Case Bolt Torquing process

[88911coupe]

OK...reading a million posts here and about to mate the case halves together but need some clarification to put my mind at ease. I plan on using 574 on all surfaces, as per Wayne's instructions and decided to not go out and try to find 1104 for the perimeter. Will put it on the webs as well...risky I guess. I also plan to bolt it all up and let the 574 cure THEN remove the through bolts one at a time, add the o rings (blue one's from Pelican...probably should have specified the Viton, but oh well), add the black RTV and Torque to spec.
Questions...

1. Do I tighten the 22 bolts on the periemeter FIRST, then the large through bolts? My concern is the 574 starting to set up so I was thinking (dangerous) that it would be best to tighten the large bolts first, then the 22 smaller ones. I think JW suggests the perimeter bolts first...to reduce leak potential?

2. I assume that even though they'll be removed and torqued again later the initial thru bolt installation needs to be at torque specs as well so that the 574 sets up under final conditions...over thinking again?

3. Any suggestions on holding the bolts steady as I tighten/torque the nuts? I'll probably be doing this alone and my lower power torque wrench is the arrow indicator type so I have to actually see it. Any tricks here?

Any suggestions or flaws in the plan?

TIA

[cgarr]

I always just snug the ends first, flywheel and #8 nose, this puts the case in alignment, then do the mains, then the outside, should not take more then 15 min if everything is ready to do.

[dtw]

1. Yes, though somewhat similar to Craig I snug down the nut inside the timing chain area first. I do save the flywheel end for last though. You can do it either way, just give your crank a whirl periodically to make sure you're not binding. But yes, short answer, perimeter first is a good practice. You should consider doing a dry assembly or two to build your confidence and rhythm. Managing the chain and rod stands, the upright studs, oil pump seals, etc. is a handful the first few times, particularly when working alone.

2. Yes, torque to spec.

3. If you don't have a helper, making sure your o-rings are lubed is a good start, and hand-snugging them before torquing seems to help too. Otherwise grab a helper to hold the washers steady. This is particularly important with the 'fiddlier' blue o-rings. I did my first engine with the green Viton o-rings and found them much easier to work with.

Suggestions/comments:
If you are using 574 and have never done a case before, the biggest 'rookie' mistake is using too much glue. My rule of thumb with it lately has been to ensure I can't see any spots of opaque orange - you should have just enough there to darken the metal, but not really see any orange. If you've ever cracked a virgin case sealed from the factory, you'll barely be able to tell there's any glue there. I am still using 574 on the mains. If you aren't completely gonzo in your application you shouldn't have any issues with bearing clearance or oiling route contamination.

Do a search on using the silicone on the o-rings. I would strongly recommend against doing this. Read some of the big threads on it and form your own decision, though. I just use some sil-glide on the o-rings and a bit of 574 on the washers as a last line of defense. Tedious and probably overkill (I do everything I can think of to keep my mag case dry) - you'd be fine with some sil-glide.

[304065]

Buck,

A few suggestions if I might.

1) Induce a neighborly type to join you, this procedure really is easier with some assistance. Can be unskilled labor, you just need a helper to hold a wrench while you torque.

2) From the moment the 574 hits the left side of the case, (the flat side without the studs, that is what I did and what the factory says to do) it's game time. You have nominally 45 minutes before it skins over but you should take no more than 15. You CAN do this but you need to have a plan.

The plan should be:
get through-bolt tool (I use a sharpie pen cap with the clip filed off)
preassemble through bolts and lubricate with DOW CORNING 111
set torque wrench (not needed if it's a beam-type)
gather required tools (box end for the other side, M17 socket, M13 socket for perimeter bolts)get sealant for #8 main bearing (see sealant thread)

Have Wayne's book handy that shows the order of torquing, it's basically a crisscross pattern. You could even use a sharpie to mark the order on the case, it's easily cleaned off after you are done.

An aesthetic tip: the factory assembled engines with all the nuts on one side i.e. the nuts on the LEFT case half. So you insert the bolts from the BOTTOM side. Think about it like this-- all the bolts and studs point in the same direction.

When you are ready, roll on the 574 and apply the sealant to #8. Do NOT contaminate the backside of #8 where the oil relief slit is located! Nor should you contaminate the #8 o-ring, it has to be able to move to seal. Not too much 574! If it looks like frosting you have too much.



Carefully place the case half over the chain and rod supports. Verify chains in place, you would not be the only one to assemble the case without chains!

Tap the case halves together with a rubber mallet.

Insert the through-bolts from the bottom side. Then lubricate the o-rings with 111, slide them over the exposed tips one at a time, apply washer (with correct chamfers both top and bottom side!) and put the nut on. Once you get all the nuts on (13- 11 on the bolts, 2 on the cooler area, 2 M10 nuts on the studs) then torque to spec. This is FINAL torque, no remove and replace.

THEN reset torque wrench, apply FACTORY aluminum crush washers (no aftermarket!) and DIN 985 self-locking M8x1.25 nuts to the 21 perimeter studs and torque those down.

It is, in my opinion, more important to set the bearing clearance right away with the through-bolts than to worry about the perimeter. If you insist on gluing the main bearing webs OK, many do that here, but remember that the through-bolt holes are part of the oil system. FOR THIS REASON I DO NOT RECOMMEND THE USE OF RTV SILICONE ON THE THROUGH-BOLT O-RINGS, OR ANYWHERE ELSE IN THE ENGINE! Sorry Wayne, we just differ on that.

Good luck!

[mca]

I used 574 and I applied it to the left case half. The book shows it on the right but it seems like a chap trying to work around those case studs.

I probably used too much but I don't see that as a concern. The excess that squeezes out will simply wash away once you crank the engine. And the 574 wouldn't affect bearing clearances. It just isn't that thick of a sealant.

Also, I installed all of the through bolts first as per Wayne's insructions. After torqueing to final value, I moved to the perimeter nuts.

The next day I removed the through bolts one by one, installed o-rings, applied silicone, and then reinstalled ... then move to the next bolt.

** note: I had to seal it twice b/c one of my IS bearings was knocked out while lowering the left half onto the right half. When I separated the case again (2 hours after sealing it) there was hardly any sealant on the mating surfaces. Just goes to show how precise the mating surfaces are.

[88911coupe]

Great information and thanks for the replies....
Any alternatives for Dow Corning 111, i.e. just motor oil? I'll see if it's available locally but if not I'd rather just get going on this project.
John, are you saying there is no real need to do the through bolts twice or it should not be done at all? Just trying to get clear.
I'm slowly talking myself out of the RTV...just curious...what does the factory use? I don't recall anything being there.
I've about talked my wife into helping but actually TOUCHING an engine will be somewhat traumatic for her....she'll need several hours of Nordstroms therapy afterwards I'm sure. That's fine...they have a bar inside the store.

[im4duke]

Buck, I would glad to help and repay you for your assistance with dropping my engine. Let me know when and where. It will be good practice for me as I hope to seal mine up in the next couple of months.
Maxx

[MatthewBrum]

I would get the Dow Corning 111, the stuff is awsome and I use it on all my o-rings. Helps prevent them from getting cut or torn. I also used the stuff on the RSR rocker shaft seals. It is soo critical to get the thru bolt o-rings right, I would just get the viton o-rings. I was able to get mine at a local supply house they were black but at least I did not hold me up.

[304065]

Buck,

DC 111 is widely available locally, I would be surprised if you couldn't find it with a few calls. I don't see it in the Pelican catalog but it's certainly available from McMaster-carr, www.mcmaster.com.

It allows the o-rings to slide on smoothly and makes a nice seal. It is also recommended on the oil return tube o-rings, these have to be free to move as the engine expands/contracts.

Anyway, once you pull the main bearing webs together they should stay together until the engine gets torn down, particularly if you intend to glue them with 574.

You'll notice I didn't, neither did the factory and remember that the bearing shells are halves, the distance between the halves affects the bearing clearance-- the further they are apart, the more bearing clearance you have. Anything, 574 included, that separates them is increasing the bearing clearance so whatever you do don't lay it on like butter there, make it nearly invisible.

So I would not run the risk of disturbing the bearing alignment by removing and reinserting the through-bolts. You will have plenty of time to properly preassemble the "head" end of the through-bolts- washer (correct chamfer facing out as this is required to clear the cylinders), 111 under the washer to hold the o-ring in the inside chamfer, pen cap over the threads, o-ring on (rather like another fairly common manuever ) and you're ready to stick it through.

Once it's through, pen cap on, o-ring over, squeeze on some 111, washer on, castle nut finger tight. You can do the whole operation in less than the time it took you to read that.

RTV is a crime against humanity.

[mca]

Originally Posted by john_cramer

John,

Is that a gasket I see or just old RTV that was used to seal the heads to the cam housings?

Just curious.

Craig

[304065]

No gasket, just the worms of RTV, ready to break off and fall into the oil return tubes. OK, there's a sump screen that should catch them and a filter after that so there they aren't a problem. But visualize the same kind of crap on the inside of the through-bolt hole where if it breaks off it's going directly to the bearings.

[mca]

I will try not to visualize that ... since I used RTV on my through bolt o-rings.

In theory, I understand why you would be concerned. Especially considering the RTV could clog tiny oil passages.

Maybe this topic should be covered in another thread (and maybe it has already). I would like to hear about some documented cases where RTV was shown to cause problems / failure / wear.

If RTV is in fact as bad as you say it is (not disagreeing with you by any means), I would hope that a third edition of Wayne's book would make that correction and eliminate the use of RTV.

[88911coupe]

Thanks for all the information guys. Also thanks Maxx for the offer, I'll let you know if my wife balks at the process! I was doing a sort of dry run (no pun intended) last night and it does appear I can get them in there pretty quickly. I'll just try a little harder to find the 111. I'll admit I have not tried that hard, I was just assuming it was going to be as evasive as the 574 was. Would it be at a Pep Boys or O'Reillys type places or will I need to go back to Fastenal (very limited hours 8-5:30 M-F)?

[88911coupe]

OK...I give up...can't find 111 and don't want to look any further. I'll assemle them without any lube and without the RTV, despite Wayne's suggestion, but is there anything ELSE that might help for installing the o rings, or is DC 111 the only substance annointed for this process. What about sweat?

[dtw]

Sil-glide...as I mentioned 2x above...any quality silicon lube will work.

[88911coupe]

DTW...sorry, thanks. I have silicon lube already...I guess I'll just use that, in small quantities.
Thanks

[ChrisBennet]

Torquing the through bolts first would be the logical thing to do - it's also the wrong thing to do. esp. with 574.

Snug the perimeter bolts first to get the sealant squeezed out before it can firm up. You aren't torquing the perimeter bolts, just snugging them up. I use an electric ratchet with the clutch set lightly. Zip, zip , zip....

You also want to put the sealant on, thin like sunscreen, not like frosting. More is not better.

Steve Wiener was the one who clued me into this.

-Chris

[88911coupe]

Looks like I have a problem...the crappy blue orings everyone said don't use appear to have shredded on a couple of through bolts. Am I hosed? Can I just get the green viton orings and replace, obviously using the correct torque? Note to Chris, I actually did do this before I read your email but not on ALL 22 perimeter nuts, just a few of them.
Am I risking problems by removing one through bolt at a time and replacking the orings?
I wish Pelican would not even CARRY the blue orings considering the Viton ones are such an improvement. I didn't know the difference back when I ordered the parts.

[dtw]

Yes, the blue o-rings like to squeeze out on install. If your washers didn't spin on install, you can probably run it and be ok. First motor I built, I had squeezeout and replaced them all with more blue o-rings - didn't know about the Viton back then. On the 2nd try, I didn't have any squeezeout. If it was me? I'd hold out for the Viton.

No, there's no problem at all to remove the bolts one at a time and replace o-rings. Be sure you are not leaving any bits of shredded o-ring in your oil passages.

[88911coupe]

OK...just went and got the Viton orings locally to save time. In talking to the guy at the shop (Zims) he said Porsche now, as of about a year ago, recommends Loctite 5900 on all metal to metal seals like case halves and cam towers. He said his 911 mechanics had not been overly happy with 574 on cam towers but loved Dry Bond (I may not have the name correct). They have used 5900 on cam towers and confirm it does a great job BUT there's a little bit of black exposed and the dry bond is effectively clear (and it works) so they tend to keep using it.
Any experience here with Loctite 5900? I think I'll use it on the cam towers.
...just what we need, more fuel to the "which sealant to use" debate.