Putting used 3.0 in my '74 2.7

Hey guys, here's more in the saga of my failing '74 2.7. I have three options I'm considering: (1) sell the car and buy a 3.0SC, (cost $20,000 less $3,000 for my my car = $17,000) (2) buy a 3.0sc engine and have it put in my car (cost $5,000 for the engine + $1,000 labor = $6,000), (3) have my engine rebuilt (cost $3,500). I'm leaning toward having a 3.0SC engine put into my car, but I am open to suggestions.

Is $5,000 a good price for a 3.0 engine with 85K on it. The compression is 180 psi on all six and 2% leak down on all six. This is with exchange of my 2.7 engine.

I'm really trying to find the most economical way to keep the car running for the longest time, cost per mile. The car has 185K on it, and the engine was rebuilt around 90K. I've been quoted $3500 for a complete rebuild of my existing engine, if it is rebuildable.

Any advice and recommendations would be appreciated. On another note, I wish I had seen this bulletin board and Bruce Anderson's book before making this purchase.

------------------
David Huffaker
1974 911 2.7L

5,000 is high retail...but it sounds like a good engine....$5,000 without yours in trade is a better deal....unless the 3.0 engine has had substantial upgrades, like studs redone, chain tensioner upgrade etc...I would try to bargain a little more...it also depends on the year. The 78-79 is the best of the lot. The 80 and up has an extra brain for the CIS which needs more wiring and such.

[This message has been edited by mikez (edited 04-25-2000).]

You may not have to pay $20,000 for a decent SC, but I'm not suggesting this option. if your criteria is cost per mile it would make sense to keep your car. Besides, I believe your car is much lighter than an SC.

I'm not sure about prices, but the engine you're considering sounds pretty fresh still. If it has Dilivar head studs with Time-cert inserts, and carrera chain tensioner upgrade, then you can reasonably expect probably hundreds of thousands of miles left on that engine.

------------------
'83 SC

5K+ sounds a tad high but if he is willing to do a quality job then it might be worth it to you.

One word of caution, get it all in writing and don't pay him until it is done and it runs to YOUR liking. If he does not agree to all terms in writing don't walk, run away.

Remember that you are paying for a little peace of mind too (hopefully in the form of many future miles) and sometimes it is worth the extra couple grand. People buy new cars for that reason every day.

Steve

[This message has been edited by H2O911 (edited 04-25-2000).]

It is my opinion that the '78/79SC 3.0L is more desirable than the others. The reason is the lack of the Lambda loop on the CIS and the larger intake runners. I am planning to sell the engine in my car when I complete the preparation of the "new" engine in about a year. This engine is a no smog '78SC 3.0L CIS with SSI, all upgrades, 78K documented miles. I plan to sell it while in the car so potential buyers will know exactly what they are getting. Price will be $5500 firm, no exchange. This example should give you something to go on.

The $5K price may be a little high, if there is no documentation or records on the engine in question. Does that price include the CDI-box and 'console' or is it just the engine and nothing hanging off the end of the 14-pin rectangular connector?

As far as the installation price, THAT does sound high!!! In fact, for that price you could buy a brand-new set of factory service manuals, a new heavy-duty 3-ton floor jack, and a Perma-Tune CDI replacement for an SC ... study up a bit on the wiring changes required ... rather TRIVIAL changes, in my opinion, AND then just DO IT Yourself!!! Please take a look at these two tech. articles at Perma-Tune:

http://www.perma-tune.com/tech/911sc.htm

http://www.perma-tune.com/tech/911.htm

The wiring diagrams shown are the SAME, whether talking about the Perma-Tune units, OR the factory Bosch CDI-unit, so study closely!!! Pretty simple, right? If you have a reasonable set of hand tools, and can change your own sparkplugs, and adjust your valves on your 911 without major blunders, then you can change engines!!!

A couple of final notes in favor of keeping your car ... there is NO weight difference between your car and an SC, if your car has A/C!!! The SC 'numbers' include standard A/C, and factory specs for '74s did not. Also, your '74 has a 7:31 (4.429:1) ring and pinion in your 915 transaxle, whereas all SCs have the 3.875:1 gearing, so your car will outperform an SC with no weight change, just because of the lower gearing in your car!!! Good luck!



------------------
Warren Hall
1973 911S Targa

Thanks everyone for the advice, and the comparison price. Warren, I'll take a look at those articles. I can change the spark plugs, have a decent set of tools, but no porsche manuals as you pointed out. I have never adjusted the valves. The engine in question does come with the "brain". I assume that's what you were talking about as far as the electrical parts. I would love to do this myself, but I'll have to read those articles and think about it. I'll post again later this week, though I'll be out of the country all next week.

------------------
David Huffaker
1974 911 2.7L

Looks like you are in the Hayward area. Check with PartsHeaven there. They have told me 3.0 engines are about $5000 complete with wiring, brain and all needed parts. I don't know if that was with exchange or outright. They always have a huge supply of parts and are very helpfull. I have purchased parts from them before.

------------------
John Birkett
72'T Targa

Thanks, John. That's exactly where I may get the engine from.

------------------
David Huffaker
1974 911 2.7L

Hey, I'm selling my 3.2 for $5000. It is still in the car so you can check it, drive it and all.
Mike

Now that's a thought. The 3.2 is quite a motor and has the carrera tensioners. And more horses.

I did not know that the weight difference was (it sounds like) purely related to all the SC bells and whistles. but it makes sense.

And I also would suggest you consider using the $1000 some other way. I've removed and replaced a number of engines, and the Porshce is about the easiest. The parts all fit well, generally they only fit only one way (the right way), the engine goes pretty straight up and down into the "engine room," etc.

Also, the procedure makes you a little taller, if you know what I mean cowboy.

------------------
'83 SC

OK, three things. The 3.0 mentioned above has been sold to someone else. They have another, an '82 with 95K on it, 145 to 150 psi on all six (cold, the other numbers were hot), and 2 to 3 % leak down on all six. Still wants $5000, because it has carrera chain tensioners - the first one did not, but he was still unmoveable on the price.

Second, putting a 3.2 in my car sounds good too. Any thoughts on how much more is involved.

Third, I would love to do the work myself, but this is my only car. I will have two weeks off (also to move to San Diego) starting two weeks from now, so I can afford about 5 days -max- to do this. I've been reading Bruce Anderson's book, and it does not really seem like a step by step book. Are the Porsche manuals considerably more detailed?

I know this is a lot of questions, but I want to do this right. Thanks for your help so far.

------------------
David Huffaker
1974 911 2.7L

Just an observation: There's a good discussion of the changes needed for your conversion (to 3.0) on pages 83 through 86 of Up Fixin der Porsche Volume 7 (I think). I hope nobody already said this. Do you have access to that?

It looks like some parts will be needed off the donor car. These (Up Fixin) articles are pretty good. Reading it might make you feel like you know what needs to be done.

That being said, I'm a slow poke and would have a challenging time with this conversion in two weeks. Well, if I didn't get distracted by cleaning, etc. And if a used parts source were nearby, and I had the time off...well I changed my mind. It could probably be done in two to four days. Well, I guess I'm saying its a big job.

------------------
'83 SC



[This message has been edited by Superman (edited 04-28-2000).]

The actual work to convert to a 3.0 would not take more than a day ... but that assumption is based on not having to make any trips to buy a tool you suddenly discover is needed, but nothing in your toolbox will handle, OR any 'side trips' to go find hardware that vanished into the grass beside your driveway when your hand slipped at a most critical point!

As I see there are two wiring changes that have to be dealt with:

1. Converting the CDI-unit wiring from a 3-wire system with a point-type distributor to a 6-wire system with an inductive-trigger distributor.

2. Converting from an external regulator--alternator system to an internal-regulator alternator.

Another system that MAY require adapting/installing is the A/C system ... maybe if the old engine has the mounts and the new one DOESN'T, or it was stripped off!

Since the 911 is your only car, have you considered a rental for emergency trips while the beast is 'incapacitated' and not available?

------------------
Warren Hall
1973 911S Targa

<< $5,000 a good price for a 3.0 engine with 85K on it. The compression is 180 psi on all six and 2% leak down on all six. This is with exchange of my 2.7 engine.

I'm really trying to find the most economical way to keep the car running for the longest time, cost per mile. The car has 185K on it, and the engine was rebuilt around 90K. I've been quoted $3500 for a complete rebuild of my existing engine, if it is rebuildable.>>

Hi David,

When replacing your motor no matter what it is, 2.7 to 3.0, 3.0 to 3.2 or 3.2 to 3.6, you have to look at your options.

Number one, look at the year you have number one, which most do not.

You have a 1974 car, that means you have something differant then ANY other 1975-1986 911, you have a 7;31 transmission, what does that mean? Well this makes your car FLY from 0-60 compared to all other late model Porsches, it lets the power band come on around 3000 RPMS compared to everyone else at 4000 RPMS, (just think all you other Porsche owners, if you car would take off at 1000RPMS lower, how much fun that would be) and one more note on the 1974 ONLY transmission, you have a over drive feel 5th gear, see the 1974 had the longest 5th gear used in the 915 transmission. Also this is what the RSR's used in their 915's, so it is hard to beat. We just did a Porsche owners transmission Don Enderline's transmission he loves it and was SHOCKED on what a differance it made.

NOW, one more note before you leap into the water no matter what you choose.
#1.What is wrong with your motor number?

#2. Your motor was rebuilt before what was done?

#3. What is the car to be used for?

Now, getting back to going to another motor then your own>.

If you go to a 3.0 the motor is 20 years old or more. So if it is a 1980SC it is 20 years old, and if this motor you said only has 85,000 miles on it then that means it was only driven around 4000 miles a year, that is kinda low and not the norm. See most have around 200,000 miles on the motors at 10,000 miles a year, that is why most warranty motors 1000 miles per month. See the problem you have is when you buy a used motor you just never know? UNLESS its still in the car and the motor numbers match the car. See in the early 90's it was VERY popular to go from a 2.7 to a 3.0 because the motors only had around 80,000 to 100,000 miles, but this is 10 years and usually 100,000 miles later, those days are over. That is why we have 3.0's, 3.2's and 4-3.6's getting rebuilt at our shop right now.

Now lets say the motor has only 85,000 miles and runs GREAT, there is still another problem with 3.0's and 3.2's "HEAD STUDS" see it is not miles that makes the 3.0's and 3.2's break studs it is age, fatigue and corrision. We have seem them break on a 70,000 mile 3.0, car sat in the garage and was not drivin for almost 10 years, parked it running great and drove it for awhile and WAM! SNAP! (Gee' What was that Batman?) yep head studs, that is why if you buy a used motor 3.0 and 3.2 get a gaurantee on the head studs are not broken, because if one alone is, motor will have to come down and you will need the motor rebuilt, so you actually bought a core. Simple rule, 2.7 pull studs, 3.0's and 3.2's BREAK THEM!

Now lets say you want to go to a 3.6, get away from all those studs problems, well you better get a 1991 and newer, because the early 3.6's had problems to cylinders and head leaks and dist problems, those motor are comming in WAY to soon and they will be a lot more work then installing a 3.0 CIS in a 2.7 CIS.

If you wish to go a 3.0 try to look for a 1978-1979 the there is NO brain so its a lot simplier and it has the large ports and manifolds.

Now one more note, why I asked you what the car is to be used for and HOW it was rebuilt before is a 1974 911S has 175HP and a 1978-83 911SC has 180HP, hmmmmm? So not a HUGE differance .

David looks to me like with even one of your options was to SELL the car you are just a little frustrated. Have you ever thought about doing you own motor?

Roy at http://www.motormeister.com

Thanks everyone for your advice and patience.

Warren, after reading the articles you posted, I think I would have no problem making the electrical changes. My car has an aftermarket A/C. Not working now, though I don't know why. It does not have oil cooling, so I know this is another thing I will have to add. Yes, I will most likely rent a car whether I do this myself or have it done, rebuild or replacement.

Superman, you're making me think I can do the replacement myself. I'm even considering doing a straight rebuild myself. I'm starting to look for machine shops now.

Roy, The problem with the motor is that it has pulling case studs on at least one cylinder (only one as of 3 months ago). It may have more problems. It now sounds like it's about to blow one of the cylinders off the motor completely. What problems would cause it to be unrebuildable? I will have to go home and look up my file on the prior rebuild. The car is used as my daily driver, though I could definitely see myself racing in the future. I agree with you that the mileage given for the used motors I've considered is suspiciously low. I've definitely thought about doing my own motor - both having somebody such as yourself do it and taking the various parts to a machine shop myself. I'm just starting to look into the last option.

------------------
David Huffaker
1974 911 2.7L

PS, I will be unable to respond here again until May 8. May 15 to 25 is when I will be doing something.

------------------
David Huffaker
1974 911 2.7L

<>

Well, what is sad is you had it rebuilt WRONG, if the case is pulling studs then it was never machined or rebuilt correctly from the start. What is bad also sad is I have seen lots of $$$ being spent on very good parts and by very good mechanics but in rebuilding a 2.7 or a 3.0 there are many special things you have to have the experiance in knowing for you will not have problems down the road. It is just like time serting case, I have owners or mechanics say "I know how to have it Time Serted", well, to do a time sert jop correctly make sure you do the following:

Time serting:
#1.Time sert case with correct time serts they make a few, you want corse thread outer and standard thread inner to fit the studs
#2. Time sert case all 24 outer head stud holes.
#3. Time sert the 1-inner LONG 8mm studs that holdes case togeather
#4. Chase time serts innere threads after they are installed
#5. Machine spigot face for flat surface form cylinders comming loose, against warpage.
#6. Machine spigot holes from cylinders wobbling around, you will see once you are done high points that where mahcined.

So that is 6 differant things that need to be done in Time Serting a case. not including studs and other things to build a reliable 2.7. But, if you just miss one of them, then there is a loose link in the chain.



Damage that can not be put back, but on a 2.7 parts are not hard to find since there was so many made in production.



Do it YOUR-SELF, it is not as hard as US shops sometimes make you think , hahhaa.

Good luck

Roy at http://www.motormeister.com