83 911SC Engine Rebuild
 

Hello everyone,

My vision is to have a drivable street car and also one I can track.

The Heads, crank, and cams are coming back from rebuild this week.

Here is what I am considering and would appreciate guidance if this planning is flawed or if you have a better idea.

CURRENT SITUATION:
The case is a late model 3.0l and seems fine.

The crank had # 5 rod journal under spec, oil starved. The machineshop was able to modify the rod so that I can still use a standard rod bearing on the crank and the rod is so marked.

The rods have been resized

The cams were pitted and repaired.

The heads have been rebuilt and flycut. The cam has been assembled into the rebuilt heads.

All this for $3100.00 good or bad I don't know but it is money spent and a bit more than budgeted.

I had planned to reuse my Alucil P&Cs but #1 has pitting on it. I could find a replacement P&C but then I still have the Alucils and concern that it will smoke.

I plan to keep the CIS

NEXT STEPS and request for comments:

I could just reuse the Alucils and replace the pitted cylinder. Does that make sense?

I am also considering 98M 9:5 JE Pistons and 3.2L replated cylinders. This is about $3,000.00. Does the investment increase power accordingly or should I just stay with the Alucils?

Would installing carrera sport cams $500.00 with the JE even though I had the original cam repaired improve performance enough to make the investment?

I had originally planned to add the SSIs, but from reading posts, understand that they have dimishing returns at the 3.0l engine range.

Instead I am now thinking of using a MK or Fabspeed cat bypass premuffler setup for track days. Would this equal the performance of the SSI's?

I have also read about a Supertrapp system for a muffler replacement using differing combinations of discs for tourque and sound. Has anyone ever heard of this or used it?

One other thought is to convert to a 3.6 95. Any opinions??

Please let me know your opinions.

Thanks,
Roadster49

I've got 3.2l 95mm p&c's for sale. EBS, LN Engineering, etc can bore and replate. They are Mahle. You could also use them as is.

Todd

"The crank had # 5 rod journal under spec, oil starved. The machineshop was able to modify the rod so that I can still use a standard rod bearing on the crank and the rod is so marked."

Do you know what they did to modify the rod?

I would also recommend the SSI's. They will provide a nice 15-20 HP in the 2500-4000 RPM range.

I don't mean to spend all your money, but you have the engine all apart and seems to want maximum power. I'd upgrade the cams and go with the 3.2 P&Cs. That 8% increase in displacement and improved flow would then make the SSI more viable.

Just my $.02 and your $5k...

mreid,

Sorry. This could be a dumb question, but how did you get the 8% increase in displacement using the same size cylinders? Thanks.

Tony

Tony

They are referring to the 98 mm 3.2 short stoke kit.

Thanks for the clarification........
 

Tom,

I knew I missed something obvious and could not follow the logic reading the post. Thanks.

Tony

Hi Tom,

Regarding the Crank Journal, I will find out on Saturday, when I pick it up and let you know.

I too have ahard time getting my head around this.

Before I took the crank to the machine shop, I measured the journal and it was at the low end of the spec and the most worn of the 6. what worried me was that it had a blue streak at the oil port about 1 inch long. This machine shop also resized the rods.

Yes, build the "short stroke 3.2"
A friend did this with misc. parts and PMOs and put into a '71 -- runs great/fast!

Do you mean a blue streak like this...no problems...
964 #5 rod...polished crank, rebuilt rods, ARP bolts...now runs great...

Regards,

http://forums.pelicanparts.com/uploa...1355241616.jpg


http://forums.pelicanparts.com/uploa...1355241653.jpg

my rod bearing was loose but not scored.

The 3.2 your friend built. Did he use SSIs? I am thinking that a cat bypass pipe would do the same for a lot less. plus I don't have to buy special mufflers and oil pipes etc.

Sorry, can't see photo...

Friend's short stroke 3.2 is race car - headers, s-pipes, old muffler
-- he used 3.0 case, heads, crank and put 98MM (3.2) pistons and cylinders...

Regards,