Rebuild/Hotrod my 3.2 or Transplant a 3.6?

gtc · gtc's Garage

Does anyone have advice on this decision?
My motor is coming up on 200k miles, and according to my PPI in May, cylinder #2 had ~60% leakdown, if I recall correctly. I'm not sure where the leak is; the engine runs well, makes good power (dyno'd at 195 in July), doesn't consume an unreasonable amount of oil, doesn't smoke, and doesn't drip (though it does weep a little around some of the heads I think). Regardless, I'm guessing it's time for this engine to be rebuilt.

I want more power, but going to a twin-plug 3.4 with all the goodies looks really expensive, not to mention time consuming. I've been looking at cost-effective upgrades, like a SW chip, 964 cams, and a more open exhaust, but I'm afraid these are the gateway drugs for the 3.4. When I read about people who have done the 3.4 upgrade this is generally how they start out.

If I were to buy a 3.6 and a kit from Steve Timmins, it seems like I could perform the transplant in a couple of weeks, sell my 3.2 as a core, and come out ahead in terms of both time and money.

I'm aware of the issues and opinions regarding suspension, oil coolers, and the 915.

Aside from the fear of buying an unknown motor, are there any other downsides to a 3.6 swap that people have experienced?

Thanks for the advice,

Jeff Alton · 12-13-2007, 03:24 PM

My 3.4 (build detailed on this forum) was indeed expensive.

There are pros and cons for everything.

Before my own 3.4, I ran a 3.2 with 964 cams, SSI's and a SW chip. Nice motor, but not in the same league as what I built now.

The thing I like best about the motor is the throttle response offered by the ITB's, just like an early MFI motor.

To me a 3.6 in an earlier chassis is a good combo, I have driven a few. But, they just feel like the same thing only with more power. If that is what you are after, then it is a good way to go. I wanted more "character" in my motor.

A used 3.6 of unknown history may turn out to be a good purchase, but what if it needs a rebuild soon too?

Cheers

gtc · gtc's Garage

Ok, here's a sort of related question. Would running single plugs and stock compression ratio in my hot rod 3.2 place a limit on the RPMs I can reach?

Eagledriver · 12-13-2007, 05:07 PM

Single plug and stock compression ratio are not the limitation factors of RPM. The first limit is the valve springs and rod bolts. The second is the rods. Your engine can safely turn 7200 RPM with stiffer valve springs and aftermarket rod bolts(IMO). You'll be well past your power band however with your cams. To go higher on RPM you will need to go with titanium rods.

-Andy

NoEardGoat · 12-13-2007, 06:28 PM

I just had to make a similar decision. I have a 1981 911sc coupe that I got with a broken motor. I was going to rebuild the motor and added up the costs and decided I would be much happier with the power improvement of the 3.6l. Well there is a reason they call a used engine "used." Even if it only has 48k miles and comes out of a running car! It turns out one of the cylinders was leaking over 60% and had a broken top piston ring. Basically I paid $7k for an engine that needs to be rebuilt, and I am in exactly the same spot I was with the 3.0l motor. At least I sold the 3.0l w/ a good set of pistons for $2300. Don't forget about the cost of the conversion stuff itself as well as upgrading brakes, oil cooling, etc......... Should be a bad ass car though.

If I were you I would continue driving the car and purchase a rebuildable 3.6l and rebuild that motor and while rebuilding it work on the conversion stuff as well. Then when ready to swap sell the 3.2l. Probably worth more than 2500 as a core alone. I found shipping via DHL the cheapest.

Jeff Alton · 12-13-2007, 06:41 PM

For the record, I had a 3.6 shipped from the east coast to the west coast for 320.00 by Forward Air.

I agree with what noeardgoat suggests, if you are sold on the idea of a 3.6.

Cheers

schnellmann · 12-13-2007, 06:48 PM

I am in the buildup phase of my 3.2 -> 3.4. I am into it for a over 7 grand now. What tipped me in favor of a hot rod rebuild were the stories of late where guys are getting 3.6s that turn out to need a rebuild, but were supposed to be "good low mileage" motors.

Even the newest 3.6 is 10 years old at this point. Build up your 3.2 and enjoy your brand new motor...

alf · 12-22-2007, 04:20 PM

You are welcome to take a spin in my rebuilt 3.2 when JWW is done with it. I have all the low hanging fruit upgrades...SW chip, pre-muff, sports muffler and now 20/21 cams.

wolfrennen · wolfrennen's Garage

Now this is a great idea. Enjoy the motor that's in your car while planning for a future 3.6-L swap with a rebuilt 3.6-L.

Quote:

Originally Posted by NoEardGoat

Well there is a reason they call a used engine "used." Even if it only has 48k miles and comes out of a running car! It turns out one of the cylinders was leaking over 60% and had a broken top piston ring. Basically I paid $7k for an engine that needs to be rebuilt, and I am in exactly the same spot I was with the 3.0l motor. If I were you I would continue driving the car and purchase a rebuildable 3.6l and rebuild that motor and while rebuilding it work on the conversion stuff as well. Then when ready to swap sell the 3.2l. Probably worth more than 2500 as a core alone. I found shipping via DHL the cheapest.

johnsjmc · 06:43 PM

I went through the 3.6 install in a 1980 several years ago. I wouldn,t bother again I now have a 993. I sold the 3.6 SC for $18.5K and picked up a plain 1995 993 6 spd,LSD coupe with similar miles. Both cars had about 110,000 mi. I bought the 993 for $19K plus tax. I found Pss9's and sways had been added by a PO . I,ve replaced the tires and brakes in the last 2 yrs . BUT I have big brakes,6 spd,working AC and a much newer feeling car which is probably just as fast or faster. I,d look for a 993 or 964 C2 and test drive several before you decide to spend a ton on an old car.

Jimmy18E · 08-15-2011, 08:46 PM

Graham,

It all depends on what your budget is and what exactly you are looking to have in the end.

A 3.6 in an early car is a hoot, turn the key and it starts without praying to the carb gods", is fast, big torque and less money than a full on 3.4 build.

I went for the hot rod full on built motor route, my car pulls the 3.6s around here, has an 8K red line, sounds great, looks great when you lift the deck lid and is in character with the early cars..

Again, it what you want in the finished project and most importantly what is the budget...

Good Luck,

Jimmy

wolfrennen · wolfrennen's Garage

Sounds reasonable also. You're getting a much better tub with a 993 I suppose. I do like the lightweight '88 Carrera tub on the track--which is the draw to doing the 3.6-L v-ram conversion--if I go that route rather than re-doing my 3.4-L.

Quote:

Originally Posted by johnsjmc

I went through the 3.6 install in a 1980 several years ago. I wouldn,t bother again I now have a 993. I sold the 3.6 SC for $18.5K and picked up a plain 1995 993 6 spd,LSD coupe with similar miles. Both cars had about 110,000 mi. I bought the 993 for $19K plus tax. I found Pss9's and sways had been added by a PO . I,ve replaced the tires and brakes in the last 2 yrs . BUT I have big brakes,6 spd,working AC and a much newer feeling car which is probably just as fast or faster. I,d look for a 993 or 964 C2 and test drive several before you decide to spend a ton on an old car.

gtc · gtc's Garage

Funny, I had forgotten about starting this thread almost 4 years ago. In the last few years I've put 100,000 miles on the car (now it has a bit over 300,000) and I'm finally beginning to think about this topic again.

For the record, my PPI's high leakdown was probably just due to carbon buildup or something of that sort, because I had it retested some time after my first post and #2 was back in line with all the rest.

I've pretty much ruled out the 3.6 (I can't rationalize the conversion costs) and I've decided that I don't really need huge power (I've grown to appreciate that the driver makes more of a difference than the engine), so a simple 3.2-based hotrod seems like what I'll shoot for.

wolfrennen · wolfrennen's Garage

Sounds reasonable to me. You can't ignore the risk of getting a bad 3.6-L

Quote:

Originally Posted by gtc

Funny, I had forgotten about starting this thread almost 4 years ago. In the last few years I've put 100,000 miles on the car (now it has a bit over 300,000) and I'm finally beginning to think about this topic again.

For the record, my PPI's high leakdown was probably just due to carbon buildup or something of that sort, because I had it retested some time after my first post and #2 was back in line with all the rest.

I've pretty much ruled out the 3.6 (I can't rationalize the conversion costs) and I've decided that I don't really need huge power (I've grown to appreciate that the driver makes more of a difference than the engine), so a simple 3.2-based hotrod seems like what I'll shoot for.

gtc · gtc's Garage

I'm a little skeptical... from all the horror stories you hear about people buying junk 3.6s, you'd have to assume that the motors are fairly unreliable to begin with, which, despite some of their known isssues, is not true AFAIK.

I'm more concerned with the conversion costs for the flywheel, computer/harness, oil system, exhaust, etc etc...

Quote:

Originally Posted by wolfrennen

Sounds reasonable to me. You can't ignore the risk of getting a bad 3.6-L

arrivederci · 08-17-2011, 10:18 AM

Quote:

Originally Posted by gtc

I'm more concerned with the conversion costs for the flywheel, computer/harness, oil system, exhaust, etc etc...

What's the concern? They're pretty well known and predictable because it has been done so many times. The biggest variables (as I see them) are the health of a 12+ year old motor and the while-you-are-in-there factors. Do you bother going beyond stock for things like brakes, suspension, and transmission? Many don't and are fine, but is that good enough for you?

Maxhouse97 · 08-18-2011, 06:07 PM

Buy Euro pistons - drop in replacement - will help get that much closer to a stock 964 3.6 (in hp not torque).

johnsjmc · 08-19-2011, 07:26 AM

Quote:

Originally Posted by Maxhouse97

Buy Euro pistons - drop in replacement - will help get that much closer to a stock 964 3.6 (in hp not torque).

The compression increase to Euro will also need a custom chip to see very much real hp gain . Seems to me the difference is hardly worth it unless you need P&C,s anyway. A 3.6 will have even higher compression,twin plugs and knock sensors plus a more agressive cam profile and 400 cc displacement.
I did an install with 2 Carrera fender coolers, rebuilt 915 ,Sachs power clutch,and a custom fabricated 993 HE based exhaust . It,s doable on a budget of under $10K including engine using my labour and careful parts purchase. Or you could buy one already converted when they show up. My old 1980 3.6 has sold again since I sold it with new front tires and a few more miles it sold for same as I sold it $18500. . It had big brakes, Carrera sways, and custom valved Bilsteins.
When they are done and running you can do a leakdown,compression check at least. It is risky buying an unknown 3.6 or 3.2 for that matter.
With a full rebuild going over $10K I would still come back to looking at a newer car and selling what you have as a complete car while it is still running.