3.0L Rebuild at 250k miles
 

I've been working on tearing down my 3.0L in my '76 S, the chassis has a touch over 365k on it and the engine has just over 250k...initial reason for the teardown was a large oil leak on the top of the engine but has slowly progressed into more the further I get into it.

Some pictures:
The Beginning:
http://forums.pelicanparts.com/uploa...1397183268.jpg

Bumpers Removed:
http://forums.pelicanparts.com/uploa...1397183296.jpg


http://forums.pelicanparts.com/uploa...1397183327.jpg

Fan Removed:
http://forums.pelicanparts.com/uploa...1397183383.jpg

Engine Out:
http://forums.pelicanparts.com/uploa...1397183352.jpg

Engine on Stand:


http://forums.pelicanparts.com/uploa...1397183420.jpg

Intake Removed:
http://forums.pelicanparts.com/uploa...1397183496.jpg

Shroud Removed:
http://forums.pelicanparts.com/uploa...1397183524.jpg

Found some standing water in the intake port on cyl 1:
http://forums.pelicanparts.com/uploa...1397183543.jpg

Beginning of Timing Component Removal:
http://forums.pelicanparts.com/uploa...1397183594.jpg

Timing Components and Valve Covers:
http://forums.pelicanparts.com/uploa...1397183642.jpg

Case Components:
http://forums.pelicanparts.com/uploa...1397183669.jpg

One Bank of Heads Removed:
http://forums.pelicanparts.com/uploa...1397183697.jpg

http://forums.pelicanparts.com/uploa...1397184755.jpg


http://forums.pelicanparts.com/uploa...1397184773.jpg

Broken Divlar Head Stud:
http://forums.pelicanparts.com/uploa...1397184797.jpg


http://forums.pelicanparts.com/uploa...1397184822.jpg

2nd Bank of Heads: Something found its way in there and did some damage...exhaust valve is burnt as well :(
http://forums.pelicanparts.com/uploa...1397184840.jpg

Watching with interest!

Curious if anybody knows if these RUF 98mm short skirt pistons will work with the 3.0l? I have Nikasil Mahle P&C's but I found a stress crack on one of the pistons...

http://forums.pelicanparts.com/uploa...1398736300.jpg

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/794501-98mm-pistons.html

I understand I will need to have the rods resized and the cylinders bored and replated...

It's been a while since I've updated this but some progress has been made in the past few months...After being unable to source a replacement 3.0 piston, I bit the bullet and purchased a set of 98mm 9.5:1 JE Pistons and matching cylinders from EBS Racing. Don at EBS is great and their work is top notch.


http://forums.pelicanparts.com/uploa...1413966167.jpg

http://forums.pelicanparts.com/uploa...1413965967.jpg

http://forums.pelicanparts.com/uploa...1413965982.jpg

http://forums.pelicanparts.com/uploa...1413966007.jpg

Head studs were replaced with new all steel studs and a set of 964 camshafts were purchased. Cylinder heads are disassembled and off to Randy at Aasco Motorsports in Anaheim for a complete rebuild.

http://forums.pelicanparts.com/uploa...1413966539.jpg

After break-in, the engine will be on the dyno at 911 Design in Montclaire for some power figures.

Great stuff,
and great to see big miles on your engine
And better to know that its going to do even more!

I would split the case and do bearings after 250k.

Great work! Just curious as to why you decided not to split the case.. I am doing mine at 115k and decided to split the case and found a rod bearing that was on the edge of giving out

I've battled back and forth with splitting the case. The car has been in my family since 1978 and we know the entire history of the car and the engine. There has never been any metal in the oil, no abnormal noises, and never revved above 4000 rpm but maybe a handful of times. The case does not leak a drop of oil and my grandfather (retired Porsche Racing mechanic) rebuilt the engine in 1983. I had him take a look at the engine after teardown and he deemed it not necessary. But then again you can't know without tearing down completely and inspecting.

I must admit, I've had a few sleepless nights contemplating the idea of splitting the case and as the engine sits now, it's not too much work to get it back down to the case and split it. My biggest concern is the intermediate shaft bearings (which I have new ones). I'm still contemplating at this point.

There are plans for turbo down the road, Carrillo rods are in the future for this engine. When these are installed (perhaps a year from now when funds become available again), the case will be split and bearings replaced on the bottom end.

This is similar to a build I am currently doing.

Will you have twin spark? What, if anything, will you use between cylinder and head?

The intermediate bearings are probably trashed. Has nothing to do with your use of the engine, they just go. Split the case and reassemble probably adds about 10 hours to the job. You can go with ARP rod bolts so you don't waste a set of Torque-to-Yield, same with bearings.

Sigurd,

No twin spark. The 9.5:1 compression will not require twin plugging. As far as the cylinder-to-head surface, no gasket is needed. The mating surface on the cylinders is slightly tapered for sealing purposes.

What are the specs on your build?

Yea I'm really leaning towards splitting the case now...I have a week or more to wait for the heads to get back to me. This would be the time to do it. Thanks for the insight.

Thank you for the info on the cylinders being tapered. I was not aware of this.

I have 98 mm EBS cylinders with JE pistons. I am, however, planning to have distributor and twin spark. I have been waiting since Easter for the machine shop to start working on the heads. I am in no hurry, but I am looking forward to continue the build. I have 964 cams available.

I am also planning to use a PMO efi setup but I have not decided on what computer to use.

Sigurd,

There are many different options available for EFI on your engine. I work for the company that designed and built all of the electronics systems and engine management systems for the Singer Porsche builds. If you have any questions or need help with your setup, feel free to PM me and we can talk.

Update:

I have decided to split the case, inspect, and replace all the bearings. The replacement bearings will be sent to WPC in Torrance, CA for their "coating" process and should be returned within a week or so. Thanks for all the advice so far guys.

I am watching with interest.
Thanks for sharing

Peter 78 3.0 SC

PS: I gather the Singer EMS is a Propriety development?

Thanks Peter.

PS: I can't get into the details on the project, sorry.

Cylinder Heads ready to have seats cut and new valvetrain installed.

http://forums.pelicanparts.com/uploa...1415837345.jpg

Finally got to splitting the case last night. Found some issues that would have been catastrophic had they not been found. Thanks again everyone for convincing me to split the case.

#3 rod bearing was within hundreds of miles of failure, IM shaft thrust bearing was on it's last leg as well.

I've purchased GT3 main and rod bearings and am having the crank mic'd and polished as well as the rods refurbished and ARP rod bolts installed. IM shaft will be refinished and I've found some pitting on the Aluminum IM shaft gear so I'm most likely replacing that as well.

I still need to crack open the oil pump and inspect for wear as I fear that bearing material made its way in there.

Case Split:

http://forums.pelicanparts.com/uploa...1416517424.jpg

Crank Removed:

http://forums.pelicanparts.com/uploa...1416517463.jpg

Crank on Flywheel:

http://forums.pelicanparts.com/uploa...1416517503.jpg

Cylinder Heads Finished:

http://forums.pelicanparts.com/uploa...1416517653.jpg

ARP Rod Bolts:

http://forums.pelicanparts.com/uploa...1416517679.jpg

Failed Rod #3 Bearing:

http://forums.pelicanparts.com/uploa...1416530473.jpg

Yikes... that was a lucky catch.

Here's looking forward to revving past 4k some day real soon ...

wow great post. And great pics.

Yes, lucky indeed. I'm awaiting small end rod bushing to arrive so that I can have my crank and rods refinished.

On a side note, does anyone know of anywhere (specifically in the Southern California area) to have my oil pump checked for proper pressure and flow characteristics?

Well that has convinced me to split the case on my rebuild!!

What was your oil pressure when this motor was running?

Peter 78 3.0 SC

Glad I can help Peter! Honestly I do not remember. It's been almost 8 years since the engine was ran last. Last I recall, pressure wasn't low but was not super high either.

Oil pump is trash too...large gash in the lower housing.

http://forums.pelicanparts.com/uploa...1416884019.jpg

http://forums.pelicanparts.com/uploa...1416884108.jpg

Picked up a 964 oil pump at a screaming deal courtesy of a friend :D

http://forums.pelicanparts.com/uploa...1417632381.jpg

Now I am in need of the shorter oil pump drive shaft...

I was checking the rod bearing clearances with Plastigauge and found this...to my dismay. This does not look correct to me; however, I put the original bearings in place that came out of the engine and they sit the same way.

Has anyone experienced this, is this normal? I did not have the foresight to check this when I disassembled the engine :mad:

The numbers are aligned on the cap and rod, and the rods were resized to original spec.

http://forums.pelicanparts.com/uploa...1422334056.jpg


http://forums.pelicanparts.com/uploa...1422334083.jpg

That's just not right.
I know that isn't very helpful but the best I can do from this end of the keyboard.

Is only one rod like that or all of them?

He started a new thread over in the tech forum to get a broader audience. Looks like his Porsche Tech said it was correct and a non-issue
http://forums.pelicanparts.com/porsche-911-technical-forum/848942-rod-bearing-misalignment.html

Some progress from last night...

http://forums.pelicanparts.com/uploa...1423005069.jpg

Got the case halves together tonight, all in all not too bad of a process if you have an extra hand or two around to help guide everything and install the nuts and bolts with you.

Used Drei Bond on the case halves and Loctite 574 on the thru-bolt o-rings. I did not apply any sealant to the #8 bearing and did not install the rear main prior to sealing up the halves. It's a great feeling getting to this point, this forum is an invaluable resource and I'm looking forward to finishing this build soon!

http://forums.pelicanparts.com/uploa...1423211148.jpg

http://forums.pelicanparts.com/uploa...1423211169.jpg

http://forums.pelicanparts.com/uploa...1423211187.jpg

Very good job !!!

I'm subscribed to this......

Installed the pistons and cylinders, triangle of death, and timing chain guides tonight...

http://forums.pelicanparts.com/uploa...1423299099.jpg


http://forums.pelicanparts.com/uploa...1423299135.jpg

And the car freshly washed patiently awaiting a new heart...


http://forums.pelicanparts.com/uploa...1423299189.jpg

I am not familiar with the case sealant you used. It is not one recommended on this forum to my knowledge. Suggest you pull up the postings entitled "The Complete Sealant Thread" to review suggestions from successful builders on proven sealants.

And, I cannot understand why you would use Loctite 574 on the case through bolt O-rings. You should have used either Curil T or the Teflon paste recommended in the sealant build article. The Loctite 574 should be totally ineffective as an O-ring sealant.

Though your case is now sealed, I would suggest re-tracing your steps. It is a lot easier to re-seal the case now then after the install and finding that the case leaks.

Sorry to be Debbie Downer on this item. Perhaps it was just a typo on your part.

Drei Bond is 3-Bond (drei = 3 in Germ) and is an excellent sealant. Dunno which version used or if it's good for the 911 cases but we use it a lot in the Ducati world on the engine cases which have a similar sealing need.

Dunno about the o-rings.....

The Drei Bond 1209 (3Bond) is the case sealant the Porsche dealership sells and is what is used on the 996 and 997 GT3 cases. As far as the Loctite on the o-rings, that is what was recommended to my by the engine builder I consult...