Swap 180bhp for 204hp 911SC engine?

08-22-2002, 11:56 AM

Hi,
need to do some head stud work to my early 911sc Engine ( 180 bhp )

Think it may be a better bet to just fit the later 204 bhp SC engine as this will cost about the same.

Are there any anciliaries/engine mounts etc. that I woudl need to change as well?

Thanks

Jdub · 08-22-2002, 12:02 PM

My understanding is that the two hp rates were not nearly that far apart. They purposely played down the hp on the '78 so as to ensure no competition with the water-cooled cars that were meant to take the lead.

I would be happy to hear any other opinions.

John

Wayne 962 · Wayne 962's Garage

There's a big misconception that replacing your 2.7 with a 3.0 or 3.2 will cost you less. The 3.0/3.2 that you replace it with better be a very fresh engine with no head stud or rod-bolt problems. Otherwise, you'll just drive it for a year, and may then have to rebuild it.

-Wayne

pbs911 · pbs911's Garage

How exactly did the late model 3.0 increase hp to 204 over the 78-79 3.0 @ 180? Aren't the only differences the smaller ports and valves o2 sensor in the late models.

island911 · 08-22-2002, 12:20 PM

I think Jdub is right, though I'm sure the higher compression ratio pitons in the later 204 bhp SC engine did give it a good bump. . .just not 24hp worth. (my 2¢ worth)

08-22-2002, 12:28 PM

hanks,
just to clarify - the current engine in my SC is the 3.0 180 bhp. and my reasons for going for the later 204bhp engine were more based on cash, rather than for the claimed extra 24 bhp.

I've been offered a 1983 3.0 91sc engine for a good price, with low miles and paperwork to show servicing etc. and it's had a top end rebuild.

my choice is either have my existing engine rebuilt, or...

for the same cash, replace it with the later 1983, 3.0 engine ( with the claimed 204 bhp ) and then still have my old engine to sell.

think ithe 204 engine is 'supposed' to give better mpg as well???

what do you guys think?

hilandscott · hilandscott's Garage

If the engine checks out (leakdown/compression), and it has the updates that you'd want anyway (popoff valve, Carerra tensioners) then might be a good way to go.

I wouldn't mind having a low cost, build-it-myself upgradeable project motor as back myself.

Superman · 08-22-2002, 01:04 PM

Ah Hah! I know this one. Porsche specified 180 hp for ALL North American SCs, 78-83, even though there are differences. The 204 hp 3-liters were Euro engines.

Yes, the early SCs had bigger intake ports, but the later SCs had 9.3:1 pistons as opposed to early SCs with 8.6:1.

Just put a 3.6 in there and be done with it.

TimT · 08-22-2002, 01:28 PM

Why not buy and install the 204hp engine, then with your "extra" engine, build yourself a monster? tear it done do all the mods to make a bullet proof bottem end, port the head increase the cr, wilder cams, lighweight flywheel and RSR clutch? Along with a host of other thigs to make with your soare engine!!

1980SC · 08-22-2002, 03:18 PM

My 1980 euro is rated at 188hp and has 8.6:1 compression. The 204hp '81-'83 has 9.8:1 compression. Seems logical to me.

Rob
1980SC euro

Superman · 08-22-2002, 03:32 PM

Again, if you think you have a 204 hp factory 3-liter, and if it is not a Euro engine, then you are incorrect. All NA 3-liters were specified at 180 hp. If you do have a chance to get a good price on a verifiably fresh 204 hp Euro engine, then you will have all the parts necessary to make a really fun engine. Use the early heads, intake runners, air box and fuel distributor, and combine them with the Euro bottom end, including the 9.8:1 pistons, and you'll have an engine that will REALLY scoot. This is assuming that the larger early ('78 - '79) intake parts are not already on the Euro engine. Then bolt the remaining parts together and sell that engine to someone whose early 911 needs a motor at low cost.

1980SC · 08-22-2002, 03:49 PM

Not the fuel distributor from the early SC's though. You would need the '81-'83 euro fuel distributor #911.110.977.00 as it flows more fuel than any of the other n/a 3.0 fuel heads, and should be used with the higher compression. The larger ports were only on '78-'79 regardless of euro or USA.

Rob
1980SC

08-23-2002, 04:49 AM

Superman - et al,

thanks for all the suggestions,

tempted by the idea of combining the best parts from each,

but as it's a couple of the head studs on my early engine that need the work this might rule out using it, as if I have the head studs replaced then that will push the budget too far.

but I'll buy a lottery ticket for tomorrow and keep my fingers crossed!

THnks
Tim