Author Topic: T head engine by Brian  (Read 18674 times)

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #45 on: July 26, 2021, 12:47:12 AM »
And as the sun sets into the golden west, two valves are finished. The second valve went quicker than the first, but with that extra long stem both valves required more attention than I have ever given to a valve before.

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #46 on: July 26, 2021, 09:34:27 PM »
Today, the crooked carb adapter and exhaust have been straightened. I hunted around in my box of assorted springs, and come up with two likely candidates for valve springs. I made two brass stepped bushings which fit over the end of the valves (which are shown in place with "handles" still in place) and retain the valve springs when they are compressed. I still have to cross-drill the ends of the valves for 1 mm pins that hold the spring retainers in place. Not a whole lot to show for a days work, but then I didn't work on the engine most of the day. It was a beautiful 88 degree sunny day here today, and I didn't feel like doing much!!

Offline Kim

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Re: T head engine by Brian
« Reply #47 on: July 27, 2021, 05:45:39 AM »
It was a beautiful 88 degree sunny day here today, and I didn't feel like doing much!!

That's funny... when it's 88 here, it's stinkin' hot!  And I also don't feel like doing much!  :Lol:

Enjoying following along with your T-head build, Brian  :popcorn: :popcorn:

Kim

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #48 on: July 28, 2021, 12:23:35 AM »
Kim--the last two years my arthritis is so bad during fall and winter that I dearly love this hot weather. I wouldn't want to have to do any work in it, but my old bones don't ache when the weather is hot like this.---Brian

Offline Kim

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Re: T head engine by Brian
« Reply #49 on: July 28, 2021, 12:37:23 AM »
Well, I'm glad you enjoy the heat, Brian.  Looks like we'll be getting a lot more of it going forward! :)

Kim

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #50 on: July 28, 2021, 01:28:04 AM »
Today was a semi quiet day, finishing up little things. The valve seats were cut with my special George Britnel tool. (Actually a larger version of my original tool for valves with 1/8" stems). The valves were lapped into the seats using first 320 grit paste, then 400 grit paste, and finally with 600 grit paste. Then the "handles" were cut off the valves because they were no longer needed. A bronze endcap for the exhaust system was turned, drilled and loctited in place. I found that I had screwed up the design of the valve cages, by not leaving a "tit" of material on the end of the cages to register the springs on. I fixed the design drawing, but rather than remaking the valve cages I turned a couple of "add on" bushings to the end of them with a cavity on one end to fit the o.d. of the valve cages and a cavity on the other end that the o.d. of the valve spring would fit into. The rods hanging out the end of the valve cages are temporary, just in there overnight to ensure correct positioning of the bushings until the loctite sets up. If you don't have this spring locating feature, the spring will ride against the side of the valve stem and cause problems. Tomorrow I will probably make the tappets. I picked up a piece of 01 steel yesterday, long enough to make the tappets and the cams from. ----Both tappets and cams will be flame heated and quenched in oil to harden them.

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #51 on: July 28, 2021, 07:01:13 PM »
Today was tappet day. Doesn't look like much, but these were all machined from a length of 3/4" diameter 01 steel. They will be flame hardened and quenched in oil, as will the cams when I make them. The cams are almost the only remaining part of the valve train to be machined.

Offline Roger B

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Re: T head engine by Brian
« Reply #52 on: July 28, 2021, 07:08:48 PM »
Still following in the background, another interesting build  :ThumbsUp:  :ThumbsUp:  :wine1:
Best regards

Roger

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #53 on: July 29, 2021, 12:01:30 AM »
The tappets have been heat treated and assembled and installed in the bushings in the tappet guides. The valves are ground and cut to length, assembled with springs and keepers. I have a couple of sewing needles installed as temporary cross-pins, until I see how everything fits together. I may have to cut one coil from the springs, but I won't hurry to do that. They can always be shortened later. I'm very happy to see that the valve stems line up properly with the tappets.

Offline Art K

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Re: T head engine by Brian
« Reply #54 on: July 29, 2021, 03:09:15 AM »
Brian,
You're making good progress, looks like you'll have it running any time. I have to say that I've had a t head engine percolating in the back of my mind. Based on the straight 6 Pierce Arrow series 33 engine. haven't gotten past the thought stage as there is a serious lack of information about it out there.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #55 on: July 29, 2021, 11:21:52 PM »
Today I have prepared a piece of 01 material to make two cams from. The length of the piece is determined by the depth available in the three jaw chuck which is attached to my rotary table. The center diameter is determined by the maximum bore inside the chuck. The diameters at the ends are equal to twice the 0.382" dimension on the drawing, which determines the size of blank to cut the cam from. The material is just long enough to grip in the three jaw chuck with 3/4" of material stuck up above the chuck jaws. The cams will be .688" long, which should keep the cutter above the chuck jaws. I go a little bit crazy every time I make a cam, because I don't do it often enough to remember all the set-up steps. Attached are the picture of the prepared stock, a drawing of the cam, and a model of the milling machine cutter and the cam in their relative positions on the milling machine. The milling cutter will be turning clockwise, and the center of the mill spindle will be offset from the centerline of the rotary table chuck by 0.346" and 0.200" which, as you will notice on the drawing is the centerline of the flank radius. This should give the cams being cut a 99% chance of matching the drawing. Every time I do this, I write myself a bunch of notes on how to do the set-up, and then read thru all of my notes before I do it again.


« Last Edit: July 29, 2021, 11:37:26 PM by Brian Rupnow »

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #56 on: July 30, 2021, 05:44:10 PM »
Today was not a good day. I fought the cams and the cams won. The cutting tool slipped in the holder. The stock slipped in the chuck.
I was overwhelmed by a truckload of zombies. I was bitten by a rabid bat. I was stung by a murder hornet. My day has turned to crap.  Perhaps a different approach to making cams will be investigated.

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #57 on: July 30, 2021, 07:32:45 PM »
Okay, maybe it's time for some wheeling and dealing. Any of you CNC guys out there want to make me a couple of cams as shown? Surface around outside has to be good quality finish and 3/8" center-hole must be reamed to 3/8" finished size. There are other holes to go in but I can do them later, and I can do the hardening later.  In return, I will send you a complete set of detail drawings to build this engine.----Brian


Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #58 on: July 30, 2021, 11:13:21 PM »
A kind gentleman in the USA has volunteered to cnc the cams for me. I am moving ahead working on the crankshaft.---Brian

Offline Brian Rupnow

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Re: T head engine by Brian
« Reply #59 on: July 30, 2021, 11:28:11 PM »
I like to make my one piece crankshafts from 1144 stress proof steel. It moves very little while machining, far less than mild steel or cold rolled steel. The only catch is, it is not available in flat-bar. This means that you buy a round piece and machine a flat-bar from it, before you can actually start to machine the crankshaft. I always start by machining one side off in the milling machine, so you have a flat reference to machine or saw away the other side. In this case, I had to machine to a depth of 0.531". Next step will be to saw off the other flat, or flip it over in the milling vice and machine away the other side. Milling is probably as fast as sawing, because my sawblades are always a bit dull, and you end up having to machine that sawed side anyways to get it flat. My mill seems comfortable with 0.015" depth of cut, so that is a lot of cranking back and forth to take off 0.531".

« Last Edit: August 02, 2021, 11:27:44 PM by Brian Rupnow »

 

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