Carrera 3.2 top end rebuild

[preston_brown]

Well I may be going with 95mm Nikasil Mahles after all, stay tuned.

[Porsche_monkey]

Originally Posted by preston_brown

Do you think I'll have to split the heads/cam housings when I install the new cylinders? I assume so because they might have minute variances in height compared to how the old alusil cylinders sat. Or will the torquing process compensate for any variance?

You should be setting the deck heights identical, using copper shims on the base if necessary.

[preston_brown]

Blame Henry, he told me I should do it.

As you all said, intermediate shaft bearings are shot, main bearings have some minor wear.

[911 tweaks]

and to think that all you "wanted" (thought) to do was freshen up the heads. This happens to most.

Actually, only the ones who really care about doing the job right!!

Just think of the peace of mind you will have when you are all done. Basically a brand new engine AND hopefully no more oil leaks!

Best of luck! You can do it! Especially in that spotless and cool looking garage. ;-)

Bob

[Bullet Bob]

Preston,

You are exactly where I am at right now. I pulled the engine/ tranny for a clutch replacement and now I have the case split :-) I too had Alusil P&Cs and I was not too thrilled to find that out (190k miles, 3.2). They are also well worn so time to replace. Cry once, right?

Good luck,
Bob

[Eagledriver]

I've reused several sets of Alusil's some with original rings and others with new rings. These are on Toyo spec race motors (240 HP) and I have not had any problems with them. If you want the increased power of the 3.4 by all means use them but I wouldn't be afraid to reuse your old set if they measure up. Especially if the rings are still good and you keep them in the same locations. IMO the Alusil's got a bad rap from being associated with the 2.7 engines.

-Andy

[Henry Schmidt]

Originally Posted by Eagledriver

I've reused several sets of Alusil's some with original rings and others with new rings. These are on Toyo spec race motors (240 HP) and I have not had any problems with them. If you want the increased power of the 3.4 by all means use them but I wouldn't be afraid to reuse your old set if they measure up. Especially if the rings are still good and you keep them in the same locations. IMO the Alusil's got a bad rap from being associated with the 2.7 engines.

-Andy

For those of you leaning this direction I have many Alusil piston and cylinder sets that I would be willing to sell at a reasonable price.

You plop down your money and roll the dice.

[911 tweaks]

but Henry, don't all of your "USED" parts come with a money back guarantee of 30,000 miles or 2 yrs? ;-)

Listen to Henry here or roll the dice "WITH YOUR MONEY"!
BOB

[preston_brown]

I sent my rods off to Henry @ Supertec to be resized and cleaned up, and ordered a bunch more parts. Started re-assembly last night.

Rods look great, all balanced with the new ARP hardware in place. The crank was cleaned and polished locally, it was still well within limits. I got the rods back on the crank, and torqued them down last night. As per ARP's recommendation, I torqued and backed off 5 times on each bolt, and then did a final torque to 35 ft-lbs. Well guess what, that isn't enough, at least on my torque wrench (calibration might be iffy, need to have it checked before I continue reassembly) to get to 0.012" of bolt stretch. I don't have a stretch gauge, but I can use a micrometer. I mic'ed each bolt before and after, and all the nuts needed a bit, and sometimes more than a bit of extra twist to achieve the recommended stretch. I'd say between 40 and 45 ft-lbs, as measured by my torque wrench, which is nothing fancy.

Work will continue tomorrow or Saturday, I hope to get the bottom end put back together.

-- Preston










OOPS! This last one is a picture of my other hobby, i.e. other time sink. Hopefully I'll have this one together in far less time than the Carrera motor has taken me.

[preston_brown]

Also, this is how I dealt with the piston and cylinder solution:

I bought a low mileage set of Nikasil P&C's from Supertec that Henry and/or his crew cleaned up and balanced. Very fair price. Very. Then, I took my old Alusil cylinders and sent them to EBS racing, who gave me store credit, again for a fair price. The net cost to me was low (relative to Porsche parts prices!) and the peace of mind more than makes up for it.

More reassembly tomorrow.

[lindemans]

Originally Posted by Henry Schmidt

For those of you leaning this direction I have many Alusil piston and cylinder sets that I would be willing to sell at a reasonable price.

You plop down your money and roll the dice.

What is a reasonable price for a part that you strongly recommend not to re-use ?

[ZOA NOM]

Preston, I just noticed what appear to be Dilavar head studs in one of the early pics you posted. With all the beautiful work you are doing, those should at least be replaced with good ol' factory steel.

[preston_brown]

I replaced the whole lower row of studs with new steel ones from Porsche (OEM). The top ones on my 3.2 are supposed to be and appear to be steel already.

I got the mainshaft and oil pump/intermediate shaft assembly placed in the right half tonight. Can't seal anything up until I get some Yamabond 1104/1194, I ordered some but it hasn't shown up. I may get impatient and use Loctite, because I have that. What's the main advantage of the Yamabond? Increased working time? I've used the Loctite on the 356 engines I've built.

-- Preston

[ZOA NOM]

I used the Locktite 574 in a single bead, and had no issues. I did not put anything on the mating surfaces of the main webs.

[preston_brown]

Well, after a pretty stupid screwup which damaged the #7 plain bearings and required both time and money while waiting for a new set, I've got my case halves together. I used Threebond 1194 on the perimeter, Loctite 574 on the bearing webs, and Threebond 1211 for the #8 bearing seat. Everything went together smoothly. The 1194 is quite different than the 574 -- it tacked up but remained soft long before I joined the case halves. I hope that is how it is supposed to perform. It looks a lot more like RTV than the Loctite as well.

[efhughes3]

Congrats Preston, that's a big first step.

[preston_brown]

The two short case perimeter bolts were different lengths. Which one was supposed to go in the front and which one in the back? I guessed, and it didn't appear to make too much of a difference.

[preston_brown]

Seems I've been here before. Just wish I had more time to move the project along. Things will hopefully proceed faster now. My plan is to work on the valve train and timing chain case stuff tomorrow.

I did want to verify that I could install the heads as I did. When I originally decided to pull off the old Pistons & Cylinders, I simply removed the heads and camshaft housing as two assemblies, rather than removing the cam housing and then pulling off the individual heads. So I put on the new pistons and cylinders, and simply installed the two head units, and torqued the head nuts back down. No need to do anything else I hope.

OK Ed, maybe you can't eat a banquet off my engine like you can with yours, but at least its clean enough to not be embarassing anymore.

And let's hope no leaks either.

Any answer to the case perimeter bolt question above?

[john walker's workshop]

finish installing the cam and all the rockers and shafts first, them install them as an assembled unit. turn the cams so the keyways face straight up and set #1 and #4 pistons to TDC before joining things up. then you can hang the sprockets, chains and tensioners, slip in the timing pins, snug the cam bolts and then it's ready to set the cam timing.

[wmunchovie]

Originally Posted by preston_brown

I replaced the whole lower row of studs with new steel ones from Porsche (OEM). The top ones on my 3.2 are supposed to be and appear to be steel already.

I got the mainshaft and oil pump/intermediate shaft assembly placed in the right half tonight. Can't seal anything up until I get some Yamabond 1104/1194, I ordered some but it hasn't shown up. I may get impatient and use Loctite, because I have that. What's the main advantage of the Yamabond? Increased working time? I've used the Loctite on the 356 engines I've built.

-- Preston

I used yamabond on my last rebuild on 930; it never leaked once, ever where I used it - used no locktite at all. I also put a very, very light coat of lithum grease on several o-rings - especially on oil return tubes o-rings.
munchovie.