Hostie de calice de tabernacle…

Well on the up side, its no longer summer and your 2nd drop will be faster and in more confidence.

Here is one of the review of the product:

Fragile
By KTL, submitted July 22, 2013
Comments: Just a paper seal so need to be wary of installation. Sometimes can shift when installing cover plate and causes pesky leak. Look behind chain box after install to ensure good alignment, otherwise you'll be… (well you can guess what)

Sorry to see that. Quite the killjoy, I know. I posted that Fragile comment after experiencing the killjoy myself after having that leak on the race car after its maiden voyage (and race winning- first ever I'm proud to say) after the engine build 7/2012. Posted my review when buying parts this year.....

Will be interesting to see the seal position when you disassemble. Only thing I can recommend is to put 574 on the gasket next time

Did you surface the cover plate? The can be not so flat after many years of the clamp force on the plate. I doubt it's the o ring leaking

I did not surface the cover plate. I now have a nice piece of laminated float glass in the garage and will look into it.

I've googled this and it seems that John Walked posted in a prior thread that its not necessary to remove the cam to get at the seals - Kevin did you find that to be the case?

I can weight in that there's no need to remove the cam to do the seals. I surfaced my plates and installed the paper gasket dry after cleaning all surfaces with brake parts cleaner. I would recommend using a coating of grease on the o-ring the same as you used on your case through-bolt o-rings. Although we're accustomed during these builds to dress most surfaces and gaskets, the paper gaskets seal quite well naked; they're not plain old paper and do bond with the surfaces when prepped correctly.

If JW says it, publish it.

No need to remove the cam as you can just peel the gasket off since it's fresh. Could probably do it in the car but the time spent fiddling around the engine bay probably isn't worth it? Got to be a bit tough to manage the cam counterholding tool and setting the timing with the engine in there.

Truthfully im not upset about redropping, im more worried that i dont have a clear plan about how to do this better. I suppose tearing it down will reveal a lot as will checking the flatness of the thrust plate. Without removing the cam, can i remove the chain carrier to check the flatness of the mating surface on the cam carrier?

Russ, sorry about the leak, you have had great progress the whole time. Sucks!!

So what should I do to prevent this? Surface both the chain housings?

Do I have someone else do it or is the flat glass WD40/sandpaper good enough?

Sorry again Russ!

Sorry to hear about that leak - I'm wondering if I just got lucky on mine since I used the same gasket that you did, light smear of Curil, pretty much the same process. As KTL said, at least everything should come apart readily, and since you had practice, you'll buzz right through this.

Having the engine out, you'll be able to thoroughly visualize all the parts without a lot of gymnastics too. Something's got to be out of whack, that's more than just seepage, so I would expect the source and cause to be fairly self-evident.

On the up-side, you know she's running great - congrats on that! - so that little bit of suspense is out of the way...

GK

I suppose it makes sense to order a few extra cam seals and o rings? Anything else? Don't see why i cant reuse the graphite gaskets on the chain cover, which i installed dry. Ditto for the chain tensioner o-rings, right?

I'd recommend minimums:

2x thrust plate rubber o-rings.
3x thrust plate paper gasket.
Both graphite chain cover gaskets.
2x hydraulic chain tensioner o-rings.

Never hurts to have extras on hand of items that are low cost and that have to ship.

Definitely get a new paper gasket or two to make sure you re-seal it as best as possible. The big o-rings should be fine to reuse. Same goes for the chain cover gaskets. Chain tensioner o-rings might be wise to grab another. Sometimes taking the cover off can disturb that.

I would just do the cam cover plate on the flat surface. Use 600 or 800 grit to save yourself some time. No need for it to be super fine surface like 1000 or 1500. But feel free to make the surface as smooth as you like. Color it with a permanent marker so you can see your progress.

I will be interested to see how your gasket looks when you get the cover off. I think it's more the lack of contact area between the cover and the cam housing, than it is the actual gasket position itself. I recall my leak being a strong one that ran down the case, right onto my exhaust (my exhaust was a set of crazy expensive custom headers from MODE that I inherited with the car and the exhaust was plumbed toward the inside of the engine) and made for a big mess. Definitely not a leak that can be ignored, unfortunately. Not to mention nobody likes ANY leaks after their hard work!

http://forums.pelicanparts.com/911-engine-rebuilding-forum/729496-another-gasket-sealing-question.html

The picture below is pre-rebuild, just to show the routing of the exhaust. I will be honest that the leakiness of the engine was the primary reason for the FULL rebuild after my first failure, which turned out to be a chain tension problem (seized idler arm) and there's no way an anal retentive nutjob like me could tolerate leaving all that filth on there......

http://forums.pelicanparts.com/uploa...1386516518.jpg

I'm developing a theory...

If anyone remembers I had trouble fitting the chain housing because my overzealous JB weld application was pushing it away from the cam housing/heads. I filed down the JB weld but if I didn't go far enough and left it slightly proud, could this cause a lack of contact between the thrust plate and cam carrier sealing surface? The thing that's odd about this area is that the three tiny M6 bolts in the thrust plate are the only fasteners that set the alignment of the chain housing with regards to the cam carrier. These surfaces must be parallel and yet all the big fasteners in the chain housing are running E/W not N/S so to speak.

Good point about the JB weld. That would definitely affect the ability of the cam plate to seal. But remember also that the chain box has some M8 nuts that fasten it to the case, along with a couple of alignment dowel sleeves in the case to reliably locate the chain box repeatably every time. The cam plate has some "float" to it due to the lack of restraint on the OD by the o-ring. Meaning the o-ring allows for some misalignment to ensure the plate is sealing on the cam housing. But if the chain housing is a bit off due to the JB weld interference, that could be the source.

The M8's were the "E/W" fasteners I was referring to, but what sets the alignment of the chain box for/aft? I realize that to a large extent this is done by the M8's, but they are restraining the chain box in the weak axis with regards to fore/aft movement. In other words, they don't have the strength to overcome a little bit of an interference with JB Weld. The downside to this theory is that I'd need to pull the cam to truly investigate.

The confusing thing is that I removed some of the engine tin to get a better look at what's going on and I truly can't see any drips forming from the circumference of the cam seal, certainly not from the top. It must be weeping from the bottom and wicking directly down the chain housing.

Got all my disconnections done and should have the motor down tomorrow. Want to place my parts order asap, going to err on the side of more gaskets. Debating a new thrust plate. Not cheap ($42) but might be good insurance?

I noticed a bit of wetness at the soft line that attaches to the oil crossover line. This was the line I had to replace with a hose from a hydraulic shop. hard to tell if the wetness is from the threaded connection or my hose / clamp arrangement. Because of how PET is drawn its really hard to tell what the part number for this line is. Can anyone help?

http://forums.pelicanparts.com/uploa...1386555602.jpg

I think its part # 930 107 743 12

Which PP re-routes to this part http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=930-107-743-10-M127&catalog_description=&Oil%2520Line%252C%2520Oi l%2520Crossover%2520Pipe%2520to%2520External%2520T hermostat%252C%2520%2539%2531%2531%2520Turbo%2520% 2528%2531%2539%2538%2530%252D%2538%2539%2529%2520

The problem being its $100 and requires me to wrangle with the famously cranky thermostat fittings.

Placed my parts order. Took the belt and suspenders approach.

A few non leak related questions:

I drove for about 50mi to make sure there were no other issues needing attention during drop no 2. Only things i found were:

1. When engine braking there is a rough spot / resonance / vibration at 3500-3200rpm. Happens every time. I did switch exhausts. Didn't notice any immediate interference and the sound is not clangy or metallic, it is similar to a misbalanced wheel type of shake. I know these types of things are hard to diagnose, but are there any common mishaps? As mentioned before, i didn't level the rear engine carrier using any sort of science, just sorta nudged it into shape. Is it possible to hang the engine off center such that there is some engine/trans rubbing of the body or other components?

2. Also notice a subtle thud thud thud sound at idle. Cant hear it outside the car, can just about inside the car. Seems to away with clutch in.

Any thoughts?

Looks like your running the Bursch with turbo style muffler. It may be making contact with the car body underneath somewhere.

Guys -

Motor is back down, chain cover off. Have yet to remove the cam nut but took a closer look at the cam seal and noticed that on the leaking side the thrust plate is just about proud of the chain cover. Here's my pic from assembly:

http://forums.pelicanparts.com/uploa...1386645671.jpg


Whereas on the non-leaking left side, the thrust plate is proud of the chain cover by a few mm.

http://forums.pelicanparts.com/uploa...1386645694.jpg

I'm trying to think what could be causing this? The geometry of this area is still a bit of a mystery to me. If anyone happens to have pictures of what their thrust plate looks like installed, please post. Wondering if I did something so monumentally stupid as not torque the 3 bolts on the right side? Or maybe since the torque values are so low, I got false readings from a binding o-ring? Should be able to tell tomorrow.

If you oiled or silicone pasted the o-ring, there should be no binding that would funk up your torquing of the thrust plate IMO. It's a tight fit but the force applied by the screw threads is plenty sufficient to move the plate along while the o-ring creates some drag due to it's squish

The geometry is a bit confusing. You've got to remember that the plate "floats" in the chain housing. Meaning it's got the ability to have varying depth in the direction of the cam axis & it can account for misalignment in terms of if the chain housing is not truly parallel with the face of the cam housing. The o-ring fit also slightly allows for potential eccentricity of the thrust plate vs. the chain housing opening.

Simply put, as long as the o-ring is engaged in the chain housing, it will seal via the compressed nature of the o-ring. That compression is all that is necessary since it's just splash oiling in the chain housing- no oil pressure is in it. It's really a pretty ingenious design to allow the cam housing & chain housing to interact together.

Your pictures of varying thrust plate exposure validates what i'm saying about the "float." The designers realized that controlling the seal depth in both the axial & radial directions is very difficult. So they chose to focus on the cam seal as the primary one, with a bolted gasket, and left the chain housing seal to just work itself out with the o-ring. The o-ring has proven to be very reliable here in my (limited) experience

The more important seal is (obviously) the cam housing seal. The sealing surface is fairly narrow on the housing itself. So it's critical to ensure the gasket is well aligned. Plus, the sealing surfaces are not all that flat. I don't have a picture of the thrust plate before surfacing but I know mine were not very true. You'll see this when you wet sand the plate. I suspect the plate uneven-ness is the result of being bolted in place for years & slightly distorting. So, if you don't reinstall the plate in the same clocking/orientation that it was originally installed, it seems like they can leak? Just a guess on my part.

Even more telling is the surface of the cam housing itself. See this picture of the sealing area that I colored with a marker and then ran a fine cut file across it in all directions.

http://forums.pelicanparts.com/uploa...1386694594.jpg


Notice how much un-colored area there is, which means the red area is lower than the bright areas. This cam housing is a work in progress as I just did a test area on the housing to see how much work it needed to get it ready for installation. Point here is, the sealing surface on the cam housing is very narrow. The bright area on my housing is the result of running the file in all directions for a few minutes. That means before I even touched the surface with the file, the sealing surface was VERY narrow.

Hope that helps. Sorry I didn't mention this earlier during assembly. My limited experience is with a handful of these engines. So I don't want to make blanket statements like "be sure you resurface the thrust plate and cam bore sealing surface" if its truly not an epidemic problem? :confused:

Thanks Kevin this is a very clear and useful analysis of the sealing surfaces.

I now can understand why short of ripping the o-ring, it is a less problematic surface to seal. I can also see that since the thrust plate is floating it would seem that even if I have a minimal JB Weld conflict on the back of the chain box, the floating thrust plate would be allowed to find the surface of the cam carrier, true and flat with the bolts tightened down. If anything, I now guess that because there is more thrust plate proud of the chain box on the non-leaking side, its possible that the non-leaking side actually has more JB Weld pushing it away from the cam carrier.

I went ahead and bought a new thrust plate just to eliminate it as a variable.

The most irksome thought is resurfacing the cam carrier. Honestly, that would just kind of suck to have to take the cam out at this point.

I really don't know anything about how to pick a good sealant for a specific application. Via PM John Walker recommended a thin thin film of Dirko on the paper gasket, which is RTV. He mentioned that the wrong sealant can soften the paper and lead to it ripping. I mentioned that I have Ultra Gray on hand, not Dirko and he said, sure fine. Does anyone reading have enough of a grasp on what sealant you'd use if you suspected slightly out of flat parts ie what sealant has the best gap filling ability? Whatever sealant is used it will be used sparingly and as a dressing not alone, so In my view there is limited danger of it finding its way into oil passages etc. I don't ask to second guess John, but to help me get a deep understanding of the chemicals on my shelf, past "use this one here".

And finally, is this an area, like the rockers, where slightly higher than stock torque specs may be called for? I don't have the specs in front of me but I recall the number being surprisingly low