Milling a Snyder's head

[Brian T]

Brian,
I have no idea what Snyders does, but you should talk to Larry about how his heads were made so you would know the real story. (I have).

Heads were not 'seasoned'. Cast iron (and steel) with critical machining or tolerances is heat treated and stress relieved as part of machining processes, as I have indicated in earlier posts. Larry's heads were heat treated and heavy shot-peened for stress relief as well.

I still maintain that clamping strategies and practices (and programming errors) are the primary cause of dimension issues. Not 'seasoning' or lack thereof.

I am also involved in the design and buy off of quite a few large Class A automotive injection molds each year.
Heat treating and stress relief is standard mold machining practice in achieving final dimensional machining. "Seasoning" is nonsense.

My post #53 was not meant to demean Larry or Snyders, it was that you stated, post #30 (Where do these theories come from) well it was the norm in the early years, this I learned from my best mate who was an apprentice at the Dagenham plant in the 60s.
I do believe that better casting practices and materials have done away with seasoning castings, stress relief and heat treating, saving much real estate and labor.
Your mention of Dagenham on your web site brings back memories, they employed close to 50.000 at one point, there are now less than 3.000 employed building over 1 Million diesel engines per year, now Ford vehicles are built outside the UK, I think Henry would be rolling in his grave.
Regards Brian. Thanks for your web site.

 

[Y-Blockhead]

My experience is the heads were not the same size as the block exposing much gasket around the edges. Also the stud hole bosses are too thick

Do all Snyder heads look like this? This head has ~1/16" - 1/8" gasket exposed all the way around. Why didn't they just make it bigger so it would look like a stock head as they advertised?

 

[Brian T]

Vince, you totally MISREAD my post---sorry i upset you. Maybe someone else
will understand.

 

[CarlG]

Do all Snyder heads look like this? This head has ~1/16" - 1/8" gasket exposed all the way around. Why didn't they just make it bigger so it would look like a stock head as they advertised?

Don't know if you can tell much from this picture, but this is a Snyder 5.5 head on my engine, and it fits/looks just like the original police head that was on there when I bought the vehicle. There is no gasket overhang anywhere.

 

[hardtimes]

Don't know if you can tell much from this picture, but this is a Snyder 5.5 head on my engine, and it fits/looks just like the original police head that was on there when I bought the vehicle. There is no gasket overhang anywhere.

X-2, only mine is a 6:1 !
Hmm, nice exhaust maniford !

 

[40 Deluxe]

Thanks for using some logic and reasoning instead of repeating tiresome old myths. I might add: this alleged seasoning exposes the castings to temperature swings of maybe 100 deg. from winter to summer whereas in operation it is double that, up to 200 deg. and more in localized hot spots. My question for the "seasoners": Is a 100 deg. swing going to affect the casting the same as the 220 deg.+ swing in real life? I think not, so any seasoning is ineffective.

 

[40 Deluxe]

Question for the machinists: What is the correct way to clamp a head or block in a mill or broach to avoid distortion?

 

[DaWizard]

That is a good question, usually it is done magnetically with a mill magnet, or grinder magnet, that way nothing gets in the way.

 

[Brian T]

There are no myths regarding seasoning cast iron, It was done for years, maybe not so much now days, however there's is plenty of info on the web if you care to look on why it is done, what I see here with the non believers are pseudo engineers that know little, but have all the answers, castings were seasoned before machining and put to use, not afterward, do some reading before making opinions in a rude manner.

 

[BRENT in 10-uh-C]

That is a good question, usually it is done magnetically with a mill magnet, or grinder magnet, that way nothing gets in the way.

Not true. They are mechanically clamped. For example, how do you propose to magnetically clamp a cylinder head that is inverted??

 

[George Miller]

Question for the machinists: What is the correct way to clamp a head or block in a mill or broach to avoid distortion?

It all depends on whether it is new or used, and what you are going to do it on.
To mill one that was already done, I support from the head bolt holes, with the head up side down on the mill bed. I use adjustable supports. Indicate the head surface. Then clamp the head through the spark plug holes. Then check the head again to make sure I have the same reading. If you do not do it some what like that, and mill it, when you release it it will not be flat again. It also is important to use a milling cutter or fly cutter that is wider than the head. If not you are going to have a step in your work.

Remember metal is elastic. It will move when you mill it and so will the cutter.
We used cast all the time where I worked in a manufacturing plant.


The best head I ever done, I did on a Blanchard grinder after work one day.
came out perfect. But I do not have one of those laying around.

If the head has a long curve that is a reasonable amount, lets say .005, it will flatten out when bolt on to the block. What will hurt you is a short cure or groove.
Not responsible for your results.

There are many grades of cast iron.

 

[1931 flamingo]

OR an alluminnium one??
Paul in CT

 

[George Miller]

Question for the machinists: What is the correct way to clamp a head or block in a mill or broach to avoid distortion?

Should have added this to my other post. The block is easy, just bolt it down to the bed. Then take as little as possible. I do not like to mill the top of the block. I find it is not necessary very often. Then we hope that a lost sole did not mill the pan rail.
Because that is your base line for your dimension. We need to keep the milling to only when it is really needed. I know no one will lessen, but a lot of time your shop that does the milling might make them worse than they were.

Forgot to say the cutter has to be flat to the milling table. if to is off you will have nice curve in the head. It will be low in the middle of the head all the way the the other end of the head.

 

[George Miller]

Makes me want to cry. that is not needed in my IMHOP. I hope he does not move the center line of the crank up. If is it will be a little tight with the gear mesh. My home made boring bar locates from the pan rail and the cam shaft bore. If I used a block like that My crankshaft would no longer be square with the bore. Of course I guise that does not mater to some. I just did a engine that had a .020 over cylinder bore nice block right. Well had to go .080 over to straighten the bores. It just made it. Hard to say how they get this stuff to work.

Like you said before, the cylinder bores are all over the place. I think they like to locate in top of the cylinder were it is worn, then they do not have to bore it so far over. I have always located in the bottom, but if some poor lost sole beats me to it you have new set of problems.

 

[old28]

It was posted in #6 that if you take .060" off 5.5 head it will be a 6.1.

Will .060 off a 6.1 head make it a 6.7?

Will .060 off a 7.1 head make it a 7.7?

 

[inex01]

Hiker,Ora builds a good motor.He did the babbiting,set the crank and installed the pistons and rods.I did everything else.I have about 7000 miles on the motor and does not use a drop of oil or leak any oil.I'm very satisfied with the finished product.He may be a little pricey,but does top notch work.It drags my 30 Tudor around with no problem and will do 55mph all day long.

I also had Ora do my engine three years ago on my 31 Town Sedan and now has 15K on the engine, it has no vibration and can run all day long at 50 or 60 when I engage my Mitchell. My Friend had Ora do his 29 Sedan and that engine now has 60K on it, not burning oil and runs strong. Money well spent