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An acquaintance is culling the herd of vintage cars and my favorite is available. I got specifics and now the engine scares me. Or, thirty five thousand and then the potential of a twelve thousand engine is a bit nervous. I grew up with the venerable A-series BMC engine my entire life but these flat 6 things made out of magnesium...above my skill set. Fuel injection also new. So, likely I would wimp out and find someone to do work. What to do? Seems like an opportunity to own a beautiful car I have lusted after since a teenager. I just did not grow up with them and now, a few years from retirement, do I step into the 911 thing as a newbie with this 2.7? Zero rust. Owner maintains himself. Have not found a well referenced PPI independent. I read this post and folks say this is the worst engine Porsche ever made. That breaks my heart. I like the older 911. Don't need, desire matching numbers. Just want the fun of driving something with synchro on all forward gears, 5 forward gears. 1L extra displacement. Would like do weekend drives. Maybe a club meet up but zero track. Just something fun to experience and see what it is all about. Keep asking questions or walk away? From what I can tell the upgraded tensioners...I don't think were done. Or maybe they were. We did not discuss the block studs issue and still learning the solve there. Appreciate input from those that have owned this era car. As well as an independent shop in NH that would give me a solid PPI on the engine that both seller and buyer could rely on. And still stay buds. Thanks!
Nothing inherently wrong with the 2.7 engine. It's just that in 1976 Porsche started putting thermal reactors under the car for emission control, which cooked the engine and made it worse with a 5 blade fan instead of the old 11 blade fan. How many miles does the car have? Does it have a 5 or 11 blade fan? Does it sti have the thermal reactors? Has it been running regularly for all these years? Those questions should help you assess what kind of car you are looking at.
Having said that, there are a million things that still can be wrong with any 45 years old engine so far from me to suggest that there's nothing to fear. Just wanted to put in perspective the "worst engine" statement
I bought a 77 2.7 this past fall and was similarly scared by everything I’ve read. Then I spoke to several Porsche mechanics who put much of those concerns at ease.
keep in mind the 2.7 mag case was used for the RS and in most of their race cars until the aluminum 3.0. Yes there were differences in cams and pistons but the 7R case was the same. It seemed to work pretty well in those extreme applications.
2.7 engines are really torquey on the low end, fast revving and fun to drive. They run out at about 120-130mph but at real life speeds they deliver agility and thrill that the larger engines lack. On the track the 3.0-3.6 are better suited but racing is a whole other story.
as mentioned, the issue of pulled head studs and warped cases (not solely limited to mag, all 911 cases have these issues) is related to the heat cycles the engine goes through. The addition of thermal reactors and the 5-blade fan put too much thermal stress on the case and accelerated-not caused, these issues.
if the 2.7 had the thermal reactors removed a long time ago and an 11-blade fan installed it’s likely fine. Of course have a mechanic look at it.
a rebuild will be expensive but much less than an engine swap as the days of 5k 3.0 engines are loooong gone.
keep in mind that the other maintenance you’ll face for a 43 year old car will add up quickly if you’re paying a mechanic to do it.
things like an oil cooler, chain tensioners, SSI, new exhaust, new valve covers are all really great additions to a 2.7 and make it run very well but will cost a lot if you can’t/won’t do the work yourself. The good news is that all of those are pretty simple to do and there’s so much information on how to do them that lest you have the cash to burn, are starved for time of just don’t want to get your hands dirty there’s little reason to pay a shop.
35k would be a fine price if, and I mean if the car is very well sorted and has no outstanding maintenance. Otherwise the mid-to-high 20s is more appropriate.
If there is no rust on the car, or no accident damage.... this is the big issue.... the 2.7 does have a reputation for pulling headstuds, but most of these have probably been retro-fitted with time-certs, which generally solve the issue.... check for this.... also it is not hard to check for broken or pulled headstands on a PPI.... just take it to a really good specialist, who knows what they are doing.... if the studs check out.... you are probably good to go.... head-stud failure on these cars is not going to hurt your engine as long as you address it quickly....
BTW, headstuds on SCs and 3.2s fail also.... its just goes with the turf.... it is as much a matter of age as mileage.... corrosion or over-heating can cause it....
Also, a top-end re-build is probably in the cards on these cars, anyway........ don't panic.... its about $5-7K depending on how crazy you want to get, but things like valve guides, timing chains, gears, and tensioners do wear..... so replacing them is good insurance, because if they fail, you have a big problem.... then you have an engine that's good to go for decades..... and if you ever go to sell it.... you'll likely get most of your money back.... just keep all your service records....
A full rebuild on these engines can run $12K+++, but honestly, unless the engine has 150K+ miles on it, you probablyly don't need to split the case.... the bottom ends are very robust....
$35K in today's market is a really good price if the car is in top condition.... this means you can budget $1-2K a year for maintenance and not get hurt....
You may or may not need machining done to the engine. It is a risk factor for 1975-1977. That price is pretty good if the car is in the shape you say.
If you do have engine problems, you can do what many others do and put in an SC or 3.2L motor which gives more power. Many people are looking for the Mg engines to match up with a period correct hotrod.
Thanks for the feedback. Still contemplating what to do. Car has 162k. IIRC he said he had someone else do the tensioners. AC removed and gone. I was not aware of the thermal reactors. Seems like a roll of the dice. Drive conservatively and she may be great. Run her hard and hot... May hasten failure. Seems like a roll of the dice. Sure wish I could find a local independent in NH. Electric windows I guess is not a win. Sunroof, it works is a win. But I understand that is also fragile part of the car. Tells me the front pads and rotors are new and genuine Porsche, not after market. New seat covers from CA. New seatbelts. Just more complex than my current vintage toy.
If you PM me I can probably help you find some good resources here in NH to do a PPI on it. I'm in the Amherst / Milford area and have owned my 74 2.7L car for a long time. These engines are fantastic once sorted and all air-cooled 911s have various expensive issues. Mine went 115K miles before needing a full rebuild and it was a boatload of money for sure - if the one you are looking at has over 160K miles than it is hard to believe the top end has gone that long without a refurbishment at some point especially if it hasn't had its thermal reactors removed and the exhaust backdated to a 74 early in its life. No rust is key on these - that is where the money can really go.
Middies are awesome. Cool G looks. LIGHT. Drive an early G and drive a later G and they look similar, feel totally different.
As mentioned, most have had the sins of the past retrofitted. They are good motors. And good cars. But, you'll want one that has had the expensive stuff done.
The 7R motors are the BEST mag motor porsche made. What they did, as was mentioned, surround it with crappy dated ancillary equipment to meet emissions standards of the day. That heat (crappy fan and those thermal reactors which are like a primitive cat) caused a lot of heat, they didn't come with secondary coolers, so they ran hot. Well, no motor likes to run hot.
gth452. Please IM me or use durantjud [a] yahoo to email me. I am a newb and not yet allowed to IM members. I am heading home next weekend....I work in another state just to make things more complicated. Will spend some time looking at the car, drive it for the first time. All my reading points to an engine rebuild during my ownership. I read 'top end only' a false economy approach. I ordered Wayne Dempsey's book. Seems like good reading for anyone with vintage air cooled 911 on their want to own list. Looks Like I should have purchased one 10 years ago. Oh well. Should have bought a AH 3000 30 years ago and not just a Bugeye.
Jud from Hopkinton NH
I assume it is one of these engines and somewhere I find a 911.85 as I have since learned the 911.90 is the Sportsmatic. So much to learn.
10" of snow headed our way in NH. I can always benefit from some advice. I did end up acquiring the 1977 2.7. Maybe put 500 miles on her. Enjoyed 1 Porsche club event at Bug Light park in Maine. Otherwise, just tooling around. Toward the end of the season I went out after work and I either failed to note the Alternator light was on or....it went. Much review of that red light and next steps. Ended up taking the alternator to a reputable rebuild shop who confirmed the regulator was not well and the Alternator needed a rebuild. Done. Was putting it back in and..well...alternator housing cracked. I don't think I was over tightening but... Closer review, the rear housing had been repaired before and..in tightening the alternator to the fan housing, it cracked. Repairable but....note to self, take TONS of photos of something BEFORE you send it out for refurb!
In looking closely at the Magnesium fan housing 3 of the 4 "fixed blades" had significant cracks. Read up on that well known problem and concluded, learned only ALU replacements are available. Or, a Porsche guy in Wisconsin has the skill and know how to repair/weld magnesium. That is done and, snow storm permitting, I get it back this weekend. I learned my 1977 had the smaller 120A alternator. Seems cores are unobtanium. Maintenance history shows it was replaced 8 years ago. 20k+ miles ago. From my reading, the later and higher amp generator fits in a different shroud (depth). Mine has part number 901.10610.5R. So. Purpose of this post is to ask for input and or confirmation that I have not completely failed in my first DIY effort. Not new to wrenching, just new to Porsche.
Alternator shop will take alternator back, re-weld housing. IIRC 6 bolts. Of which 3? extend and are used to secure alternator to the fan housing. Sorry, parts 500 miles away. Finding a core, donor with non cracked housing unlikely. Crack is barely noticeable. Ok plan or would others take a different approach?
When I took out the alternator, my car had 5 washers, not 6 on pully. I of course noted exactly which side had what but should I get a 6th washer on the outside to return it to 6? Or, it ain't broke, put it back the way it was?
Fan housing...when everything is off you get a nice look, access to the top of the jugs. I found old drier sheets...gunk...stuff...in and about. Not good but removed now. One could get in there with a brush and brake cleaner and work to remove...let "wash down" oil and gunk. Or...just leave it be?
Of note. Thermal reactors removed. Carrara cam tensioners. New SS exhaust. I think the car has good bone...I hope.
Appreciate any guidance. I believe I am on a decent path but....it can never hurt to get opinions from others who may have already lived this fan housing, alternator rodeo.
04-11-2021, 10:05 AM
Considering a 1977 911S 2.7
