Building a 400bhp+ 2.5 ltr 944 Turbo
- Thread starter PSH
- Start date
TTM
Well-known member
In my experience the original Reinz black/orange seal leaks very often. The only one that seems to never leak if installed correctly is the black one from Elring, and this is what I've been running leak free for 16k miles.ORIGINAL: PSH On reading various articles on the web it seems that there are two main companies who do this seal Kaco (black in colour) and Victor Reinz ( red/brown), according to what I've read the black seal is prone to leaking, lucky for me then that I have the other..It seems that most ( state side) use Curil T to help seal the outside of the seal against the block, others fit dry while some use grease. Since Curil T is basically a high temp oil resistant silicone I've used a similar alternative available here, I also read that if the main bearing frame has been seperated it's not advisable to fit dry, hence why I choose to use a sealant. You also need to lubricate the inner seal with either a very thick oil or assembly lube so as to stop the seal burning out to give the engine oil time to fully reach the seal when first run.
PSH
PCGB Member
That's interesting Thom and goes against most info on the web, perhaps the black seal needs fitting better than the brown and you've done a better job in fitting it than most. Certainly the info that I've read often has warnings about using the black seals, so well done to you mate for proving them wrong..ORIGINAL: TTMIn my experience the original Reinz black/orange seal leaks very often. The only one that seems to never leak if installed correctly is the black one from Elring, and this is what I've been running leak free for 16k miles.ORIGINAL: PSH On reading various articles on the web it seems that there are two main companies who do this seal Kaco (black in colour) and Victor Reinz ( red/brown), according to what I've read the black seal is prone to leaking, lucky for me then that I have the other..
Pete
TTM
Well-known member
Well, each time I have read about this from RL is that the Elring seal was good and the Reinz seal was bad. Same conclusion was drawn from discussions during various meetings in Germany with other people having only good experience with the Elring seal. Not sure where you got your info from as it is the opposite of what "everyone else" says.
PSH
PCGB Member
Actually it was on RL that I first read about the different seals and the problems associated with them. Elring and Reinz get the nod whereas Kaco get voted out, Kaco are black and Reinz are red/brown which is what I was referring too, only quoting what I read. However I'd bet that most problems are due to poor install and the damage caused during the process. Pete
Indi9xx
New member
Good work Pete. For what it is worth, never had a problem with a V-R RMS. More often than not an issue is caused by not lubricating the inner sealing edge with assembly lube or poor install. If oil leaks around the outside of the seal, it is often an alignment issue between the block and girdle/saddle. The ribs on the outer edge are designed to create a several stage seal, which is only overcome if the two halves of the housing are damaged or not aligned properly. Did you just torque the rod end cap bolts or did you go for a fastener stretch indication as well?
PSH
PCGB Member
Hi Jon I had to torque them as I don't have the right gear to measure the stretch, I could probably have jury rigged something up but I doubt that I could rely on its readings when measuring .0100"to.0105" so I torqued them down. However I did torque the bolts down 3 times to ensure that the rods were fully seated cleaning the threads and using fresh oil each time before I re torqued them. Fingers crossed they'll be up to the job..
PeteGeorge Elliott
New member
Jon, do you mind me asking how that is measured, I never heard of it? thanks George 944t
PSH
PCGB Member
Hi George To do it properly you need a dial gauge that looks a little like a micrometer and has a long enough neck to allow the rod bolts to be measured. You first measure each bolt in it's natural state, ie under no stress, next you tighten the bolts until the dial records the correct stretch, I guess there will be digital versions these days. Reason for this is OEM bolts can be out when torquing by up to 10lb/ft, I would hope that Raceware bolts are a lot more accurate but just in case I torqued them down 3 times to make sure they are seated and minimise any variation in torquing force between the bolts. Hope that helps..
Pete btw most top engine builders will only use the stretch method for the reasons given above.
Indi9xx
New member
Stretch versus torque. When you tighten a fastener you want the clamping force to be at a set level for the two mechanical items you are trying to keep together, so they do not loosen and so that all stresses can be transmitted and shared by the two items in whatever way the designer has planned. All fasteners have an optimal point where they are offering optimum clamping force, which is specified by many factors including their construction, material, thread pitch etc. All fasteners, not just "stretch bolts" will stretch as they are tightened, and will stretch by a specific amount when they are at their optimal clamping force. Too much stretch and the fastener will be overstressed, not enough and it will not be clamping with enough force to transmit stress properly or the two parts of the component will not be able to transmit their stress properly as designed. Usually, torque figures are provided by component designers (such as Porsche in workshop manuals) because with some fasteners it is difficult to measure their stretch, and because main dealers are unlikely to have the correct equipment to measure stretch. So they provide a torque figure, or torque and degree figures, which will provide (in theory) the correct loading or stretch for the given fastener. The problem is, when you tighten a fastener to a torque level, you are not measuring the clamping force of the fastener, but resistance to being tightened, which is influenced by friction and imperfections in the fastener thread or the face that the fastener is turning against. With torque and stretch, there is a window of accuracy (tolerance) dependent on the application and a good practice that you see the correct stretch for a lightly oiled fastener which is within tolerance of torque also. This is because a faulty fastener may stretch to its specified stretch at too low a torque (weak fastener), or in another example a faulty thread, washer or components being clamped may require a higher torque to reach the stretch, in either case, further investigation is required, which could well be the difference between a great engine and one that blows up before it has even run in. Its a rare practice, so no slant on Pete whatsoever for not measuring stretch, but a worthwhile practice where possible, especially where the build cost and stakes are high. A good example of assumption being the mother of all f***ups, I used to find that maybe one in 10 brand new arp fasteners did not pass the stretch and torque comparison, normally it was just down to a thread based issue, which could be cured with a little additional attention, but one in 100 would be a weak fastener needing to be discarded. About the same ratio was found with the new fasteners included with even new exotic con rods. On the other hand, how far do you go? When I am especially paranoid I get parts x-ray'ed by a friend in MOD Aviation, time consuming and a pain, and often just paranoia but it is reassuring. I currently have a slipped disk in my back, during a visit to the chiropractor last week you should have seen the look on the xray nurses face when I asked how much she would charge to xray car parts for me, I just thought it may be a quicker solution (if indeed their equipment could do it) The same MOD engineer will also be cryogenic cycling some of the engine components in the build of my personal 3.0 Turbo engine.. way over the top maybe, but I hate building the same engine more than once.
944 man
Active member
That reminds me that I wanted to try to find somewhere to cryogenically cycle my new big brake discs, or at least quote me. Im under the impression that brake rotors and such are expensive and that it can be justified soley on a cost basis. I have a massive pile of race engineering magazines to trawl through now.....
George Elliott
New member
Pete, Jon, thanks, I am familiar with torque as a Quality measure of component assembly fastening, but not heard of the stretch measurement. Interesting. Hope the back isn't too painful Jon, mine plays up when i spend too long leaning over the front wings of a 944 reaching into the depths of the many hidden bolts...[8|] George 944t
PSH
PCGB Member
Your explanation is so much better than mine Jon, as George said I hope your back recovers soon.. Oil cooler housing or for a Turbo Oil filter housing as the cooler is separate, whichever you have both need to be aligned correctly. I'm not one for spending money when I can make something to do the job myself so after a short while on the lathe I produced this home made alignment tool. The narrower end is a slide fit for the OPRV guide fitted in the block and the other end is wider to be a close fit in the threaded section in the housing, made from alloy so as not to damage anything.
Before refitting the housing I needed to replace the main facing gasket along with the two 'o' rings on the connecting tube. As I have done every stage of this build I first did a little R&D on this, Porsche improved the connecting tube seen in the picture and also had a bulletin advising the use of Loctite 638 to help hold a washer in place if the recess for it measured more than 14.2mm deep. Not knowing what tube I had fitted or if it was sealed with loctite I first used a depth gauge so I could record the amount of tube protruding from the block, so I would know if I had refitted it correctly.
The manual says to remove it by hand but if stuck to wrap it in cloth and use molgrips to pull it clear, I had to use grips. Looking at the state of it I'm not surprised that it wouldn't come out by hand, you can see that the inner seal has failed evident by the hardened black crud around the tube. BTW this is the later tube that Porsche fitted so at some point in time this part has been updated, you can tell by the fact that the tube seal recesses are equal-distant from the ends, the early version had one seal closer to the one end than the other.
Tube fitted with new seals, I first cleaned off the crud that I could.
This is the inner face of the housing with the new gasket in place, when I first took this off it was obvious that a sealant had been used along with the gasket when last done, not wishing to risk a leak I also applied a small amount of Loctite gasket sealant to ensure it would remain dry.
Next was to refit the housing, this is done by first loosely fitting it ensuring that the gasket is in it's correct position, then before tightening insert the alignment tool to ensure the housing lined up properly for the OPRV and torque the four bolts to 14ft/lb. Now after doing this the alignment tool should easily pull clear, mine didn't meaning it was still a fraction out. Although you couldn't feel any difference I slackened the bolts and re-torqued them being extra careful to do so in small steps. This time the alignment tool easily slid in and out of the hole , no binding whatsoever so I'm confident the housing is now positioned correctly.Picture shows the alignment tool protruding from the OPRV opening.
This is the 3 piece OPRV, I have decided to keep this for a number of reasons, mainly that the replacement OPRV for an 86 turbo is a ridiculous price and also the fact that it worked well perfectly before and I can see nothing to indicate that it will not do so again, plus I like the simplicity or it that can easily be reproduced if needed by myself.
Finally as usual a reference picture to show work so far.
Pete
Oil cooler housing or for a Turbo Oil filter housing as the cooler is separate, whichever you have both need to be aligned correctly. I'm not one for spending money when I can make something to do the job myself so after a short while on the lathe I produced this home made alignment tool. The narrower end is a slide fit for the OPRV guide fitted in the block and the other end is wider to be a close fit in the threaded section in the housing, made from alloy so as not to damage anything.
Or use an engine crane and hang glider harness[][]
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PSH
PCGB Member
Hi Rob I was thinking about doing the oil thermostat but during my R&D reading sessions there was a comment, can't remember where from, that suggested leaving alone unless there had been issues beforehand. Since I have enough to do already I have left it for now, plus if it did need my attention later it's not that difficult to get at. Needless to say anything that would be a pig to do once the engine is back in the car I intend to take care of now during this build. Happy to hear yours is coming along too...ORIGINAL: robwright Looks just like mine except a lot shinier and nicer mate [
Pete
robwright
New member
Lol that is exactly the response I was expecting mate. I admire your attention to detail but your ability to think if it aint broke don't fix it. I popped mine open just out of curiosity but really couldn't see any cause for concern. BTW I may have to have a lend of that DIY fashioned 86 block OPRV alignment tool []
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PSH
PCGB Member
your more than welcome mate, let me know when you need it and I'll stick it in the post. PeteORIGINAL: robwright Lol that is exactly the response I was expecting mate. I admire your attention to detail but your ability to think if it aint broke don't fix it. I popped mine open just out of curiosity but really couldn't see any cause for concern. BTW I may have to have a lend of that DIY fashioned 86 block OPRV alignment tool [
PSH
PCGB Member
To finish off a few oil related items: First the 3 piece OPRV refitted to the Oil filter housing, for those not in the know, this is what the old type looks like when fitted into the oil filter housing, a new alloy washer was used.
Next the turbo oil return, refitted after a coat of paint
Lastly for tonight the Air Oil Separator filler tube AOS, can you believe I sat in my living room polishing this to get it nice and clean before refitting, lol... This will have to come off again at some point to remove the small rubber elbow seen here for a new blue silicon replacement, but for now I wanted to fill as many holes in the block as possible to reduce any risk of foreign objects finding their way in, even though it's covered in bubble wrap while not being worked on, two new 'O' rings where also fitted.
Pete
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