Closing The Case. How to re-build your Air-Cooled Porsche Engine

[@john2ndname]

thanks Kurt. i watched this video many times and learn every-time i watch it. thanks for your time.

[@klassikats]

Glad it was helpful! Kurt

[@rodgraff1782]

I always have a helper when closing the case. Ales things a lot easier, and faster. No worries about the sealant going off before you’re done.

[@klassikats]

Yes, a helper makes the job go a lot faster and smoother. Kurt

[@haraldseifried8013]

Fantastic video. Never found this in german. Rebuilding the heart of the best sportscar in the world ! Greets from germany !!!

[@klassikats]

Glad you enjoyed it! Thanks Kurt

[@kavs911]

Great video! I did some things correct and some things not so on mine but nothing too worrying! I can sleep at night now! Thanks Kurt & Sarah!

[@klassikats]

Always a good thing!

[@toml.6450]

Many Thanks for all the important details. Very professional. I like it

[@klassikats]

Thanks Tom.

[@Chunkerdunkers12]

That is a crunchy sounding torque wrench

[@klassikats]

Just the video sound. Kurt

[@ZOANOM]

Just did this. Sure feels good when it's together.

[@klassikats]

Yes it is a good feeling when everything is closed up and the crank rolls like it is sitting on roller bearings. Thanks for watching

[@varmays]

What a wealth of information! Thank You...

[@klassikats]

Glad it was helpful! Thanks for watching

[@kazstrankowski8721]

Great video! I've never seen those tools for the rods and the chain must make it super easy to rebuild an engine by yourself.

[@klassikats]

They are all factory Porsche tools and are still available today from the dealer. And yes it makes it very easy to put the case together without having to juggle rods and chains. Thanks Kurt

[@doggerracing5243]

I just discovered this channel and have been binge watching the content for a couple of days. I would like to say many thanks for the time and effort you put into producing such high quality videos explaining all that goes into bringing these air cooled wonders back to good as new condition. I just wanted to know if you’ve had the “torque by feel wrench” you used on the marginal access nuts at the back of the cases, calibrated lately? Looking forward to watching the rest of the videos. I started at four years and am up to two years ago. Webers are next.

[@klassikats]

Glad you found our channel. Funny enough Kurt once competed with a friend on a hand torque challenge and won every time. Try it for yourself. kzbin.info/www/bejne/oquuqIGuncmAfqc Carburetor videos are only popular with a small group. S.

[@pcar5]

I would definitely have two people working the assembly process with such a short working time.

[@klassikats]

not required, its an easy one man job. Kurt

[@robhurley5258]

Great video! Good reminder to check to make sure the rods are rotating freely. Ask me how I know that 😂

[@klassikats]

Does not sound good if you know that for a specific reason! Kurt

[@robhurley5258]

@@klassikats I had everything tightened up and when I was done flipped the engine over and went to rotate the crank and found one of my rods had gotten jammed and wouldn’t turn. I had to take everything apart and spent the rest of the night cleaning off adhesive 🥲

[@scottzito4797]

In your online parts store do you sell a rebuild kit with all the right lube, gaskets, washers, Etc.? Bare necessity specialty tools would be great also.

[@klassikats]

We do not have an online parts store. We sold Partsklassik 5 years ago and are no longer affiliated with it. Thanks Kurt

[@GarageTimeAutoResto]

Thanks I'll be needing this soon!

[@klassikats]

Thanks for watching and glad you enjoyed it Kurt

[@shanesmaineshop]

Never worked on a Porsche but have worked on many air cooled vw bugs.

[@klassikats]

Same principles apply, more expensive parts and tools!

[@tycotoys]

I watch these one after another

[@klassikats]

Glad you enjoy them Kurt

[@kevinthomas8768]

Hey Kurt , in regards to the through bolt o rings. Do you prefer the blue ones over the Porsche red / brown ones. There are many thoughts on which to use and wether to use any other sealant like RTV to prevent leaks . Is Curil T ok to use there? Have you had leaks happen and if so what caused them. I see that you used oil to lubricate the threads. I don’t want a leak here and I have read that it is common. Your videos and knowledge are a big help Thank you.

[@klassikats]

Kevin, First RTV silicone has no place in this engine, Especially when you use it on a gasket or Oring. I NEVER use any sealant on those Orings, just oil and I have never had a leak there. There are two reasons why that area would leak. No lubrication and allowing the washer to rotate while tightening. This will cause the oring to bind and tear. Or the other cause is the gasket surface on the case is in poor condition and it has not been spot faced during the case machining operation. When it comes to an oring choice I have used them all and have not ever had any problems with any of them. The big take away from this is dont use any sealant material at all ever on an Oring seal. Make sure the sealing surfaces are in good shape, and make sure that the Orings are lubricated before installing and that the washers are not allowed to rotate while tightening the bolts. Hope that helps Kurt

[@kevinthomas8768]

@@klassikats Kurt , thank you for the great answer and explaining it at length. I cringed at the idea of using RTV or anything else. I will follow your advice and make sure not to let the washer rotate. Thank you for the fast response answering my question .You eased my mind on this part of the job.

[@klassikats]

@@kevinthomas8768 Your Welcome Kevin

[@dennisvogel]

Does the alternator ground strap attach to the same stud on a 914-6?

[@klassikats]

Yes, it does Kurt

[@kevinthomas8768]

Kurt , is reusing the case through bolts , nuts and washers ok, mine look great but lack the original yellow plating. New o- rings of course.

[@klassikats]

Kevin, Yes that is totally fine to reuse the Through Bolts, Nuts and Washers. Thanks Kurt

[@dennisvogel]

Hi Kurt. Do you recommend putting anything on the freeze plugs? My understanding is the factory covered them with epoxy? We had something that looked like old gum on our case. I've not been able to find a reference to the specific epoxy that was used, but have read some places that folks cover them with JB Weld.

[@klassikats]

Dennis, I use Loctite 574 when installing plugs. You wont find any references to what the factory used as Porsche did not expect you to have to remove those plugs in normal service. Kurt

[@rodgraff1782]

What is the need for freeze plugs on an air cooled engine? Are you talking about the plugs that are covered with the epoxy on these engines?

[@dennisvogel]

@@rodgraff1782 Technically they are not freeze plugs, but they are commonly referred to as such. It's the dowel pins and plugs.

[@kevinthomas8768]

Hey Kurt what brand Torque wrench is that in the video ?

[@klassikats]

That one is a Snap On wrench

[@patricebecquerelle53]

Thanks for the video! ;)

[@klassikats]

Thanks Patrice.

[@herminethewolfyt]

Hi Kurt Another great video. Can you tell me your opinion about using 574 on the other flange versus the use of ThreeBond 1104/1184/1194? Also i've seen a few other builders putting sealant on the number 8 bearing behind the o'ring......any thoughts? Thanks Steve

[@klassikats]

Steve, using three bond or any type of silicone sealants is about the worst thing you can do for your engine. I have written an in depth article about why silicone sealants should not be used with the air cooled Porsche engine. You can read it here, www.klassikats.com/2019/11/08/porsche-crankcase-sealant/ The same goes for applying sealant to the number 8 bearing oring. There is one caveat to the #8 bearing sealing surface on the case. Often the magnesium case's can corrode at the sealing area of the oring. What I do in there is use a small amount of JB weld to repair any imperfections and then sand back to smooth. Then assemble using silicone grease to lubricate the O-ring. Thanks Kurt

[@herminethewolfyt]

@@klassikats Hi Kurt, its exactly what i was thinking but a very experienced (supposedly) builder has been banging on about it on the Pelican forum for years........i know i know...forums !! 🙂 Silicon or RTV floating around an oil system is the worst. About sealant on the o-ring (or behind it) i could not believe what i was seeing. I am an aircraft engineer.......i know fun well that o-rings need a clean surface and a small amount of lubricant but it's amazing what i've seen.......including people putting 574 on the o-ring itself! But all this said.......material technologies change with time ...so research is important!! Thanks very much for you reply......more questions to come on other videos!!

[@herminethewolfyt]

I read your article by the way...very good

[@klassikats]

@@herminethewolfyt Steve, Yes I know exactly who you are talking about. I have been doing this for a very long time now and I must say all the builders that I know and respect do not post on forums and never use anything but 574 as a case sealant. It is a subject that I could go on for hours about in the damage I have seen as a direct result of the use of these sealants. As an engineer, you understand the design principles and the method of returning the surfaces to the original design specifications and correctly applying the specified jointing compound.

[@frederikbeernaert8113]

Stupid question perhaps, just out of curiousity, why not paper gaskets?

[@klassikats]

Paper gaskets add material thickness to the case halves that cannot be accurately controlled and accounted for. The Loctite sealant does not change the metal on metal contact of the case halves and there maintains the bearing clearances and tolerances. Kurt

[@911engineguy]

@12:58 are the through bolt bevelled washers, bevelled on both sides?

[@klassikats]

There are two types of case through bolt washers. The early style washers are only beveled on one side to accept the oring. The ones we used on this engine were the superceded part that is beveled on both sides. There is no advantage or disadvantage to using either washer. Thanks for watching

[@dennisvogel]

I noticed that the washers that came off our engine were only beveled on the ID. I got worried when I looked up the part number and found that the current supply is beveled on the OD too. Referencing Bruce Anderson's Porsche 911 Performance Handbook, I learned that the inner bevel only design was a correct for pre-1973.

[@davidwhite6830]

Just so people are aware, putting sealant on the main bearing webs is not recommended by all engine builders. This can result in changes to the main bearing clearance, and possible noil pressure issues. Being able to quickly assemble the case and get the through bolts torqued down quickly does make it possible for experienced builders. Porsche didn't do this at the factory,.and I won't be doing it to my 1986 930.

[@klassikats]

David, So the only way I could agree with you was if you were using the wrong sealer like any type of silicone sealant. The only approved sealant to use is Loctite 574. Because of its viscosity being thixotropic, it is able to allow for a very close metal on metal bond. Only filling those areas of imperfection in the joint. This results in a very stable dimension between the two flanges. When the case halves are joined using Loctite 574 it is not only sealing the joint but also chemically bonding the two halves together. This makes the case assembly as if it is one solid piece, which helps the case maintain stability. There are several reasons why I use Loctite 574 at the main bearing webs, Firstly, it was how I was trained when I attended the Factory Porsche engine school. Secondly, oil is under pressure at the case through bolts as oil is directed to the main bearings and piston cooling squirters. An oil leak here will result in a loss of oil pressure. Lastly, the chemical bond between the two halves at the main bearing tunnel helps to prevent tunnel misalignment while in service. Another good property of Loctite 574 is that it is an anaerobic sealant. Meaning that it will only go off in the absence of air. One of the reasons that Porsche uses this sealant is that any excess sealant that is pushed out of the joint will be washed away by the engine oil. When it comes to final assembly 574 has a working time of 10 minutes once the two halves are joined, it usually takes me between 5 to 10 minutes to fully torque the case. So a couple of take away's, one only use loctite 574 sealants, two do not over-apply sealant to the flanges, three have all your hardware ready so there are no delays in tighting, and lastly apply sealant to all mating flanges. thanks for watching Kurt

[@davidwhite6830]

@@klassikats I have discussed this with machinist who did the case work and he specifically told me multiple times to NOT put 574 in the main bearing webs. When I took my 1986 930 engine apart, there was no factory installed sealant in this location. It would be interesting to do a test with some gauge blocks and measure the actual change in dimensions with 574 torqued between. I will reach out to Fred Apgar and Peter Dawe who have been consulting me as I go through my engine build. I am striving to build a reliable engine and its amazing to me the differences in sealants recommended, and the variety of procedures followed by different experts. I am pretty sure both Fred and Peter are factory trained in building Porsche race engines so will be interesting to see what there method and recommendation is. I am a mechanical engineer and work on precision tooling, to rework aircraft so am familiar with and able to perform precision measurements. This is not to say I am an engine expert, far from it, I am just trying to learn from people like yourself who are truly experts in this field. Great videos you have up, I am going though all the engine ones and watching as I will be doing final assembly in a few weeks. David

[@klassikats]

@@davidwhite6830 David, don't know who Fred is but do know Peter Dawes, don't know if he was factory trained or not. He is a smart guy though. We have been planning to do the gauge block test and video it for some time now, just does not ever seem to be enough hours in the day. Good luck with your engine build Kurt

[@3.2Carrera]

Love you videos and using them as an important source for my rebuild. Important question though: Are the later aluminum cases strong enough in your experience to not use 574 on the main bearing saddles? I just measured my bearing clearances yesterday and like them right where they are and if the factory didn't use it there I'm thinking I can skip that. Thoughts?

[@klassikats]

The aluminum cases are a lot more stable. However, I still coat the bearing webs with loctite 574. Kurt

[@3.2Carrera]

@@klassikats Thanks Kurt. I did it last night exactly the way you did it. Outstanding instruction.

[@rodgraff1782]

I’ve never used sealant there either. It would do nothing to add stability to a mag case. To do that, you would need to shuffle pin the case. This is usually performed when 250 or horsepower or over is expected, especially when it is a long stroke engine like a 2.9. I had to remove shuffle bins from an old magnesium race case that I had purchased, as it had slightly warped from storage, because we had to re surface the mating flanges. They were really hard to remove.

[@pedrokd5439]

Good

[@klassikats]

Thanks Kurt

[@ocmacman17]

Is the 574 applied to both case halves or just one?

[@klassikats]

Hi Trenton, the loctite 574 needs to only go on one side. amzn.to/31TEkzE

[@nicktrigonis823]

My dear sir is it possible I can buy a torque spec copy from you?

[@klassikats]

what model car do you have? write to us at [e-mail] and we should be able to get you what you need. Kurt

[@tdkyt46]

This guy scares me how he puts the bolts orings and nuts on

[@klassikats]

Scares you how good he is.

[@putinisgod6814]

Wayyyyyy to much sealant. You only need a really slight coat

[@klassikats]

There's Nooooooo Waaaaaaay you can tell from this video how much sealant I used. But what ever works for you is fine just make sure your using the right sealant. Kurt

[@rodgraff1782]

@@klassikatsit’s better to have a little to much than scrimp on sealant. Any extra will do no harm.

[@klassikats]

@@rodgraff1782, you may change your mind on that when you watch our next video, tearing down the turbo. S