Topic: Engine Build Advice - Sealant, Thread Locker, and Anti-seize.

[iron_worker]

Hey guys,

I will be building my engine up soon for my 1974 CB750 K4. I've measured all the bearing clearances and inspected everything closely. The cylinders have been bored our +.25mm and fresh pistons and rings on the way. I'll have a full gasket, seal, and o-ring kit coming too. The head and cylinders and blasted and resurfaced and new guides, valves, springs, and seals in the head. The crank and alternator have been balanced and the oil galleries cleaned out.

I know how to fit all the pieces together. I'm not worried about that but I would prefer if the pieces would STAY together and NOT LEAK... and thus my questions:

Sealant:
-What brand do you use? Different types needed for various areas?
-Do you put it on gaskets or install dry?
-Head gasket? (In car engine building I've seen advice either way.)
-Base gasket?

Thread locker:
-Particular areas to be concerned with? (Exhaust studs/bolts, bearing support for the secondary transmission shaft?)
-Which level ... Medium --> Blue or Permanent --> Red?

-Anti-seize:
- Steel bolts going into aluminum casings is a corrosion concern but will it affect my torque values?
-Head studs?


Let me know your thoughts on these things and what you do and WHY! Any other tips like particular torque values to pay attention to or critical steps?

Thanks!

IW

[iron_worker]

...no one? lol

IW

[Jerry Rxman Griffin aka MuthaF'er]

Myself, to answer most of your questions I'll make it simple.

I apply a VERY light coat of ThreeBond to the case halves and wipe any excess lapping off the actual surface.

Thread chase all holes.

Anti-sieze on covers.

Period

[BobbyR]

Concerning thread locker and anti seize. When using an anti seize the torque value of a given fastener is about 20% lower by industry standards. You will see wet and dry torque values listed.

Hi Temp anti seize is very good on parts subjected to heat like exhaust. It prevents bolt snapping later on.

Locctite blue is fine for vibration and a thin even coat will also prevent the aluminum to steel reaction that drives you nuts. Rather than Loctite, I use Nylock nuts on things like the fork tube clamps. I use red on the lower front axle studs, I don't trust those nuts down there.

[cabrala]

I'm really only good for the anti-seize portion of your question. Zinc is going to be your best bet for a steel (stainless?) to aluminum connection. I bought a pint size container, that will last me forever, from an aircraft vendor. PM me if you want the details on that and I'll dig through some history to find it for you.

I don't have experience putting together motors, but am in the process of my first rebuild. There is mixed views on sealant due to all of the oil galleries that have the potential to be plugged if overzealous during application. I've read that the head gasket is designed to go on dry. IIRC, they will be impregnated with some oil during startup, swelling the gasket and sealing off any imperfections. Nevertheless, you'll find that many still have certain ways of doing it, some with copper sprays, others with sealant goo and yet others who assemble the whole engine dry.

Best of luck. If I come across any info I'll be sure to pass it along.

[iron_worker]

Thanks guys. I guess I should say that most of my hardware will be freshly zinc plated so I guess the corrosion factor should be reduced a lot.

I would just like to build this motor once and just ride ride ride after that if you know what I mean.

Sounds like sealant basically only for the case halves and gaskets dry mostly everywhere else. I have heard of people putting sealant on the rubber "pucks" that seal the head bolts. Any info on this?

Are the torque values given in the service manual dry torque values? I would assume they are but I don't really know.

Thanks again,

IW

[Jerry Rxman Griffin aka MuthaF'er]

I put a little film on the pucks JUST TO HOLD THEM IN PLACE while installing the cam towers.

[matt mattison]

I prefer Honda bond for sealer, especially to seal the pucks .

[iron_worker]

Just wanted to bump this one more time to see if anyone else wants to chime in.

I was wondering about the screws that hold the exhaust flanges in on my K4 CB750. Mine seem to back out over time and cause exhaust leaks. Anyone use loctite on these?

IW

[camelman]

I have had great results with coppercoat for head gaskets. It helps seal around oil galleys that can easily (and often) leak.  There's nothing as disappointing as assembling an engine to find a head gasket leak. I've run across that when using dry gaskets, but never with coppercoated (or similar) gaskets. Coppercoat comes in a spray can.

[iron_worker]

From what I have read Copper Coat shouldn't be needed if your head surface and cylinder surface have been machined properly ... I had mine done at CycleX.

Maybe it's a question I should ask to CycleX since I'm using his MLS head gasket and his machine work. I'll fire off an email and let you guys know what he says.

IW

[sweet_baby_james]

I've been watching this thread with interest as I am about to start the reassembly of my 78 550K motor.  Lots of good info here.  A couple of questions that have sprung to mind after reading this:

Are there any place on the motor that should definitely have or not have anti sieze applied?  Since I had a pretty tough time disassembling  would be tempted to put anti sieze on all connection.  Is this a reasonable approach?

Second, since the internals of the motor and transmission have been sitting around in the garage now for some time (many pieces in ziplocs where possible), should I dunk them in motor oil during assembly to clean them off?  Are there any other recommended techniques here?

Don't mean to hijack the thread but the questions seemed relevant to the topic!

[iron_worker]

There are probably some critical areas where you may not want antiseize. The 750 has a bearing support on the secondary transmission shaft that is held in with three screws. These screws felt like they may have had some type of factory thread locker on them. It makes sense though because if those screws backed out and allowed the secondary shaft to jump loose... all hell would break loose! I'm thinking if something jammed up your cases might actually explode. lol

I think anti-seize on all cover hadware is probably not a bad idea. If one of those backs off then you end up with a leak. No big deal.

I would definitely make sure all your parts are free of all dust and dirt before reassembly. Everything should be spotless if possible. A coating of oil is not a bad idea either.

IW

[sweet_baby_james]

Very good, thank you.  What type of sealant are people using for the crankcase halves where there is no gasket?  Seems to be a whole variety available from ThreeBond:

http://www.threebond.com/LGasket.html

[Ricky_Racer]

Threebond 1104. RR

[iron_worker]

That's what CycleX includes in their "Git Kits" and they seem to know their #$%* about buildin these old bikes:

http://www.cyclexchange.net/Git_Kit_3+.JPG

IW

[Ricky_Racer]

Yeah, the TB1184 replaced the no-longer-available TB1104 about six months ago.  Check with your Honda dealer; mine stocks it. RR

[tlbranth]

Regarding antisieze, here's sound advice from Inox in the UK, manufacturers of stainless hardware for motorcycles.

Why is it really that important to use copper anti seize and not something else?
 
When stainless steel is fastened ‘dry’ into Aluminium, galvanic corrosion can occur as the result of two different materials at opposite ends of the ‘metal nobility’ table being interfaced. In practical terms this means that alloy crankcases can oxidise around the fastener area very quickly. Copper based anti seize provides a third metal as the ‘sandwich’ and, as copper is placed in the centre of the ‘metal nobility’ table, it prevents Galvanic corrosion. Ordinary grease or oil will not work as they do not contain the vital element. UNDER NO CIRCUMSTANCES use Aluminium grease of any sort - including aerosols - as it will probably seriously damage the castings.

I've read that when using antisieze or thread locker, you should decrease your torque settings by 20%.
Gasket cement shouldn't be necessary on Japanese gaskets or homemade gaskets made from rubber fiber.

[Kickstart]

Thanks for the tip tlbranth.  I was wondering what type of antiseize to use.

I'm glad this tread was started, because I'm also approaching the re-assembly phase of my engine and I had the same question.

This is now my tentative plan:

• Hondabond 4 on the engine case halves
• Hondabond HT on those pucks under the cam/rocker holders (only because I have some Hondabond HT left over from when I worked on my Honda Odyssey - but seems like it will work well for this application.)
• Copper antiseize for the APE HD crank and cylinder studs when screwing them into the cases
• Copper antiseize on all the 6mm case bolts (probably not necessary)
• Cylinder bolt / head nuts dry (don't see any need to use antiseize here as all but 4 of them are inside the valve cover.
• Crank stud nuts - I'm probably going to go with blue loc-tight, or leave them dry
• Exhaust studs - copper antisieze but dry with the nuts that hold the flanges on (I have a 75F)
• Copper antiseize on all the cover screws (valve, alt, trans, etc.)

Thoughts / Comments?

Only thing I'm not so sure about now is the HD studs... I think I read somewhere that you're suppose to use engine oil when installing the HD cylinder studs.

[iron_worker]

I'm hoping the studs will come with instructions.

IW

[tlbranth]

I don't know what you mean by "HD" studs.
When I did the top end on my K0 many years ago, I managed to strip out the aluminum on several head bolts. I had to helicoil them. It occurred to me that studs would be a better choice than bolts so I replaced all of the bolts with studs from Tacoma Screw. I don't think they were anything special. But when I put them in, I just screwed them down with channelocks or some such because, if you think about it, it's the nut that needs torquing, not the stud. Imagine it as a bolt. the bolt body isn't bottomed out.
Don't know if that answered any question but maybe it did.

[Ricky_Racer]

Regarding oiling the HD studs... If you allow oil to drip into the stud hole, you risk hydro locking the stud and getting false torque readings. If you're going to lube them, a light oiling will do.

BTW, this site has a wealth of knowledge and the search function is your friend! RR

[Jerry Rxman Griffin aka MuthaF'er]

I'm hoping the studs will come with instructions.

IW

If they are APE's HD (Heavy Duty) studs they will have info.

[Kenzo1979]

I did a complete rebuild of my '71 500/4 engine last winter and I did a ton of research on this site as well as others before I finally assembled everything.  Here's basically what I wound up doing, and (knock-on-wood) have had no problems after an entire season of riding:

Mate the case halves -- Hylomar
Oil Pan -- Hylomar
Head Bolts -- Loctite Blue threadlock
All internal bolts and screws -- Loctite Blue threadlock
All external bolts and screws that you need to undo at some point - Permatex 80208 anti seize
Head gaskets - Nothing but a THIN film of grease to hold it in place

The manual will give you all torque values as well as the order of torquing certain bolts.  The manual also tells you what to and what not to put sealants on.  HAVE A MANUAL!!!  I used 2, haynes and clymer shop manuals. 

I also cleaned all parts in mineral spirits, soaked internals in fresh oil, used engine lube on crankshaft and crank bearings, and chased all threads and cleaned up old bolt/screw threads with wire brushes and compressed air.  I'm probably forgetting something, but that's the gist.

Good Luck!

[Kickstart]

I don't know what you mean by "HD" studs.
When I did the top end on my K0 many years ago, I managed to strip out the aluminum on several head bolts. I had to helicoil them. It occurred to me that studs would be a better choice than bolts so I replaced all of the bolts with studs from Tacoma Screw. I don't think they were anything special. But when I put them in, I just screwed them down with channelocks or some such because, if you think about it, it's the nut that needs torquing, not the stud. Imagine it as a bolt. the bolt body isn't bottomed out.
Don't know if that answered any question but maybe it did.

APE Heavy Duty cylinder studs and main bearing/crank studs.  The instructions on their website say to bottom them out and then torque to 8 foot pounds.  Which isn't a lot... probably just enough to keep them from vibrating out.  Like you said, it's the nut that needs torquing.

The APE instructions don't mention anything about using a lubricant, but I thought I read some people here using motor oil... My gut feeling is the cooper anti-seize is probably the best way to go with these.