head retorque

[12960]

I just rebuilt my R75/7 engine.

When is the head due to be retorqued?

Miles?

Gerry

[20774]

Probably a variety of opinions...I rebuilt a /2 engine and I did the following. I retorqued after the first heat cycle (I also changed oil...the /2 has slingers, no filter). I retorqued after 50, 100, 500, and 1000 miles. The valve clearances were pretty steady during that time period. A bit over the top, but it was the first time I'd done something like that.

As for retorquing, I think the ideal way is to back off the nut about 1/8th turn or so and get a running torque reading. On my /2, I decided to just run the wrench up to the number (25 ft-lbs is what I used)...if it didn't turn, I called it good.

The /2 cylinder/head is a little different than the /5-on engines. The /2 head bolts directly to the cylinder and the cylinder bolts separately to the engine case. So, I don't have as much concern about pulling the head bolts because mine were steel into steel, not steel into aluminum.

YMMV...you didn't ask about break-in procedures...ho, boy, that will get even more opinions...

[47512]

I would retorque after 2/3 heat cycles, 500/600 miles, and check valve clearence. 25 ft lbs is good. Then at about 3000 miles I would check them again. Just crack the nut loose then titen. I have used this method on many BMW twins.

Ken G.

[beemerguru]

One important step during the torqueing action...for the 2nd and 3rd stage, move the torque wrench as slllloooooowwwwwllllyyy as you can. You need to let the metal and head gasket adjust to each other..and metal moves slowly. In other words,,don't just jerk the thing.

When I rebuild a motor, I turn it over a few times to prime the oil, start it and immediately run it up to 3-5K for about a minute or so. Shut down and come back the next day for a retorque and valve setting.

Ride for 500 mile and retorque and set valve...then it's just checking valves every 3K miles or so.

I've got G/Ss that use virtually no oil between 5K mile oil changes.