Vintage V-Twin Engine Build

Tom TG

Tom TG

Active Member
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.
IMG_2059_zps1d8fe217.jpg

This is how the crankcase started out.
IMG_2075_zps4dee5d4c.jpg

This is what the crankcase looks like after the parts are welded and ground down.
011_zps5fe3a25c.jpg

The x brace and bosses were added here.
IMG_2142_zpsb8752587.jpg
 
This shows the bearing boss being bored. After boring the other half was bolted to it and bored to align the bearing fits.
IMG_2157_zps96d1e36f.jpg

IMG_2158_zps2d54a7e3.jpg

inside view of the crank cases after the cylinder mounting holes were bored.
IMG_2164_zpsf7a36629.jpg

The Cylinder before and after. A cast iron sleeve was pressed into these steel jugs.
IMG_2415_zpsf80e5021.jpg

And this brings you up to where I am on this project.
IMG_0755_zpsaeb7886d.jpg
 
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? ;)
 
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.
 
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
 
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?
 
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
 
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.
 
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.
 
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.
 
Last edited:
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.
 
You must log in or register to reply here.
Back
Top