Results 1 to 5 of 5

Thread: Expert's opinion- 73 S stock 2.4 liter engine to 2.8 liter

  1. #1
    Senior Member Haasman's Avatar
    Join Date
    Apr 2011
    Location
    N.Calif., south of SF
    Posts
    1,965

    Expert's opinion- 73 S stock 2.4 liter engine to 2.8 liter

    In your experience, what would the expansion of a 73 S engine from 2.4 to 2.8 liter mean in terms of horsepower and torque? (Stock specs 194 hp/154.0 ft lbs -correct me if I am wrong here) The car I purchased recently already has the 2.8 expansion done.

    Thanks

    Haasman
    Haasman

    Registry #2489
    R Gruppe #722
    65 911 #302580
    70 914-6 #9140431874
    73 911s #9113300709

  2. #2
    Senior Member
    Join Date
    Aug 2005
    Location
    VA
    Posts
    338
    Depends on a ton of things. Compression ratio being the biggest followed by induction, heads, cam, etc. If done poorly, longevity is going to be an issue in the form of pulled head studs. If done correctly, a screaming car making 225 - 240HP?.

    Chris

    73 911 E

  3. #3
    Senior Member Haasman's Avatar
    Join Date
    Apr 2011
    Location
    N.Calif., south of SF
    Posts
    1,965
    Chris- Totally agree with your concerns. I am awaiting the previous owner's paperwork to determine the quality of the conversion.

    Any opinion on the engine's redline? Because of the larger displacement does that mean a more conservative upper RPM limit?

    Haasman
    Haasman

    Registry #2489
    R Gruppe #722
    65 911 #302580
    70 914-6 #9140431874
    73 911s #9113300709

  4. #4
    Senior Member NorthernThrux's Avatar
    Join Date
    Jun 2012
    Location
    London, Ontario, Canada
    Posts
    2,258
    RPM will depend on crank used and reciprocating mass of the pistons used and the connecting rods. Also will depend on the valve springs. So no easy answers. When I punched out my 865 Thruxton to a 1087, with new pistons, conn rods, crank, camshafts and shim under bucket valves, I also took the rpm from 7500 to 10,0000. So it really depends on the quality of what was done.

    Oh yeah, and it whent from 63 to 110 rwhp ! So you can see its more than just the displacement increase that counts.

    Ravi
    Early 911S Registry # 2395
    1973 Porsche 911S in ivory white 5sp MT
    2015 Porsche Macan S in agate grey 7sp PDK

  5. #5
    Midnight Runner popowitz's Avatar
    Join Date
    May 2009
    Location
    West LA
    Posts
    1,003
    Quote Originally Posted by Haasman View Post
    In your experience, what would the expansion of a 73 S engine from 2.4 to 2.8 liter mean in terms of horsepower and torque? (Stock specs 194 hp/154.0 ft lbs -correct me if I am wrong here) The car I purchased recently already has the 2.8 expansion done.

    Thanks

    Haasman
    If your car is matching numbers I would recommend building a second engine on a 7R case and putting your case on a shelf. This way you reserve the right to take the car back to stock in the future.

    Just my $.02

    Dave
    Registry Member #1583
    '73 911 S Aubergine (VIN#9113301295)

Similar Threads

  1. FS: 3.0 Liter Engine w 25k
    By joetiii in forum For Sale/Wanted: Other Porsche Cars and Parts
    Replies: 0
    Last Post: 01-23-2013, 05:42 PM
  2. FS: 3.0 Liter Engine w 25k
    By joetiii in forum For Sale: 911 Parts
    Replies: 0
    Last Post: 01-23-2013, 05:42 PM
  3. Stock early Leistritz on a 3.0 liter?
    By Jens in forum Technical Info
    Replies: 3
    Last Post: 06-09-2011, 06:06 AM
  4. Wtb - 2.4 liter engine
    By edl0944 in forum For Sale: 911 Parts
    Replies: 5
    Last Post: 07-28-2009, 03:41 AM
  5. FS: 2.7 liter engine
    By lechon in forum For Sale: 911 Parts
    Replies: 1
    Last Post: 05-09-2007, 05:53 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Message Board Disclaimer and Terms of Use
This is a public forum. Messages posted here can be viewed by the public. The Early 911S Registry is not responsible for messages posted in its online forums, and any message will express the views of the author and not the Early 911S Registry. Use of online forums shall constitute the agreement of the user not to post anything of religious or political content, false and defamatory, inaccurate, abusive, vulgar, hateful, harassing, obscene, profane, sexually oriented, threatening, invasive of a person's privacy, or otherwise to violate the law and the further agreement of the user to be solely responsible for and hold the Early 911S Registry harmless in the event of any claim based on their message. Any viewer who finds a message objectionable should contact us immediately by email. The Early 911S Registry has the ability to remove objectionable messages and we will make every effort to do so, within a reasonable time frame, if we determine that removal is necessary.