2.7L, So why is 2.7L the motor to avoid? Options

[qa1142]

If someone is going to start looking for a 6 to build what do you want and what do you want to avoid?

2.2

2.4

2.7

3.0

3.2

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[dr914@autoatlanta.com]

as all 911 engines are very very expensive to build, I would try to buy a running 3.0. All of the power, easily runs carbs, does not suffer the 2.7 pulled stud problem, and fits into the 914 cavity nicely. Opinions below about the others:

If someone is going to start looking for a 6 to build what do you want and what do you want to avoid?

2.2 only made two years not much power no oil cooler needed when installed in a 914-6

2.4 only made two years good power especially if an e or s does not need an oil cooler when installed in a 914-6

2.7 made three years notorious for pulled case studs, plenty of power, they ALL need rebuilding and need an oil cooler to work in a six

3.0 Made from 78-83 readily available needs an oil cooler but works well if carbureted, virtually bulletproof except for fatigued lower case studs that break not pull, needs an oil cooler great power

3.2 larger engine to fit into the bay needs an oil cooler hard to adapt to carburetion very expensive to buy and rebuild, not a tremendous power increase over the 3.0 made only five years so hard to find

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[EdwardBlume]

As George said, the 2.7 had head stud problems, but as with anything, the later the better unless you know the quality of the build / builder... then what you want per cost matters...

If you're just buying and plugging... a 3.0 is a good option.

[Rav914]

I think a lot of the perceived issues with the 2.7 are urban lore. The stud issues with the 3.0 seem to get glossed over in discussions like this.

I'd ask a bona-fide mechanic/machinist who has seen it all to give you his opinion.

BTW, I have a '74 2.7S. I rebuilt the motor last year after 105K and its studs were fine. I installed SC cams with a M&K muffler and the car really hauls the mail. I recommend the 2.7.

[scotty b]

2.7 is a great hot rod motor, especially if you plan it right and have the money. To specifically answer your question. The first 2.7 were not as big an issue. When the thermal reactors were added ( emissions b.s. ) THAT is when the 2.7 became a real (IMG:style_emoticons/default/stromberg.gif) The cams were flat, the reactors caused the engines to run hotter than they rightfully should, the head studs were a real issue with either pulling from the heads or flat out breaking ( usually flush with the head) Yes the 3.0 still had stud issues but no where near as great as the 2.7 did. I personally have one of each and plan on full rebuilds, each with different specs, but each just as reliable in the end.

[brant]

the 2.7's seem to rev a little nicer too
I think the case is more stressed on the 2.7 as compaired to the 3.0... but the components are just enough lighter that they can be built to rev a tiny bit nicer.

I'm about to build a 2.4 for a street car
It seems to rev a bit better than the 2.7 in my book, and I really like the feel of a low-hp, rev happy early type motor.

plus with the 2.4 and carbs it's very "vintage" feeling and still able to get 180hp with out much struggle or expense. Nearly the same hp as a stock 2.7 or stock 3.0..
probably a higher redline, and less torque

brant

[carr914]

I think a lot of the perceived issues with the 2.7 are urban lore. The stud issues with the 3.0 seem to get glossed over in discussions like this.

I'd ask a bona-fide mechanic/machinist who has seen it all to give you his opinion.

BTW, I have a '74 2.7S. I rebuilt the motor last year after 105K and its studs were fine. I installed SC cams with a M&K muffler and the car really hauls the mail. I recommend the 2.7.

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2.7s are Great motors in a 914. Yes they did have Stud problems, but if you are finding an engine these days, the studs have probably been replaced. The correct studs to use are Porsche Steel studs, not the Divilar(?). The other perceived problem of a 2.7 (and partial cause of the original stud issue) was the heat that was created by the Thermal Reactor exhaust system that Porsche used to combat the stricter Emission standards of 1974. Again these exhausts have long been scraped as they were more trouble than their usefulness and would not be used in a 914. The 2.7 7R case is much stouter than the earlier 2.2 or 2.4 cases. You can easily make a 200+HP on a 2.7 case. (see my Pro-Built 2.7 in the classifieds)

And yes, while 3.0s are almost bullet-proof, they also had Stud & Tensioner issues

T.C.

[qa1142]

So it took me 4 years to get my 2.0L built and into my car (IMG:style_emoticons/default/headbang.gif)

that said it is a sickness and I am already looking to the next step

Found a 2.7 that turns but does not run complete out of a '76 that I can get for under $1k. Maybe a paperweight, maybe a starting point. No idea if it is a G, H, I or K. Still just sniffing it out. But $1k for complete core sounds like a start

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Or my neighbor has a '79 911 targa 3.0 SC I could get for < 8K I know history and it runs strong. Part it out and keep the motor (IMG:style_emoticons/default/idea.gif)

Just not that much in mid-west vs you lucky west coast folks (IMG:style_emoticons/default/shades.gif)

[pcar916]

So it took me 4 years to get my 2.0L built and into my car (IMG:style_emoticons/default/headbang.gif)

that said it is a sickness and I am already looking to the next step

Found a 2.7 that turns but does not run complete out of a '76 that I can get for under $1k. Maybe a paperweight, maybe a starting point. No idea if it is a G, H, I or K. Still just sniffing it out. But $1k for complete core sounds like a start

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Or my neighbor has a '79 911 targa 3.0 SC I could get for < 8K I know history and it runs strong. Part it out and keep the motor (IMG:style_emoticons/default/idea.gif)

Just not that much in mid-west vs you lucky west coast folks (IMG:style_emoticons/default/shades.gif)

All 2.7L cases have to align-bored and TimeCert'd. As well many need to be shaved before they're align-bored. That makes for an expensive beginning for a case. After that though, they are delightful and super-light. Used to be they were all shuffle-pinned as well but that process created stress points that generally created a bigger problem than they solved.

I loved mine. Especially the sound through Webbers and a Porsche sport muffler. This 3.6L motor I have now sounds great but it's a completely different timbre. Can't get that specific scream out of it that the 2.7L and smaller displacement machines gave us.

[J P Stein]

The 993 Divilar, full thread, coated studs are the way to go. Steel studs come loose due to uneven expansion rates......no big deal if you don't mind retorquing the heads a few times till the aluminum is done coldworking (if you don't know what type of coldworking I'm speaking of, ask)......this assumes case savers have been installed.

The 2.7L gets a bad rap. All the motors have weak points and need to be rebuilt to adress these issues. With a mag case just keep it cool and it'll live. That said, if I was gonna do it again I'd use a 3.0L unless I was building to class.

[PRS914-6]

2.7....A great deal since people think they are junk and can be bought cheap.

You need:
1. case line bored and decked
2. stud holes repaired with inserts (many 911 years need this)
3. Pressure fed chain tensioners (they all need that)
5. replace the 5 bladed fan for a later fan
6. install a front oil cooler (anything above a 2.2 needs it despite what you hear)
7. lose the thermal reactors. (a no brainer for a 914)
8. Standard overhaul (replace what's needed)

With the above you get a GREAT engine that will cause you no problems. Repair it right and keep it cool and you'll have a happy engine. No need to hide from a 2.7

[SirAndy]

If someone is going to start looking for a 6 to build what do you want

3.6 (IMG:style_emoticons/default/biggrin.gif)

[qa1142]

If someone is going to start looking for a 6 to build what do you want

3.6 (IMG:style_emoticons/default/biggrin.gif)

Too much Money (IMG:style_emoticons/default/hissyfit.gif)

[patssle]

I just drove home from Austin to Houston my 911 today, has an '81 3.0L SC motor. The plan is to put it into the 914.

Everything I've read...the 3.0L SC's are the best aircooled Porsche motor you can get. Yes they do have head stud issues, but that seems to be about the only common issue.

I also got lucky and found a pair of Weber 40IDA3C carbs for an insanely cheap price at a garage sale...and plan on converting CIS to carb.

[carr914]

What's wrong with the 911? Rust? 3.0 liters are Great as well, but to scrap a 911SC for it (IMG:style_emoticons/default/confused24.gif)

[patssle]

It's a 1974 with the 81 motor. I'm not sure on my plans for it yet, but it is a beautiful car with a rust free chassis - but it lacks an interior/rear window, needs a lot of work.. I think I might keep it in storage and work on it after the 914 is complete - or sell it as a roller. Not sure yet.

[Cap'n Krusty]

2.7s pull studs from the soft metal mag cases. Porsche has found the Dilavar studs weren't the answer to the problem, and they've gone back to steel studs. Case savers are a requirement. 3.0 engines break studs, often right down at the deck. An EDM is required to fix this, along with case savers. My guy gets 50 bucks a hole. We just did an SC engine with EIGHT broken studs.
Pressure fed tensioners are OK, but the conversion is major dollars, bucks that could be better spent elsewhere. They CAN fail. I've seen it. A good rebuild of the late SC tensioners and the addition of chain guards sets you back 50-60 bucks in parts and they last for ages.
2.7 engines need a well designed front oil cooler setup. Built 2.4s might, too.
As for weight, everything that moves is the same weight between a 2.7 and a 3.0, with the exception of the pistons. I doubt they rev any more freely.
A 5 blade fan works fine if you have the correct fan ring and drive pulleys. The urban legends regarding the subject are like most urban legends ..............

That said, if I were building a performance motor for my car, I'd build a 2.5 based on a 2.0 S crank and an aluminum case, with ported big valve heads. The machinists I use say they can get me right about 200 HP from a street drivable 2.2, so a short stroke 2.5 should be a revvin'n fool, and have even better HP.

The Cap'n

[degreeoff]

I think a lot of the perceived issues with the 2.7 are urban lore. The stud issues with the 3.0 seem to get glossed over in discussions like this.

I'd ask a bona-fide mechanic/machinist who has seen it all to give you his opinion.

BTW, I have a '74 2.7S. I rebuilt the motor last year after 105K and its studs were fine. I installed SC cams with a M&K muffler and the car really hauls the mail. I recommend the 2.7.

(IMG:style_emoticons/default/agree.gif)

2.7s are Great motors in a 914. Yes they did have Stud problems, but if you are finding an engine these days, the studs have probably been replaced. The correct studs to use are Porsche Steel studs, not the Divilar(?). The other perceived problem of a 2.7 (and partial cause of the original stud issue) was the heat that was created by the Thermal Reactor exhaust system that Porsche used to combat the stricter Emission standards of 1974. Again these exhausts have long been scraped as they were more trouble than their usefulness and would not be used in a 914. The 2.7 7R case is much stouter than the earlier 2.2 or 2.4 cases. You can easily make a 200+HP on a 2.7 case. (see my Pro-Built 2.7 in the classifieds)

And yes, while 3.0s are almost bullet-proof, they also had Stud & Tensioner issues

T.C.

(IMG:style_emoticons/default/agree.gif) here are my #'s at the wheel with DC 40 cams 9.5:1 comp single plug, and PMO's....taking a 15% loss for driveline that puts me @ 220 hp at the crank and I will tell you it had more but my revlimiter is set @ 6750....
[

[Eric_Shea]

Build a 2.7 right and it should be fine. Thermal Reactors took down a lot of them and gave them a bad rap.

All have to be rebuilt. All will cost money. 2.7 will give you some nicer torque than the smaller motors and still rev as Brant points out.

That said, a 930 block (SC motors) is kinda bulletproof, There have been stud issues there but, 3.0's done right are set-it and forget-it.

[J P Stein]

Well, Cap, remind me to not have you build a 2.7L.
My home built has been running fine or 10 years...with a rebuild at 7 years of age.
Both the *993 Divilars* and the Carrera tens have worked flawlessly.

Here's the latest chassis dyno sheet.....but hay, I'm just an amateur with no preconceived notions.