[DeTomaso] Cleveland HP limits

[Sean Korb]

I think 500HP is doable but you should rebuild it once a season.  Once a
racing season, that is.  600HP is doable but you should tear it down every
race.

As often as we actually drive our cars and seem to rebuild them every 10
years, 550 at 6000RPM isn't a bad target if you don't mind a bit of low end
drivability sacrifice, tunable a bit with EFI.

Do a google search for Dan Jones Dyno Project and you can get some ideas.
I'm happy with 400 reliable HP at the moment.

sean


On Mon, Jul 14, 2014 at 10:57 PM, Boyd Casey <boyd411 at gmail.com> wrote:

>    Chuck,
>    I am working on a build using a sound 4 bolt main, forged crank, shot
>    peened and polished rods , Ported A3 heads built with high quality
>    roller rockers a springs, Forged flat top springs, Arp fasteners
>    melling oil pump, 180 degree headers, a cust ground HR roller cam and
>    lifters. And an IR efi system. The reason for my question is because
>    the dynomation predicts HP in the 550- 600 range @ 6500 rpm. Someone
>    said to me that they thought 500 hp was the safe limit for a stock
>    Cleveland iron block. I have heard of stroked Cleveland iron blocks
>    making over 600 hp so was curious to know if there was an accepted HP
>    limit that one would be advised not to exceed. ( Like piston speed) Not
>    how much HP or torque CAN be made but how much can the block withstand
>    (assuming you are using the best parts so that the block would fail
>    before the rotating assembly or a valve something like one of the mains
>    letting go or the engine exploding. I hope this makes my question more
>    clear.
>
>    On Mon, Jul 14, 2014 at 10:30 PM, Charles Engles <[1]cengles at cox.net>
>    wrote:
>
>      Dear Boyd,
>      A  A  A  A  A  Oh, boy. A  An opinion question.................
>      A  A  A  A  A  See below.
>      "Greetings Pantera brethren ! Is there an accepted HP limit for a
>      Cleveland four bolt main iron block at it's normal displacement? No
>      A over bore, stock stroke, natural aspirated. Using heads , headers,
>      cam, ignition, all the trick valve work , porting polishing,
>      strongest possible rotating assembly.
>
>    Is there a limit that one should not exceed? 550hp, 575 hp, 600 hp
>    higher?
>    If it is possible to reach A these HP numbers while not exceeding 7000
>    rpm what is the DO NOT EXCEED LIMIT?"
>
>      1) A Answer: it all depends on dozens and dozens of details. A
>      Block quality, budget, application for street, track days or ORR or
>      drag racing, carb v. efi., dollars, etc, etc.
>      2) A New question: Given a reasonable Cleveland block, reasonable 4V
>      quench heads, stock rotating assembly, new pistons, new intake
>      manifold and a reasonable budget (what does that mean?) what can you
>      do? A  Well, it depends. A  It depends on the application. A It
>      depends on the machinist and the engine builder. A I am not an
>      engine expert, but I have built four engines and I am about to
>      finish another one and I am making plans for the next one. A  Facts:
>      a rookie can build a 400 hp engine with stock block, crank, rods and
>      heads plus after market bits. A Rpm max about 6000 before valve
>      float. A  More attention to detail can result in a 485 hp engine and
>      a 6,500 rpm limit before valve float. A The current engine with the
>      same formula but pushed a little harder with a lighter and more
>      expensive valve train is expected to see 500 or so HP with a 7000
>      rpm limit. A  The cost goes up with HP and rpm limit. A  The higher
>      goal you set will require higher dollars.
>      3) A I expect that given solid lifters, an aggressive cam, high
>      compression ratio, race gas, EFI and a relatively short functional
>      life span numbers north of 550 hp and 7000 rpm can be obtained.
>      A  A  A  A  A  A  A  A  A  A  A Warmest regards, A Chuck Engles
>
> References
>
>    1. mailto:cengles at cox.net
>
> _______________________________________________
>
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>
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>


-- 
Sean Korb spkorb at spkorb.org http://www.spkorb.org
'65,'68 Mustangs,'68 Cougar,'78 R100/7,'60 Metro,'59 A35,'71 Pantera #1382
"The more you drive, the less intelligent you get" --Miller
"Computers are useless.  They can only give you answers." -P. Picasso
-------------- next part --------------
   I think 500HP is doable but you should rebuild it once a season.A  Once
   a racing season, that is.A  600HP is doable but you should tear it down
   every race.
   As often as we actually drive our cars and seem to rebuild them every
   10 years, 550 at 6000RPM isn't a bad target if you don't mind a bit of
   low end drivability sacrifice, tunable a bit with EFI.
   Do a google search for Dan Jones Dyno Project and you can get some
   ideas.A  I'm happy with 400 reliable HP at the moment.
   sean

   On Mon, Jul 14, 2014 at 10:57 PM, Boyd Casey <[1]boyd411 at gmail.com>
   wrote:

     A  A Chuck,
     A  A I am working on a build using a sound 4 bolt main, forged
     crank, shot
     A  A peened and polished rods , Ported A3 heads built with high
     quality
     A  A roller rockers a springs, Forged flat top springs, Arp
     fasteners
     A  A melling oil pump, 180 degree headers, a cust ground HR roller
     cam and
     A  A lifters. And an IR efi system. The reason for my question is
     because
     A  A the dynomation predicts HP in the 550- 600 range @ 6500 rpm.
     Someone
     A  A said to me that they thought 500 hp was the safe limit for a
     stock
     A  A Cleveland iron block. I have heard of stroked Cleveland iron
     blocks
     A  A making over 600 hp so was curious to know if there was an
     accepted HP
     A  A limit that one would be advised not to exceed. ( Like piston
     speed) Not
     A  A how much HP or torque CAN be made but how much can the block
     withstand
     A  A (assuming you are using the best parts so that the block would
     fail
     A  A before the rotating assembly or a valve something like one of
     the mains
     A  A letting go or the engine exploding. I hope this makes my
     question more
     A  A clear.
     A  A On Mon, Jul 14, 2014 at 10:30 PM, Charles Engles
     <[1][2]cengles at cox.net>
     A  A wrote:
     A  A  A Dear Boyd,
     A  A  A A A A A A A A A A A Oh, boy. A A An opinion
     question.................
     A  A  A A A A A A A A A A A See below.

   A  A  A "Greetings Pantera brethren ! Is there an accepted HP limit for
   a
   A  A  A Cleveland four bolt main iron block at it's normal
   displacement? No
   A  A  A A over bore, stock stroke, natural aspirated. Using heads ,
   headers,
   A  A  A cam, ignition, all the trick valve work , porting polishing,
   A  A  A strongest possible rotating assembly.
   A  A Is there a limit that one should not exceed? 550hp, 575 hp, 600 hp
   A  A higher?

     A  A If it is possible to reach A these HP numbers while not
     exceeding 7000

   A  A rpm what is the DO NOT EXCEED LIMIT?"

     A  A  A 1) A Answer: it all depends on dozens and dozens of details.
     A

   A  A  A Block quality, budget, application for street, track days or
   ORR or
   A  A  A drag racing, carb v. efi., dollars, etc, etc.

     A  A  A 2) A New question: Given a reasonable Cleveland block,
     reasonable 4V

   A  A  A quench heads, stock rotating assembly, new pistons, new intake
   A  A  A manifold and a reasonable budget (what does that mean?) what
   can you

     A  A  A do? A A Well, it depends. A A It depends on the application.
     A It
     A  A  A depends on the machinist and the engine builder. A I am not
     an

   A  A  A engine expert, but I have built four engines and I am about to

     A  A  A finish another one and I am making plans for the next one. A
     A Facts:

   A  A  A a rookie can build a 400 hp engine with stock block, crank,
   rods and

     A  A  A heads plus after market bits. A Rpm max about 6000 before
     valve
     A  A  A float. A A More attention to detail can result in a 485 hp
     engine and
     A  A  A a 6,500 rpm limit before valve float. A The current engine
     with the

   A  A  A same formula but pushed a little harder with a lighter and more
   A  A  A expensive valve train is expected to see 500 or so HP with a
   7000

     A  A  A rpm limit. A A The cost goes up with HP and rpm limit. A
     A The higher

   A  A  A goal you set will require higher dollars.

     A  A  A 3) A I expect that given solid lifters, an aggressive cam,
     high

   A  A  A compression ratio, race gas, EFI and a relatively short
   functional
   A  A  A life span numbers north of 550 hp and 7000 rpm can be obtained.

     A  A  A A A A A A A A A A A A A A A A A A A A A A Warmest regards, A
     Chuck Engles
     References
     A  A 1. mailto:[3]cengles at cox.net
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     DeTomaso mailing list
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   --
   Sean Korb [6]spkorb at spkorb.org [7]http://www.spkorb.org
   '65,'68 Mustangs,'68 Cougar,'78 R100/7,'60 Metro,'59 A35,'71 Pantera
   #1382
   "The more you drive, the less intelligent you get" --Miller
   "Computers are useless.A  They can only give you answers." -P. Picasso

References

   1. mailto:boyd411 at gmail.com
   2. mailto:cengles at cox.net
   3. mailto:cengles at cox.net
   4. mailto:DeTomaso at poca.com
   5. http://poca.com/mailman/listinfo/detomaso_poca.com
   6. mailto:spkorb at spkorb.org
   7. http://www.spkorb.org/