The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: Big Nick on 01.08. 2013 22:07

Title: What grease to use
Post by: Big Nick on 01.08. 2013 22:07
i am putting the head back on ( iron head ) what grease do you use to put on the tread ? in the past i have used copper ease is that right ? also double checking to take it down to 34 ft/lb ?
thanks
Title: Re: What grease to use
Post by: a10gf on 01.08. 2013 22:14
Don't know about grease (...should one use it at all?) but here's some pretty good reading about torque and more.

http://www.a7a10.net/forum/index.php?topic=2452.0
Title: Re: What grease to use
Post by: RichardL on 01.08. 2013 22:48
Before putting on the grease, I think it would be a good idea to hear some opinions about torque values and greased bolts. You could be putting way more tension on the bolt than is typical for the wrench reading.

Richard L.
Title: Re: What grease to use
Post by: KiwiGF on 02.08. 2013 04:43
Also check yr torque wrench ! Mine was reading almost twice the actual torque on bolts, result was a blown head gasket 500 miles aftervthe rebuild, and then a full engine strip to redo the con rod bolts  *problem* *problem*

My non std billet rods came with instructions to oil the threads so I did, this obviates the abilty to use threadlock of course

Im not sure whether the head bolts should be oiled or not, but I oiled them and they fairly easily got to 32 ft lbs without any sign of over stress and fingers crossed no repeat of the blown gasket after 1500 miles, I checked the visible bolts after a few runs and they were still at 32 so ive taken the chance of not taking the rocker box off to check the others. I may regret that laziness of course  *eek*

Note I think I got 32 lb ft from the SRM site, and thats the figure for an iron head.

Edit: the second gasket fitting attempt I fitted the gasket dry, as it took SOOO long to remove the blackened goo that was the remains of the cement I put on the first time, also I made sure the gasket was fully soft before re using it.
Title: Re: What grease to use
Post by: Big Nick on 02.08. 2013 06:23
yep the 32 tiger comes off the srm web site so i will go with that and having googled around a bit i will put a pit of copper ease on the threads
Title: Re: What grease to use
Post by: wardleybob on 02.08. 2013 09:02
Hy nick I always use a copper head gasketi and I have never had a problem. Make sure you anneale it.
If you use a composite gasket you will have to re tighten it down.
Title: Re: What grease to use
Post by: bsa-bill on 02.08. 2013 09:45
Sorry - bit late here, did reply but must have missed the post button.
Anyway I don't lube my bolts, but would think if you want to then high melting point grease so copper slip would be fine on a cast head ( think copper can interact with alloy but there are alloy alternatives)
Would be interesting to here from anyone who has had corroded head bolts seized in - not one I've heard of but .............
Title: Re: What grease to use
Post by: Big Nick on 04.08. 2013 15:45
so got her running after a bit of jumping up a down and swap of plug caps , the engine dumped a load of oil on the ground , i hope that is just after it sitting for some time ( yes i had drained the crankcase first ) now run out of petrol there i a bit sloshing around in the bottom of the tank but it will now have to wait till monday.
Title: Re: What grease to use
Post by: RichardL on 04.08. 2013 17:17
It seems to me that oil blowout through the breather port occurs when the level in the tank is about half or less than max level (assuming you had filled to max level). If I'm anywhere close to that I try to drain the sump. If it's questionable and I'm in a hurry I'll throw a tray under the bike just in case and run it slow (while on the stand) until the pump has time to clear the sump.

Richard L.