Torque Specs for '72 GT380 jugs...

[JFISHSOLEVIBE]

Hey guys! Putting the top end back together on my 380 and I cant find the specific torque spec for the base bols on the cylinders. I considered just giving them a good twist, but dont want to effect gasket spec and piston clearance if I do too much or too little. Also, the motor is IN the bike, anyone have a good wrench solution for getting in to those tight spaced to tighten them down? I dont have a torque wrench that small.

Thanks in advance!

John

[H2RICK]

There are special flat wrenches available with an open end 12mm or 14mm on one end and a 3/8" female opening on the other end to accept the male 3/8" on your standard torque wrench. You really have to look hard to find them but I believe Snap-On sells such a thing, IIRC.
Then you have to sit down and figure out what reading you need on your wrench because of the multiplier effect of the extension of the special flat wrench onto the nut. This math escapes me completely unfortunately.
Maybe someone on here can chime in with the formula for that calculation.

[jabcb]

Precision Instruments has a good explanation of the multiplier here: http://www.torqwrench.com/Info/extens.php

Motion Pro has a torque wrench adapter for 12 & 14 mm: http://www.motionpro.com/motorcycle/partno/08-0134/
Have seen them on eBay. I got one at a local bike shop that had them in stock.

[H2RICK]

Many thanks for the GREAT info, jabcb !!!!

[Craig380]

Hey guys! Putting the top end back together on my 380 and I cant find the specific torque spec for the base bols on the cylinders. I considered just giving them a good twist, but dont want to effect gasket spec and piston clearance if I do too much or too little. Also, the motor is IN the bike, anyone have a good wrench solution for getting in to those tight spaced to tighten them down? I dont have a torque wrench that small.

Oh man, those base nuts are just about the biggest PITA on the 380. To be honest, I wouldn't worry too much about affecting piston clearance etc, by overtightening. The base gasket is pretty thin and is unlikely to over-compress.

I would recommend using new spring washers though, this does help to ensure the nuts don't loosen off quickly in use.

I bought a special 'obstruction' ring spanner which has a curved shank (pic below), alternating between this and a conventional flat ring spanner makes it a LOT easier to get around the frame tubes to tighten the base nuts at the front.

I did also buy a ratchet ring spanner but the head of the spanner is too big to fit over the nut.

[H2RICK]

Craig:
Over on this side of the pond, that wrench was known as a "starter wrench" because you used it to get at the horizontally mounted top bolt on engine starters with integral solenoids on North American built engines......especially V8 motors with the starter tucked up under the one bank of cylinders. This all changed when manufacturers went to a vertical-bolt style of starter mounting sometime in the '80's, IIRC. I assume, though, that this style of wrench is still known by the original name.....at least over here.

[Craig380]

Interesting! Nations divided by a common language

So to fix your starter by the roadside, you'd open the boot of your car, get your special 'obstruction spanner' then lift the bonnet, right?

[tz375]

And don't scratch the front wings (fenders) as you reach in under the bonnet (hood).

The expression that makes me laugh is "Spanner Wrench". That's as bad as PIN number (Personal Identification Number number). I'm sure there are others.

[H2RICK]

VIN being another quite common one.....

Things are now beyond the "creeping illiteracy" that was worried about in the '70's. We are now approaching
"rampant illiteracy", IMO. Of course, with the median IQ in North America now below 100, this was bound to happen. Just think.....your odds of interacting with a functioning halfwit in the course of everyday life are now 1 in 2. Oh joy......

Example:

Joe goes to the bank to withdraw cash to buy a motorcycle. He mentions to the teller that he'd like "large bills" thinking they'd take up less space in his wallet. The teller says: "I'm sorry sir but all our bills are the same size." True story.......

[JFISHSOLEVIBE]

Thank you guys! Great info. Ill just give em the old "man unit" of tightness and hope that I dont have any clearance problems. Thanks again!