Holt Engine (I hope)

The flywheel looks great! As are all the other pieces. When I built mine the castings were still available so not wanting to carve the large flywheel from a chunk of iron/steel I bought the casting. I also bought the intake and exhaust manifold castings. When I made all the modifications and revised the drawings I showed how to fabricated the manifolds so they looked close to the original shapes. This requires a bit of silver soldering but shouldn't pose any problems. Your mounting for the flywheel should work fine. I learned a long time ago that set screws/grub screws won't hold a flywheel in place so that is why I went with the keyway.
gbritnell
 
Thanks George, I looked at castings but the shipping to Canada is ridiculous, and I had a cutout from a plate sitting there. What the flywheels and shipping would have cost I'm sure I recouped at least $2 an hour whittling that 8 x 1 1/4 blank into a flywheel. lol
Would have went with a keyway had I gone the set screw route but wanted to try the taper lock, have certainly never made one this small before.
My spindle and collets are getting worn, with the flywheel mounted on a 1/2 dowel pin I was getting about a 1 1/2 runout on the end of the dowel pin and 2 to 2 1/2 runout on the side and top of the flywheel. So mounts pretty true, happy with that.
The manifolds are certainly going to be a challenge. They must have been a challenge to cast, certainly small cores for the runners.

Greg
 
Got the second one made. A bit of dremel work removed the machine marks on the spokes, then masked off the rim with electrical tape and gave them a go in the blast cabinet.

IMG_4562.jpeg

Thanks for looking

Greg
 
Lapped the liners to within 0.0001 of 1 inch.
Bought a commercial lap this time, money well spent. Have made my own before, they worked but this design is superior. Can now use the spindle and adjusting rod on barrels that I make.
IMG_4566.jpeg

Picked up this bore gauge a number of years ago from a member on another forum, (actually forget which one). Its a joy to use and reads to 0.0001 "
IMG_4563.jpeg

Thanks for looking
Greg
 
Managed to make a set of rings, a bunch of spares as well. Still need to expand them and heat treat. They're .030 thick, used a disk that fit the inside diameter on the surface grinder to locate them and ground to thickness, broke quite a few. There's so little metal there the magnet wouldn't hold them at all
Machined the pistons. Tried to hand grind a tool to cut the groove for the rings, failed, set up the sine plate on the surface grinder and ground one 0.032 thick with 3 degree side clearance, worked great.

IMG_4567.jpeg

Thanks for looking

Greg
 
Its starting to look like an engine, but still a long way to go.
IMG_4568.jpeg

IMG_4569.jpeg

The valve seats need some attention, I made a 45 degree cutter but gave it too much relief resulting in it grabbing and leaving a wavy surface. Spun it by hand with a mandrel through the valve guide hole.

IMG_4571.jpeg
Sandblasting the heads gave them the cast look I was after.


IMG_4570.jpeg

Thanks for looking

Greg
 
That's looking great Greg!

I appreciate you sharing this build.

Brian
 
Been too hot to work outside, and Im caught up, waiting on material on other peoples projects, so spent some time on the engine.
Made the intake manifold, its built up from 3 sections silver soldered together. Made from bearing bronze salvaged from these monsters. Been cutting one up for years, finally needed to break into the second of 4. They weigh about 60 pounds each.

IMG_2022-08-20_19-13-54.jpeg

Greg
 
Back
Top