Restoration’s Final Touches: 2-1/2 HP Ottawa Engine

Author Photo
By Staff

1 / 25
Peter Rooke’s completed 2-1/2 HP Ottawa.
2 / 25
Sections of cut pipe, ready to be welded to form the four wheel hubs.
3 / 25
Drilling holes to start the five spokes for a small wheel.
4 / 25
Chain milling a triangular cut out for the spokes.
5 / 25
The completed core spoke and hub after rounding all the edges.
6 / 25
The finished spokes after welding.
7 / 25
Beginning to form the rim of the wheel.
8 / 25
Bending to form the rim of the wheel.
9 / 25
Starting to fabricate the 9-inch wheel.
10 / 25
The inner support of the rear assembly.
11 / 25
Starting to weld the rear assembly, inserting the central filet with card patterns for the curved pieces.
12 / 25
The completed rear assembly.
13 / 25
The front pivoting bracket after initial welding of the axle supports and pivot support.
14 / 25
The completed pivot.
15 / 25
The first stages in forming the mounting to cart timber.
16 / 25
The finished front axle assembly.
17 / 25
The completed cart handle.
18 / 25
The completed drip tray.
19 / 25
The casting after cleaning but before being filled with epoxy to cover the worst defects.
20 / 25
The water hopper marked out for lining, after being sprayed and preliminary polished.
21 / 25
The template used to mark the design on the crank guard.
22 / 25
The completed crank guard.
23 / 25
A flywheel partially lined.
24 / 25
The hopper lined and the decal applied.
25 / 25
Peter Rooke’s completed 2-1/2 HP Ottawa.

Most stationary Ottawa engines were sold without carts. Generally just the engine was shipped to keep down transport costs, and then once received the engine was fitted to any available truck. This made it difficult to get a picture of an original cart to know how to start making one. This was the only time that Ottawa Caretaker Helen Myers, who has since passed away, could not fully help me with an original picture for this engine, although she provided a lot of detail for the next size up but, unfortunately, that was a different style of cart. A plea for help on Smokstak also drew a blank. Helen was able to provide dimensions for the timber for this engine and advised me that the cart would have been similar to the Warner catalog of carts, for which they had a rather indistinct picture. At least this catalog print gave some hard facts, including the specification of the wheel diameters and face sizes.

The cart itself was said to be similar to a Galloway cart, so after studying the catalog picture at some length I came up with the following design, which I believe is a true representation.

Cart wheels

The wheels of the cart had five spokes, the front being 7 inches in diameter and the rear 9 inches, both with 1.50-inch-wide faces. I then drew up plans for both wheels.

To make the hubs of the wheels without wasting a lot of solid bar, I cut four lengths 1.50 inches long from both 0.750-inch and 1-inch NPT pipe. I had to fractionally bore out the inside of the 1-inch pipe on the lathe so that the smaller pipe slid in before I could weld it in place to form a hub for a 0.750-inch axle.

Starting with the smaller wheel, I clamped and centered some 0.250-inch steel plate to the milling table. I would use this to form the basis of the five spokes and ridge under the rim. This provided an opportunity to try out the recently acquired DRO (digital position readout) tool fitted to my mill, so I didn’t mark any reference points on the metal. After centering and drilling a pilot hole in the middle, I used the DRO to drill a series of holes for the corners of the five triangles that would be cut out of the metal. Next, I used a milling cutter to plunge mill between the holes. I bored the central hole for the hub that would be welded in place. I sawed off the surplus metal around the outer edge before turning it to size on the lathe, an overall diameter of 6.5 inches.

To complete the five spokes and give them a cruciform cross section, I fixed tapered bars at 90 degrees on the core plate. Then I cut short lengths of 0.250-inch-thick bar and clamped them on the milling table with a spacer at one end, so it was an easy matter to mill one side to get a tapered profile. I welded these pieces on the core section to complete the spokes.

The final stage was to form the rim. I heated then bent some bar 1.50 inches wide around a former to start creating a ring. I kept the bar as a long length as long as possible to improve leverage when bending. Once the circle was half formed, I put the hub of the spokes section on a short length of rod held in the vise and wedged it so that it wouldn’t turn. I tack-welded the rim at one end then heated it before bending it around the wheel a short section at a time. I clamped it in position so I could add further weld and repeat the process.

Once at the very end of forming the rim, I cut off the surplus bar then used a clamp to force the last bit home, holding it against the spokes for welding.

Then I closed the gap on the rim with weld and applied a bead around both sides of the core spokes to firmly anchor it to the rim. I used a die grinder to clean up the wheel before painting with red oxide primer.

I made the larger wheel following a similar process, apart from the initial stage of starting to form the spokes. Milling out the gaps in the spokes on a bigger scale would prove an expensive waste of steel, so I fabricated this piece by using 0.250-inch strips of steel, which I cut and partially shaped before laying them out on a full-size plan, clamping and welding them together.

Once I welded the base spokes, I followed the operations outlined for the smaller wheel to complete the larger wheels. The only difference was I cut some 9-inch diameter pipe with a 0.250-inch wall thickness for the rim, rather than bending bar again.


The two wooden spars for the engine were made from old, well-seasoned pine. They were each 36 inches long and 1.625-inch by 3.625-inch sections. The engine itself rested on two cross pieces 0.625-inch-thick by 2.50 inches wide.

I drew plans for the cart iron work using the computer, then printed out full-size plans to provide an accurate guide for bending the metal.

Once again, I cut the hubs for the axles from lengths of tube that I welded together with narrow rings cut and fitted to each end, which I then grounded to get a rounded ridge.

Unless stated, I used 0.250-inch steel bar to form both the front and rear axle supports.

I bent some steel, 1.750 inches wide, to form the outer part of the rear fixed frame, making a distance from the underside of the wood to the center of the axle of 4.50 inches. Rather than try and bend a piece of steel starting with the correct length, it was easier to use an oversize length, measuring from the middle. This meant that the only thing to worry about was getting an accurate distance between the two downward bends. I cut off any surplus from the ends before profiling them to fit around the axle supports. I heated the steel to soften it, the large vise providing the pivot for bending. I marked the center of each bend with a shallow cut made with a hacksaw.

I made the inner part of the bracket from steel 1.50 inches wide and, to overcome any difficulty in bending it accurately to fit the outer frame, I made it in two sections. I bent two overlong lengths of steel to fit the plan and then bored the holes for the axle supports. Then I sawed off the surplus on the two pieces and welded them together to form a perfectly sized inner piece.

I clamped these four pieces of the rear axle bracket on the welding table, putting a length of axle rod through them to keep everything in alignment before welding them together.

To complete this rear bracket, I had to fill the gap between the two rails, again with 0.250-inch thick, 1-inch wide bar. On either side of this central filler piece I welded in 1-inch diameter steel at 8.125 inches centers. I tapped these 0.375-inch by 16-inch to hold the tie bars securing the bracket to the wooden rails. To make it easier to shape the filets for the curved areas, I cut cardboard patterns then sawed and filed steel plate to match.

Adding small triangular filets at each end of the axle support completed the welding. I then shaped the weld with a die grinder and rounded all sharp edges so that the assembly had the appearance of an iron casting.

Construction of the front turning bracket followed a similar course. I started with the lower part of the bracket, which was again bent from two pieces then welded together. I fitted this to the tube supports for the axle, again using the axle to hold parts in alignment for welding.

I made the central support and the rubbing plate for the pivot by brazing together steel 1.25 inches and 1.750 inches in diameter and drilling for a 0.625-inch pivot pin. Then I welded this to the first part of the bracket.

I also made the top of the moving part in two pieces. Before bending, I tapered both lengths to give a greater width at the pivot, 1.750 inches, narrowing to 1.250 inches at the point of the axle. I bored out the ends of both so as to fit around the pivot and the round axle support. I clamped the components for the front axle together for welding before adding the inside and triangular supports.

To finish the bottom half of the bracket, I made two lugs from 1-inch by 0.500-inch bar. I drilled and shaped these then clamped them together with a rod passing between the 0.375-inch holes, aligning them for welding.

To secure the turning section to the wooden frame, I tapered some steel plate 2.50 inches wide, 0.250 inch thick from the middle to a width of 1.75 inches at both ends.

I turned two pieces of 1-inch steel with a slight taper then threaded them to be used for the securing bolts. I used 1.125-inch-diameter steel for the core of the pivot, with a 0.250-inch piece of 1.750-inch-diameter steel used to match the piece on the moving part. It was then a case of cutting, forming and welding filets of steel to provide supports around the center point.

I made the pivot pin from 0.625-inch round steel with a cap 1.50 inches and a hole for a split pin at the bottom. I made a piece of rod 0.375 inches thick with split pins at each end to hold the handle in place.

I made the handle in a “Y” style with a cross piece to hold when pulling. I used two pieces of 1-inch by 0.250-inch steel to form the arms of the “Y,” then bolted these to a piece of timber 1.50-inch by 1-inch.

Drip tray

To prevent oil spillage on the show field it is a good idea to fit a tray to catch any oil leaking from the cylinder or other points of the engine. When at the local store I noticed a baking sheet that appeared to be the right size, and for $1 it was cheaper than buying the metal sheet. The addition of a small extension at one end made it a perfect fit, resting on the two wooden rails of the cart and sliding between the two cross pieces supporting the engine. With the addition of a small drainage hole and rubber bung it was quickly finished.


The castings for this engine were possibly some of the roughest that I have worked on. There were no traces of paint left on this engine (apart from a couple of tiny flakes under the tag). I cleaned up the various castings with a wire brush and a selection of abrasive discs using the angle grinder. Then I used some epoxy filler to cover up the worst faults in the casting.

When I completed renovating each component, I immediately covered them with two or more coats of red oxide primer as the workshop gets damp in the winter and it takes no time at all for cast iron to start rusting.

Ottawa stationary engines were generally red and the saw engines green. Long before starting to paint I had obtained a paint swatch of the red from Helen Myers that she said was a good match for the original. I mixed paint to match this color and, after lightly sanding down the earlier brush-painted primer coats, gave the engine two further coats of primer and then several coats of the “Ottawa” red.

After leaving the spayed paint a couple of days to dry and harden, I cleaned up the surface of the paint with a lightly abrasive polish then cleaned it with solvent, ready to start the lining.

Helen Myers provided details of the lining layout that I followed, marking the position of the lines with a glass pencil. Not being adept at lining, I completed this in easy stages so that the painted lines could dry before drawing curves or crossing another line. This way I could easily wipe off any mistakes damaging earlier work. For straight lines I used masking tape for one side, removing the tape as soon as I finished the line in case there was any bleeding that I could correct with a push stick before it started to dry.

To get a pattern for the flywheel spokes and the crank guard, I drew the design on the computer. I printed it out and checked it against the spokes. When satisfied with the size and the design, I printed it on thick paper, which I then cut out to form a stencil. I used a glass pencil to mark the design on the flywheel spokes and the crank guard.

When it came to lining the flywheel, I lined alternate spokes until the paint dried. This left a spoke on each side of the one being worked on to rest against and reduced the possibility of touching earlier wet lining paint.

The correct style of decal was only available in Mylar, a polyester film. While I waited for my set to be delivered, I scanned the image into the computer then printed it on some waterslide decal paper. I affixed these to the hopper and sealed them with some clear lacquer spray.

Setting up

I gradually put the engine back together, starting with the piston and con-rod, moving to the crankshaft, then the gears (which were marked before disassembly), governor and pushrod. Once I had fitted the flywheels, with new keys, igniter bracket and cylinder head, then I adjusted the timing.

This proved straightforward as the flywheels were marked, “Exhaust Opens,” “Exhaust Closes” and “Spark.” I had already adjusted the magneto on its bracket. As usual with a Webster, I moved the flywheel until the word “Spark” on the flywheel was level with the top of the pushrod. I used the starting lever to cock the magneto. With the cam for timing in the running position and the wedge on the push bar slid back, I adjusted the length of the push bar so that it just touched the push finger and then tightened its lock nut. I moved the wedge forward until the lower edge of the pushrod was level with the upper edge of the magneto push finger and then tightened its bolt and locknut. Then I checked the timing by removing the starting lever, turning the flywheels to see if the magneto tripped when the word “Spark” was aligned with the top of the main pushrod.

All that remained was filling the drip oiler and grease cups. I put liberal quantities of oil on all moving parts, particularly new ones that needed to be bedded in. This was particularly important around the new piston and rings.


Once ready, I wheeled the engine outside and filled it with gas. It took a little fiddling with the mixture needle to get the right setting for the engine to run properly. After running the engine for 10 continuous minutes, I stopped the engine and gave it a thorough checking over, in particular all nuts. Then I ran it for a further couple of hours to bed in before checking all bearings. It was at last ready for its first rally.


Read more about the beginning states of the restoration in Ottawa Engine Restoration, 2-1/2 HP Ottawa, andFixing a 2-1/2 HP Ottawa Gas Engine.

Contact Peter Rooke at Hardigate House, Hardigate Rd., Cropwell Butler, Nottingham, NG12 3AH, England • peter@enginepeter.co.ukwww.enginepeter.co.uk

Published on Dec 24, 2013

Gas Engine Magazine

Preserving the History of Internal Combustion Engines