Vintage V-Twin Engine Build

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Tom TG

Tom TG

Active Member
Dec 10, 2012
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Oklahoma
Hi all, I have been working on another custom engine. I am building a 1000 cc
V-Twin, with roller bearings and sealed crank case. I have no blue prints just figuring it out as I go. Here are some pictures of what I have built so far. This is the crankshaft. It has 8" flywheels, with 1" crank and rod pins.

This is how the crankcase started out.

This is what the crankcase looks like after the parts are welded and ground down.

The x brace and bosses were added here.
 
Tom TG

Tom TG

Active Member
Dec 10, 2012
113
49
28
Oklahoma
This shows the bearing boss being bored. After boring the other half was bolted to it and bored to align the bearing fits.


inside view of the crank cases after the cylinder mounting holes were bored.

The Cylinder before and after. A cast iron sleeve was pressed into these steel jugs.

And this brings you up to where I am on this project.
 
Ludwig II

Ludwig II

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Jul 17, 2012
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The bores are on the same centreline, so will the rods be knife and fork, or will you be heretical and have one as the master and the other as a slave using a pin on the main rod, like a radial engine? ;)
 
Tom TG

Tom TG

Active Member
Dec 10, 2012
113
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Oklahoma
Ludwig, No the flange on the bottom of the cyl goes into the case held on with 4 studs, not shown in this picture.
The rods will be master and slave.
 
hsvmick

hsvmick

Member
Mar 23, 2011
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hobart tasmania australia
tom tg
i just completed looking over your first engine build then the bike build then showed us all the ride wow how good are you
what have you done with that machine ?
are you planning to build another bike to fit this amazing looking engine,you sure know how to spin same metal up and turn it into fine art i not seen before well done sir
 
Ludwig II

Ludwig II

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Jul 17, 2012
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It occurred to me to ask about the rods, as both methods have pros and cons. Will the front rod be the slave, as that cylinder will run cooler, and the side loads will be slightly greater?
 
silverbear

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
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northeastern Minnesota
Tom,
Thanks again for sharing your wizardry. i know so little about what you guys are talking about that it looks like magic from where I am. So I will quietly sit back and watch the magic show as it unfolds.
SB
 
Ludwig II

Ludwig II

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Jul 17, 2012
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To explain the master and slave rod:


Knife and fork:


Side by side:
 
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S

Slogger

Member
Sep 8, 2014
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nohio
Nice work, what a project to take on.. I wonder, what is the bore and stroke? With a long stroke twin like this one it should develop plenty of hill climbing torque.
 
Tom TG

Tom TG

Active Member
Dec 10, 2012
113
49
28
Oklahoma
hsvmick, I have taken the other bike to several shows most people ask what brand is it. I tell them it is custom built, then they ask where did you get the engine. Yes I am planning on building a bike for this engine, not sure of the type yet.
Ludwig II, The master rod will be connected to the rear cyl. I have read where on the old v-twin engines the rear cyl ran cooler than the front because the crank shaft slings oil up inside it.
Slogger, The bore and stroke is 3.25 x 3.75 aprox.
 
Ludwig II

Ludwig II

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Jul 17, 2012
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I am a dreadful engineer, but I ask engineer questions. Had I understood this 45 years ago, I'd have worked at going into mechanical design; with humility, asking engineers what actually works, not just what the numbers said.

I read recently about the old Panther M100 and M120 singles, 600cc and 650cc. The 120 had a reputation for poor lubrication, as the oil scraper wasn't close enough to the flywheels to run it to where it could be picked up, as a design compromise. Most 120s now are modified, so the scraper edge is the same distance from the flywheels as in the 100. Ernie Sheldon, a racing motorcycle builder I knew, was obsessed with having that scraper just thou's away from the flywheels, to reduce drag and point it at the scavenge side.
 
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Ludwig II

Ludwig II

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Jul 17, 2012
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Everybody here would have liked Ernie. He enjoyed his whisky, and had monograde 20w in his veins.
 
Ludwig II

Ludwig II

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Jul 17, 2012
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Pumps! What is planned, based on the 500, about oil supply and scavenging? Will it be a roller/ball bearing engine, or plain? At low rpm, roller/ball offers little inertial penalty, and low pressure requirement. At high rpm, plain can be made lighter, but requires lots of oil at high pressure.
 
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