Small V8

[stevehuckss396]

Hello all!

Now that the Zanesville show is behind me, I can get back to the V8. I started on some valve cages today. I made the blanks in the chuck and then switched to the collet to machine the top of the cages. I have 5 heads to trim out so I had to make 40 pieces. Yikes!

 

[1hand]

Steve looking good. I got a question, is your lathe CNC?
40 pieces would take me all month to make!!!

 

[stevehuckss396]

Steve looking good. I got a question, is your lathe CNC?
40 pieces would take me all month to make!!!

No it is not CNC. That was done by hand but i do have a DRO so that speeds things along.

 

[stevehuckss396]

Hello all!

Managed some more time so I got back to the garage.

I had to take a skim cut across the face of the cage to knock off the nub that was left when I parted off the blanks

Then the piece was center drilled and drilled thru .010 less then the diameter of the reamer.

Then the piece gets reamed to the stem size to create the valve guide.

Then the piece gets drilled to depth to create the port. I also like to cover the face of the part with a sharpie at this point. It helps me to see what is going on when i cut the seat surfaces in.

And finally the valve seat is cut in with a micro boring bar. Make sure that you use the sharpest tool you can find. The seats need as good a finish as you can get, almost mirror finish. A good finish will give the best chance of getting a good seal when the valve is installed..

One set down, 4 sets to go. There are many ways to do these things but I like to do things this way because it gives me the best chance of getting the stem hole in alignment and concentric with the seat

 

[stevehuckss396]

Cross valve cages off the list. HOLY CRAP!! there are alot of them!!

 

[steamer]

Cross valve cages off the list. HOLY CRAP!! there are alot of them!!


Ohh come on now...YOU wanted to make a V8 didn't ya! ;D

Looking Good Steve....another beauty is coming!

Dave

 

[1hand]

If I knew what a cross valve cage was.......I say they look really good! LOL :big:

Matt

 

[stevehuckss396]

If I knew what a cross valve cage was.......I say they look really good! LOL :big:

Matt

Matt, a valve cage is a valve guide, valve seat, and runner passage all in one. The cage is pressed into the head and then the intake or exhaust port is drilled thru into the cage. The fuel flows thru the head and passes thru the valve cage and into the head as long as the valve is open. The exhaust then flows thru the cage and the head to the pipes.

If you need more info, PM me and i'll send over some drawings that will clear it up further.

 

[stevehuckss396]

Cross valve cages off the list. HOLY CRAP!! there are alot of them!!

Ohh come on now...YOU wanted to make a V8 didn't ya! ;D

Looking Good Steve....another beauty is coming!

Dave

If I wanted a V8 I would have only made 16 of them!! I WANT 2!!!

 

[BlakeMcKee]

Noooooo please don't give up, this project is sooo awesome! You're doing a fantastic job! Truly inspiring for me, a complete beginner.

 

[stevehuckss396]

Noooooo please don't give up, this project is sooo awesome! You're doing a fantastic job! Truly inspiring for me, a complete beginner.

Don't panic Blake, I'll keep plunging forward!!

 

[dreeves]

Steve

What ever happened to your little cannon?

 

[stevehuckss396]

What ever happened to your little cannon?

I haven't unpacked from the Zanesville show. It's in there somewhere. Tomorrow sounds like a good day for a test fire!!

 

[stevehuckss396]

Hello All!

Spent the afternoon pressing in all the valve cages. I made a simple drive tool slightly smaller than the ID of the cage and pressed them in a drill press. I like the fact that the press fit does not need to be very tight because the cage cant be shot out by the compression of the cylinder.

I also started to make some valves. These wont go as fast as the cages.

Stand By!

 

[Lakc]

Just how tight a press fit is that?

 

[putputman]

I'm curious as how you machine your valves. It appears that you turn all the shafts to size and later machine the valve seats. I thought everyone machined the entire valve in one setup to achieve the required concentricity. I have seen enough of your engines running to know that what ever process you use has been very successful. Could you show some photos of your setup for machining the valve seats.

 

[LongRat]

^^ Ditto on what Putputman said.
Also, can you confirm those cages are brass (or are they bronze or something else?)
How are you going to achieve exactly the same angle on the valve as you have in the seat, all questions about concentricity aside? I have seen in several places it mentioned that model engine valves are not 'ground-in' to their seats. Why not do this? Is there something that would stop it working?
Anyway beautiful work. Keep it up Steve!

 

[stevehuckss396]

Just how tight a press fit is that?

The hole was reamed to .250 and all the cages were .2503 - .2508. When I press from the top I make them .001 - .0015 over size but they press hard for such a tiny piece. These slide in much easier.

 

[stevehuckss396]

Put & LongRat

First the seats. When I cut the seats I set the compound to 45 degrees. I always make the valves after, and cut the angle on the valve having never moved the compound slide. This way I know that the angles are exactly the same. If I were to grind the valve I cant be sure the angles are exact using 2 machines.

As for concentricity. When I cut the seat I will hold the valve stam in a collet. I did not spend my money on a cheap chinese set of collets so the accuracy is better than the cheap ones. I'm confident I will be inside .0005.

There are many ways to do it and this way works for me.

 

[stevehuckss396]

Oh sorry! Yes they are brass