[DeTomaso] Cleveland HP limits

[Julian Kift]

What is your intended use of the engine and the HP? How often will it see peak HP/Revs or is it mostly for bench racing? How much do you want to be fettling with it to keep it on song?
 
I have heard that 550HP is a good reliable number to get an engine that has some degree of drivability, reliability and longevity.  Dan Jones is able to spec motors that reliably provide that sort fo HP.
 
Before you spend any money on a build take the block and get the cylinder wall thickness sonic checked. Just because it's a stock block doesn't guarantee it is free of core shift. Better still if you are spending $$ on all those other parts why not buy an aftermarket iron block of the likes that MME or Tod Buttermore are casting, then you can increase the HP number somewhat and for sure be the fastest guy on the bench.
 
Julian
 
Date: Mon, 14 Jul 2014 22:57:31 -0400
From: boyd411 at gmail.com
To: cengles at cox.net
CC: detomaso at poca.com
Subject: Re: [DeTomaso] Cleveland HP limits

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
>
>
>

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   What is your intended use of the engine and the HP? How often will it
   see peak HP/Revs or is it mostly for bench racing? How much do you want
   to be fettling with it to keep it on song?

   I have heard that 550HP is a good reliable number to get an engine that
   has some degree of drivability, reliability and longevity.  Dan Jones
   is able to spec motors that reliably provide that sort fo HP.

   Before you spend any money on a build take the block and get the
   cylinder wall thickness sonic checked. Just because it's a stock block
   doesn't guarantee it is free of core shift. Better still if you are
   spending $$ on all those other parts why not buy an aftermarket iron
   block of the likes that MME or Tod Buttermore are casting, then you can
   increase the HP number somewhat and for sure be the fastest guy on the
   bench.

   Julian

   Date: Mon, 14 Jul 2014 22:57:31 -0400
   From: boyd411 at gmail.com
   To: cengles at cox.net
   CC: detomaso at poca.com
   Subject: Re: [DeTomaso] Cleveland HP limits
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
>
>
>

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