3.0 vs 3.6 what to do?

[manonmasi]

I have a tired 3.0 in my 83 911 and was thinking of having it re-built with a racing cam and high compression pistons to get more hp. Someone sad I would be better off just getting a 3.6 instead. Any thoughts on this out there. Thanks

[jorian]

Plan on spending 3-4 times the price of rebuilding that 3.0 to properly get the 3.6 in there. Money no object? Go for the 3.6!

[jorian]

Top end rebuild with a bit more aggressive cam and SSI heat exchangers will wake up that sleepy 3.0

[Craig T]

A rebuild with more aggressive cam, bump in compression, and SSI's will see at least 20-25 more HP. That'll really wake her up, although mostly at the top end. The cost...probably $15,000 to do it right.

A 3.6L varioram will get you a BREATHTAKING increase in low-end torque and likely an extra 75-80 hp at the top. If you find a strong low mileage 3.6L varioram, and have access to somebody who can do the conversion properly, you'd be looking at around $30,000 before it's done. Finding a slightly cheaper 964 3.6L will save you maybe $1,500, but cut the performance increase in half...and If the used $3.6L ends up needing work, then that $30K will ramp up fast!

$$$ per HP on the rebuild it $600 per HP.

$$$ on a 3.6L varioram is $400 per HP

Best value...Strip the weight out.

[Craig T]

With that said ^^^ The 20-25 extra HP with a more high-strung rebuild is only incremental dollars, because you'll have the base cost to rebuild the motor anyway. The cam, high-comp pistons, and SSI's will probably add about $3000 to rebuilding stock.

I certainly would NOT do the cam and compression mods without using ARP bolts, ti retainers, upgraded valve springs, etc. That'll add another $1,500 at least.

A high-strung 3.0 motor will NOT have the lifespan of a stock 3.6L.

[manonmasi]

Thanks for the info guys, I think I will go for a rebuild and some upgrades.

[Craig T]

If you like to open your hood and look inside, you'll be happier with the performance-built 3.0.

My 3.4 has a little less torque down low than Joe Bob's 3.6, but likely about the same HP up top. The main reason I went with the 3.2 base is this...

What do you think looks better? This.......




Or, this........

[jorian]

Another great point Craig. Looks mean something too.

Lifting the lid and seeing those rain hats standing at attention is just plain cool. 3.6 doesn't look nearly as neat either. Twin plug dizzy on the 3.2 also looks the business.

[johnsjmc]

I will throw this out there for you to consider. The air cooled 911s are increasing in value at a dizzying rate. It will eventually affect your SC. I would keep the original engine with the car and add SSI ,s The 3.0 has bigger rod bolts than the 3.2 or turbo anyway so the rods and bolts are plenty strong to start with. The 3.0 will benefit from new case studs as the dilivar ones will be very brittle and should be replaced during a rebuild. I wouldn,t add a cam hotter than a 964 type. Keep it bolt on modifications so you can return to dead stock if needed in the future.
I have gone the 3.6 route myself and could do it again for way less than $30, but if an engine change is what you want ,consider a 3.2. Easier install(no oil cooling mods needed, and stock exhaust works OK.

[manonmasi]

@ Craig, that is one beautiful sight. They say form before function, you sure have both.

[Josh D]

The biggest challenge you have with an '83 SC is the small port CIS. You already have a decent compression ratio for a single plug motor at 9.3:1. An increase in compression within the confines of a single plug motor won't do you much. 964 cams and early heat exchangers (or SSI's) will net some gains, but again your limited by the intake side.

A 9.5:1 3.2 SS with opened up intake ports, hotter cam and PMO's would be a good bang for the buck, probably about 240 HP at the crank. but your looking at at least $10K right there. These cars start getting really fun when you get the HP/weight ratio below 11 lbs per HP. Get weight down to at least 2500 lbs with 240 HP and you're there.

[wayner]

My personal opinion is that a lot of the common advice is aging.

Buy a "rust free galvanized body" used to be more appropriate 10 years ago when galvanized bodies were actually rust free.

Buy a G50 over a 915 was more practical 10 years ago before G50s needed rebuilt

Same goes for 993 motors vs. rebuilding what you have already got. Low mileage ones are harder to find now.

[safe]

If you get a 3.6 it might still need a top end rebuild.
You will also need to put 3-4 k into the 915 to make it last.

[arrivederci]

Not sure where everyone is getting the 3.6L conversion costs from...have they really gone up to $30K? There are plenty of threads documenting what people have spent, but here is a ballpark for my conversion.

3.6L motor (993 Vram) : $8K
915 trans, refreshed '84 with factory cooler : $2K
Conversion kit w/ clutch, fuel lines, additional oil cooler, etc : $3.5K
Custom exhaust : $600

Granted I got a few good deals on the above prices maybe saving a few K. But that's about $14K without labor and assumes that you don't sell your existing 915 or motor...and that the existing 915 won't work with the 3.6L. It is true that a 3.6L may need a rebuild as well. So beware of that possibility and choose your source carefully.

Many have found the 3.6L to be a turn-key, 1 or 2 weekend project. And it is a factory built/tuned motor. Pretty painless -- can't say the same about a 3.2SS or 3.4L motor. You need to know your stuff or have a mechanic that knows his. The 3.4L motor does look clean and tidy though. Not a lot of room to maneuver in the 3.6L engine bay...

[johnsjmc]

I said earlier you could do a 3.6 for way less than $30k as well. I picked up a 1977 911 with a 91 3.6 in it for $17on ebay ..It was a rather sloppy install with inadequate oil cooling and a mid year targa .
I had a 1980 SC ,with a rebuilt 915 upgraded suspension ,brakes and fresh paint and interior.
I installed the 3.0 from the SC in the 77 and resold it for $12500,after stripping some stuff like 17" wheels, a tube style fender cooler and an early tail off it.
I installed the 3.6 into my 80 and added a second fender cooler and used 993 HEs and a new muffler ,instead of the cobbled (pinched 964 based exhaust that was under the first install.)
Other than labour (I,m a retired tech) I ended up with a 3.6 in an SC for a net cost of about $4500. don,t forget a 3.6 install needs better brakes and suspension along with the minimum to get it running. The better brakes, suspension work and refreshed trans were much of why I swapped instead up cleaning up the original shoddy install.I also wanted to keep my coupe more than a midyear targa.
I sold the 3.6 SC about 3 years ago for $20 after using it for 3 yrs. and replaced it with a high miles 993 for about the same. High miles is relative because all 3 cars I have mentioned here had about 110k mi on them.
The 993 has needed a clutch and tires during the last 3 yrs but it,s almost as fast as the 3.6 in the early car and the AC works .(LOL)

[Craig T]

Originally Posted by safe

If you get a 3.6 it might still need a top end rebuild.
You will also need to put 3-4 k into the 915 to make it last.

This is a very good point. The 915 wasn't built to handle the torque of the 3.6L. A stronger rebuild is a must if you want it to last more than a year.

A 3.2 swap is a good idea. I did this to my race car, jumping from POC class IP to JP. These were both bone-stock motors and the 3.2 was a couple seconds per lap faster at all tracks.

Allan Faragallah at Aase Motors will give you an exchange credit on your 3.0 for one of his 3.2 cores. You can build that 3.2 how you like and plug it right in with a Steve Wong DME for half the cost of a 3.6L conversion.

A 3.2 with GE-60 cam, 10.3:1 JE's, and PMO's will put out 240 on pump gas...But you won't pass smog

[Craig T]

It sounds like labor and parts are cheap in Canada and CO.

Here in Los Angeles where the OP lives, if you're not a "retired tech", you have to pay somebody to do this. Also, where do you find a freshened 915 with a cooler for $2K? I'll take five! Custom exhaust $600? I'll take five of those too!

LA Porsche Dismantler wants $9800 for a 993 Vram and harness, with NO guarantees. These are high mile motors by now and any reputable shop will recommend a freshen-up before installing it.

No shop around the OP's N Hollywood location will build a 3.6-ready tranny for $2K...More like $4K. We're talking TRE, TLG, Aase Motors.

$9800 Used Motor, brain, harness from LA Dis
$5000 $3.6L highly likely freshen-up
$4000 tranny with HD clutch
$3500 conversion parts - Oil lines, hoses, elec, etc
$1000 3.6L exhaust with heat

$23,000...Now, unless you're a retired tech or live in Colorado, you have to pay somebody to install it. Even if you have good leak-down numbers and compression on the 3.6, it's still going to need a service after sitting in a junk yard. You can count on $2000. That still puts you at $20K before install.

Of course shopping Pelican classifieds and ebay for used parts and sticking them in there untested can bring this cost down. Personally, I don't want to put a car back together with unkowns. I want to do Targa California without breaking down, and a couple track days without a trailer.

[arrivederci]

Originally Posted by Craig T

It sounds like labor and parts are cheap in Canada and CO.

Here in Los Angeles where the OP lives, if you're not a "retired tech", you have to pay somebody to do this. Also, where do you find a freshened 915 with a cooler for $2K? I'll take five! Custom exhaust $600? I'll take five of those too!

I am not a retired tech and there are many documented 3.6L installs that were done by the average Joe. This isn't rocket science if you are willing to spend some time working on your car.

I found my motor right here on the Pelican classifieds. It was from Valley European in Van Nuys Cali. It included the ECU with driveblock removed (it came out of a customer's conversion), 993 headers and cat. I found the trans through Pelican as well, although I found it while inquiring about a different 915. I spent $1800 plus shipping...shipped from Meadow Vista, Cali. Sure, I had to wait for the right one to come along and be there to snap it up. But it can be done. Could I find those same deals today? I bet they exist if you look for them.

Custom exhaust was actually $700 I think, so maybe you don't want 5. But that was just a muffler that Ben @ M&K sets up to work with 993 heat exchangers. His sport mufflers go for $750 now. All it takes is a phone call and a credit card. Nothing special there.

The conversion kit (I used Timmins / instant-g) included an HD clutch, conversion flywheel, wiring harness, DME relay, carrera fuel pump and filter, fuel lines and fittings, throttle cable, oil feed lines, power steering blockoff, and second oil cooler kit for front drivers side, along with all the bolts and stuff to finish it off. Pretty much everything you need, including tech support if you get stuck. From the instant-g website, they'll quote you a tested crate motor with conversion kit for under $16K with exhaust...so my bargain hunting prices aren't far off.

Short of sourcing a rebuilt 915 (which many don't need) and 'freshening' the motor, we aren't that far apart in terms of the cost of parts to convert. The last unknown is the installation labor...which certainly have to be factored in if you don't want to install it yourself. I still don't see this as a $30K endeavor...I think that's the extreme case, not the norm.

[Craig T]

Yes, the shop labor was the factor that pushed it up for me. I agree 100%, do it yourself and you can probably save $10K (if you don't count your time).

Seriously now though...How many of us on this forum are really capable of this level of DIY project??? VERY few. Congrats to those of you who have the confidence to take this on. I don't. It doesn't sound like the OP'er does either. So, the DIY cost isn't really relevant.

When I built my hot rod two years ago I researched this to exhaustion. My first choice was a 3.6 Vram. I spent hours at Aase Motors, TLG, TRE, RS Enterprises, on classifieds, etc. No matter how I spun it, sourced it, or negotiated, with new or reliably REBUILT parts it was $30K before it was done.

[johnsjmc]

I built a copy of Timmons "happy crab" exhaust for about $300 . a 2 in 2 out magnaflow muffler is about $200 add 2 mandrel bends and 4 welds. .
I had the engine from the other car so I would guess about $7500 should buy you a good engine What little comes in Timmons kit would surprise you. the block off plate forpower steering and an adapter for the oil return comes to mind. I made the oil line adaptor in about 30 min.
The biggest part of using the 993 HE,s is flipping the flanges on the pass side. About 2 hours.
A clutch change on a 911 is about 5-6 hours so installing the basic engine is the same.
There are threads on pelican detailing adding extra oil cooling and I followed someone else, s method.
Adding a DME and the harness is easy. I used a part wiring kit from Timmons for a couple hundred.
If you already have a working 915 you don,t need another ,the SC aluminum one is strong enough for most installs. The sachs power clutch if still available is hardly more than a regular 911 replacement clutch.
Labour in Canada is about $100 per hour at the local P car dealer but they wouldn,t do the job if I asked. Our shop gets $65 but I was the only tech who would have touched this job.
I would have estimated about 25 hours total if doing it again. I was contributing more about how it can be done for much less than $30k .(Parts are more here because they invariably come from the States.
My first contribution to this thread suggested a 3.2 would be a cheaper way to upgrade the car. I don,t recommend the 3.6 conversion and that's after owning one ,not just installing them.