| Author |
Message |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 227
Registered: 11-2001
| | Posted on Tuesday, July 16, 2002 - 5:06 pm: | |
OK
Got to the heads installed part (head gasket leaks, see different posting), and did a pressure test. The O-ring HOLDS. There is no water leakage around the orings. |
Verell Boaen (Verell)
Junior Member
Username: Verell
Post Number: 201
Registered: 5-2001
| | Posted on Tuesday, July 16, 2002 - 12:53 pm: | |
Consider Hylomar instead of PST (or RTV). Hylomar is a non-setting up sealant. It always stays flexible, & is resistant to all automotive fluids.
It lets the o-rings find their own position while still providing some lubrication & tackiness to help retain things.
MAZDA requires it for the o-rings that seal the housings that make up the 'sandwich' comprising a rotary engine. Allegedly you can't get a rotary to properly seal up without it!!
Use it sparingly as you don't want to have enough that it won't let the o-ring seat itself in the groove(don't ask). |
Steve Magnusson (91tr)
Member
Username: 91tr
Post Number: 845
Registered: 1-2001
| | Posted on Sunday, July 14, 2002 - 10:22 pm: | |
Yes, probably reasonable to try it as-is (minimal labor/$ from here to test, and you'll have the test to confirm OK or not) -- sounds like the liner would have slipped up/down at the o-ring ID interface rather than rolling the o-ring/RTV physically upward then downward.
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Matthew J. Morgan (Kermit)
New member
Username: Kermit
Post Number: 21
Registered: 8-2001
| | Posted on Sunday, July 14, 2002 - 9:49 pm: | |
Now that I know more about how you went about assembly. If it were my own, I'd go for it. I personally think it will work just fine the way you have done it. |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 222
Registered: 11-2001
| | Posted on Sunday, July 14, 2002 - 5:12 pm: | |
What I did when I installed the Orings is as folows:
1. Squeeze a small amount on black RTV into the corner of the step of the liners where the Orings fit.
2. Use my finger to squeegee it and form a smooth concave bead all the around the liner
3. Use razor blade to clean off all the excess except for that area.
4. Push the orings onto the liner recess and push it into the RTV, and use my finger to smooth it out once more
5. Push the liners on the block as far as I can
I am going to take a chance here and finish putting the heads on, torque them down and do a pressure check. If pressure holds, I will continue. If there is a leak, I will tear it up and do it over with new orings and NO RTV this time.
Sounds good? |
Matthew J. Morgan (Kermit)
New member
Username: Kermit
Post Number: 20
Registered: 8-2001
| | Posted on Sunday, July 14, 2002 - 10:46 am: | |
I agree with Steve. My experience is too often uncured RTV is "slippery' and I have seen gaskets get squirted out of place instead of compressing. It's gonna be a bit of work, but then once the motor is in, it would be a heck of a lot more work to fix one of the O rings. If it was me, I would re the rod caps, push the liners up to check the O rings, then if you want, place a SLIGHT coating of RTV on the block surface below the liner, tighten them down with the plates. I would keep the thickness of RTV Very slight, and only about �" wide, so some shift may occur during head torque. And DO NOT forget to wipe off the excess that is pushed thru. It will end up in the oil every time. |
Steve Magnusson (91tr)
Member
Username: 91tr
Post Number: 843
Registered: 1-2001
| | Posted on Sunday, July 14, 2002 - 9:53 am: | |
Mitchell -- RE: "should I pull it out and redo the O-ring installation on that cylinder again?" -- I think you'll be taking some risk if you don't redo all the liner/o-rings (but you should certainly redo the one that shifted -- the cured RTV will have been "torn"). Since the RTV has cured and some/all of the liners might not be in their fully-seated positions, when they are fully-seated the cured RTV might tear and the high-point of the o-ring contact might be shifted onto some cured RTV rather than the liner ID. The deflections here are small and RTV fairly flexible, but I think the F engineers were trying to convey in the instruction:
do not use any curing-type sealant on the liner o-rings since the liners are not in their final postions until after the head & head gasket are in place.
Personally, I'd be tempted to try some non-hardening Loctite PST on the liner o-rings if I could be sure that it would stay with the o-ring (but no experience with that so don't give it much weight). |
Mark Eberhardt (Me_k)
Junior Member
Username: Me_k
Post Number: 75
Registered: 5-2002
| | Posted on Sunday, July 14, 2002 - 9:00 am: | |
The wsm shows a rertaining tool (a washer on a head bolt) to prevent them from moving, my did the same thing when I turned it over with nothing.
Generally, RTV on o-rings is a no-no. The o-ring/gasket joint of the valve cover gasket is the only exception I can thin of. If the liner moved and you had RTV on it, it needs probably needs to be pulled out and cleaned. You really should pull them out and clean the RTV off all of them anyway. While they�re out, and the rings off for cleaning, you can install them without the o-rings and measure the height the way the manual says. Then you�ll know it�s right. If you add RTV and let it dry before assembly, it will take up space, but you won�t know how much, so you won�t know if it will work or not. It wouldn�t give me a warm feeling. Good luck.
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Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 221
Registered: 11-2001
| | Posted on Saturday, July 13, 2002 - 8:07 pm: | |
One more question.
As I am installing pistons inside the engine, one of the liners (#3) rises up about 1" from the friction of the piston rings when the crank was turned. I caught it and pushed it back down again. It happened a couple of more times before I got tired of it and cut some spacers out of aluminum pieces and use the head nuts to hold down all the liners.
Question is: since the #3 liner rose up out of the seat, should I pull it out and redo the O-ring installation on that cylinder again? |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 220
Registered: 11-2001
| | Posted on Friday, July 12, 2002 - 11:38 am: | |
You are correct, the WSM does not specifically state RTV, but it does not state any other lubricant either.
In any case, I feel good that you feel 0.010 is good enough without torque.
Thanks
ML |
Ric Rainbolt (Ricrain)
Junior Member
Username: Ricrain
Post Number: 179
Registered: 2-2002
| | Posted on Friday, July 12, 2002 - 11:23 am: | |
If I not mistaken (this is from memory), the WSM specifically states to install the liners with no RTV... or did I dream that up. I'm not at home, so I can't reference the good book.
Anyway, 1/100 of an inch (with O-rings and before torque is applied), sounds OK to me.
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Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 219
Registered: 11-2001
| | Posted on Friday, July 12, 2002 - 12:20 am: | |
According to Ric Rainbolt's earlier message, the liners protrude above the deck "more than the specs until things are fully seated."
I guess what I am asking is this
"is 0.010 inch protrusion at liner installation time before the liners have a chance to fully seat good enough?" |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 1905
Registered: 12-2000
| | Posted on Friday, July 12, 2002 - 12:07 am: | |
I would follow the WSM (page B12) and assemble without O-Rings, then check liner protrusion. With these directions, Ferrari must be accounting for O-Ring compression. |
Dave328GTB (Hardtop)
Junior Member
Username: Hardtop
Post Number: 188
Registered: 1-2002
| | Posted on Thursday, July 11, 2002 - 10:35 pm: | |
One way or another, you need to get them in spec. Nothing but trouble otherwise. I know of one block that was cracked when heads were torqued because of liners sticking above the deck.
Dave |
Mitchell Minh Le (Yelcab1)
Junior Member
Username: Yelcab1
Post Number: 216
Registered: 11-2001
| | Posted on Thursday, July 11, 2002 - 6:47 pm: | |
Hello all,
I am installing old liners into old block in the same positions with new o-rings and a thin layer of RTV. Heating the block up makes it easy to push the liners in. But the best I can do is 0.010" (specs is 0.002" without o-rings installed).
Is this OK at this stage. I am guessing that the o-rings springiness is keeping the liners up and once the head gasket and the heads are bolted on, the o-rings will compress, everything will seat and be within specification.
Is this the correct assumption, oh you engine rebuilders???? Or, do I knock them out and do it again? |