on the planet have a longer port.  You should flow an FE head with at least two inches of extension, properly sized and shaped for the port to represent that piece of the port that is attached to the intake manifold.  Then put your normal radius entry on that.  The 30 cfm jump from .500 to .600 looks a little odd to me.  I usually see 315 on that particular port on the intake at .500, and low 330s at .600.  All benches and methods vary wildly throughout the industry, but your “detached” comment isn’t accurate if you flow the head more like it is represented on the engine.  Also, that valve is not parked at the measurement points in a running engine.  The mixture has mass.  I want that mixture excited and moving fast at .550-.600 lift, like a semi truck wide open down a hill.  The piston is changing directions and working against you after BDC.  I want that mass to run right through the stop sign at the bottom of the hill….like the truck that can’t stop.  I make it move fast at .600 on purpose.  If the mixture has no momentum it will stall.  A big .700 or .800 lift number on a bench won’t help your .660 lift if it is lazy coming to the party.  Enough theory………it usually works for me.

The person who bought those heads supplied cam specs.  .683 before lash.  I finished the ports and used a valve job to maximize flow between .600 and .625 lift based on information supplied by the customer.  The information supplied is what I used.  If that is your lift range, which was supplied to us, you should put that head on and run it.  It will work really well if you have the right combo above and below it.

I will post these folks some dyno info on the various new BBM head combos, on various engine sizes, as we get them through their processes.  I am sure others will circulate info on the new heads when they use them.