Engine evaluation part I

Tim arrived with the engine in the back of his truck. We off loaded it with an engine hoist and then I got it onto an engine stand.

The engine block # 10066036 is a ‘hencho en Mexico’ GM Goodwrench crate 350 from around 1990. The heads are #93417369 (or 33417369) also made in hencho en Mexico. They are 76 CC heads with 1.94″ intake and 1.50″ exhaust. This engine as it stands is supposed to make 250 HP @4300 rpm with 350 lbs of torque. Respectable as a donor for the Chevy until I can get the original motor rebuilt.

First thing removed. I was surprised to find out that it is an aluminum unit. I’ll save it in case someone needs a 4 bbl intake.

When doing over an engine I like to keep all the bolts, etc marked in bags. The lifters, and push rods are all marked so they go back in as they came out.. I”ll likely use the original cam. It is supposed to be good for low end torque – something like a stage 1 replacement cam which is often used to improve towing. They is a replacement truck engine so that makes sense.

Heads off and time to check the cylinder wear – ignore the numbers on the pistons.

This is my handy-dandy cylinder checker. I was gifted it from an old mechanic friend Arnold Legrow of Springhill, NS who sadly has passed away along with the love of his life Doris.

The bar on the bottom has a number of collars of differing sizes. I used a combination that gave me exactly 4″ between the uprights. I then used a combination of gauge extensions so the gauge fits between the uprights. I then set the dial to 0 and I was ready to check the cylinder wear. I’ll use it also to check the top to bottom cylinder wear when the pistons are out.

I checked each cylinder one at a time while rotating the engine. All the cylinders ranged between 4″ and 4.002″ Satisfactory for a re-ring with the original pistons.

Using a compression calculator I came up with a ratio of about 8.9:1 Which is quite respectable. The parameters I used were 4″ piston, 3.5″ stroke, 4.03″ gasket bore, .026 compressed gasket, 76cc combustion chamber, dish depth -5 and deck clearance of .025″.

The gallery is quite clean and free of sludge. there was however quite a bit of sludge in the pan. Also in the pan were bits of rod bearings – not all showing.

Next: more engine evaluation.

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