Thinking of converting my 1968L motor to an"S"

[svonkampen]

Hi all,

I was told that the 911L is basically a detuned "S".....

Is this true?

If so, what would it take (money wise) to have it converted to an "S"

SvK
1968 911L

[rzepko6194]

Yes it's true. You'll need new pistons/cylinders, bigger valves, cam reprofiling and carb rejetting. It will probably cost you at least $5K if you do the rebuild yourself. Pretty expensive for an additional peaky 30 hp, unless your engine needs a rebuild anyway.

[svonkampen]

thanx for your reply.......

SvK

[svonkampen]

I take it will decrease the value of my car as well?

SvK

[Grady Clay]

SvK,

Yes, it is very expensive to do properly and your 911L is probably better as a two-liter street car as it is.

Yes, it will probably reduce the value of the car in the long-term.

What can you do?
Carefully preserve your engine and buy a good used later engine to play with. With the right set of parts, almost any engine thru ’89 can bolt right in. I would recommend a nice 2.4E or S with carburetors.
If your “L” engine is tired, just do a proper rebuild as original.

Maintain all the original details of your 2.0 911L engine so someday it can go back in exactly as originally delivered. You can do the same thing with the transmission and suspension.

Best,
Grady
gradyclay@hotmail.com

[svonkampen]

thanx.....Grady........

A 2.4S motor.....how much would that run?

SvK

[dotorg]

Grady, in terms of judging if its worth making the change, keep in mind the L is a car that has never been in high demand... ie, it may not impact value as much as many other 911 models.

For what its worth, I have a L motor with S cams. I believe my valves are still the L valves. P&C are stock L. Its a configuration I've been told was one Porsche used in their rally engines.

I have no idea what power it makes, the engine builder suspected around 150hp, but I haven't gotten it onto the dyno yet..

I can tell you, its a blast to drive when I can keep the revs up. Its a beast above 5000rpm.

[svonkampen]

So the s-cams gave you a boost of 20 HP ?

Hers's what I'm looking for my car does 0-60 in about 8 seconds.........I'm looking for 5.9 or so....

What are my options?

It seems buying a 2.4S Engine will run me less than rebuilding my L.........plus if I buy a second engine....I'll also have a spare....

SvK

ps: Dotorg....my L loves shifting between 5000-6500.......luv it

[dotorg]

Thats his theory... a nice gain very high in the rev range... the car really doesn't like being below 4000rpm at all, and likes to run between 5000-6000 rpm.

There's no way I get a sub-6 second 0-60, though, no matter what I do. I just have far too little power at low revs... from a stop it'll take me a few seconds just to get into the power band.

Its a dog around town, from what I was told its more so than a normal L motor, but its a beast when once you get going.

Its not a configuration I would've picked, but the guy I bought it from went with it...

[svonkampen]

my "L" hates 1st gear......so crap.....hate it....

MY L loves.....being in 5th at 60mph (3500rpm) downshifting to 4th and hiting the gas......and vvvvvrrrrooommmmm

SvK

[Grady Clay]

SvK,

It depends on your DIY skills and willingness to light into an engine project.

Here is an example:
Buy a running 2.4T, complete out thru the valve covers but no accessories.
Rebuild it yourself per Wayne’s book. Have the cams ground to E or slightly more specs, match the intake ports to your ‘68L manifolds. Assemble with your entire intake system, fan, shroud, and tin. Use your flywheel & clutch. Use your heat exchangers and muffler.

Here is another example:
Buy a running 2.4T, complete out thru the valve covers but no accessories.
Rebuild it yourself per Wayne’s book. Have the cams ground to S or slightly more specs, match the intake ports to new PMO manifolds and 46 mm carbs. Install 92 mm RSR P&Cs at 10.3:1. Modify the heads for twin plug. Assemble with your air filter assembly, shroud, and tin. Install the later fan ratio parts. Use a later clutch. Use new SSI headers and muffler. At this level the transmission becomes an issue.

Help me out here guys.
The first example probably can be noticeably under $5K for 160 hp and much improved torque. The second example is probably noticeably over $10K for 230+ hp and outrageous performance.

AND … you still have the basics of your original engine. BTW, the ’68 engine has almost no significant value to anyone else but you.

Best,
Grady

[dotorg]

Originally posted by svonkampen
my "L" hates 1st gear......so crap.....hate it....

MY L loves.....being in 5th at 60mph (3500rpm) downshifting to 4th and hiting the gas......and vvvvvrrrrooommmmm

SvK

Thats the difference I guess between a stock L motor and mine... at 4th going 100km/h, I don't have enough power to really take off... I usually drive in 4th on the highway and 2nd or 3rd on side streets. I have to be in 3rd at 60mph/100kmh to really take off.

I rarely use 5th... if I do its just putzing along going 75-80mph for a long drive, just zoning out.

Or perhaps when I run out of revs in 4th, but I'd never do that on the street.

[sixbanger]

HEY, This is cool as I just bought a 1969 911E that has new floor pans and a S engine upgrade.Carbs need a rebuild.

[larry47us]

From what I've heard, the ideal street solution is to stick with the "E" cams, but put in "S" pistons. I have even heard to take a 2.4 engine, and put 2.2 pistons in it. This gives you more horsies because of the higher compression.

In this case, the E cam will bring the torque into the street driving range, giving you more power off the line. The Higher compression more horses and torque to pull you forward. You aren't really looking for acceleration after 60 - 70 mph anyway, are you?

I am getting a 73E Targa, and the engine is tight, so I can only dream of RGrupping the machine. But I have heard . . . . . . . . .

larry

[svonkampen]

Grady.........

thanx for elaborating on my engine options......


food for thought......i can afford option1.......

now i have to find that engine....

SvK

[ttweed]

Buy this engine quick, before it gets away, and then put your original one in storage, or rebuild it at your leisure.

There's no replacement for displacement. If you want some nice torque off the line, a 2.7RS motor or larger is the ticket.

TT

[svonkampen]

yummy ;-)

[Grady Clay]

SvK,

Plan first, buy later, and above all be patient. Your 911 is running now and can be running through most of this process. Don’t disable it any sooner than absolutely necessary.

You will probably be able to find a 7.5:1 CR (2341 cc) 911T engine. Your 911L is 9.0:1 CR (1991 cc). You may want to bump the compression a bit. That CR is limited by your fuel octane availability. There has been lots of discussion about this subject on this Forum, do lots of searching.

Before anything else you should read Wayne’s two books and Bruce Anderson’s book. Read several times, make notes, and devise a plan. Make a proposed parts and outside services list with your cost.

Remember, Murphy is in charge. No matter how good your planning is, something unexpected always crops up. Usually it is more expensive. Be prepared.

Where are you located?

Best,
Grady

[svonkampen]

thanx Grady,

Im in San Diego County (Carlsbad) My mechanic is Joe who owns European Motorsports.....He races old 911s.....And was recomended by my PCA chapter......I know nothing of engines but am willing to learn .....this rebuild or 2nd engine install will be handled by Joe......however multiple opinions are always better than one.......I am looking for power of the line.....I rarely go faster than 75 - 85 on freeway so my main excitement will be of the line............I need the most cost effective solution for this since I am far from rich................

Off Topic: Next week i get SSI heat exchangers installed.....hopefully that will decrease most of my backfire spurts when I deccelerate.......

The car is a recent purchase......and I can afford to put in about 1500.00$ a month (benefits of being single) Last month she recieved adjustable KONIs (feels much better)

So anyway........after that it's time to put some guts in her of the line.....

By the way......I can't seem to find the SSI muffler on the PELICAN site, only the exchangers

SvK

[Grady Clay]

SvK,

Never, ever try and light up the tires in first gear with a Type 901 transmission (or Type 911, 914, 904, 906, 910).

A 901 transmission absolutely will fail catastrophically if pushed to the limit “off the line” in first. The first gear is cantilevered in the nose piece and it is a relatively small part of the input shaft. Very, very expensive problem.

If you want to use “off the line” performance you need a 915, 930, or later transmission. Less $$$$$ than trashing several 901s.

Start putting your $1500/month in the bank and do some planning. 2c

The engine costs I suggested were based on Do It Yourself (DIY).

Best,
Grady