Author Topic: Flathead V-8  (Read 142682 times)

Offline gbritnell

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Re: Flathead V-8
« Reply #90 on: January 22, 2015, 11:01:35 PM »
To complete the major machining on the block the bearing caps needed to be made, bolted on and the whole thing bored. The bearing caps don't follow normal automotive practice of recessing the block to locate the caps laterally. For more accuracy in both directions I used hollow dowels. The caps were machined and the dowels set in place, light press, and they were bolted to each other in pairs. With the accuracy of the dowels to the outside of the caps when set up I could drill and bore then in pairs. I left about .030 stock on the diameters for finishing.
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Offline gbritnell

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Re: Flathead V-8
« Reply #91 on: January 22, 2015, 11:17:21 PM »
The next step would be very critical, boring the crank holes and keeping everything in line. I set the angle plate back up and indicated it square and plumb. The block, mounted to the fixture plate was clamped and indicated to the angle plate. As with some of my other setups this required a little ingenuity. Where's a horizontal mill when you need one?
Indicating from my camshaft hole I set 0's and then moved to the center of the crank hole. I mounted the longest boring bar I had into the boring head and commenced boring the mains. From the front end I could only get the first three so when they were finished the block was rotated on the fixture plate and the rear two were bored. The fixture plate has small dowel pins installed that match the holes in the top of the block so flipping the block on the dowels should have gotten me where I wanted to be. When I got through I set the block on my layout plate and using the cam hole as my gauge point I checked the location of the main bores. The first three were dead on in both directions while the rear were accurate top to bottom but out .002 side to side. I then went through the whole boring process again starting from the front then flipping the block and doing the rear. When I got to the rear I shifted my position by .002 and finished the bores.
The block then went back to layout and this time the front 3 were still spot on and the rear two were within .0005 so I can live with that.
An accumulation of dimensions starting from the angle plate setup, flipping the block etc can only get so close.
The final photo is just a comparison of the block to a well known tool to give a size relationship.
gbritnell
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Offline gbritnell

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Re: Flathead V-8
« Reply #92 on: January 22, 2015, 11:28:02 PM »
The next pieces in the build are the heads. These like the block would require a fixture plate and multiple setups to machine. The tricky part about making the heads is that they are made in two pieces. This is to form the internal water jacket. The parting dimensions would have to be dead on because this is the only way to seal the perimeter of the head.
The upper part of the head would have the fins on one side and a cavity in the other side. The lower part of the head would have all of the bosses machined onto it. These would provide stock around all the head bolts and spark plugs. The back side of the lowers would have the combustion chambers.
The blanks were all machined to size and all the holes put in. The head bolts are 5-40 so all of the holes were drilled for clearance except the end two which were reamed .125 for the locating dowels to be used with the fixture plate.
The second photo shows the inside of the lower plate and the material left for creating the bosses.
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Offline gbritnell

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Re: Flathead V-8
« Reply #93 on: January 22, 2015, 11:29:56 PM »
Further machining on the lower plates shows the development of the internal bosses.
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Offline gbritnell

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Re: Flathead V-8
« Reply #94 on: January 22, 2015, 11:36:29 PM »
The back side of the lower plates has the combustion chambers. These were first roughed with progressively larger end mills to form the main cylindrical shape of the chambers. This was followed with a boring bar with a radius on it for the final cut. The next cuts were to rough the valve pockets. These would be finished later on.
The final cuts in the combustion chambers was with a ball nosed mill. The roof of the chamber is at an angle so using the previously machined diameter as a witness the angled surface was stepped off.
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Offline gbritnell

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Re: Flathead V-8
« Reply #95 on: January 22, 2015, 11:38:38 PM »
This is what they look like after burring, filing and polishing. The area around the valve pockets looks rough because as I mentioned further machining would need to be done to finish them.
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Offline gbritnell

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Re: Flathead V-8
« Reply #96 on: January 22, 2015, 11:43:03 PM »
The next step in the operation would be to cut the fins on the outside of the upper halves. This would need to be done before the cavity work so that they could be mounted squarely to the fixture plate.
Using a slitting saw and a lot of patience all of the fins were cut on both blanks.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #97 on: January 22, 2015, 11:48:05 PM »
The uppers were then flipped over and the cavities cut out. The second photo shows the development of the angled parting surfaces. It wasn't until if finished them up that I realized I could have achieved what I needed for the perimeter shape without having to cut and match the intricate angles. They came out ok so everything is fine. I did go back and change the drawing in case anyone in the future would like to have a go at this engine.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #98 on: January 22, 2015, 11:53:23 PM »
The final machining on the combustion chambers was to set the head up on the required angle and using a cutter with a radius on the corner go in and spot each of the valve pockets. While the heads were at this angle I went in with another cutter to finish the angled wall that connects the valve pocket to the combustion chamber.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #99 on: January 22, 2015, 11:57:43 PM »
On the top front corner of each piece extra stock was left to create the water outlet. The two pieces of the head were bolted together using the fixture plate and the angled outer wall was cut along with the outlet hole and threaded mounting holes.
In the second photo you can see the parting line between the two halves.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Flathead V-8
« Reply #100 on: January 23, 2015, 12:00:36 AM »
Here's some pictures of the finished heads sitting on top of the block.
gbritnell
Talent unshared is talent wasted.

Offline b.lindsey

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Re: Flathead V-8
« Reply #101 on: January 23, 2015, 01:00:02 AM »
Wow George...that is a lot of work since November. Thanks so much for posting the work that has been going on. You have a LOT of fans here :)

Bill

Offline Don1966

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Re: Flathead V-8
« Reply #102 on: January 23, 2015, 01:05:21 AM »
Wow George...that is a lot of work since November. Thanks so much for posting the work that has been going on. You have a LOT of fans here :)

Bill
Yep! And I am one of your biggest fan. That is just awesome George. We need to get a "sculpture of the year award". To see you carve that out of a chunk of metal is under believeable. Your still my hero!  :praise2: :praise2: :praise2:

Don

Offline ths

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Flathead V-8
« Reply #103 on: January 23, 2015, 01:14:20 AM »
George, it's hard to be able to comment rationally on your work beyond "great work" or some such platitude. And who am I to pass judgement? I've always watched what you've been making, it's so educational and at such a high level. Glad to see it back. Cheers, Hugh.

Offline gldavison

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Re: Flathead V-8
« Reply #104 on: January 23, 2015, 01:20:46 AM »
I to check every day to see what progress you have made. Can not find any words to better the comments all ready made. I am looking forward to seeing this at NAMES this spring.