[DeTomaso] Cleveland HP limits

[Boyd Casey]

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 <cengles at cox.net> wrote:

> Dear Boyd,
>
>
>           Oh, boy.   An opinion question.................
>
>
>           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  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  these HP numbers while not exceeding 7000 rpm
> what is the DO NOT EXCEED LIMIT?"
>
>
> 1)  Answer: it all depends on dozens and dozens of details.   Block
> quality, budget, application for street, track days or ORR or drag racing,
> carb v. efi., dollars, etc, etc.
>
>
> 2)  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?   Well, it
> depends.   It depends on the application.  It depends on the machinist and
> the engine builder.  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.   Facts: a rookie can build a 400 hp engine with stock block,
> crank, rods and heads plus after market bits.  Rpm max about 6000 before
> valve float.   More attention to detail can result in a 485 hp engine and a
> 6,500 rpm limit before valve float.  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.   The cost
> goes up with HP and rpm limit.   The higher goal you set will require
> higher dollars.
>
> 3)  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.
>
>
>                      Warmest regards,  Chuck Engles
>
>
>
-------------- next part --------------
   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