1.7 Rebuild First Start Up Advice, 1.7 Start Up on stand Options

[Robroe]

Have 73 1.7 bought in pieces. Engine has been rebuilt and ‘souped up’ however I don’t know what internals were installed. New crank, cam, pistons, rods and heads. but I don’t know which ones. Weber 44 idf carbs. Never had oil in it and been stored unstarted for 10 yrs in climate control. I’ve added oil by slow dripping 2 quarts through the oil pressure sensor hole. Oil dripped out of the rockers so I’m pretty sure it got some oil as pre lube. It’s on a home built test stand with the transmission mounted with the starter.

I’m trying to turn the engine over by hand with the plugs out. Have squirted oil in each plug hole. I’m able to turn the engine by hand about 45 degrees and it gets harder to spin so can’t go any further. Would it be a good idea to pull the rocker arms to see if the builder installed some wild cam without checking valve/piston clearance? It doesn’t feel like internals are hitting each other but who knows? Would hate to pull the heads if I don’t have to. Any thoughts before I break something?

Rob Roe
Newbie

[technicalninja]

Piston to wall

Bore clearance. You measure the bore with an inside micrometer and the piston skirt with an outside micrometer and the difference is the PTW clearance.

The point you measure the piston is CRITICAL. Most manufactures have a specific spot, normally about halfway down the skirt below the pin bore as the measuring spot.

Pistons ARE NOT perfectly cylindrical. They are shaped like a barrel (a little tint bit) and measuring diameter of the crown or skirt will give you different readings...

[930cabman]

Piston to wall

Bore clearance. You measure the bore with an inside micrometer and the piston skirt with an outside micrometer and the difference is the PTW clearance.

The point you measure the piston is CRITICAL. Most manufactures have a specific spot, normally about halfway down the skirt below the pin bore as the measuring spot.

Pistons ARE NOT perfectly cylindrical. They are shaped like a barrel (a little tint bit) and measuring diameter of the crown or skirt will give you different readings...

I have used a feeler gauge, will get you close. maybe not close enough for a race application, but for the street I think it's fine. Generally at 90 degrees to the pin

[Robroe]

Piston to wall

Bore clearance. You measure the bore with an inside micrometer and the piston skirt with an outside micrometer and the difference is the PTW clearance.

The point you measure the piston is CRITICAL. Most manufactures have a specific spot, normally about halfway down the skirt below the pin bore as the measuring spot.

Pistons ARE NOT perfectly cylindrical. They are shaped like a barrel (a little tint bit) and measuring diameter of the crown or skirt will give you different readings...

I have used a feeler gauge, will get you close. maybe not close enough for a race application, but for the street I think it's fine. Generally at 90 degrees to the pin

Cylinders are 96mm bore. Intake valves are 44.06 or so. Exhaust valves are 35.95 mm or so. Will measure pistons and deck height next.