Gray 2-cylinder Marine Engine
Date: Unknown, Use: Unknown
If you have seen one of these, or know something about it, give
me a holler.
Very stuck and needing a lot of TLC.
I have talked to several people about this one
and the concensus is that it may be a rail car engine. The flywheel
on the right is inscribed with usual "Gray Motor Co."
logo while the flywheel on the left is extra heavy with no inscription.
The engine is actually suspended from the two brackets on the
base of the cylinders.
Getting out the pistons called for some
elbow grease ! I machined blanking plates for the exhaust port
and the bypass port out of some 1/2" alum. The bypass port
plate was made on the mill using a boring head to make an arc
with the same diameter as the piston. After that, getting out
the piston was a breeze. There was about 3 lbs of grease used
on each jug...pumping the grease gun was better than using a thighmaster.
The rod bearings were shot...here is a jig to do both caps at
once. The brass shims are 0.032. The center brass is 1.50".
The final bored size will be 1.685" Since it is way undersize
as poured, exact centering of the center post is not that critical.
Babbit was poured. with molds preheated to ~350F . Small holes
were filled with Fiberfrax to prevent babbit from leaking out.
Pour temp was ~820F. After cooling, the center was removed and
the excess babbit was removed with a coarse file. A 0.032"
shim pack was installed on each side of the cap. The rod has locating
holes in the left side to keep the bearing shell from turning.
Fixture I made to bore the bearings. The post on the right is
scrap aluminum screwed to a aluminum base. This ensures the bore
of the main bearing is parallel to the wrist pin bearing. Downfeed
Finished rods. Corners were beveled for radius in crank with scraper.
Oil grooved cut with Dremel using 1/16 burr. Note the old bearing
shells which were very egg-shaped. This whole job took ~10 hours;
half of which was making spent making the fixtures to do the pouring
June 6, 2001; Finished ! I started
it up for the first time tonight and it sounds neat... Steady
bleat, bleat, bleat from both cylinders firing at the same time.
Had to switch from a Tillotson carb to a nice Wheeler-Schebler
(Ford A model) to get it running and it kicked right off!! Lots
of fabrication to get it mounted but worth every minute.
Check out those TIG-welded stainless exhaust elbows I made in
my shop. The grease gun is for Alemite fittings on the mains.