Rebuild Start to Finish

Here is how we rebuilt a 1928 Twin City.

Twin city before work

Before Work

Twin city after work

After Work

Twin city block before work

Before Work

Twin city block after being bored

After starting machine work

Block being bored
Boring the Block

Boring the block .045 over.

block after boring
Boring the Block

Block after boring.

Crankshaft before machine work
Crankshaft Grinding

The crankshaft needs grinding to become round and straight.

Crankshaft being machined
Crankshaft Grinding

Crankshaft being ground by a van-norman 429 machine.

Crankshaft being machined
Crankshaft Grinding

Crankshaft being ground.

Crankshaft after machine work
Crankshaft Grinding

Crankshaft after being ground.

Connecting rod to wide to fit in new piston
Connecting Rod

The connecting rod is to wide to fit into the new piston.

Rod needs to be machined to fit new bushing
Connecting Rod

Need to change the rod bushing I.D.

Rod needs to be machined to fit new bushing
Connecting Rod

Connecting rod machined to new I.D. to fit the new bushing.

Machining rod to fit new bushing
Connecting Rod

Installed new bushing with a .008 press fit.

Machining rod to fit new bushing
Connecting Rod

Machining the connecting rod on a mill to fit the new piston.

Rod bushing installed
Connecting Rod

After machining to fit the new piston.

Connecting rod to wide to fit in new piston
Before

Connecting rod before machined to fit.

Piston attached to rod
After

Connecting rod after being machined to fit the piston.

Showing babbitt bearings before machine work
Babbitt Shells

Shell is re-babbitted and ready for machining.

Showing babbitt bearings before machine work
Babbitt Shells

Re-drilled doll holes.

Showing babbitt rod bearing before machine work
Machining Bearings

Installed bearings. Bearings are now ready for machining.

connecting rod being machined
Machining Bearings

Connecting rod bored .0015 larger than the crank pin.

Comparing original piston to the new piston
Pistons

Piston .045 over. 6 to 1 compression ratio which is almost twice stock.

Machining piston
Pistons

Making the dome on the piston.

Weighing piston
Pistons

The new piston is 2.4 lbs. lighter than the stock cast iron pistons.

Showing four pistons with connecting rods
Pistons

Pistons hung on rods ready to install into the block.

Machining bearings
Main Bearings

Boring rear main bearing to size.

Machining bearings
Main Bearings

Cutter to machine thrust-end play.

Machining bearings
Main Bearings

Thrust being machined to .003 end play.

Showing freshly machined bearings
Babbitt Work Finished

Babbitt work finished on the block. Ready to install the crankshaft.

Bottom of twin city engine showing crankshaft
Crankshaft Installed

Installed the crankshaft.

Twin city
Top of Block

Top of the block with pistons installed.

Watch the video below to see this engine run.