MadModder
Gallery, Projects and General => Project Logs => Topic started by: OKTomT on May 26, 2014, 07:10:34 PM
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I am starting a new engine build. its going to be a v twin this time.
This is going to be a scratch build just make it up as I go.
my goal is to make this engine better quality then the last one. lighter, more cc, more rpm,less oil leaks, and keep the vintage look.
Fill free to give advice about my construction ideas.
I have started building the crankshaft. Here is a picture of it.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2059_zps1d8fe217.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2057_zpsc9fde4b9.jpg)
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Awesome! I am going to watch this one with anticipation!
Eric
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Oh boy, this is going to be good! :coffee: :coffee: :coffee: :coffee: :coffee:
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Tommy T-
Here we go again....only with two cylinders this time. Great! Can't wait for the rest.
Idea: Use two scaled up, "Hoglet" cylinders for a 60 degree V-Twin. Drawings for the "Hoglet"are easy to find. Or.....adapt a cylinder design from an air-cooled, radial, aero engine. If there is a crankcase a large diameter steel tube for the crankcase, and weld on two pieces of steel channel-iron, or square steel tubing, for the mounting flanges for the cylinders. The sides of the tubing can be cut with the same radius as the crankcase for a close fit. The channel iron/tube then can be welded to the crankcase at 60 or 90 degrees
So far this new build is starting off like your first engine. I see tapered roller bearings, and cut outs for balancing, in the two flywheels.
Because your engine builds are so informative, please note all the design changes that will use to make this engine lighter, a better quality, have less oil leaks, etc. To the experienced builders these changes might be obvious, but to me, with so little experience, it helps if changes are explained, and noted. It would be great if you can mention the dimensions of the major parts e.g. con-rod length, bore, stroke, etc.
Looking forward to seeing your progress.
Frank
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Ok, popcorn and soda in their places, Check
Comfy chair in front of the computer, Check...
BRING IT ON!
Kjelle :D
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Tom-
Already some questions....
What material(s) did you use to fabricate the crankshaft/flywheel combination, and also the crank pin? Diameter of the flywheels?
Frank
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Awesome, can't wait.
The last one was a classic, in fact best post on this forum for the whole year.
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I am looking forward to this too Tom, enjoyed every post last time , so good luck and keep up the good work :thumbup:
Cheers Mick
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Hi Tom,as the others have said this project will be worth following.
I see you're using taper rollers for the main bearings. You may experience some problems with brinelling and surface fatigue due to the slight flex of the crankshaft when it is running.
Taper rollers do not tolerate bending loads which load the outer edges of the roller elements and outer race.
My own preference would be barrel roller bearings or spherical roller bearings as these are designed with shaft flexure type of stresses in mind. Even the humble ball bearing has better resistance to the type of loadings seen on a crankshaft than the tapers do.
Just my thoughts and views on the matter of suitable main bearings.....OZ.
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thanks for the support guys.
Here are the specs.
Flywheels 1.250 x 8"
Crank pin 1" 3* taper
Rod pin 1" 3* taper on one end press fit on the other
bore 3.275 x 2
stroke 3.75
1036 cc :thumbup:
This build is going to take a little longer than the last. I am going to try to make the best parts that I can with these worn out machines before I move on to the next part.
The crank has a tir .030 because of the rod pin and I need to figure out where I am off and get it right before I move on. The crank in the last engine had a tir of .008 and the rod pin was tapered on both ends. so I know I can get this one a lot closer. I will keep you all posted as I make progress.
Manxmodder thanks for pointing this out before I built the crank cases I think you are right. I am going to change to roller bearings Tom
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I strongly agree with Manxmodder: taper rollers are wrong for this application. Best would be barrel rollers on the drive side (or both), deep groove on the non-drive side....
Taper roller bearings need to be preloaded to meet their design parameters - and you can't do that with a crankshaft since you introduce bending forces on the crankpin if you did.
Cheers and enthusiastically anticipating the build log!
Joe
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Sorry but I disagree about the taper rollers.
In theory what you say *may* be correct but Velocette's used taper rollers all thru the production life of their later series of machines with no problems.
You assembled the engine cold with an 8 thou gap between the crankcases so that was the preload
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Just to add to what John has said about Velocette bottom ends. The design resulted in a rather narrow bottom end which raises its stiffness significantly. This is a big advantage in a high performance single (or even more so a V twin) , because it reduces the deflection in the mainshafts and crankpin and tends to produce a smoother running engine. In the case of the Velocette it also allowed the unusual arrangement of the clutch and final drive sprocket, which are quite different to any other similar machine. I seem to recall that Joe Craig of Norton fame believed that the Velocette bottom end was a better design than his Manx Nortons, although he didn't have the same high opinion of the rest of the engine. I can't find a quote for that so maybe my memory is faulty, but in any case I think the OPs design is interesting and if the crankcase is made strong enough will result in a great engine.
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Already a great read! Learning a lot.
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Thanks for all the input. I do appreciate you taking the time to post your opinion.
Frank the flywheels are 1018 and the pins 1045 ground and polished. this will work for me but I am sure there is a better material.
Getting the crankshaft to run true is quite a challenge for me. I would like to know how you would contain the rod pin and how you would machine the fit in the flywheels. The main pins are tapered at 3* and run true with the fly wheels but rod pin is off by .030 tir. I bored and cut the taper for the main pins in the lathe then put the flywheels in the mill and bored the rod pin fit. One of them was bored for a press fit and the other was left under size and put back in the lathe and the taper cut. I think there must be a better way. On the last engine I put a 3 jaw self centering chuck in my 4 jaw chuck and set it off center to bore and taper the rod pin holes but the finish was bad due to the slow speed I had to use. Thanks Tom
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Hi Tom, I have made flywheels for 2 stroke cranks in the past(about 4.75 inches dia) and my method was to bolt the 2 flywheels together and machine the crankpin holes right through as one.
I have also seen other guys tack weld the flywheels together and then separate them after all the main pin and crankpin boring was completeed . These methods guarantee alignment of the pin bores.....OZ.
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Hi Tom.
A TIR of .030" for the crank pin is way too much unfortunately (as I am sure you appreciate) regardless of the type of bearing you intend to use. The suggestion to bore the flywheels together should help, but you obviously can't do the taper turning right through that way. A tapered fit crank pin is traditional, but not all engines were made like that. Some had parallel pins and were a press fit in both flywheels. This makes lining up the flywheels to get the mainshafts running concentric more of a challenge of course. With a taper fit you can pull them up on the nuts lightly then 'bump' the flywheels on a big lump of wood or a chunk of brass or lead until you get them true, then pull them up tight. It is best to use lathe centres (or bench centres) to test for this alignment.
Just a thought that might give you a way forward - Villiers engines used a parallel fit crank pin that was a light press fit. This allowed for alignment adjustment. The crankpin was bored at each end and after alignment you pressed in a plug in each end, a good press fit. This caused the ends of the crankpin to expand minutely and increase the strength of the overall fit in the flywheels. The Villiers design perhaps was not the best, but they made them in the tens of thousands so might be worth investigating this method, since it would allow you to bore out your flywheels together and in one setting, which should give you much better alignment. You might be able to rescue your existing flywheels this way, but you would obviously need a new crankpin.
Watching progress with interest.
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So I'm scratching my head what does "tir" stand for?
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Total Included / Indicated Runout or similar ... :thumbup:
Dave
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Ok thanks, I was just wondering I'm going to have to make one of these soon for a twin.
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TIR stands for Total Indicator Reading. If you set up an indicator so that it bears on a shaft, then rotate the shaft, the TIR is the difference between the lowest and highest readings on the dial. Or you can find the minimum, set the dial to zero, then the TIR will be the maximum reading that you get on the dial.
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Just my take on it when making flywheels with tapered crank pins is to make one side and finish both bores and skim the outside to be true.
Leave the other side oversize but machined up all round.
Then mark out and bore the other tapered hole for the pin, machine the mainshaft hole to about 3/4 finished size
Make a dummy crank pin with just two tapers on it and virtually no parallel part, you need to be between centres to do this accurately. The idea is to get both halves to clamp together tight but with no gap.
Then holding the whole assembly on the good mainshaft and clock the good flywheel side you can then bore the other mainshaft hole to finished size.
That should get everything running true.
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John -
Took me a few minutes to understand what you are saying, but I really like that method. Will file that away for later.
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Following this one with interest
Jim
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Thanks guys
I had thought of boring the crank pin holes straight through with the fly wheels welded together and drill a hole in the ends of the crank pin for a tapered pipe plug to expand the pin for a tight fit. but I chose to go with proven method thinking that the plugs would not hold the pin tight. Press in plugs sound like a good idea but may be hard to remove.
John your way sounds good but making a pin with two tapers that seat In there tapered holes and the face of the flywheels meet up at the same time in beyond my skills. but what I could do is leave one of the rod pin ends a press fit that way I could just press them together after I tighten up the taper end. I am going to do some checking and see where I am off then make a plan to repair. Tom
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I got the crank repaired. I really felt that the problem was the tapered crank pin hole because it took one more setup than the press fit hole. But after checking it I found that the offset of the press fit hole was off so I bored it over size and made a new crank pin out of 4130 pressed it back together and the main pins run at tir..002.
I think if I do this again I will make the taper on the pins the same as a morse taper and use a reamer to clean up the holes.
I have started on the crankcase. Here is a picture of what made so far.
spec.
9" od tube x 2.375
end plate .250 (http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2072_zps9f8fab7e.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2075_zps4dee5d4c.jpg)
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Very glad to see that you got your crankshaft fixed.
Just a suggestion for your fabricated crank case. With the taper roller bearings it is very important that the sides of your crank case are as stiff as possible. A flat plate may lack a bit in that area, but you can easily fix this by welding in some tapered webs radiating out from the main bearing area. This would also make your engine look much more like a typical cast crankcase. With your welding skills this should be fairly easy to do.
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Thanks Bill
I will definitely add the webs to the drive side of the case. The cam side will get support from the cam box .
I am working on the cylinder base and need to decide on the v angle. 45 degrees is what I am thinking of using and use a master rod and slave rod rather than a knife fork. Anyone have any thoughts on this ?
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45 degrees would be appropriate if you are making a Harley type engine. How about being a bit more radical and going for a high cam short pushrod design with about 50 degrees to get a Vincent look? It would be a bit more work but visually interesting. I guess the decision depends on what you want to do with the engine when finished. If you want to build a vintage frame around it then perhaps a vintage look engine would be better.
A master slave rod design is typical of radial engines and should be doable in a twin. I think there would be some interesting design issues you would need to resolve though. Cam timing and design would need some thought. Master rod design from a stress viewpoint would be interesting - easy to get some significant bending stresses. Master/slave might be easier in a wide angle twin than, say 45 degrees.
If you have sufficient room, a side by side big end might be easier than a knife and fork, but I'm not sure whether your crank case design will permit this. If it does, then it should aid cooling the rear cylinder a bit - cooling would definitely be a concern for a cast iron (or steel?) rear cylinder/head design.
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Hi guys
I have made a little progress on the crankcase Here is some pictures of it.
The v angle is 45 degree.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/021_zps74ce6c4c.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/019_zpsa08c1760.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/015_zpsdc41ef8a.jpg)
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Brilliant Tom.
Following this closely but without doing too many 'me too' posts. You are making a nice job of it.
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Keep up the good work Tom , this looks like it will be as good a post as your last build :drool:
Cheers Mick
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Been a while since I have been poking around so I am a little late to the party, but this looks like another great project!
Not sure what you decided, but I can offer my 1st hand experience and opinion on the bearings. Opposing Tapered (Timken) bearings on the Chain side (properly preloaded) and flat rollers on the cam side. With Flat rollers on the cam side, you don't have to worry about expansion, binding, shimming between cases, etc, which would be a major concern.
I can't speak for other models, but early Harley's used Flat rollers Until evolution came about in '57 and then used Tapered on chain side from then on out with flat rollers on cam side. This was a major improvement in every singe way (1st hand).
I would use either flat rollers on both side (if you want an earlier period correctness) and thrust shims to prevent walk, or Timken on chain side and flat rollers (or bushing) on other but def not tapered on both sides.
Are you going to do an oiling system? Oil hole through shafts and flys into crank pin? ..you mentioned more displacement and more RPM than the last, but not how much more, haha :thumbup:
Regards,
Shawn
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I can't speak for other models, but early Harley's used Flat rollers Until evolution came about in '57 and then used Tapered on chain side from then on out with flat rollers on cam side. This was a major improvement in every singe way (1st hand).
Regards,
Shawn
A simple oilite bush would be a major improvement on a Harley. :lol: :lol: :lol:
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thanks for your input guys
Shawn I am going with tapered roller bearing on both sides and splash lube.
I have made a little progress on the crankcase . Welded in boss and drive side supports, bored the bosses to fit the bearings , added hollow dowel pins , bored the holes for cylinders.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2142_zpsb8752587.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2157_zps96d1e36f.jpg)(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2158_zps2d54a7e3.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2161_zps21d8dcbb.jpg)(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2164_zpsf7a36629.jpg)
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It is looking good!
Eric
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Yah! :thumbup:
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Hi guys.
I have been working on the cylinders. They still need the liners installed and I may cut some more off of the fins to make them thinner.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2415_zpsf80e5021.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_0755_zpsaeb7886d.jpg)
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Hi Tom , its coming along nicely :thumbup: :bow: , I dont really think the fins look too heavy as they are myself but no expert on bike engines mind so do not know what they are meant to look like but they dont look wrong to me .
Cheers Mick
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That looks really good Tom! :clap: :clap:
You nearly got away from me! :palm: I've just had a crackin', catchup read....... :thumbup:
David D
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Hi guys. Thanks for your comments.
I have made a little progress on the engine . pressed in cast iron sleeves in the cylinders and bored them to 3.125, drilled the mounting stud holes in them and the block and built a master rod.
Here is a picture of the rod. I am not sure the slave pin hole is in the right location does any body know how to figure out the proper location??
45 degrees 3.75 stroke
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2477_zpsa115c58b.jpg)
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I only have experience with KNife and Fork VTwin design.
I would think though that when the Rod angles match the the Cyl Angles (45*), the slave crank pin's centroid should be linear with the Main Crank pin and the wrist pin, and Rod lengths the same at that point. i.e. extend a line though all 3 pin centers at 45* ...that is off the cuff though.
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Thanks sdezego.
That is how I think it should work too. but that would put the slave pin hole way out there. I have found pictures of rods that look like the one that I built but no info on the rest of the engine. Here is a picture of my rod in the crankcase and it wont work like this so I am going to make knife and fork rods for it.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/002_zps417c2bab.jpg)
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Kind of interesting actually. I would need to pull out the old kinematics book :)
Fork and knife would definitely be a sure thing. I thin it is odd that I have never come across this before. But in a quick search, I found this thread http://thekneeslider.com/drysdale-godzilla-v-twin/ (http://thekneeslider.com/drysdale-godzilla-v-twin/). Doesn't give you any dims or specific insight, but interesting non-the-less!
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HI Tom,
Some vintage V twins used side by side rods with off set small ends,
I think these would be a lot easier to make than knife /fork setup
The other alternative is to source some rods or complete assembly from a breakers or ebay
HTH
John
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Hi guys. I built some new rods, pistons and heads. The heads still need the fins cut but I need to wait until I get the valve train worked out first.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2516_zps892afa05.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2519_zpsd048f323.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2573_zps7d5e2e9c.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2579_zpsa83a1b79.jpg)
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Amazing, as usual!
(seems like a contradiction in terms, but it just is, to me....)
:bow:
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shapin up nice
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Hi Tom , looking nice :drool: , I like the no nonsense industrial look but it looks like it will do the job to me , top class work as usual.
Cheers Mick.
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Hi Tom.
Any updates on your V-twin? :poke:
CS
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Crankshafter back in the fall I bought a 1930 model A ford that had a bad motor so I have seen busy overhauling the engine. I have that done now so I can get back on the engine.
I have been looking at different way to build the valve train and would like to have all of the push rod line up. For me doing it this way is the hard way. Here is a picture of the car and valve train I am thinking of using on the engine.(http://i1323.photobucket.com/albums/u592/Toms1909engine/006_zpsbc5ee8d0.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_0445_zpse5d06f96.jpg)
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Nice car. Well done.
Jim
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Hello Tom-
Can't say or add to anything that has not been said before. Just another wonderful tutorial showing what can be done with just some simple weldments, bar-stock, and the guts to forge ahead and do what needs to be done to make a USEFUL engine that will actually do something.
Thanks for sharing, and documenting all your failures and triumphs. Very inspirational. (My secret "bucket list" includes fabricating a larger scale, made-from-weldments/barstock, inline, twin, or, 3-cylinder, air-cooled engine). Your tutorials showed me that it can be done.
Frank
Frank
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Tom.
That's a beautiful car. :thumbup:
Can't add to Jim and Frank's comments.
Looking forward to more engine adventures. :D
David D
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Tom,
Valve train looks fine to me, proven design so why re-invent the wheel.
John S.
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Tom, anybody....
Trying not to be a PITA by asking questions, but I have a few....
Have you found that your air-cooled cylinders are in fact, adequately cooled by the cooling fins, or, are you experiencing any overheating problems?
Just curious. Any comments would be helpful.
Frank
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Frank feel free to ask any and all the questions you want to. I will try to answer them if I can but am a little slow to respond some times.
I have not had any heating problems with the first bike engine but it has not been run very hard or for long periods of time.
when I get the v twin done I plan on running it for long periods of time and with a load to see how it performs. I think having thick cylinder walls and cylinder head takes a lot of btu to over heat but makes for a heavy engine. It would probably better to build it out of aluminum .
I am back to working on the engine and have decided on a design for the valve train . here is a picture of the mock up.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2657_zpsebf1b4f1.jpg)
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Tom-
Thanks. Encouraging comments regarding the overheating question. Looking forward to your remarkable progress.
Frank
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I made some more parts for the engine. Cams, lifters, push rod guides, rocker box and cover. they are just ruff built and will be finished at final assembly.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2676_zpsb22aea76.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2680_zps7a0e0160.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2683_zpsc41aa73e.jpg)
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Stunning work Tom,this is a really nicely executed project. :bow: :bow:
Please keep them photos coming,I can't wait to see this beast running.....OZ.
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I have been working on the rocker arms and the rocker supports.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2711%20-%20Copy_zpsmynxhp8w.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2717_zpsnnbus518.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2721_zpsax8myecq.jpg)
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Looking very nice as usual Tom, always interesting to see what you have been up to :thumbup:
Cheers Mick
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I cut the fins on the heads a job that will either make this engine look cool or like a dud it was tuff making that first cut, Here is how it turned out,
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2732_zpsqmqkthar.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2751_zps9c3es71p.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2752_zpsug50tlvz.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2748_zpsqxuv17mb.jpg)
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Another absolutely unique and first class engine carved from base metal! :thumbup: :thumbup: :thumbup: :clap: :clap: :clap: :beer:
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Hello guys I built the exhaust and ignition. Here is a picture and a video of it running it is running ruff and wont idle down but it runs.
(http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2844_zpsxkagzafp.jpg)
(http://i1323.photobucket.com/albums/u592/Toms1909engine/th_IMG_2871_zpsdvw9fkit.mp4) (http://i1323.photobucket.com/albums/u592/Toms1909engine/IMG_2871_zpsdvw9fkit.mp4)
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Marvellous ! :clap: :clap: :clap: :clap: :clap: :bow: :bow: :bow: :bow: :bow:
Dave
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Well Done! (That, just doesn't sound enough Tom).
(http://smileys.on-my-web.com/repository/Respect/king-033.gif)
David D
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Absolute magic.
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Total quality job Tom :drool: :drool: :drool: :bow: :bow: :bow:
Cheers Mick
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Awesome! :bow: :bow: :bow:
Kjelle