The fog clears... Edelbrock head mystery solved.

First off,let me start by saying this is not a bash on Edelbrock...it's a thread meant to educate you on what your buying, and why things cost what they do. I use properly prepared Edelbrock heads often, and we have no issues with them. The previous thread on valvetrain setup is just part of the process needed to ensure the best result from your purchase.

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For those of you paying attention, you have continually heard me and others telling you that you have to take new Edelbrock heads out of the box, and size the guides and the touch up the valve job.

It's not uncommon for the the valve seat not to be concentric with the valve. Picture two circles.. one being the valve, one being the valve seat. For the valve to seat properly, the "circle" created by the face of the valve must match the circle that the seat makes.. exactly. In both location and out of round.

That's simple to understand.

That is never true of Edelbrock heads, as they come out of the box. I have personally see them vary .010 and have had calls where another shop measured them, and found then to be up to .012 out of spec. Rarely do we see seats that don't need to be re-cut.

Keep in mind, the ideal concentricity spec is zero........ most performance machinists will allow up to .001 Factory tolerances can be as much as .002 for every 1.5" of seat diameter.. so our stage 1 intake seats should have a worst case reading of just shy of .003 (For a sloppy production tolerance, not high performance grade work)

This morning, I am sitting here drinking coffee, checking my emails and internet stuff. I come across this video on facebook, linked by a guy in one of my engine building forums....

Watch it, it shows Edelbrock making a SBC cylinder head, from casting to box.

There two fundamental cylinder head machining processes missing.. skipped for the sake of reducing cost per piece... see if you can spot them. (you engine builders and machinists will see it right away, so don't give it away, let's see if our customers can notice it.

The missing processes are exactly why you need to spend $200-300 bucks on your brand new shiny Edelbrock heads.

I, and my peers in the aftermarket assumed they just did "production" type work.. turns out they don't do it at all!!


https://youtu.be/M8cOVp2kjRg

JW

 

Ok, now I fell dumber than normal.

What aren't they doing?

I've been around machine shops, but never a foundry.

 

I watched the video, I got the impression, actually always had the impression that Edelbrock is interested only in the Chevy market.
When they came out with the 455 heads, I got the impression they hurried them to market " just use the Chevy type rockers"
I wonder if the Chevy aluminum heads have that issue with the valve jobo No:

 

Yes, all Edelbrock heads have these issues, regardless of make.

And don't feel dumb... remember, Edelbrock allowed this to be shown to the public, because they know the vast majority of their buyers will be impressed by the CNC machinery and the CMM inspection... notice how many times accuracy is mentioned.. and that they won't notice the omissions.

Now to be fair, Edelbrock does not consider them omissions, they consider their process to be proper mass production manufacturing.

As with all mass production facilities, they "factor in" an acceptable failure rate on their products.

JW

 

Fun video. Really shows what it takes to be efficient and cost-competitive. Only a few people are using tools on the parts. Most of their people are servicing the machines. Must have a big engineering department for all the fixturing and programming. This where your gearhead kids can make good money.

Ya gotta wonder if the video skips some steps. They don't show lapping the valves or honing the guides.

We'd get more supplier love if the Buick market was more than %5 (?) of the Chebby market. The video really illustrates that once it's set up that last part rolls out for little more cost than the raw materials. That first part cost a lot ($500K?) for all the design work, fixtures and testing.

 

Yet another reason to leave them sitting on shelves and BUY FROM TA PERFORMANCE!!!!!!,, I said from day one there is NO SAVINGS with them heads, just availability, patience is necessary in all things, everyone is in a rush to do everything, but I will not compromise quality in favor if time

 

Same answer as Larry - They don't machine the seats relative to the valve guide location. That would require two CNC machine setups. So they just pound the seats in and the concentricity tolerances are the total of the tolerances between the machined valve seat area in the aluminum head relative to the valve guide plus the concentricity and size tolerance tolerance in the hardened valve seat itself. Its a production-friendly process but at the expense of minimizing the tolerance stackup.

 

Did they skip lapping the valves? Is that still done in this day and age? It sounds like they drop in the valves after they install the seats, install the springs and package them. Whatever steps they missed is this unique to Edelbrock or do other manufactures such as Trick Flow, Dart, or even TA Performance, omit these steps on their assembled heads. That reminds me of when I purchased my Stage 2 heads back in 2011. I ordered them through Scotty G and he recommended I have them shipped bare and let him do the assembly. I'm assuming he wanted more control over the quality of the assembly.

 

And the CMM (measurements) are done before the seats and guides are installed? They should be checked after assembly..... Like you said, tolerance stackup! They at least need to be machined after assembly to insure guides and seats are concentric!

 

I've only machined and assembled a few engines, and I've never done any head work.
I'm also responding to this thread without reading any of the other responses.

Lackadaisical sprinkling of lube on the seats before hammering them into place.
Used an impact to tighten studs instead of a torque wrench.
They didn't cut the valve seats after they were hammered into place.
They didn't lap the valves.
They didn't send the head back to QC for final inspection before shipping.

[Quote TITAN] MANUFACTURING IN 'MERICA, EVERYTHING FROM THE PRECISION SAND TO THE MACHINED CASTINGS BOOOM [/Quote TITAN]

 

So many times I have staunchly supported using TA cylinder heads over EBrock only to be chastised, called biased, etc. This is only one reason of several that I have done so. Everyone knows I have called TA out a few times when I felt it was warrented, but No doubt TA offers the best heads hands down for our buicks. The lowest price isnt always the lowest price, or the best value. Thanks for posting.

PS: I have personally visited the TA facility and witnessed first hand the testing and rechecking of their machining processes before an item is released. Made me not want to go into manufacturing!

 

I'm just happy I saw the video on FB this morning too.
I don't know enough about this to comment accurately, however,
to see how the head was made, I would believe this is best possible for a Aluminum head.
the video looked pretty good to the novice eye. (me)

 

Larry picked up on it first, then several of you saw it.

They do not size the guides after install, nor do they cut the seats based on the guide center line. One could argue the two most important processes, regardless if your making new or refurbishing used heads.

They pound in pre-sized guides, and pre-cut seats. Then they slap the head together. Note they did not mention the country of origin of any of the parts.

TA does in fact final size the guide, after install, which is the only way you can hold a precise tolerance. They then cut the seats based of that guide center-line, the only way this can be done with any accuracy.

At TSP, we buy bare castings from TA, and then start with honing the guides and cutting the seats..

We actually lightly touch every valve with the valve grinder, one would be surprised at how many new valves are not perfectly round and straight.. TA may do that also, I don't know..



Next time you price TA and Edelbrock heads, call your local machine shop and get the price to disassemble the E heads, hone the guides, and re-cut the seats.

Then you will have a proper price comparison.

This video makes it crystal clear why we see exhaust guides with .001 clearance, bent valves, and seats with two and three times the concentricity allowed.

I cannot state this strongly enough: IF YOU TAKE EDELBROCK HEADS OUT OF THE BOX, AND BOLT THEM ON, YOU ARE RISKING DESTROYING YOUR ENGINE.


That is not an exaggeration. A stuck valve will get the head broken off by a piston, and at best, severly out of round seats cause poor valve sealing, at worst, the valve breaks.

Do a search on the internet of "Edelbrock sent me a check to fix my engine" after a valve broke in one of their heads. They factor that cost into the overall program, what they don't factor in is your beautful new engine, that will never be the same, short of starting over.. they give you money to "fix" it..

My head guys refer to Edelbrock heads as "nice cores to start with".

Be a smart, well-informed consumer.... to do that, you need all the information.. that's at least part of the reason your here.

JW

 

Moral of the story...You get what you pay for!!! We all knew that for many years..

 

Before people get too wound up, I don't believe they are really showing everything.
This is definitely the TV version "fluff and buff" (Oooooh, C...N...C... :laugh: )
Even the sequence shown of the Makino's tool change and rapid feed to the work pallet was slowed way down for dramatic effect.
If they have errors or defects that you aren't seeing, it's in the process and mgmt. They have full capability with that equipment to produce any level of quality.
That being said, I've never been impressed with the finished product.
All I can say is, "Yep, it's an aluminum casting".

Industrial espionage and intellectual property are still HUGE concerns, and consultant time is expensive to make those types of facilities profitable...even ignoring the comments about skipping steps.
Notice they showed mostly foundry info and not machine technology?

There are some really insightful customers here though, and I've been involved in quite a bit of this, so I'll really limit my comments.

Lapping or honing isn't normally done anyways. The idea is to get a finished hole or features with the machine's tool.
Lapping is done only to verify concentricity, and it's messy to clean off. Ink does the same thing. Not appropriate for a modern manufacturer.
Those machines are more than capable of producing any type of accuracy or surface finish needed.
No matter what the facility, that's how seats are installed. Maybe not lube dumped though...
They are pounded in and always require cutting afterwards.
The angle machined into the seat is never intended to be finished, it's solely to save the manufacturer time.
If needed, I'll comment on this later.

It isn't logical that a couple of guys would assemble a pair of heads at a time NOT in an assembly line area, and NOT with high tech equipment.
An example of something probably just done for the camera would be the sequence shot showing studs installed with an impact.
OEM's such as Honda require the use of a really expensive (ergonomically correct) air wrench that records final torque in a computer, hooked up to the fixturing in a way that if torque is inadequate, you cannot remove the part from the fixture.
Torque determined after testing, not an arbitrary value given based only on thread size or engagement.
Sounds expensive until you calculate the cost per part to be pennies.
I can't imagine them spending so much on machining centers, automation and robotics just to lose it back at assembly, so that part stands out as 'probably not accurate'.

Keep going, I won't spoil the the fun

[I left this hanging for a while, prior to Jim's last post]

Sad that they wouldn't spend more than a few dollars per head in machine burden time to Serdi the seats after assembly (which I don't think they are really showing what they are doing) The cost is roughly $5/head or less in a facility like that.

 

I had to chime in on this one... I've got first and second hand experience with the Makino CNC cell they show. I worked on those machines about 16 years ago when we did the turnkey for Edelbrock at Makino. Trust me, assuming they have taken even reasonable care these machines they are more than capable of holding any tolerance you should see in a cylinder head. As mentioned above though, driving in the seats after the machining and assuming the hardened seats are concentric along with all the machining and about a dozen other variables I can see stacking up a few thou. of error in pretty short order. Nothing will fix a bad process.... Measuring the assemblies and components on a CMM only means you are checking the parts. We have no idea what the actual tolerances are from nominal that Edelbrock expects to hold.

 

Not to mention worn guides on one side due to the valve slamming down on a unconcentric valve seat!

I happened to check the T/A oversize valves at work that I installed, and found the seat contact area to be concentric to the stem by .0001-.0002. Needless to say, I didn't bother to regrind them with those findings, but I was ready too if needed!

 

When bare E/B heads are purchased rather than assembled ones, are the guides already to "size" and need to be either replaced or plus .001" or a plus .002" valve stem valves need to be used?

I had to replace the guides in a set of new bare Dart heads so they were sized properly to use standard size valve stem valves, is this the case with the E/B heads as well?





Derek

 

I know the comments come crashing in all at once but way back, I set up an assembly line within a factory to correct a mass quantity of mis-machined new castings. (I've been involved with much more than this, just giving an example)
They aren't showing everything.
It's nothing to put a Serdi or Peterson in the line and assembly-line-style cut seats.
Those machines are insignificant compared to the cost of what they are using there...
EVEN with a Serdi operator, the plant still deals with seats not fully driven in that move after running, a hurried operator cutting OOT seats, etc. etc.
One guy with one machine can cut 80-100 heads a day and still have time to do a cross trained job adjacent to his work area.
The machines, however...are very 'feel' based.
The inspection processes could easily catch and prevent any of this, and that's the shame here.