Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties Copper gaskets < Filthy

Copper gaskets < Filthy

Post Sun Jan 09, 2000 7:39 am

Posts: 540
Location: Kansas City, Mo USofA
what did you tell me about torquing the copper gaskets? I started to scan the old BB but figgured I get it faster here. I recall you telling me to alum paint them. (WL, 6.0 alum. heads) I know the book says to get them tight, but weze cumded a long wayz sense den. Is there an accepted ft lb (stock bolts&washers)

Post Mon Jan 10, 2000 8:44 pm

Posts: 783
Location: Victoria, Australia
Hi Hotrod, I just put my 45 barrels and heads back on afer extensive relieving and porting work. I've got studs rather than bolts fitted and was advised to torque them them to 35 ft lbs. I used new copper gaskets.
It all works fine. ~ Vince

Post Tue Jan 11, 2000 3:08 am

Posts: 3159
Location: Central Illinois, USA
Are we talking headgaskets? I find copper ones notoriously hard to seal, even at 65 ft/lbs with anti-seize on the threads. I use 35 ft/lbs on the base nuts with Locktite.

Post Wed Jan 12, 2000 1:30 am

Posts: 136
Location: oxford, NC USA

When I put on a head, I torqoe it down to the proper value in the right sequence, then start the engine and run it till it gets hot. I shut it down, let it cool long enough for the heat to even out - just a few minutes, then torque it down again. Have never had a head gasket fail, including recycled copper.



Post Wed Jan 12, 2000 4:19 am

Posts: 146
Location: Utah,USA
A good old book is Modern Motorcycle Mechanics by JB nicholson. Has a lot of general stuff on old Harleys.

Page 288 1965 5th edition comments that when reusing old copper head gaskets they should be heated red and then quenched in water to soften


Post Wed Jan 12, 2000 12:27 pm

Posts: 783
Location: Victoria, Australia
Hi Cotton and all. Yes I did only torque the "head studs" to 35 ft Ib in 3 stages. I used new copper head gaskets (so the ridge around the perimeter was still intact to seal under compression from torquing the head nuts). The torque specs were on the advise of the 2 engineers, one of whom completed the porting and relieving of the barrels "a la" KR. I'll post the jpegs as soon as I get the film processed. The barrels and heads were both milled to give a completely uniform and unmarked face for the gasket to seal. There are often a lot of compression marks on heads that have been used over the years without having been milled for a truly flat surface, leaving lots of ridges and the like for pressure leakage. I also used 1mm thick washers of a large diameter that spread the load over the entire surface area of where the studs come through the holes in the head. It works fine. Vince

Post Wed Jan 12, 2000 2:29 pm

Posts: 3159
Location: Central Illinois, USA
Headbolt taps and the helicoils kits (including other special threads) are available from V-twin Mfg.(Tedd Cycle)
They also have the pre-war races in oversizes, manufactured by Eastern, and not Jim's as I thought. Jim's Machining has supplied me with special order oversizes of various hardware in the past, such as .50"-over mains for line boring to correct cases that are extremely warped by massive weld repairs....Cotten

[This message has been edited by Cotten (edited 12 January 2000).]

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