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

Hey fellow Pelicans!

My '79 SC has about 124000 miles on the clock and I am considering a rebuild in the next couple of years and I am curious to everyone's thoughts here. My options are:

• 3.0 rebuild to 3.2
• Engine swap

My mechanic is telling me I need to have $25-30k for a rebuild. I am new to 911's having owned this car as my first for just 2 years. I am about to go through Wayne's 101 list of oil leaks, upgrade to the turbo chain tensioners, as well as potentially fitting SSIs and and M&K Active Exhaust to accommodate a 3.2 rebuild next year, but if a rebuild is this much I need to start thinking and saving for this now.

Another option I have been wondering about is that if a rebuild is gonna cost me $30k companies like Vertex Auto are selling rebuilt engines for $15-18k and should I not just go that way and send in my core to them which would bring that down to around $12k (for a 3.2).

So I guess my questions are:

• Would your rebuild or swamp?
• If swapping does can anyone recommend Vertx Auto are any other builders who offer this kind of service?

Thanks as always everyone!!

Dan

Wow! I would get a second opinion! That cost seems kind'a high!

why does it need a rebuild.

you could do valve guides/top end. that engine has a very good bottom end on it if oil pressure is good.

price seems very hi to me too.

Exactly my thoughts! I am definitely shopping this around after being told this and I assume he is going on a worst case scenario. As I am pretty inexperienced in this what would you say is a respectable "ballpark" amount to rebuild a 3.0 bored out to a 3.2? (I do know this can fluctuate greatly but when I was told $30k... well, let's just say I wanted to check!)

There was (maybe still available) a 930 turbo engine for sale on Pelican for $23,000.00 US, which is a bargain, especially if you compare those rebuild prices. I'm from southern Ontario & can tell you pricing is always a little high in Ontario to begin with, but you have options so try not to rush into any harsh decisions.

First, is that CAD or USD? Big difference as you know.
Second, is that a TOTAL rebuild? Better be for that $.
Third, why is he recommending a rebuild? What are the symptoms? Oil leaks don't always spell rebuild. They can be fixed.
Fourth, I'd get a second or even third opinion.
Fifth, if everybody is on the same total rebuild page(which I highly doubt), I'd shop the hell out of it. At that price you can buy and entire SC. I'd even consider shipping the car to the states for the right shop.
Lastly, there's only one shop I'd consider spending that type of money with and they're local and extremely well known, experienced and have a great reputation.

They better. That's a lot of dough and a big job.

SC's can last a lot longer than 124K miles without a total rebuild. Top end rebuilds are sometimes required, but they're $7-9KUSD.

I smell fish.

Dan as the boys said get a second or 3rd opinion..For that money i fly from Czech to you with my tools do your engine and still have the money for beer in Cayman islands beaches...;-)

Ivan

Yea... totally agree with everyone else. I looked at the prices of modding my 3.0 (3.3 ss with ITBs and EFI) and a 3.6 swap. $25-30k you're in that territory -- not just a straight rebuild.

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.

Thank you guys! You are helping me see the light - my mechanic is a solid dude and I trust him but he is also an absolute perfectionist and I believe this is reflected in his estimation.

The car, in my opinion, has always run really well. Oil temperature never gets too high, I don't seem to be getting through too much oil, there are (touch wood), no worrying sounds. Here are the result from a compression test that he did in August 2018:

One - 155, Two - 150, Three - 150, Four - 140, Five - 150, Six - 145

I don't know how to read these yet but they are all within 10% of one another with number being 9.7% lower than number 1. This seem ok right or have I just further proved my lack of experience? ;)

One more thing... speaking from personal experience here... the Porsche community has some top-shelf human beings. It also occasionally has some less scrupulous people. I'm gathering you're a little new to Porsche ownership. I was too almost a decade ago. In the early days of my ownership I dealt with a shop that smelled my newness a mile away and tried to take advantage of me. I'm not saying that's what is happening to you. But I certainly agree that you should get more than one opinion. And this forum is an excellent resource for level-headed advice.

Thank you guys! You are helping me see the light - my mechanic is a solid dude and I trust him but he is also an absolute perfectionist and I believe this is reflected in his estimation.

The car, in my opinion, has always run really well. Oil temperature never gets too high, I don't seem to be getting through too much oil, there are (touch wood), no worrying sounds. Here are the result from a compression test that he did in August 2018:

One - 155, Two - 150, Three - 150, Four - 140, Five - 150, Six - 145

I don't know how to read these yet but they are all within 10% of one another with number being 9.7% lower than number 1. This seem ok right or have I just further proved my lack of experience? ;)

Yea, it all depends on what you're starting with... my point is that you're much closer to a 3.6 swap cost territory than a straight-up rebuild at the price he was quoted. And it's entirely possible that the quoted rebuild price was just high enough and this mechanic just happens to have a "deal" on an engine that would be perfect...

You just have to be careful nowadays.

Dan......does your 911 smoke at any point..morning or warm-hot?As you said ,it is not using oil that is good.Oil leaks are easy fix....Also , with this mileage you are just barely broken in the engine...

Swapping for 3,2 takes more than just the engine ,el.harness, computer and e.t.c.

Ivan

Haven't heard your reason for a rebuild yet. Certainly your compression numbers are fine but hardly tell the entire story.

Thank Ivan - I get a touch of smoke at startup but that lasts no longer than 2 seconds. I have experienced some issues before but only on a spirited drive and only when I dump down through the gears. I know that I have a disconnected oil breather hose (I can feel it loose at the back) and after looking with a borescope I see a lot of leaked oil around the breather hose and gasket area at the front of the engine. This is dripping down on to the heat exchangers (which I will be replacing with SSIs soon too) and giving off smoke when hot, so I definitely need to deal with the T.O.D. which I plan to do over the next 2 months (it's winter here so I am not driving her anywhere for a while).

My goal over next 2 months will be: fuel pump replacement (it died and I have a new one shipping up here from our host as we speak), TOD oil leaks, replace both breather hoses which are wet with oil valve cover gaskets, sump pump gaskets and replace crush washers because I have a leak there as well, upgrade to turbo chain tensioners while I am at it. From there I think I'll just sit tight and see how she runs for the summer before jumping into a rebuild. I have also just done a bunch of reading on a top end vs full rebuild and if I do someday need to do this perhaps a top end only would be the way to go.

I don't have a reason - I just keep being told by my mechanic that my engine is "tired" and needs it. Don't get me wrong - he is not pressuring me in anyway, it's just hanging in the air and making me assume I need it. This forum and the advice from all you guys is a real help in getting a more balanced picture!

This. It's more usual for an SC to go double (some have gone triple) that mileage without requiring major attention.

Your trans would probably benefit from going-through @ 120K, upgrade tensioners and fix any minor oil leaks while motor is out would be my plan.

Unless there's something you're not telling us.

Everything I know I am putting out here for help from you guys so not holding anything back. I'll be fixing the list of oil leaks and hopefully doing the tensioner upgrade engine-in. I don't have room to drop, the car is basically parked in the hallway of my studio!

I definitely agree on the transmission - look what I found last night. I was cleaning the bottom of the car with some AT30 and a toothbrush and after removing 20 odd years of oil and dirt I uncovered this crack/hole right where the starter is mated to the transaxle:

http://forums.pelicanparts.com/uploa...1578673870.jpg

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!! ;)

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.

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.

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! ;)

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. ;)

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...

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...SmileWavy.

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.

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! ;)

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.

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,

http://forums.pelicanparts.com/uploa...1578681838.jpg

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!

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 :)

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.