911 SC engine upgrade. What would you do?

[Vereeken]

Yes I know how to search but I do not want to trawl through 1.000 pages

I am hoping to get some pointers as to the different paths to take.

My SC decided yesterday to succumb to the head stud problem. I had planned for this to happen around October, but he had other plans.

So off it is for an engine rework. The engine is just fine, no oil usage to speak off good power, etc....

I am in no need for a race monster. This is a street only car that I enjoy for the looks and the nostalgia.

What would you do to the engine?

Is there an easy way to extract some extra power? Would you go for 964 cams? Would you work on the exhaust side?
Or is it all not worth it ans simply rework to standard.

[T77911S]

depends on if you need P&C's and what type you have. then I would break it down into 2 categories, one with new PC's and one with old ones. then I would break it down again as far as what induction system you want to go with. carbs, EFI or CIS,

[Vereeken]

Old p&c and I do not want carbs. I have no issue with CIS but understand it is limited performance wise.

[Steve@Rennsport]

Make it a 3.2 with stock cams and CIS.

You will be VERY pleased.

[Shaun @ Tru6]

sell it and get a 3.2.

[wayner]

I think that when it comes to Cams, CIS is the limiting factory is it not?

[GaryR]

964 Cams, (assume you already have Euro SC Pistons?) have the dizzy rebuilt and re-curved, tweak the CIS a little to get good A/F. Done

[Vereeken]

I am not going to get a Carrera. i drive a SuperCarrera ;o)

Yes indeed; this is a euro car with 204hp (actually 213 on the dyno)

Can you start from the 3.0 casing to move to a 3.2?

When done are there any evident visual clues?

[Trackrash]

Originally Posted by Vereeken

I am not going to get a Carrera. i drive a SuperCarrera ;o)

Yes indeed; this is a euro car with 204hp (actually 213 on the dyno)

Can you start from the 3.0 casing to move to a 3.2?

When done are there any evident visual clues?

If money was no object. 98 mm P&C, 964 cams, Carrera crank and rod set. Would make a 3,4 and look stock on the outside.

[Vereeken]

Originally Posted by Steve@Rennsport

Make it a 3.2 with stock cams and CIS.

You will be VERY pleased.

Moved to #1 spot.

[JabsZA]

Speak to William Knight!

[BK911]

Change cams, early exhaust and verify throttle linkage is properly adjusted.

[GaryR]

Originally Posted by BK911

Change cams, early exhaust and verify throttle linkage is properly adjusted.

Actually put some equal length headers (no heat) on her if you don't drive in winter!

[RDM]

Originally Posted by GaryR

Actually put some equal length headers (no heat) on her if you don't drive in winter!

In Belgium, it's never really winter. It's never really summer either.

I did 964 cams and SSIs, hollowed out muffler, heat backdate and A/C removal. My goal was more responsiveness (less weight, more power). Next round, I hope to go with ITBs and electronic injection / ignition for the same reasons. I'm not ever going to be a racer, but driving my Targa will always be an event.

Will return 6 empty cases to Malmedy this weekend. May pick up 6 full ones!

[Spumato]

If you are finding yourself in a very similar boat as I was in 2 years ago when my numbers matching engine in my MY74 911 coupe suffered with pulled head studs, then I would follow the same course of action as I underwent:

Obtain low mileage SC for rebuild
Add ARP Head Studs
Add ARP Rod Bolts
Add Titanium Valve Springs
Use High-Flow CIS
Add Carrera Chain Tensioner upgrade
Add real 964 Cams

The 3.2L engine will have more HP, and more top-end, but lacks the peppy punch you will find in a 3.0L. Add that you will probably want a Motronic engine management system on the 3.2L that will add better fuel reliability, while adding complexity.

The 3.0L from an SC 911, when you use an early 70's era SSI setup that goes into a dual in dual out muffler, coupled with a short ring and pinion set 915, and you have one hell of a ride! Trust me as I know firsthand.

[dad911]

If it's an original car with matching numbers, I would put the engine on a shelf and find a 3.2

[wayner]

Originally Posted by Spumato

If you are finding yourself in a very similar boat as I was in 2 years ago when my numbers matching engine in my MY74 911 coupe suffered with pulled head studs, then I would follow the same course of action as I underwent:

Obtain low mileage SC for rebuild
Add ARP Head Studs
Add ARP Rod Bolts
Add Titanium Valve Springs
Use High-Flow CIS
Add Carrera Chain Tensioner upgrade
Add real 964 Cams

The 3.2L engine will have more HP, and more top-end, but lacks the peppy punch you will find in a 3.0L. Add that you will probably want a Motronic engine management system on the 3.2L that will add better fuel reliability, while adding complexity.

The 3.0L from an SC 911, when you use an early 70's era SSI setup that goes into a dual in dual out muffler, coupled with a short ring and pinion set 915, and you have one hell of a ride! Trust me as I know firsthand.

I did the same thing (keeping the same jugs) but added 10.5:1 pistons and twins plug with carbs cam and porting

[wayner]

Originally Posted by Vereeken

Can you start from the 3.0 casing to move to a 3.2?

Yes, its called a short stroke 3.2 (done with displacement)
vs the factory long stroke 3.2 (done with different crank)

[Josh D]

Originally Posted by Steve@Rennsport

Make it a 3.2 with stock cams and CIS.

You will be VERY pleased.

Do you not recommend a 964 or a DC19 cam with this combo? I would think the bump in displacement would help support a little more cam than stock.

This was the route I am heading with an '80 RoW big port with Mahle 98mm wedge (Max Moritz style) pistons.

[Bob Kontak]

Originally Posted by wayner

Yes, its called a short stroke 3.2 (done with displacement)
vs the factory long stroke 3.2 (done with different crank)

+1

Just food for thought and just talking.

My 81 had the head mating ring surface re-faced with a six thousandths of an inch reduction. I did the math, posted calcs here years ago and it was confirmed. CR went from 9.3:1 to 9.5:1. A mini bump. I would be amazed if it was over a couple of HP increase, but don't know.

What I also don't know is if a 9:8:1 to 10:1 mini bump pushes you into a step change scenario that requires all kinds of tending to, given gasoline octane obscurities I know nothing about.