53 Engine Dyno Results - NCRS Discussion Boards

53 Engine Dyno Results

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Russ U.
    Expired
    • April 1, 2004
    • 345

    53 Engine Dyno Results

    Dave Elie, the long-time owner of 1953 #276, upgraded his 53 Corvette for performance in a number of ways. Elie swapped out the original 235 block for a truck 261 block, which was a technique popularized by McGurk Engineering. Elie also had some head work done to improve air-flow.

    53 #276 has over 300k miles on it, and the 261 block has maybe half of those miles. So I rebuilt the engine according to Dave Elie's specs. Dyno sheet appears below.

    What do you guys think???

    Russ
    Early Corvette Website

  • Clem Z.
    Expired
    • January 1, 2006
    • 9427

    #2
    Re: 53 Engine Dyno Results

    Originally posted by Russ Uzes (41704)
    Dave Elie, the long-time owner of 1953 #276, upgraded his 53 Corvette for performance in a number of ways. Elie swapped out the original 235 block for a truck 261 block, which was a technique popularized by McGurk Engineering. Elie also had some head work done to improve air-flow.

    53 #276 has over 300k miles on it, and the 261 block has maybe half of those miles. So I rebuilt the engine according to Dave Elie's specs. Dyno sheet appears below.

    What do you guys think???

    Russ
    Early Corvette Website

    interesting as i had a 261 block in my 53 chevy after blowing up the 216. i had dual carbs,homemade headers with duals,dual point conversion and a mcgurk cam. it ran good enough to blow off those new 1954 fords with the new OHV V-8. nothing sound nicer the a straight 6 with dual exhaust and chevy truck mufflers. the water temp 103 degrees seems pretty low as a engine is a heat pump i would think it would make more HP at a higher temp like 180/200
    Last edited by Clem Z.; November 22, 2008, 12:32 PM.

    Comment

    • Duke W.
      Beyond Control Poster
      • January 1, 1993
      • 15661

      #3
      Re: 53 Engine Dyno Results

      I've never seen any other test data for the six, and I assume this was a lab dyno test to what is essentially SAE gross standards.

      Peak gross torque of one lb-ft per CID is typical for most naturally aspirated engines with relative high compression. What is the CR and what fuel was used?

      The top of the 80 percent torque bandwidth is about 4800, but as is typical with the way most operators test, the bottom of the 80 percent bandwidth is indeterminate due to the start speed being too high. It should have been tested down to at least converter stall speed with is usually in the range of 1500-2000.

      The peak power range extends beyond the maximum test speed. Unless 5000 is the recommended rev limit, the useable power bandwidth probably extends to at least 5500.

      BSFC is very good, and the rich side can be down jetted to equal the lean side, which is not too lean to cause problems. My maximum A/F ratio recommendation at WOT is 13.5:1.

      The coolant temperature is waaaaaaaaaaay too low, which cost power.

      Overall it has a fairly flat torque curve with a broad and flat peak power range - exactly what is needed with Powerglide, and compared to the original 223/150 ratings, it's a substantial improvement. It should feel very strong and responsive in normal road driving conditions compared to the OE configuration.

      Can you provide more details on the configuration - head work, flow data, CR, valve timing/camshaft?


      Duke

      Comment

      • Russ U.
        Expired
        • April 1, 2004
        • 345

        #4
        Re: 53 Engine Dyno Results

        Thanks for the info guys.

        Interesting about the water temp. I wondered about that. My mechanic and the rebuilder did a bunch of separate tests changing the jets, so I have a bunch of dyno sheets. The water temp on all the other tests runs from 161 to 175 degrees, but with lower hp and torque numbers. I suspect the engine cooled before the last jet change, but the hp and torque numbers were up a fair amount in that test notwithstanding the low water temp. So they declared victory.

        The rich and lean numbers are closer together on some of the other dyno runs, but the hp and torque numbers were still lower. My mechanic said that he and the rebuilder spent a lot of time playing with the jets, so I don't think there would be much enthusiasm for going back in to tinker.

        I don't know the current CR or camshaft, so I will have to check on that. The dyno sheet says the timing is 2 degrees, but I will check that out also.

        I met with the mechanic who installed the 261 block in the car for Dave Elie 45 years ago. He thinks the engine CR was 8.5 to 1 when he installed the engine. The exhaust outlets had been enlarged to mate better with the standard exhaust manifold. I don't know about other head changes.

        The straigh 6's most redline at 5000. The original Corvette tachs did not have a redline. But the tachs only went up to 5000. Dave Elie's mechanic told me that the straight 6 would go quite a bit higher than 5000 however.

        My 53 has a early 60s Corvette 4 speed with a 3:70 rear end.

        Russ

        Comment

        • Clem Z.
          Expired
          • January 1, 2006
          • 9427

          #5
          Re: 53 Engine Dyno Results

          here is a book to read if you want to hop up 6 cylinder chevy and gmc engines. i have one here someplace. http://www.goldengatebookstore.com/r...73&affnr=-2610

          Comment

          • Russ U.
            Expired
            • April 1, 2004
            • 345

            #6
            Re: 53 Engine Dyno Results

            Thanks Clem. I have not seen that book before. I am going to order it.

            Hot Rod Magazine published a lengthy article on how McGurk souped up a 261 chevy truck block into a fire-breathing dragon. The magazine has plenty of information and dyno test runs using different configurations. An interesting read for Blue Flame Special fans, or for guys who own a car with a McGurk modification: McGurk Article

            Russ

            Comment

            • Clem Z.
              Expired
              • January 1, 2006
              • 9427

              #7
              Re: 53 Engine Dyno Results

              my dual carb setup was a "edmunds" that use the hot wter from the engine for heat. you just ran the heater hose in one end of the manifold and out the other so i was able to use my homemade headers. i blew my 216 and the car was still under warranty and the service manager at the chevy store was a good friends dad so i got them to put in a 261 block under warranty.

              Comment

              Working...
              Searching...Please wait.
              An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

              Please push the back button and reload the previous window.'
              An unexpected error was returned: 'Your submission could not be processed because the token has expired.

              Please push the back button and reload the previous window.'
              An internal error has occurred and the module cannot be displayed.
              There are no results that meet this criteria.
              Search Result for "|||"