850 head bolt torque

D

DSpieg

True Classic
Am finishing installation of machined head and new head gasket on my 850 Spider (903 cc) and have found some differences of opinion on head bolt torque values and retorquing protocol between various manuals and writers.

For torque, some of my books say 28 ft.-lbs. and some say 32 ft.-lbs (approximately, I don't have the books in front of me and am going from memory). Anyone have the 'best' number?

The manuals say to retorque after about 300 miles and then again at 1000 miles, but Chris Obert's site is emphatic about retorquing immediately after the first startup/shutdown. Thoughts?

Finally, I've read some recommendations for adding a thin copper washer to the head bolts to accommodate thermal expansion, while some folks say that's unnecessary or maybe even a bad idea. More opinions?

Thanks.
 
David, my Autopress LTD manual says 21.71 ft. lb., then 28.9-36.2 ft. lb. in sequence. I always retorque twice, once after first warm/cool cycle, then later at around 500 miles.
 
Thanks, Greg, sounds like a good approach. Any thoughts on adding copper washers to the stack?
 
Washers...

I wouldn't. I would do it as it came from the factory. My reasoning is that the aluminum head expansion rate will negate any benefit of a softer washer in the mix.

Funny you mention washers, I just found some very thin copper washers under one of my Vanagon's head nuts. It was leaking, so I removed it to re-seal it. Found the washers, left them off. They were not even smooth, they had groves cut in them for some reason.

So far so good. Next up fuel lines, I've only replaced the long one from the filter to the tee so far.
 
Will do as you suggest and perish all thoughts of copper washers from my mind.

Off-topic, re: Vanagons, I just installed Jay Brown's "Deluxe" headlight relay and starter relay kits on my '86 GL, and I couldn't be happier with the quality of the kits and the clarity of the instructions. I'll bet you already have these on yours :)
 
More off-topic

Is he the guy with the hard-start relay as well? I have those on my cars also. And yes the headlight relay kit on my '88 GL. the hi-output 9004's don't seem to last very long though, FYI.

I'm in leak seek-and-destroy mode so I'm getting ready to replace the rear crank seals and oil pump seals. And fuel lines. And that coolant pipe on the left side, mine's rusty on the bottom.
 
Vanagon off-topic digression

Yep, "hard-start relay" is his name for what I called the starter relay kit. Here: http://www.thesamba.com/vw/classifieds/detail.php?id=1089150

Speaking of your Vanagon coolant pipes, do you still have the original long plastic pipes that run all the way forward to the radiator, or have you already replaced those? I still have mine and they worry me but seem OK externally.

Good luck with your Leak Regime Change efforts. Out with the old leaks, in with the (hopefully few and far between) new!
 
DSpieg said:
Am finishing installation of machined head and new head gasket on my 850 Spider (903 cc) and have found some differences of opinion on head bolt torque values and retorquing protocol between various manuals and writers.

For torque, some of my books say 28 ft.-lbs. and some say 32 ft.-lbs (approximately, I don't have the books in front of me and am going from memory). Anyone have the 'best' number?

The manuals say to retorque after about 300 miles and then again at 1000 miles, but Chris Obert's site is emphatic about retorquing immediately after the first startup/shutdown. Thoughts?

Finally, I've read some recommendations for adding a thin copper washer to the head bolts to accommodate thermal expansion, while some folks say that's unnecessary or maybe even a bad idea. More opinions?

Thanks.
Click to expand...

Really, my web site suggests this?
Can you send me a link to it so I can find out about it?
I have always suggested retorquing similar to the factory suggestions, so I am surprised that I suggest doing it sooner.
And I never do it on all of the motors I build and install...

As for how tight, the same head bolts go to 45 on some motors. But the old 850 block will often pull the threads if you get close to that.

Copper washers, it's an old Abarth trick. On a stock compression 850 motor I don't bother, but on older motors I always install new copper washers.

Chris Obert
 
My bad.....

Chris, my sincerest apologies, I have misrepresented your advice. What I had read a few months ago was this: http://www.fiatplus.com/members/tech1199.htm
and I should have gone back and re-read it before posting anything about your recommendations here.

Thanks for chiming in and I'm sorry for putting out wrong information.

Anyway, it seems you disagree with Gregory regarding the need to re-torque immediately following initial startup/cooldown. As a lazy person I like your approach better simply because it will save me a few hours of work.

Highest regards,
 
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