RS block worth getting?
 

Hi all,
I recently talked to a guy who says he has a '74 RS block sitting in storage that he's waiting to get rid of because he needs the money. I have yet to see the block but he wants $100 for it. I will definitely check the number on it and confirm with you all whether or not it's a RS block. I figured it's worth it RS or not just because it's a Porsche block for $100. I just bought a $200 carpet set(entire car) so I have done business with this guy. Old gentleman, doesn't seem like a liar. Any suggestions? Thanks!

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Jeff
1976 911S

Jeff,
The RS blocks, and by extension the '74-'76 2.7 Carrera blocks have a part number that ends with "7R". If it ends with "4R", it's a 2.4 block.
Heck, any block still useable is worth 100$
Regards, George

Jeff,
The RS blocks, and by extension the '74-'76 2.7 Carrera blocks have a part number that ends with "7R". If it ends with "4R", it's a 2.4 block.
Heck, any block still useable is worth 100$
Regards, George

Jeff,
The RS blocks, and by extension the '74-'76 2.7 Carrera blocks have a part number that ends with "7R". If it ends with "4R", it's a 2.4 block.
Heck, any block still useable is worth 100$
Regards, George

Ooops, sorry. I fell asleep on the button...
GeorgeK

There are two different versions of the 7R block, the 2.7 version which is identical to any other 2.7 with cylinder spigots for 90 mm cylinders, and the 2.8 version bored for 92 mm cylinders, but with the cylinder stud spacing distance/pattern of later 3.0 engines.

The later version certainly has value to vintage racers, but not much value to regular guys, as heads compatible with it are scarce! Bruce Anderson's 'handbook' has the details to identify which version of the 7R it is, if indeed, it is from an RS.

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Warren Hall
1973 911S Targa

Thanks George and Warren,
I will go read Bruce Anderson's handbook and make sure it's a RS block when I go look at it. If it's a 2.7 RS block would I be able to use it? I strongly doubt it's a 2.8, but George you're right I figured a block for $100 RS or not is probably worth it. Thanks!

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Jeff
1976 911S

Hehehehe....almost exactly 9 months later I was finally able to get in touch with this guy again (today) and found out he still had the RS block. He told me that it was from a Carrera. I will be taking a look at it tomorrow morning. Anything I should be looking at as far as usability goes? Anything I should watch out for besides the obvious (cracks)? According to Bruce Anderson's book, the two versions are one with the casting #901.101.101.7R and one with #901.101.102.7R. The 102.7Rs come with both the original 92mm and the later 97mm spigots. Which one is the better one(if there is a such thing) and which should I be avoiding? Which is best for building a RS motor? Thanks!

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Jeff
1976 911S

Can somebody please help me out? Anybody? Please!

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Jeff
1976 911S

Hi,
I don't have the references with me, but it seems you should get the block with the same spacing as the 2.4-2.7 engines, if you intend to build an RS engine. There's an intermediate spacing, like Warren mentionned, but you will never find parts for it.
I hope someone has the measures to tell you.
GeorgeK

Oops...

[This message has been edited by GeorgeK (edited 05-16-2001).]

Jeff,

All of the 2.7 blocks had 80 mm stud spacing ... the interesting thing to know is what 'Type Number' and Engine number is stamped to the right of the mounting for the fan housing. The 'Carrera' engine designation obviously meant different things in the USA vs the rest of the world in '74 and '75!


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Warren Hall
1973 911S Targa

Hello

Generally to find out if it is a usable block you have to look if the studs came loose. One indication is that the sourounding area gets whiter then the rest. Also look for "shufflemarks" in the main gallery. The case is complete machined to a given roughness. Those spots are very smoth and do light up different to the other surfaces.

Well thats normal even for lower milage but if you have seen some cases and know there age and usage you can "read" it like an oddometer. 2,8 RS cases would not show those signs as they have additional anti shuffle pins.

Watch for bigger scarfs on the sealing surfaces and for bad signs on the single long stud at the intermediate shaft galery. They get overthighten and come loose.

Watch for cracks done by spilting the case withot knowing whats up or lifting the car on the enginecase.

Watch for signs caused by crank or rod failures. ( The last is very easy to detect as they leave holes )

Look if the case come from a rear end accident.

However what you will do, the case needs messurements. Better previous you buy it but the trough is all used cases are geting oval main bores and need boring or the reuse from the original bearings.

BTW be aware that the bearings have different notches depending on the year.

Oh the 101 indicates the left side while the 102 indicates the right side of the case.

To find out if it is a mathing pair you have to look at one boss on the upper case studs. Alternator area. Both halves should have the same work number.

Also watch for additional sign saying: 025 or 0,25 or +25 ( same to 0,5; 0,75 ) This indicates overbore and those main bearings have very high prices. bearing 8 costs more then a set standard bearings.

Well if you need a case and it is usable it will be worth money but on the other side how does it happen that someone has a bare case left over ?

Also 74 RS would be a 911/77 a 911/83 is a then Standard 210 HP Euro Carrera. Other numbers are not worth to mention as noeone will search for them. The need a good case.

Building up a RS ? Be realistic. If you can´t afford a new case from the factory or have the parts somwhere on stock ( Maybe he has them ? ) it will be a illusion.

However using the 930 case is much better ( mybe thats what happend to the case, replaced by a aluminium unit )

7R race cases are normaly replaced on a 20-40000 mls basis ( get to weak )

Grüsse

Thanks Warren and George. You guys rock. I just came back from looking at the block...and now it's at my house http://www.pelicanparts.com/ultimate/smile.gif. There were a few things I wasn't sure of, but for $100, I said what the hell and went for it. As far as the "type number" goes, there's two of 'em, one on each half. One is the 101.7R, the other, 102.7R. Am I just screwed, or just S.O.L (sh** out of luck)? The engine number is *6650444* (*=stars)...does that tell you anything?

The guy told me his is a '74 (I think) Carrera, imported from Germany by its previous owner. When dealing with the EPA he had to have the MFI system removed and a CIS system installed to pass emissions. The current owner went to get his engine rebuilt, unfortunately with a sly and cheating mechanic, who swapped out many of his unique and new parts with old and common ones. (he mentioned an italian distibutor with a name that started with a "D"). Anyway, this mechanic (happens to be the guy I bought the car from) told him he had a crack in his block (after gleaming at it and looking up the numbers in his reference book). It was changed out, but the owner, after finding many parts changed, decided to get the old block from the mechanic..and the mechanic was very reluctant to. So...sorry for the long story, but I now have a RS block!

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Jeff
1976 911S

Roland,
Thanks for the reply. I'm not exactly too sure about a lot of the things that you've mentioned, but I can tell you these things.

-the case didn't come from a rear end accident

-Oh. 101 and 102 stand for both sides? I thought I was screwed. Thanks.

-story about the case on my previous post

-why is building up a RS engine unrealistic? I have a 2.7 with 115K miles. Sooner or later I'm either going to have to do a rebuild or a replacement.

-I won't be doing too much racing. Not too much action here in Hawaii. Would a 7R block last longer than 40,000 miles?

-Give me a few hours and I'll post some pics. Hopefully it's not in that bad of a shape
Thanks!
(BTW what does Grusse mean? And how do you do that umlaut on the u?)

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Jeff
1976 911S

[This message has been edited by Rufblackbird (edited 05-16-2001).]

Jeff,

The 'Type Number'is on a horizontal surface to the right and slightly forward of the fan mount, and should be '911/83' as your engine serial number indicates an RS 2.7 engine for model year 1975, and the sequence number of 0444 means it would have been one of the last RS 2.7 engines ever built!

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Warren Hall
1973 911S Targa

OOps...I thought the 901 was part number..guess I was right. I didn't see any other number on the block so I just assumed that's what you were referring to. I just tried looking again..still can't see the number. I should get this thing cleaned up and maybe then I'll be able to see it (any suggestions on cleaning? It's been sitting since '95..is that a bad thing?)

So...if it is indeed a 911/83, a RS engine for '75, and one of the last RS engines ever built, is this a good, bad, or alright thing?

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Jeff
1976 911S

Hello

Good Storage will hurt nothing. Keep the case togehter and use some bolts so it will not fall apart.

Don´t use harsh things to clean it and after that spray it with conservation wax or light oil.

Block all holes for falling in debris.


After reading the story i wouldn´t have touched the part. I will never support thives and betrayer. Those People hurt the complete Porsche reputation. Also you never can be sure if he isn´t betraying you. They never will stick to there word and whatever he claims has to be proved or made with paperwork. Always back up with such people. Mybe ten years later you will be happy to have something to clear up the trail.

The only way to buy such a thing is ask the old owner if he is interesstet in trailing up and repossesing his lost values.

Just make clear who is the REAL owner from that part. You can´t own stolen parts.

In germany the law will draft the complete car and dissasemble it if they find a stolen part. Well this is done on your costs and they do not assemble the car back. They also use to cut away sections for reading the hidden bodynumbers. This is like the car is at the butcher.

Some people bought old stuff years ago and lost many money later.

However there is no technical difference beetween your actuall engine case and that RS engine case.

It is just the correct number and if you can use it it will make saleing easier as you have not to proof all. Value will be higher too. Especially if the owner from the original car trys to find the mathing #.

But if you buy a new case the factory can stamp in the original numbers.

To make a RS you need the Nicasil P&C, S rods and camshafts, S heads. The complete Injection with all the additionals and the heat exchanger oillines. Not to forget the front oil cooler setup. The crank needs some finetuning. 11 blade cooling fan.

The first stage would be to make the short block ready. Then later making the long block and use it with carbs in the car.

Grüsse

Roland, I think you read it wrong. Jeff bought his current car from the mechanic, a 1976 911S. The guy he bought the case from, took his car (the case guy, not Jeff) to the same mechanic, who screwed him over by swapping out parts without need. Same mechanic told the Case guy his case was cracked, and needed to be replaced. After this was done, case guy though things were fishy, and demanded his original case from the mechanic, then sold it to Jeff some years later.

That is the way I read it, anyway.

Tom

Thanks Tom, that's exactly what I meant. Sorry Roland for the confusion. I'd like to build the RS spec engine one day, if and when my 2.7 blows I can just drop it in and still drive the car. I did make the guy an offer. He's kinda er..elderly and I told him if he was to ever sell the car I'd buy it from him. I'd like to put the engine where it belongs, in a '74 Carrera. He says ok, he'd probably sell it for $4-5K in a few years...sounds good to me. I'll post some pics when the f@$%ing digital camera works again. Thanks for all the replies.

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Jeff
1976 911S

Hello

Well my mistake.

The street used 7R case will manage over 150-200 000 km without pulling the studs, chances for failures are under 5-10%. At 250-300 000 km 50% have Problems, higher milages are rare as most people pull the engine previous the failure.
At that milage the oil pressure is very low and the heads need a rebuild.

I knew engines with higher milage and they work despite there oil consumption rate and a bit slopines in midrange power. In fact they still pull better then average traffic.

The most failures are on the CIS engines with 5 fan blade and without external cooler. Especially cars in city use.

Standard RS engines have a lower failure rate. Higher output rates seem to force failures.

Generally the engine likes to stay warm and driven long distance.

The heat up and cool down cycles are the critical points. As far I understand it are the 150 HP K&S Alussil P&C worser in failures then the Nicasil Cylinders.

Just becourse they wear out faster and you need to renew them earlier. The new restored pressure and the operation itself seem to stress the patient more then other things. Risk that one off the studs will come loose very short after partially rebuild is high.

Complete rebuild on 7R also forces to heli coil the stud base and aligne bore the main bearing galery. Not doing this is like building a house in the sump. Or respraying a rust bucket.

Grüsse

Thanks Roland for yet another informative post. Right now all I have is the block, the case, the two halves. That's it. Nothing else. I think when I start building this motor I'll make sure it's gonna last a while first, then put some new stuff on, ie P&C's, and whatever can be used as an "used" part will be bought used. I'd like to build a motor that will be powerful, yet last me a while (I'm not saying extracting every ounce of hp out of the motor, just hopefully something like 210hp, like it had in the Carreras they belonged in). Right now my 2.7 has a 11 blade fan, so that's one problem solved there. Also it doesn't have heat reactors; its got headers, so one less heat problem. Whether or not it was warmed up and cooled properly I don't know. I've only had it a while, and driven it less than 2000 miles. So, when the body is restored, I'll start building the motor because who knows how long the CIS 2.7 will last? (it's already got 115K miles on it). I probably won't remember all of what you've said to do but I will keep that in mind. I will sure post something before I start. Thanks!

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Jeff
1976 911S

Hello

First step is to messure the main bearing gallery.

If you have the bare case then all the studs are missing ?

The next step would be to find a crank with rods, Oilpump, intermediate shaft with a good intermediate wheel, chains and many other things.

Best is to find a old aged not worn just stud pulling 2,7 engine to get all those missing items or better a 2,4 S MFI ( and more expensive ).

Then start with the fundament. As all the parts are blueprintet from the factory ( Well thats there minimal standards ) you start to superblueprint to lets say Bruce Anderson standards.

Some things will not generate power but allowing the engine to rev higher without geting in trouble.

The 210 HP statet for the RS engine are the standard numbers. Mostly they had a that more and if you use Sportkolben for higher compression ( remember the RS runs on standard fuel ) you can reach the 240 HP border. But this will stress the case and was maybe the reason why the factory didn´t went so high.
A good made 2,4 S will show a RS his tail end as it also has 200 + HP has similar wights and lower drag. But when it comes to the race track the RS has more tourque and wide wheel benefits to get faster out of the curves and even faster into them.

How long will the 2,7 last ? Thats higher mathemyhtics. Only the engine knows. Some seem to run without problems some allways threw the hanky..or a rod.
Maybe it was the childhood and to less love & patience killed the young engine. Maybe it just happend in the melting pot when the mixture spinned left side instead of right side.

In WW II they made the first jet engines. The strange thing was that the turbine fan blades made at one branch where exploding under high speed while the others lastet longer then the rest.

The difference was in the man who castet them. One was stiring all the time and trustet his feeling while the other followed what the engeniering said. Mix it and speed up.

Guess witch blades lastet longer ?

BTW one company was in Munich at is today still well known as BMW. The other company is in Stuttgart and is today nearly unknown as Mahle. ( Those guys had more luck as there Bus stop was named "Fortuna" )

My own feeling says that the last year cases have not so much failures then the earlier ones. However in germany no reactors and people pressing hughe amont cooling air trough the fins at higher speeds while the engine only has 10-30% throttle load.

Hard to compare to a US stop & go with AC and other things preloaded cooling in hot areas.............

Grüsse

Hello Roland,

Actually I have the case, the two halves, but they are in one piece. I don't know yet if there are any studs missing yet, but they look like they should be replaced. Don't want to take any chances there.

Seems like this won't be a cheap engine to build. What are the differences between the 2.7 and the 2.4S MFI besides the MFI such as crank with rods, oilpump, intermediate shaft with a good intermediate wheel, chains and many other things?

What exactly is blueprinting? Is it like blueprints for buildings where you have a blueprinted layout for everything before starting the building of the motor? I would sure love a 7,300 redline, though. Would something like titanium valve springs make it rev higher without getting into trouble?

I got the 210hp figure from Bruce Anderson's book. Sounds pretty good to me. I don't want to push the motor to its limits, just something nice like 210 (or a tad bit more) and making it last a long time.

What is Sportkolben? Beginner level German can only do me so good. High compression = less longer lasting engine? Like I said, I don't want to stress the motor.

Do you(or anyone) have the hp and torque figures for the 2.4S vs. the 2.7RS? Is it becase the RS has flared rears and fat tires that increases the drag? Not really something that I mind, though.

I'm hoping when my engine was in the melting pot the mixture spinned to the right(correct) side. That'll give me more time to build my motor.

I'm gonna put money on the batch of turbine fan blades that were followed by what engineering said, since you mentioned "mix it and speed up". I assume it is a bad thing to speed it up.

Yes I have heard of BMW and how they used to make airplane engines...and that their insignia is actually propellers in the sky, which I thought was very historical and a nice touch. If they can't (or not allowed) to build planes they'll put propellers on every car they produce.

I have heard of Mahle. Are they really unknown?

I'm glad to know that you're feeling that this case may not be so bad. Like I've mentioned before I will post pictures...once that stupid $*#@ digital camera works again. Once my dad dropped it, it was never the same again.

The person I bought it from is the 3rd owner of this car. The original owner brought it from Germany, and due to some stupid EPA regulations he had to switch the MFI and put on CIS. Don't know if that makes any difference. I also don't know if he had AC on his car or whether or not he is in stop and go traffic. This is an elderly person, don't know if he actually goes out a lot or not. I don't care much for AC though. Thank you for your response.

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Jeff
1976 911S

Hello

The studs will not break if the are not bend or rustet.

The case will get weak and the studs pulled out including the threads.

Those studs are not just screwed in they are reamed in. You just drill a hole and pretab it and then turn in the bolt. The high tourque will flow the aluminium away making the thread. The aluminium gets pressed and will harden up making a reinforcement at the sourounding area. This is jsut like you would forge in the threads. The stud will make his own threads and after cooling down they are massivly clamped.

Hard to achive this later.

So now I need a dictionary will try to get one in the pulic library. To much missing words for further things on that subject.

Other things:


Blueprinting: Just look at a american car magazine at your local newsstand. Car Craft, Super Cevy, Auto Buff, Hot Rod, Chevy Mania. However always one covers a story like 99 Tips to blueprint your engine to the max.

Buy it and read that. This is what Porsche made stock with there engines. They even made more and for more rigid specs as they had to made much more power per Liter then the US engines.

F.E. the 2,7 RS has 210 HP witch gives 80 HP per liter.

Now if you would transfer this to a lets say four bolt main 350 sb chevy this will be 80 HP x 5,7 L = 450 HP.

I know most of those guys claim to have 500 HP+ in there cars. But to give you a number.

The first year IROC was made with Porsche 3,0 911 SCRS witch had I think 250 HP in IROC series.

The following year they used Camaros with 330 HP. Those cars hadn´t been faster.

A solid made 350 will cost as much as a Porsche engine ( well witch has a total less power then ) and will have around 400 HP max.

OH thats the numbers the new Corvette features in there new year. Well Porsche had been there in 1966 with a 2,0 S witch had no TPI Fuel injection and a tricked out to the max V8....but well no catalyc converter too.
OK thats not fair as 35 Years make comparson to hard. Now how about the 996 GT3 ? 3,6 L/340 HP = 95 HP/L incl. OBD II.

Why use a 2,4 S ? Well you just can swap the P&C, the case and adopt all the other parts to RS specs ( MFI, Distributor, Heads ).

Every thing else is similar.

Using a 2,7 S would also add "S"cams, heads, all MFI parts to your list. CIS parts are not so sought after and cheaper.

S and especialy RS parts are allways top priced and they get faster "junked" or wear out. Not becourse those parts where cheap but most people missuse them and after seeing 2,8 RSR P&C ( maybe 4000 $ today ) ramed into a case by a "proffesional" ( Who didn´t flycut deep enough ) i can imagen what will hapen at some hobby engine rebuilder. Also those engines where used hard to the max, have to survive harder overrevs by misshifts and the MFI also has the fuel up problem ( Oil gets thined by unburned gas ).


All 2,0 - 2,7 S/RS have 7300 Redline stock. However you can strech it up a bit to 7500 by doing some preparations and some blueprinting. Even 8000 is doable ( Doubles the price )

Well carillo, Titan and other stuff is expensive and better a good made stock engine with more important low end grunt.
But it is allways usefull to shift at 55 mls from 1st to 2nd :-) Or at 140 mph from 4th to 5 th and hiting the rev limiter at 175 mph.

Sportkolben = Sportpiston.

Made by Mahle.

Yes the Sportkolben do stress mor under full oad. Just make a little kick down switch that will keep you on the 200 HP border unless you really need it. Just then see that fun costs money and much fun equals more money but well thats live.

The 2,7 RS was mainly trimed to improve the tourqe. Total horses where not so important. The big benfit from the 2,7 over the 2,4 S was that you needn´d downshift to speed up faster then a shiftet 2,4 S

Topspeed is very similar as the RS has wider fenders on rear and wider rubber. The added spoilers made it more stable and do add some 5 mph.

However the 2,4 S was statet with some 230 km/h topspeed but made over 240 km/h in most indipendend car magazine tests.

Back then there was a speed discussion in germany and the staate put a speed limit from 100 km/h on the normal streets and several limits ( 130 km/h ) on the highways.

Poor BMW 2002 turbo hits a nerve back then and where beaten up as bad killer car in the puplic.

As Porsche where driven by gentleman drivers and known as fast but solid and friendly to the puplic, didn´t focus to much. Untill the RS came.....First they tried to bann the car complete then they ended with a victory on banning the duck tail.

This is one reason why Mercedes refused to continue the SEL 6.3.

Like I said that happend before we where born back in WW II.
Maybe the BMW workers just had been cleverer and shortent the war....

Those turbineblades wher built into those Jumo engines. There was a little two stroke engine driving then to preload the turbine at ignition. Very complicatet construction and on the precision limits at that time.

The Porsche fanblades do not demand such precision ( Well but they are very precise as the closer they spin to the wall the more effycient they work )

BMW still produces engines in conjunction with Rolls Royce.

Porsche is still Co-developing engines for many comopanys and sometimes they coconstruct Fork loaders, Trucks, Motorcycless, Bicycles, Racebobs, Helicopters or Jet fighters.

Well Mahle isn´t a car company and therefore unvisibly, hidden in many cars.

http://www.mahle.com

They are just specialized OEM who make development for there own future.

But normally most projects are done with Porsche, DC, BMW, VW/Audi

Many F1 engines wouldn´t run without mahle.

Grüsse

Hello Roland,

The studs look rusty, so I'm not too sure if that's still ok. When the digital camera works again I will post pictures. You will see what the case looks like.

I kinda understand what you're saying about how the studs are put in. Basically if you do it right it's not supposed to pull? Or is it once the case gets weak it'll pull?

I will go look into the American hot rodding magazines for blueprinting.

Never thought a solid 350 would cost as much as a Porsche engine. Always thought american iron was cheaper to build. I have a work car with a 5.0 sbc, with only 200hp (an '87 TA). Sounds bad with only 40hp/liter!

When you say swap the P&C, the case and adopt all the other parts to RS specs ( MFI, Distributor, Heads ), what do you mean by that? The only things you don't use on it would be the P&Cs and the case, the rest can be used for a 2.7RS spec motor?

I have a '76 911S. Does this mean I have "S" cams? Is this the same cams as the RS motor? Or is it not a "real" S?

I know S and especially RS parts are expensive. They command a premium whenever they are sold. If the person took care of the motor, made sure it was done right, and didn't always drive it to the max with misshifts, they would last long, right?

As far as redline goes I'm not really too concerned with it. I just love the sound of the engine at high revs. 7,500 sounds good (I don't need 8,000, can't afford double the price).

Carillo (never heard of it) and titanium parts make a better stock engine? With more low end grunt? I'm guessing that's what you're saying. If it's something WAY too expensive I'd probably forget about it. But if it increases life of the engine and doesn't cost significantly more it would be something to think about.

I normally shift somewhere between 3000-4000rpm, but take it close to redline when driving "spiritedly". Is it better (useful=better?) to shift at 55? Once the motor is finished am I expecting that it can top out at 175mph? (ooh I'm getting very excited)

What is the differences between regular pistons and sport pistons? What does it do? And is full load WOT (wide open throttle)? How do you make a kick down switch like you mentioned?

Fun always cost money. I'm not a rich man so I can only have a little fun, otherwise I'd be building a twin turbo motor.

Not having to downshift to speed up sounds good, much more useful in city driving. So...2.4S=more hp and 2.7RS=more torque? I like torque...torque is good.

I didn't know spoilers made that much of a difference, but since I'm living in a state where there is no use for top speed of any kind I guess it wouldn't matter too much to me.

Why did they ban the ducktail? Didn't it improve handling by increasing down force? It's funny how un-car friendly politicians are. I've heard about the Mercedes SEL 6.3. It must have been a real Autobahn burner.

BMW still produces turbine engines? Cool, I didn't know that. I guess my source was a bit off. Porsche makes motorcycles? Where can I get one? I know they tried their hand at bicycles. Very un-cheap. $4200 on a "S" bike, although with dual suspension and disc brakes, still very expensive.

I know Mahle makes a lot of parts for cars, I guess you're saying not too many people know about Mahle, right? And what is the correct pronounciation of Mahle? Which is more superior, P&Cs made by Mahle, or some after market brand like say J&E (or something like that)? Thank you. Oh, and what is Grusse? (Bear with me, I'm taking GER 201 next semester...)

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Jeff
1976 911S