Engine rebuild or swap? What would you do? ('79 sc)

[thefaculty]

Originally Posted by proporsche

Dan..yes do the necessary repairs as for the oil leaks.It is quite normal for the breather hose to leak.Most of the time the hose is very hard and the clamp does not hold it tight.That can be done with the engine in the car.Clean it and see it the other things are leaking ,oil press.switch and thermostat o ring.plus eventually the breather cover gasket.Look here for Triangle of Death..plenty of help here on search button.
Yes drive it and enjoy it later you will have more knowledge about your 911...

Ivan

Thanks Ivan - yes I have all these parts sitting on a shelf waiting to be replaced - I am replacing it all while I am back there. I am basically working through Waynes chapter on common oil leaks piece by piece. Thanks again mate!!

[darrin]

what's your oil consumption like? top end rebuilds are generally predicated on excessive (quart per 500 miles) oil consumption. Also, imo, might be best to wait on the SSIs until you're doing a full rebuild, as pulling the exhaust could create an exhaust stud problem that could accelerate other problems.

[plexiform]

When I was shopping around for a total rebuild of a 3.0SC motor I was told $15k for total rebuild. That was 3 years ago, and I was getting the impression that the price was going to go up as the project progressed. Not sure what shops are quoting for its these days. I decided to go the 3.6L swap route which cost a lot more but I was able to go with custom ITBs and lots of upgrades. I'm happy with my decision because the added power is very noticeable.

[NYNick]

Wait, this is 79outlaw I follow on Instagram? The one with the QwikJack? Oh...now I get it.

Dan, my 72T was sitting in a corner of my garage leaking like the Exxon Valdez for YEARS. I never registered it, drove it or insured it. It smoked like a wet BBQ every time I started it. Everybody, including a highly qualified friend/mechanic, told me I needed a rebuild, at least a top end.

Two months ago I literally winched it to the other side of my garage (4 frozen calipers), bought a QwikJack and dug in. In the process I discovered it had been rebuilt into a 2.7RS Spec engine but not serviced properly for years.

I fixed the brakes, adjusted the valves, installed new valve cover gaskets, new sump plate gaskets, cleaned all the burned oil and dirt off the bottom of the engine and car and performed a major tune up including all fluids, filters, plug wires, distributor cap, rotor blah blah blah.

Wow, what a beast she is now! No more smoke, no more backfiring, no more hesitation. What was an oily mess in corner has turned into a desirable hot rod. These cars recover quickly from proper maintenance.

Pull your engine and do the TOD and everything else you plan. You'll be surprised how good she'll run thereafter. Forget the rebuild.

[thefaculty]

Originally Posted by NYNick

Wait, this is 79outlaw I follow on Instagram? The one with the QwikJack? Oh...now I get it.

Dan, my 72T was sitting in a corner of my garage leaking like the Exxon Valdez for YEARS. I never registered it, drove it or insured it. It smoked like a wet BBQ every time I started it. Everybody, including a highly qualified friend/mechanic, told me I needed a rebuild, at least a top end.

Two months ago I literally winched it to the other side of my garage (4 frozen calipers), bought a QwikJack and dug in. In the process I discovered it had been rebuilt into a 2.7RS Spec engine but not serviced properly for years.

I fixed the brakes, adjusted the valves, installed new valve cover gaskets, new sump plate gaskets, cleaned all the burned oil and dirt off the bottom of the engine and car and performed a major tune up including all fluids, filters, plug wires, distributor cap, rotor blah blah blah.

Wow, what a beast she is now! No more smoke, no more backfiring, no more hesitation. What was an oily mess in corner has turned into a desirable hot rod. These cars recover quickly from proper maintenance.

Pull your engine and do the TOD and everything else you plan. You'll be surprised how good she'll run thereafter. Forget the rebuild.

Yes sir! The one and same. Amazing - this is just what I wanted to hear. So here's a question for you - did you manage a full drop using the QuickJacks? I've measured up and not sure it is possible so curious to know how you did it using this if you did. This is great - I woke up feeling pretty crapy about everything today and this makes me feel a whole lot better! Thanks Nick!

[thefaculty]

Originally Posted by darrin

what's your oil consumption like? top end rebuilds are generally predicated on excessive (quart per 500 miles) oil consumption. Also, imo, might be best to wait on the SSIs until you're doing a full rebuild, as pulling the exhaust could create an exhaust stud problem that could accelerate other problems.

Great advice - thanks! Oil consumption seems to be fine to be - aside from the leaks I[m not adding too much. What you say about replacing the SSIs later does make complete sense but one big reason for me to switch for the SSIs is that when I run heat (which we need to early spring, late fall and the rare winter drive here in Canada) I get a cracking headache after a few minutes and the cabin smells pretty rough. I suspect there are some holes in my original exchangers letting CO2 through and I desperately want this fixed because it ruins any driving when the temperatures here are lower. The goal with this is to replace with the thick flanged SSIs which can accommodate a rebuild to a 3.2 if we end up doing that later - so head studs will be replaced with longer ones than are currently on by 3.0 anyway. I'll also be adding a 2out active exhaust system from M&K which, paired with the SSIs will be a nice power addition and a preferable sound over stock.

[bpu699]

Simple math...

Take a $30,000 Porsche....

Add a $25,000 rebuild to it...

$30,000 + $25,000 =x

My guess is “x” is slightly over the $30,000 you started with.

Rebuilding a motor that works well enough, may not be needed...

[NYNick]

Originally Posted by thefaculty

Yes sir! The one and same. Amazing - this is just what I wanted to hear. So here's a question for you - did you manage a full drop using the QuickJacks? I've measured up and not sure it is possible so curious to know how you did it using this if you did. This is great - I woke up feeling pretty crapy about everything today and this makes me feel a whole lot better! Thanks Nick!

Nope, did it in situ. My leaks were primarily valve cover and sump related. BTW, wait until you do the homework on valve cover nuts proper torque value. 6 foot pounds my ass. But there's more opinions on this than what type of oil to run....I have the (NM) answer but I'll let you hunt for it....

Dropping the engine should be easy with your QJ. I'd add lift height to the QJ via those rubber block areas. I'd also get some kind of ATV jack for the engine lowering.

FWIW, I dropped my BMW engine with a couple of floor jacks and some 4x4's. Not rocket science, just be careful.

[911SauCy]

IMO, you're way ahead of yourself...

The question of "why does it need a rebuild" must be answered with certainty before action is taken.

Mine, was running on 4 cylinders .... reason enough

[thefaculty]

Originally Posted by 911SauCy

IMO, you're way ahead of yourself...

The question of "why does it need a rebuild" must be answered with certainty before action is taken.

Mine, was running on 4 cylinders .... reason enough

I am becoming quite certain I am of the same opinion! Thanks!
Oil leaks first, drive second - enjoy always!

[3rd_gear_Ted]

Originally Posted by yahh

3.6 Swaps are unfortunately much higher than that nowadays especially if you're rebuilding the motor. Motors are selling for 18-25k now + rebuild + swap parts + trans reinforcement + coolers etc.

BUT in the end you have 100HP more and a genuine MEZGER designed 911 engine which is one of the last air cooled motors by Porsche.
Or a completely fresh 3.0 and some coin for which I understand also.

[Sboxin]

Originally Posted by thefaculty

Yes sir! The one and same. Amazing - this is just what I wanted to hear. So here's a question for you - did you manage a full drop using the QuickJacks?I've measured up and not sure it is possible so curious to know how you did it using this if you did. This is great - I woke up feeling pretty crapy about everything today and this makes me feel a whole lot better! Thanks Nick!

Yes, its possible - - done several times - - remove rear bumper and muffler - - use ATV jack for engine and trans - - helps a lot to have two people and floor jack for trans end - - there are several engine drop threads on Pelican that show how to do this - - the first time is 4 hours . . . second time 1 hour . . .

But, the oil leaks can be fixed with the engine in place - - big PITA . . .

Regards,

[DonNewton]

Back to the original question:
1. SCs (most air cooled German cars) will have a bit of smoke at start-up. They didn't earn the name "Puff the Magic Dragon" because everyone is crazy for 60s Peter, Paul and Mary music.
2. As others have said, it is not uncommon for these engines to run to 250K before they'll need to have the case cracked.
3. I had owned my SC for ~8 years when I was deployed for Desert Storm/Shield for about a year. I popped a couple of head studs when I got back to San Diego and had to have the requisite upper end rebuild done (~74K on the odometer). Bottom half was pristine: No inordinate wear on the crank, oil pump "looked" good (still generates about 1 bar for 1000 rpm).
4. Yes, it leaks a bit. It's just marking it's territory. This is going to be sealed at the next major service.
5. Unless there is something that's pressing on this engine, you need to drive it and smile! Welcome to the sickness that is Porsche ownership!

[Bill Douglas]

My thoughts are"Why the urgency."

Sure, do a rebuild, but in ten years time. With good oil and not thrashing it when it's cold, it should be fine for a long time.. The SSIs plan is GOOD

[Larmo63]

Not to hijack, but....

Triangle of death repairs look quite dodgy with the engine in the car. Especially with the CIS system in the way.

Any hints on how to go about this? I have a borescope to take a look ahead of time.

[thefaculty]

Originally Posted by Larmo63

Not to hijack, but....

Triangle of death repairs look quite dodgy with the engine in the car. Especially with the CIS system in the way.

Any hints on how to go about this? I have a borescope to take a look ahead of time.

My plan is a partial drop - there are a lot of thread on here about how to go about removing the CIS with a partial drop. It's not ideal but can be done. For me it's simply because I don't have the space for a full drop, if I did I would go that route.