Rebuilding my 2.7 vs. 3.0 or 3.2 liter.

[dd74]

I'm in a quandary: what's the general feeling on rebuilding a 2.7 liter engine as opposed to grabbing a 3.0 liter? My 2.7 is healthy ('74 with no smog), and I'd like to put more power into it; i.e. 964-grind cams and JE pistons for a CR of 9.5:1. Is this possible with the CIS? What sort of HP can I expect from this set up? Has anyone done such a rebuild? If ill-advised to do so, is a 3.0 or 3.2 the way to go, and if so, how much heavier will those motors be than my current 2.7?

[jluetjen]

dd74;
I assume that your car is a "Normal" '74 with 150 HP versus an "S" with 175. If this is the case, then your heads are going to limit you to about 160 HP unless you port them.

If you have an "S" or port your heads out to 35 mm, you should be able to get about 180 HP at 6100 RPM by using a 964 cam and higher compression pistons such as you described. It might just be cheaper and ultimately will have the same affect to go with a 3.0 SC engine.

[makaio]

a 3.0 CIS motor, is only going to be marginally heavier than a 2.7 CIS motor. Due to larger pistons and cylinders.

[porsche74]

Originally posted by makaio
a 3.0 CIS motor, is only going to be marginally heavier than a 2.7 CIS motor. Due to larger pistons and cylinders.

Well,....not really.

The differences lies in the case materials. The SC and later cases are aluminum and this is what accounts for the vast majority of the weight differences.

The difference is about 24 lbs between the mag cased motors and a 3.0 SC or 3.2 Carrera, all things being equal (which they are not),....

[Swank911]

DD74,

I found it cheaper to buy a recently rebuilt 3.0L (euro) than rebuild my 2.4L.

There are a few on the web. Depending on the condition of your 2.7L internals, you could spend $6-11K on the rebuild. I picked upa 3.0 for about $4K.

The power and torque increase should offset any wieght issues.

Jon

[Swank911]

Good point Wayne.

I actually bought a 3.0L that was rebuilt a few less than 8K miles ago.

Advise for anyone would be do as I did and make sure that if the engine was rebuilt that all the update/corrections are completed during the rebuild. This is should be done on any engine.

The head studs were updated when the engine was apart.

I guess it is a matter of wieghing the pros and cons of each scenario.

[Joe Bob]

My 914/6 got the 964 cam upgrade after I broke a head stud on the 3.0. Well worth the time and energy.

I did a before and after pipe test to see what the emissions were. I was able to get it within specs for the SC IF it was in a an SC.....it did not run well, but it would have passed.

We then tuned it to optimum performance and it was high at idle due to the "lumpier cam" but not by much.

[rickeolis]

SWANK, you say you picked up a 3.0 rebuilt for $4000.00? Could you clue me in? I really want to do this to my car, but I have only seen those in the $8000 ranges, thanks-

[Swank911]

I scoured the cllassifieds, Pelican Parts, Rennlist and several PCA regions.

The one I found is a 3.0 Euro. It has 8k miles after the rebuild. It had all the updates, both head and block studs, etc.

It was rebuilt after the original head studs pulled at 70k.

There is one here in MA going for $5K. Contact me off line and I can find the link for you.

The engine and car are at the shop right now. ETA is end of this week. I am very excited

My stock engine was going to cost over 10k to rebuild. It went in for valve guide and head work. But when they pulled the heads off. The can of worms was opend WIDE.

[Vol]

[QUOTE]Originally posted by dd74
[B]I'm in a quandary: what's the general feeling on rebuilding a 2.7 liter engine as opposed to grabbing a 3.0 liter? My 2.7 is healthy ('74 with no smog

Hi,

Lot's of people like 2.7s and they can be made to be reliable. A 3.0 with a known background is a good bet for more power and longer life, all things being equal.

With a 74 you can put a 3.0 CIS with no smog on it and pass inspection easily which is a real benefit. A 3.0 with no smog gear is a great motor.

I don't have any specific experience with the 2.7 mods you mention, so I can't comment. If I was going to do a 2.7 project I would want to make it an RS, but you can't do that with CIS if you are trying to make it pass smog.

Starting with a 74 chassis a 3.0 upgrade is so painless, if it were me I would go that way.

Vol
71T 3.2

[Swank911]

If money is no object or less limiting (as it was in my case) a 3.2 or 3.6 is the ultimate upgrade

[rickeolis]

I see what your saying. I can't think about this until the end of the year, but I see what you mean by scouring the Web. I did see a recently rebuilt 3.2 in a wrecked car for $5K for the whole car last month.

The only thing that upsets me about these cars is the $$ for anything I do. I read a Corvette BBS where they constantly talk about rebuilds for their 300 HP engines for $3000.00, and I like you have had quotes for a stock rebuild of my engine (110 HP) for around $9000.000. There is something wrong with this...

[Swank911]

German Engineering!!!!!!

Parts alone for my rebuild were over $7000.

[dd74]

Hi all:

Does anyone know how much the 3.6 conversion costs from Instant G, kit and all? Additionally, what would the correct torsion bar size be so the car won't squat down on take off once the engine is installed? And do you think it's safe to run with 15x6 or 15x7 Fuchs in the rear with 205-60-15s? I'm not into putting flares on the rear for larger wheels/tires. Or is a 3.2 more feasible overall? The 3.0 still seems attractive because of its relative simplicity, but still, I'm looking into all options here.

Thanks

[Swank911]

Have you seen Jack Olsen's car?

http://members.rennlist.com/jackolsen/Jalopy.html

He placed a 3.6 in a '73t.