Grease on bolts, and other engine assembly questions

[BlairP]

Hello everyone, and greetings from frozen Burgundy. Don't expect much from us in the way of wine this year...

I'm starting on the engine rebuild, and I have several initial questions to put to the board's collective wisdom:

1. Should I grease the bolt threads during assembly? Bearings? Head? Manifolds? etc. etc...
2. I'm planning to use assembly lube for the vast majority. What about inserting the pistons into the block? They are new and will have new rings. Assembly lube? Or running in oil?
3. I'm planning on using Loctite for the core plugs and oil gallery plugs. Any reason why I shouldn't?
4. I don't know how long it will be once I get the engine assembled before I'm ready to try and start it. That being the case, once together, should I fil it with oil and prime the oil system via direct driving the oil pump with the distributor off?

As always, thanks in advance!

Blair

[Motorsport Mickey]

1 minute ago, BlairP said:

Hello everyone, and greetings from frozen Burgundy. Don't expect much from us in the way of wine this year...

I'm starting on the engine rebuild, and I have several initial questions to put to the board's collective wisdom:

1. Should I grease the bolt threads during assembly? Bearings? Head? Manifolds? etc. etc...
2. I'm planning to use assembly lube for the vast majority. What about inserting the pistons into the block? They are new and will have new rings. Assembly lube? Or running in oil?
3. I'm planning on using Loctite for the core plugs and oil gallery plugs. Any reason why I shouldn't?
4. I don't know how long it will be once I get the engine assembled before I'm ready to try and start it. That being the case, once together, should I fil it with oil and prime the oil system via direct driving the oil pump with the distributor off?

As always, thanks in advance!

Blair

Answered in reverse order

4) That's easy, don't rebuild your engine until you need it, maybe at most 4 months previous.

Although components will have assembley lube on them even the best lube flattens and drapes off engine parts especially in summertime. Why take the chance, build and then use, especially if new camshafts and cam followers are used, it needs running at over 2000 revs (engine loaded, not ticking over in the garage) to help prevent the high pressure surfaces galling (gouging and marking).

3) If you are happy with Loctite on the core plugs that's fine, I use Araldite.

2) I use engine oil but then again my engines are used almost immediately and don't suffer with oil run off. Lube does stick better but I'm always hesitant on surfaces which definately need to "wear and bed into one another" for complimentary running surfaces. 

1) Lubed threads on Triumphs ? well Triumph never bothered with them, all Triumph spec torques are with clean dry threads.

Lubing the threads removes "stiction" (sticking and friction) which is fine and laudible, except every torque setting in the official manuals are given as dry with this increased stiction built in. Lubing them increases the clamping force and reduces the necessary torque by about 20% ish, depending upon what you use to lube. So big end bolts, main bearing caps, cylinder head bolts (which are within about 10% of max torque according to bolt tables, on 4 cylinder anyway) would all be 20% overtorqued. That stresses the engine block differently and different limits are reached. Todays engines are almost all designed and built using lubricated fastenings and with final angular torque measurements which can achieve much more even and regular torque figures which gives better and more reliable clamping forces.The next scrap block I come across I will torque components at lubed figures and see at what limits the block threads strip at for example. 

Non critical studs and fastenings I sparingly lubricate and then wipe so no excess lube is left on the surface.

Mick Richards 

[PodOne]

Hi Blair

Think Mick has covered it for you.

My engine/box is built and in the car with no oil just Grahaogen/Clevite on everything and will stay that way until I start it which will be no time soon. Accept that some will run off but will pull the rocker shaft/rods and redcoat the lobes when the time comes and turn her over until the oil pressure comes up.

Had a few new engine builds Kicking around for 12 months or so can't say there was any issues for me anyway.

Keep warm

Andy

[Nigel Triumph]

Could answers above.

I use Loctite on main bearing, big end and flywheel bolts. Belt and braces perhaps, as the factory tightened them dry, as has been said already.

And Loctite is fine for the core plugs.

Nigel

[Motorsport Mickey]

9 hours ago, Nigel Triumph said:

Could answers above.

I use Loctite on main bearing, big end and flywheel bolts. Belt and braces perhaps, as the factory tightened them dry, as has been said already.

And Loctite is fine for the core plugs.

Nigel

Just beware of flooding any critical fasteners with Loctite, it does a fine job of spreading and lubeing the threads and reducing stiction itself !  I only ever use a "match head" sized dot on the threads which you'd rather remain fixed together.

Mick Richards