| Author |
Message |
Matthew J. Morgan (Kermit)
New member
Username: Kermit
Post Number: 36
Registered: 8-2001
| | Posted on Tuesday, August 20, 2002 - 2:30 pm: | |
Verell, Thanks for the info. The "staking" of the seal groove is one I had not thought of. I have found that directional grooved seals make he difference, providing the grooves encourage the oil to stay in, not "pump" out. |
Verell Boaen (Verell)
Member
Username: Verell
Post Number: 255
Registered: 5-2001
| | Posted on Tuesday, August 20, 2002 - 11:17 am: | |
Matthew,
I haven't had the priviledge of working on 2V cam seals. From the parts & service manual drawings, & previous posts, they're simpler than the QV's setup.
If my understanding is correct, the seals are clamped in place by the cam cover & head. The following is based on this understanding. If it's wrong, then your mileage may vary...
Assuming the above, then sealing the head-cam cover - seal groove joint will be very similar to sealing the o-ring joint on a QV. Also, the risk of nicking/pinching the outside of the seal would exist. However, since the seal is pretty rigid, you probably just need to be careful to make sure it's firmly seated into the head before installing the cam cover.
The seals are prone to spinning out. I remember a couple of tips on this:
- Use a center punch & put 3-4 dings each in the cam cover & head. They should be centered on the seal & pretty well evenly spaced around the circumference. The dings grip the seal's rubber perimeter.
- Clean the outside of the seal with Loctite KleenNPrime. While it is drying, put a thin coating of Loctite 515 or 518 anaerobic sealant in the head & cam cover seal mounting groove prior to installation. Use just enough so that a tiny bead is squeezed out when the cam cover is torqued down.
DO NOT USE RTV, it acts like a lubricant & the seals will spin right out!!
DO NOT get any kind of sealant on the seal lips. Just give them & the cam a smear of oil to ensure they readily slip together w/o nicking the seal's lips.
Hope this helps...
BTW, Permatex sells the same sealants, just look for the 515 or 518. Reference:
http://www.loctite.com.au/USERFORUM/forum10.htm
For tips on using anaerobic sealants see:
http://www.loctite.com.au/USERFORUM/forum11.htm |
Matthew J. Morgan (Kermit)
New member
Username: Kermit
Post Number: 35
Registered: 8-2001
| | Posted on Monday, August 19, 2002 - 9:25 am: | |
Verell, what is the hot tip for the ol' 2V? I have had pretty good luck with them, but have had one weep a bit. Any "majik" tips on this one? Thanks |
Matt Boyd (Mattboyd)
New member
Username: Mattboyd
Post Number: 41
Registered: 1-2002
| | Posted on Thursday, August 15, 2002 - 1:32 am: | |
Verrell (et al),
I just wanted to thank you for your posting. I'm trying your suggestions to see if I do better this time.
I wanted to get my car started tonight but I ran into a roadblock when a helicoil backed out from one of the tensioner bearing assemblies. Machine shop for that tomorrow and maybe I can finish up tomorrow evening.
Thanks again!
-matt |
Verell Boaen (Verell)
Junior Member
Username: Verell
Post Number: 247
Registered: 5-2001
| | Posted on Monday, August 12, 2002 - 8:59 am: | |
Matt,
Larry's remembering correctly. When the cam is torqued down it presses the o-ring out of the lower part of the groove. The cover has to force the o-ring past the head-cam cover joint back into the lower 1/2 of the groove. Hence a tendancy to pinch if the o-ring & grooves aren't good & slippery.
Here's how to avoid the all too common pinching problem:
BREAK THE CORNERS OF THE O-RING GROOVE BOTTOM
at the cam cover - head joint. Just the groove's bottom, NOT the sides.
(Which it sounds like you've done.)
OIL YOUR O-RINGS:
Put a couple of drops of engine oil on the top & bottom of the cam o-ring groove. Also in the cam cover o-ring grooves. Use just enough so that there's a film of oil in the groove & the o-ring is very slippery. You should be able to rotate the o-ring in the groove with your fingers w/o much effort.
The o-ring has to compress quite a bit, so the less oil in the groove the better.
There are 2 reasons the o-ring has to slide freely:
- To slide into it's final compressed position when the cam cover is installed.
BTW, go slowly when tightening the cover in the o-ring area so that the o-ring has time to slip into final position.
- To let the cam seals float into concentric alignment on the cam.
A dab of good oil tolerant RTV like Permatex Ultra Black or Three Bond 1211 will seal thru the oil to the o-ring.
BTW, a round gasket punch about
Here are a couple of prior threads that you've probably already found:
http://server.ferrarichat.com/~ferrari/ferrarichat.com/discus/messages/112/65844.html
Note that I made some on-the-fly corrections (newer posts) to the following thread as my most recent project progressed:
http://server.ferrarichat.com/~ferrari/ferrarichat.com/discus/messages/112/65756.html
ON GASKET CUTTING O-RING:
I haven't seen actual cuts, but have seen FerrariList posts where they've been reported. I have seen about 1/16" or so deep grooves in o-rings. I suspect the cuts may occur when the gaskets aren't trimmed at all.
SOME GASKETS ARE PRE-TRIMMED:
The most recent gaskets I got from T.Rutlands had a nice round clearance area around the o-ring groove. Really nice.
|
Lawrence Coppari (Lawrence)
Junior Member
Username: Lawrence
Post Number: 156
Registered: 4-2002
| | Posted on Monday, August 12, 2002 - 6:24 am: | |
Someone on this list (could have been Verell) said to put a thin coat of oil on the O-rings. That way the cover can slide on the ring when it tightens rather than sticking and shoving the ring downward, buckling it and perhaps getting a bit pinched at the pinch point.
I applied a thin coating of oil but I have no plans to take mine apart to see if it worked.
|
Matt Boyd (Mattboyd)
New member
Username: Mattboyd
Post Number: 40
Registered: 1-2002
| | Posted on Sunday, August 11, 2002 - 9:13 pm: | |
Hey guys,
I'd tend to agree on this. However, why did it used to not leak or get grooves in the o-ring?
I've once been told to "chamfer" the valve cover and head right where they "pinch" together.
Am I torquing the valve cover too much? Do I need to chamfer the edges more than I have in the past?
-matt |
Lawrence Coppari (Lawrence)
Junior Member
Username: Lawrence
Post Number: 155
Registered: 4-2002
| | Posted on Sunday, August 11, 2002 - 4:24 pm: | |
After someone on this list suggested dulling the edges of the cam cover where it contacts the o-ring, I dulled the edge with a file. I have 200 miles on mine now since resealing and no leaks. And I did not replace the o-rings which have a groove in them. I did, however, relieve the gasket about 1 mm as best I could do. As an experiment, I am using two different types of sealant on the covers. The one I think is better is on the front cover that had been a problem even with professional wrenches doing the job.
I think Bill is right about the pinching business. |
Bill Sebestyen (Bill308)
Member
Username: Bill308
Post Number: 307
Registered: 5-2001
| | Posted on Sunday, August 11, 2002 - 4:02 pm: | |
Are you sure it is the gasket that is cutting the O-ring? I have a little trouble understanding how a relatively soft gasket edge could cut the O-ring elastomer. To me, it makes more sense that as the cam cover compresses the O-ring, a small bulge occurs in the gap between the valve cover and head. As tightening continues, a little bit of O-ring material gets extruded and is pinched by the sharp corners. I may be wrong, but you should entertain the possiblility of this failure mode. |
billy bob (Fatbillybob)
New member
Username: Fatbillybob
Post Number: 2
Registered: 8-2002
| | Posted on Sunday, August 11, 2002 - 2:04 pm: | |
Hylomar does not adhere like rtv. It is a sticky goop. Cutting gasket 1mm shy prevents oring cut thru. Spray area with brake clean and apply Hylomar. Also note that nothing prevents a Ferrari from leaking for long. Ferrari can build a great race car and that is about it. |
Matt Boyd (Mattboyd)
New member
Username: Mattboyd
Post Number: 38
Registered: 1-2002
| | Posted on Sunday, August 11, 2002 - 8:19 am: | |
But once the cuts are there they're gonna leak if the cuts are signifigant enough.
Are you proposing that if you simply pull the valve cover and gunk up a little Hylomar (I use Three Bond 1211) that you can "close up" that leak? I'd think it'd be hard to get the Hylomar to adhere to an oily o-ring.
Which leads me to also ask what you all do if you're doing only a valve adjustment and not replacing those o-rings....how do you prep the area around the o-rings to put the Hylomar there to help seal with the valve cover?
Thanks,
-matt |
billy bob (Fatbillybob)
New member
Username: Fatbillybob
Post Number: 1
Registered: 8-2002
| | Posted on Saturday, August 10, 2002 - 5:10 pm: | |
The cuts don't bother anything. Use hylomar thick kind and cut the gasket about 1mm shy. |
Matt Boyd (Mattboyd)
New member
Username: Mattboyd
Post Number: 36
Registered: 1-2002
| | Posted on Saturday, August 10, 2002 - 5:00 pm: | |
Hi all,
I had a relatively productive day today. I already had one valve cover and the decklid off the other night. Today I took the other (front bank) distributor/valve cover off, did a valve adjustment, removed the cam belt covers, tensioner bearing assys, cam belts, and cam shafts (car is at PM1-4, of course). Today's time vested was 4 hours, so I was pleased.
So, the results? Why is my car leaking so much? Well, there IS one groove cut in an o-ring like I described above, but there were a few other leaks at the big o-rings because they look like they were pinched. They definitely didn't have grooves cut in from the gasket being too close and swelling.
The biggest frustration today is that now I'm ready to reassemble but I won't have my parts until Tues/Wed....
-Matt |
Matt Boyd (Mattboyd)
New member
Username: Mattboyd
Post Number: 29
Registered: 1-2002
| | Posted on Wednesday, August 07, 2002 - 9:45 pm: | |
Hi all,
I know this subject is hashed and rehashed, but I'm about to get at it myself again. I simply don't appear able to get it right!
This is the second time I've had signifigant oil leaks at the cam pulleys, and both times I have found the big ole o-rings have grooves cut in them where the gasket mates up with them. The first time I was ignorant and just trimmed them JUST to butt up against the o-rings, and then subsequent swelling of the gasket forced them to cut a groove in the o-ring.
The last time I left a little gap and filled it with some RTV. And now the grooves are there (I just pulled one cam cover this afternoon and confirmed that).
No need for anyone to answer here because it's all in the archives. I'll be searching archives and poring over postings on this topic and try to get as best advice as I can. I have Three Bond 1211 for gasket sealant this time.
Anyone in the DC area (I live just south) that has good experience sealing at this point that is willing to come help?
-Matt |