Itinerant Air-Cooled

Putting the heads back onto the 1600 dp build. Had to take them off because I forgot to put in the two little pieces of deflection tin under the cylinders, above the push-rod tubes.

I remember at some point some one saying that they alternate sides when torquing their head bolts through sequence. So I got to thinking about that, as I have always snugged one side to spec, and then the other.

I understand the concept, a kinder stress application for the case, but the sequence doesn't mirror on both sides. So it would end up first nut first side closer to flywheel, first nut second side closer to pulley, etc.

Does it still make sense? Perhaps first torque full sequence first side, second side first torque full sequence.

Opinions appreciated.


neal

I think this is a gray area of engine assembly. 1,000 flavors of advice. As long as the engine goes in with the proper torque at each head then I think you're OK. How many engines did VW hurl thru Wolfsburg in a day?
I've always done it one side at a time. Hell in a handbasket, yet again.

Yeah you are supposed to alternate sides as you notch up the torque. I don't know if it matters much.
When I replaced one head, I loosened the good head too so I could do it that way.

ruckman101 wrote: I remember at some point some one saying that they alternate sides when torquing their head bolts through sequence. So I got to thinking about that, as I have always snugged one side to spec, and then the other.

I understand the concept, a kinder stress application for the case, but the sequence doesn't mirror on both sides.

Neal, you do the mirror. That means you "defy" the Bentley sequence only like a dyslexic.
8146...........6418
5327...........7235
right ........... left

Where 1 right is followed by 1 left, then 2 right 2 left etc.
Remember how the Type 1 engine likes to do the bottom four first in the first pass. That's just to get a start on the pushrod tube compression.
Colin

Mirror I did. Initial sequence to 7flb, second sequence two passes mirrored at 11flb, mirrored two passes at 18flb, then mirrored three passes at 23flb.

Before I started, I chased a nut onto each stud, and noticed some hung up and wouldn't thread on by hand. So chased the nut up and down and cleaned thread until each and every one was an easy on and off by hand. There were two especially gummed up studs, so put a itty bitty smidgeon of valve grind paste on the thread and chased the nut up and down, cleaning afterward. Seem to work pretty well.

I think I'm glad I left the deflector tin off and had to revisit. I certainly paid no such attention to things the first time.

Thanks for the mirror clarification Colin.


neal