Search results

Time to withdraw the "B.R.A." item from the mystery box. :oops: A pair of unconventional looking rods to the piston emerge. Somewhat nervous here. My concerns are that the throw pin position in the webs have to be extra accurate in placement. So one web has the throw directly under a gear...

The twin crankshafts rotate in R1810ZZ bearings. Each of the brass carriers holds two. An issue I was having is the bearings were from two different venders and one set had to be a couple ten thousands undersized. Would not slide up on the shafts and not turn freely when installed in both...

Two and two point five inch round stock for the radiator and cyl. head. Cylinder liner to the head with O-ring seal. Static compression ratio under 3:1. Piston rises to .250in. from top of liner. Combustion chamber .375in. deep into head. .250in. aluminum angle deck bored close to the...

I salvage a pair of cast iron wheels from my 40 yr old floor jack no longer working and scrapped. Square it up from its hub in the three jaw. Press in a steel hub. Narrow the width by a half inch and bore 3/8 inch. Flywheel to crankshaft mounting via the collect lock method. Brass retainer...

The bottom of the piston is reduced in diameter. Milled across to near its centerline. A couple holes drilled into the flat for 4-40 screws tapped in, side by side....... ......and the piston is completed.

The nature of SPLIT MONO requires a piston that is larger in diameter and also longer in length. I use my 1- 1/4 in. DOM cylinder liner for this engine along with same size piston stock. Appreciating the difference in size and final displacement with this comparison to 1 in. piston stock...

No mechanical means. Soak and swish around the tube in soapy water. Internally dry with compressed air.

Elmer Wall Water Witch

I have a pair of single cyl. models in my collection. Want to add another......and show something that most likely, you have never seen before! Can you power up two crankshafts with one cylinder? 🤔 The SPLIT MONO story coming soon!

Thanks petertha. I see now the OP date. Yes, matching a flat or tapered seal to the flare tube for the intake via Teflon the right solution. Hope it supports the temps. My best guess is a copper seal for the exhaust side.

You need to support the inner diameter of the O-ring with an equal or oversized dia. short brass tube so the flare compression doesn't collapse and punch in the O- ring up the port.

I use O-ring (3/32 to 1/8 in.) head gaskets exclusively on my models in conjunction with the cylinder liner that rises above the deck to cage the O-ring. A matching groove is cut in the cyl. head and block for the O-ring to seat into. Not worried about the crush height and you should see the...

Thanks raveney. On the intake side of THREE BELOW, the valve action is atmospheric. Vacuum draw on the intake downstroke overcomes the valve spring pressure to open the valve for the cylinder charging of the fuel/ air mixture. I use some K&S .015 piano wire for these valve springs. The exhaust...

Let them know what you do! :) Sum guy that builds models!

Welcome to the premier of my latest model. Longboy's 'THREE BELOW" 3 cyl. gas engine. The THREE BELOW build was started last week of October. And completed 3rd week of January. OS .15 carb, CM-6 NGK plugs. 1x 1.125 Bore & Stroke. 4 inch flywheel. 3.6 OZ. fuel tank. 20/40 MXL cog...

Satin black on the 4x4 and the shoe bars. Will highlight the heads and cylinders well. Leaving all other parts natural polished. The two slots between the cylinders on vertical leg of the 4x4 an aid to airflow as the frame somewhat shields the cylinders. May follow up at a later date with...

Upon a couple of eighth inch aluminum angle pieces, the camshaft with drive sprocket and guard on the left and distributor and point set on right. Rotates on a pair of brass bushings. Valve spring retainers as lifters ride the cam lobes. They are threaded to the valve stems and adjust to needed...

Looks like a shorty block of Delrin for the carb and then continuing the theme and continuity of tubing from the manifold to the In. valve blocks. A short post extension and couple of 4-40 screws ties the manifold block to the outside corner of the 4x4. Now I can work the camshaft position...

Over onto the intake side, a set of individual valve blocks bolt to the intake ports of the heads. A short tube into the head and v-block with an O-ring seal around tube. A piece of painters tape make a good gasket here. I got a whole roll of this stuff so when I build a fleet of four valve...

The lower end completed. With five bolts the 4x4 top end attaches and I can figure out the valve block spacing to the heads. The cylinder heads In a 3/6 head bolt line up with the crank. My thought at the start is the head ports would be at a right angle to the engine length with some offset...