Installing Pistons and Cylinders on an Air-Cooled Porsche Engine

In today's lesson, we install the pistons and cylinders onto the engine block. You should check out the "gapping your piston rings" video so that you are set up for this lesson.
• How to check your Pors...
We always use the ring compression tool by Hazet and put the pistons onto the connecting rods first. Make your life easier and get the tool.
Hazet 794U-3 Ring Compressor, amzn.to/3gfzwcC
Up next we put on the heads and cam boxes. We have an eight-part series on the cylinder heads. The heads will be good as new if you prep them correctly.
• Porsche 911 Cylinder Head
If you have not gone through and checked your cam box, we have a lesson on that too.
• Porsche 911 Air-Cooled...
As our video library grows, it might be easier to find the stuff you are looking for on our website. The website has a search engine and we have a lot of technical information on air-cooled Porsche.
www.klassikats.com
Remember to Porsche responsibly.
Let us know if we are on the right track, like or comment below. Thanks for watching. Klassik ATS

[@john2ndname]

Hi Kurt. I know you have done a lot on 2.7 Magnesium engines. just one question what would a 1977 2.7 engine have as what type of cylinder barrels? do they have the Nikasil coated barrel or do they just have the other typed lined barrel that was common in the time.

[@klassikats]

Mike they were all nikasil cylinders on the 2.7L Engines Kurt

[@a.c.e.7568]

Well done and everything well explained! Videos like this for us technical people even if we are not rebuilding an engine (my 993 is low mileage) is time well spent.

[@klassikats]

Thanks ACE Kurt

[@Jonnyrockin71]

Sunday morning Coffee in hand KZbin video on Porsche engine assembly 😁😁😁😁😁

[@klassikats]

Nice, Kurt

[@brenyz5013]

Wow very well done video!!!

[@klassikats]

Thank you very much! Kurt

[@adrians6085]

Excellent video, really looking forward to the rest of the series

[@klassikats]

Glad you enjoyed it! and more is on the way. Thanks for watching

[@craiged911]

These videos are so incredible. I am literally rebuilding my '74 911 engine and have you on my computer in the garage as I follow your video step by step. However I am at this point and hit a small bump. My pistons are a lot different from what I can find here and everywhere else and I am really hoping for help. They are Mahle 90L58. They have a large concave on one side and a large bump on the other. Essentially a valley and a hill they are a mid year change that Porsche is so famous for. I can not find my pics for that day and can not remember the orientation. I would appreciate any help. Love the videos. Thanks.

[@klassikats]

C.E, Yes, you have the standard CIS pistons. The concave part of the piston faces the spark plug on your cylinder head. We have a 2.7L engine build video kzbin.info/www/bejne/e6vImqhqgNWkp7c it does not go into as much detail, but you can see the piston orientation. Thanks Kurt

[@craiged911]

@@klassikats Thank you very much. My buddy just started his restoration of his '71 911e. He started watching your tutorial and it got him motivated. He has the twin triple weber carb setup so he was excited to see that on there as well.

[@remcotissink]

You chose to install aftermarket pistons. Are they more affordable or are originals not available ? Are they just as good in your opinion ?

[@klassikats]

The answer is yes and yes. The availability of 2.0L piston sets is not good and the only original equipment replacement sets available are the Mahle motorsports 911S sets. These come with a high price tag of around $5500. These sets are also now using aluminum Nikasil barrels which means updating head studs to Dilavar to match the expansion rate. The quality is excellent and they work very well. The availability of these sets is not good and they are often out of stock. The aftermarket sets are much more affordable coming in around $1600 and are a good quality. The pistons are a forged JE piston and the barrels are a Biral design like the original design. I have used both sets without any issues.

[@thinkerdoit]

@@klassikats awesome video series! What does “birail” refer to? Also if my 930 3.3 cylinders are bored to 3.5 can i still bore to 3.6 for clean up? Or should i buy factory 3.3’s again and match to 3.5 if pistons are still good?

[@klassikats]

@@thinkerdoit Biral means that the cylinder is made from two materials. It means that the bore is made from cast iron and the cooling fins are aluminum. 930 cylinders can be overbored and custom pistons made. It just depends on what you are trying to achieve. Both buying the 3.3L Mahle motorsports pistons and cylinders or over boring and custom pistons are a pricey item

[@herminethewolfyt]

Hi Kurt, I saw you comment on another video regarding lapping the head to the barrel to get a nice seal and wondered if you could use a similar technique between the barrel and the case? i explain....noted that you say not to put any sealant on the copper base gasket......important that its clean and well prepped. I have a 3.1 SC-L which uses 97mm turbo barrels with high compression pistons......being a very rare engine there is almost no information existing for these motors. When i disassembled the motor it was fitted with turbo aluminium head gaskets which i will replace with new items (obviously) the mating surfaces condition is not spectacular so i will carry out the lapping just to clean up the surfaces. What do you think about doing this on the base also , baring in mind that the cases have not been deck-machined? Obviously i don't want to have leaks at the base of the barrel........and again others are recommending Curel-T non curing liquid gasket at this location........

[@klassikats]

Steve, I would not recommend lapping the barrel to the case. These surfaces should be a machined square surface and lapping could result in changing that for the worse. If there is any doubt in the trueness of these surfaces I would have them machined. Once again NO on using any sealant here, it just causes issues later and it is just not needed. I would also say that if your heads have any damage then I would machine them as well. lapping is only for final assembly mating and more so on the 356/912 engines where they do not use a head gasket than a 911 engine. Thanks Kurt

[@kevinthomas8768]

Hey Kurt , it wasn’t clear to me on where to locate the piston ring gaps. I see that they should not be on the thrust sides of the piston. I was thinking : oil ring gap at about 2: o’clock position while the second ring is at about 10 o’clock and then the top ring at about 4. If that’s wrong can you tell me what’s correct. Thanks.

[@klassikats]

That will work. Kurt

[@miltona09]

Enjoying the videos! Why is the wrist pin circlip direction important?

[@klassikats]

Ted, It is more of a best practice than an absolute must. What it stems from is that as a general rule you dont want to position a circlip gap 90 degrees to the direction of travel of a component. This is because if something where to rub against the part it could catch the edge of the circlip and dislodge it. However, with the gap facing up or down this cannot happen. Now I know the chances of this happening inside the cylinder is slim to none, but after having it drilled into my head as an apprentice there are some things that I just do without thinking about it. One other advantage of positioning the circlip is that moving the clip in the groove will ensure that it is correctly seated. Hope that helps to explain it Kurt

[@kavs911]

The right tool make the job so much easier!

[@klassikats]

yes having the right tools for any job is a key part of the success of the job.

[@MH-ev3wr]

So great. How many engines do you reckon you've built, Kurt?

[@klassikats]

A lot, have never really sat down and tried to figure it out how many I have done. Kurt

[@scottzito4797]

How much can you overbore the cylinders on a 2.4 L engine?

[@klassikats]

1-2 mm depending on the cylinder quality you are starting with. Kurt

[@KoenigsTiger957]

Great video!! Thank you for sharing all the priceless knowledge!!

[@klassikats]

My pleasure!

[@kevinthomas8768]

Just wondering if those are canyon brand head studs or another maker? Oem ? Thanks Kevin.

[@klassikats]

I use Canyon brand head studs for the mild steel upper studs on engines that use aluminum barrels and I use factory Dilivar head studs on the exhaust side. For engines that are using biral or cast iron cylinders you can use them on both the intake and exhaust sides. All Turbo engines need Dilivar studs on both sides. Thanks for watching Kurt

[@kevinthomas8768]

@@klassikats thanks for the info,

[@ric4623]

This is extremely helpful, thank you!

[@klassikats]

You're very welcome! Kurt

[@mqnwest]

Outstanding!

[@klassikats]

Thank you kindly!

[@nicktrigonis823]

Great information thank you

[@klassikats]

Glad it was helpful! Thanks For Watching

[@rossmoultrie885]

I was looking for some deck height checks …

[@klassikats]

Ross, I usually calculate my deck height mathematically, based on the case thickness, shim pack used and piston used. Are you just trying to calculate compression? or clearance? Kurt

[@rossmoultrie885]

@@klassikats Hi Kurt, I need to check the Piston to Head Clearance .. I understand this should be 0.9mm minimum but ~1.2mm preferred. I'm building a ~10:1 2.7RS+ engine .. I understand we don't want too much squish volume as this promotes localised detonation. I'm going to check using modelling clay. I'm cautious as the 2.4 heads do not have the chamfer as the 2.7 heads.

[@klassikats]

@@rossmoultrie885 sounds good

[@mqnwest]

Brilliant. Thanks.

[@klassikats]

You're welcome! thanks for watching

[@user-gl2eq2ly4g]

I'd totally be dropping those circlips into the engine😁😂🤣🤣🧐

[@klassikats]

Don't do that!!