Flathead V-8

[maury]

George, great job fitting those inserts. I was just wondering, why would you even need to bother with the solder? From what I understand, there is no compression pressure on this part. I use the blue automotive silicon gasket compound on my engines, seems like that would seal anything that needs to be sealed in the manifold.

maury

[90LX_Notch]

Interesting Maury.  The Gray RTV sets up real hard. It might something for George to consider.

-Bob

[dsquire]

George

You continue to amase me. Thanks for the fine work. 

Cheers 

Don

[gbritnell]

I just got home from Florida so it's time to get back on the engine. There's so many things to do but I wanted to take a break from the aluminum for awhile so I started on the camshaft. I had made the step-off chart before I left so the tedious part of calculating numbers was done.
The cam diameter is .531 so I cut a piece of W-1 drill rod and turned it to length. It needed to be polished down about .0005 to get a nice fit in the block which had been reamed to size. Next up was to chuck it in the 4 jaw and get it running true to center drill the ends. The next step was to plunge in with a .032 necking tool to establish the lobe locations.  The main bearing areas were cut with a small radius to form the oil groove.

[gbritnell]

I set up my H/V rotary table and indicated it square to the table. I then mounted the home-made tailstock and lightly clamped it in place. The cam blank was mounted in the chuck and indicated true close to the jaws. I then indicated along the length of the blank and tapped the tailstock over until the cam blank was parallel to the X axis.

[gbritnell]

Ok, time to dive in and start making chips. I used a new .25 dia. end mill so I wouldn't have to stop and change cutters mid job. Following the step-off chart I started on the first lobe. There were 8 initial cuts to form the nose radius and then the rotary table was cranked 2 revolutions per cut. (8 degrees) This is one of those jobs where total concentration is a must, unless you want to make 2 of these things.

[gbritnell]

All the lobes were cut to shape and the blank was then put back in the lathe to open up the spacing to the proper dimensions between the lobes. The reason I didn't do this the first time I had it in the lathe was because I wasn't sure how much the blank would chatter when being milled. As it turned out the vibration was minimal so it could have been done earlier.
The next step was to file all of the steps smooth. I used the same technique on the cam as I do on the casting shapes, I blue it with a permanent marker and then file till the blue disappears. Once all the filing was finished I polished all the lobes with fine emery cloth and then buffed them smooth and shiny. The cam journals were also buffed smooth.
gbritnell

[Greg Haisley]

Beautiful work! 

[vcutajar]

Welcome back George.

I assume you used drill rod for the cam shaft because you intend to harden it.

Vince

[KB]

Amazing skill and patience, yielding a beautiful result.

[gbritnell]

Hi Vince,
I use drill rod for all of my camshafts but they are left unhardened. I would suspect that trying to harden it would induce some warpage and without a means of grinding it would be junk. When using a cam with flat tappets like this one the lifters are also made from drill rod but they are hardened and polished. Over the years I have noticed no noticeable wear using this combination.
gbritnell

[ColH]

Hi George

 Good to see you back at it - I was beginning to have withdrawals. Hope you had a nice time in Florida.

Col

[b.lindsey]

I am still following along George, got caught up with the more recent posts this afternoon. As impressive as always I  must say.

Bill

[Don1966]

Gorgeous work George, your still my hero. 

Don

[Myrickman]

George, learning my way around this forum...who is doing what. Wow, functional art! Another super thread and build to keep tabs on.