Otto's Rebuild
 

Hi!SmileWavy
I am well undreway with my rebuild, but still a long way to go...
My car is a Euro spec 911 SC from 1979. (188Bhp, 8,5:1)

The plan is to perform a rebuild, and in the process replace the head studs for a racing-type, replace cams for "964" profiles, and get a higher compression ratio. Since I discovered that I have Alusil sylinders, I'll probably order a new P&S set... I don't have the money for this at the moment, but somehow, i'll get there. (I hope);)

Guess I'll post some pictures first, with a few questions.

Engine on stand:
http://i132.photobucket.com/albums/q...42008710-1.jpg

Rusty exchaust bolts, (no wonder many exhaust studs broke off):
http://i132.photobucket.com/albums/q...42008708-1.jpg

http://i132.photobucket.com/albums/q...8042008734.jpg

Heads and sylinders off:
http://i132.photobucket.com/albums/q...4042008763.jpg

Alusil... -NOT what I needed, when the idea was to put in JE pistons:
http://i132.photobucket.com/albums/q...4042008758.jpg

JE Piston test-fit in Alusil sylinders... Looks like I'll need to sell the lot, and buy new P&S set..!
http://i132.photobucket.com/albums/q...4042008753.jpg

Valve carbon deposit. Notice a spray of solvant has expanded it on the right. Are they reusable? What size should I order if I need new ones? -Valves are ridicoulusly expensive over here!:

http://i132.photobucket.com/albums/q...4042008752.jpg

Worn CV joints:
http://i132.photobucket.com/albums/q...3042008739.jpg

More updates coming as I progress further...

Removing Head studs... (HARD work)
http://i132.photobucket.com/albums/q...1052008766.jpg

http://i132.photobucket.com/albums/q...6052008768.jpg

Otto, I see you have bent one of your headstuds trying to remove it. They are locked with red loctite. Did you try to heat the case with a propane torch? That is the way to go...

Aurel

Yeah, I started doing that for the two latest ones I removed.

Luckily none of them were broke!:)

The others came off when my buddy and I worked together; One with a plumber's plyer (Is this how you spell it), and the other rotating a set of cross-tightened nuts, as shown on the picture.
As mentioned, we got out two with a propane heater so far, but tomorrow, we are starting with the remaining 5, armed with a new plyer, since the grip-teeth was quickly worn down on the previous...;)
Should work out well, just need to be patient while heating. (15 minutes/stud)

What is the issue with JE pistons and Alusil cylinders?

Hi Fliger!
The deal is that Alusil is a relatively soft metal compared to Nikasil, so it has a set of different alloy pistons to go with them also...

You can look at it this way:

Nickies cylinders (Nikasil) are hard, accompanied by "softer" pistons.
Kolbenschmith cylinders (Alusil) are soft, accompanied by "harder" pistons.

JE pistons are Aluminum, and not the right stuff for Alusil, as the friction would eventually lead to seasure. On the other hand, they work great with Nikasil...


On Pelican's page for JE pistons they explain that they cannot be used with Alusil...
I chose to ignore this, thinking I had Nikasil. -But was not that lucky, as it turnes out...:rolleyes:

Thanks for the info

you definitely need to heat up the case around each head stud. Even though it's not a good idea to heat the actual head stud, I did anyway. For me it seemed to help removing the head studs. I also used the head stud removal tool that is sold by Snap On tools. This tool is listed in Wayne's book. I carefully used a air compressor gun at 150 psi... Let me tell you these bolts are a pain in the ass to remove, if you haven't figured it out yet. I also had a head stud that was bent, it was the last one to come off the case and it took the longest time, about an hour! But, I finally got it out. Check out my thread for some possibly helpful pictures.. The best of luck! SmileWavy

http://forums.pelicanparts.com/911-engine-rebuilding-forum/405886-sabeos-80sc-engine-rebuild.html

sabeo:
Thanks, I'm sure this will be of help!:)

Now I have another question:
I have purchased a set of JE pistons for my car. I know that they cannot be used with my Alusil cylinders. But can they be used with CIS at all?

They don't have the "swaying" top on the pistons like the original has. I understand that original pistons have this shape to help the CIS make a good flow in the combustion chamber. The JE pistons has pockets on the top to accomodate high lift cams, so I'm thinking this is primarily designed for carb setup, because that will allow for high lift cams. CIS don't allow this, wich is why I've gone for the "964" profile cams.

Hmmm... Anyone?

Pic of piston below:
http://i132.photobucket.com/albums/q...4042008753.jpg

Progress so far:
I'm selling my JE pistons, and if possible my old original P&S set alaong with the old cams. Then I'll buy a brand new P&S set here, (PP), together with SSI heat exchangers and a pre-muffler to replace the cat.
I've sent out the heads for refurbishment, and the oil cooler for the engine for cleaning.

Got some parts yesterday... (The list is scary, and still, ther is a lot more to come!)

http://i132.photobucket.com/albums/q...8052008771.jpg

Otto, you can have your cams reground to 964 profile, no need to sell them, and a lot cheaper than new, or even good used cams.

Aurel

I've allready bought a set of "964" cams. So I don't need the old ones.

Otto,
I suggest doing some additional background research on your options and basic assumptions. False assumptions could cost you add'l budget. Bruce Anderson and Wayne (Pelican) have gathered some very thorough information on engine rebuilding. Reference those manuals to determine what works and what doesn't.

All contemporary engine pistons are made of aluminum alloy, including the ones designed for Alusil and Nikasil cylinders. The differences include whether they're forged or cast aluminum, if piston is compatible with the cylinder surface, type of induction (CIS, MFI, carbs), mechanical compression ratio for a given engine size, etc.

Sherwood

Sherwood:
I think I allready know what I need.
It says on Pelicans info regarding JE pistons, that they cannot be used with Alusil. And I know for a fact now, that I could have used the JE pistons with Nickasil. But with the money that I got from selling some parts allow me to buy an entire set of P&C, without braking the budget too much. This means I don't have to wait 6 - 8 weeks just for a set of cylinders, made to spec. (I'd like to get on the road ASAP);)
I have talked to many people about this in Norway, including the guys at the Porsche engine workshop here, and they all say this is the way to go.

You might want to talk to Camgrinder or Bruce Anderson about using a 964 grind with that set up with CIS. The thought is the 964 gind creates a situation where an over rev will crash valves into pistons. Something about the down slope on the cam being pretty severe and it affects the valve springs and keepers and they fail or can't keep up. Not sure I understand all I heard, but checking may save you some trouble.

I have heard the same thing about normal SC cams.
Some say that this can occur because the chain tensioner has a slack. This is taken care of with carrera style tensioners.
Overrevving is never good for the engine, so I'll have to be careful not to do so, as always.;)

Progress: Opened the block today, and it looked pretty good!
I'll only need to replace the bearings for the oil pump axle. (Of course, I'll replace the chain guides and chains also)
Pic:
http://i132.photobucket.com/albums/q...2052008780.jpg

http://i132.photobucket.com/albums/q...2052008781.jpg

Otto, you should replace the main bearings when you have the case apart, not just the intermediate shaft bearings.

That's what I thougt too..!;)
But my pal, who has opened a lot of engines, felt that this was a waste of time.
He said that since I have alomst no wear on these bearings, it means that the main shaft is nearly perfectly balanced and centered. So, if I keep these bearings, I will be sure this continues like that for the future. And a LONG time into the future as well! I choose to thrust his judgement; He does this for a living, and he has been spinning the spanner since he was 7 years old...;)

Pistons
 

All the 944 guys are stuck with Alusil. I've heard over there that JE has a coating availble that survives in an Alusil bore. Might be worth looking in to.

Yeah, that could have been a good idea.
But rather than going for a solution that may work, I opted for the much safer "no brainer" solution. I have heard so much tales of bad experiences with Alusil, that I choose to keep clear of it alltogether.;)
Besides, I've ordered the P&C set from Mahle (9,8:1), and sold the JE pistons.

Otto,


There are a few ways to measure bearing wear: plastigage, a ball-tip micrometer, a bore gage on the assembled case halves, a comparator gauge set up on a stack of gage blocks to zero, then introduce the bearing to see the difference.

The eyeball is not an objective measuring device.

The specifications are in the factory specifications book for the bore diameter and shaft diameter, and the maximum allowable clearance. Wayne has thoughtfully reproduced these in the back of his book. A comparison could be made between the shell thickness of the worn bearing vs. the thickness of a new one. These dimensions are given in the hundredth of a millimeter.

A set of bearings is inexpensive enough that they can be replaced, even if the existing ones look fine.

Hmmm....
You make a lot of sense! Thanks for useful input!
I guess I'll just replace them then...
The expence is not a big deal, as you pointed out, so why bother measuring, if it's easily replacable as well...;)
I guess I should have taken into consideration that my pal has a habit of eyeballing things all the time. Allthough this in allmost every case works out, his work is hardly in the "feinschmecher" category.:D

Thanks again!

BAD news!
Got a phone from the guy overhauling the heads today; He announced that there is a crack in one of the cam housings!! He suggested buying a new one.
This is getting EXPENSIVE!:mad:
I'm way past the point of no return, so I guess I'm screwed..!
The only component not to be replaced is the crank/block...!;)
(Anyone up for a sponsor deal? :D)

That is where the fun begins...
Get used ones. There are quite a bit for sale in the PParts classifieds:

http://forums.pelicanparts.com/search.php?searchid=1671164

Aurel

Otto, you can also try www.partsheaven.com

I got a used OEM fog light switch from them.. I'm sure they will be able to help you out for a fair price. Good luck!

Update:
Got my parts from Pelican, finally. They were dealyed in customs over here.
But I forgot to order the o-ring for the #8 bearing. So I ordered that from a dealer here in Norway.
By next weekend, I'll be assembling like there is no tomorrow!!

Some pics:
http://i132.photobucket.com/albums/q...9052008007.jpg

http://i132.photobucket.com/albums/q...9052008008.jpg

HI Otto
where is the crack and which cam housing??

"Got a phone from the guy overhauling the heads today; He announced that there is a crack in one of the cam housings!! He suggested buying a new one."

regards mike

MBEngineering:
I haven't seen the camhousings yet, because the shop isn't done with the heads yet.
But I've got a set of used housings on hand. So I'll probably go for those.

On the other hand, the guy at the shop said that I might be able to use my old ones, because the crach is small, and not all the way through...(?) -Maybe it's fixable..?
He tried expaining where the crack was, but I didn't quite get it. So I'll have to wait and see..!
;)

HI Otto
OK, long as you are sorted with parts.

regards mike

Otto,
Did you ever get any information with respect to the JE pistions and whether they would "work" with CIS (since the CIS pistions were designed with that type of injection in mind)?

With your posts and others to my related thread, I'm once again re-thinking the direction I will take. I'm thinking of NOT oversizing and initially leaving the CIS with leaving the door open for future carbs of maybe EFI. So, I'm wondering how best to decide on pistons... go with the CIS style to help initially, or would that hurt in the long run if switching to a different injection technology.

Cheers,
Todd

I can summize it up for you in a short bit:
#1 define the personality you want for the engine i.e. hp, torque, trans gearing you plan to run and where in the rpm band you want performance.
THEN, the cam profile will be defined to accomplish such
THEN, piston size & dome shape, cyl displacement, crank stroke, head design, valve size, induction...
Good Luck !! If I were you, I would call one of the expert engine builders on this forum whom continually volunteer such info, like henry s., steve w., and any of the others on this forum that know what they are doing. Theu will spec ~ get you what you want... caution: you may not like the price of such an engine, but these guys are tops and you get what you pay for!!

JMO... Bob

toddu:
I think 911tweaks has some good points and pointers here...

I have read a "tech artichle" here on this web site, where a guy tells the story of his tuning experience. He used JE in the CIS system, and it worked well. I have also heard of others with the same result. BUT you cannot use JE with Alusil cylinders. You need Nikasil. Hopefully that's what you got. (I didn't);)

Hi Otto, actually you can replate your alusil cylinder with nikasil, and fit in the JE piston, I talk to EBS about this.

Yeah, I've heard that too...
But it's not cheap, so I went for a new set instead...;)

Yes $150 per cylinder replate x 6 = $900 plus $1000 piston = $1900.

Those prices look allright in my book...!
Compared to apx. 4500 for a new set, that's a bargain!
Are you sure this includes machining to make the clearance within spec?

I've heard the cost is about $3000. (In belgium)


Small update:
I've started painting/refurbishing all the details/covers. MAN that takes up a lot of time!

http://i132.photobucket.com/albums/q...0062008013.jpg

yes included, but if your car mainly street use you are in right direction, I also want some input about why alot of thread talking street use better go for Mahle, track car use JE , is that tear and wear issue?

I don't have any input on this.
Maybe you are right on the wear issue, but cost is probably a issue too...?

Update:
Assembled the cases, looks like it's sealed up good...

http://i132.photobucket.com/albums/q...1062008025.jpg

http://i132.photobucket.com/albums/q...1062008026.jpg

http://i132.photobucket.com/albums/q...1062008027.jpg

Also, I got the parts back from the shop:

http://i132.photobucket.com/albums/q...1062008020.jpg