250 PF Engine Variations

Julio,

Have you compared your build sheet data for the component build against a 128D of a TdF?

Jeff

 

Hi Julio, firstly congratulations on the recent restoration of you PF I love these cars and kick myself for not moving on one 7 or 8 years ago for the crazy price of 65,000chf

I am by no means an expert when it comes to chassis numbers but yours rang a bell.

Had you seen this thread I started back in 2005?

http://ferrarichat.com/forum/showthread.php?t=49144&highlight=250+pf

cheers
Simon

 

Hi Julio,

When I was sourcing my 275, I came across a white PF at Jean Guikas who claimed (he claimes a lot...) that his 250 PF had a LM engine. He might (although French) give you some more info.

For the rest, good luck next sunday, you need it!!!

ciao
Oscar

 

Julio, is the block currently stamped 1157? What is the internal motor number? I think that will be what leads you to the answers re: the motor tipo and its original car. Even if the factory stamped the motor to match the telaio #, I doubt they would have re-stamped the internal motor number (but you never know w/ Ferrari).

Also, do you have the engine dyno sheet in your Assembly Data Sheets? I know that even as far back as 1961 when my father got the ADSs for his 500 Mondial, the Factory was redacting the output graph on dyno sheet, but the torque and hp numbers were still listed at the bottom of the sheet (maybe they did that because it was a comp car?). If the dyno output numbers on your dyno sheet are significantly different from what one would expect from a stock 128D motor, then that may also be a clue.

You may have already discussed this somewhere else, but what car of Enzo's are you referring to as the original home for this motor, before if was installed in 1157?

I have also seen a fabulous book that is nothing but pictures of Ferraris motors - I seem to recall that it was a factory publication from back in the day, or at least it used Factory photos of the engines. I think every manual also had shots of the motor out of the car - comparing the shots of the 128D vs 128LM pics would help identify external differences in the respective motors' architecture.

 

julio,
when you say "mounted in Enzo's car", which car are you referencing? what was enzo's car your engine came from?
ed

 

*hijacking thread mode on*
Deal! I hope sooner than the MM...and together with your brother and Marianne...
*hijacking thread mode off*

Ah I did not know it was that car. Jean is always quite standard on his cars: Peurfect (French pronunciation....theez carr ies perrfect).

ciao
Oscar

 

I think they built development engines during 128D-production and these are marked 128LM with raised letters in top rear of block. Some became racing engines and the most famous batch was used on Interim Berlinettas, which also suggests this development finally lead into making of tipo 168 engine. I think the surplus production of blocks were used on standard production cars and some of them may be hotter than others.

I'll have a closer look at the numbers next week. Best wishes, Kare

 

Julio

Ask your engine builder if it has 3 or 4 head bolts per cylinder.

Regards
Will

 

Is there such a beast as a 4-stud 128 engine with inside plugs?

 

On 3 bolt heads the upper bolts are outside the cam covers, so pretty easy to tell apart! Best wishes, Kare

 

The Jess Pourret book on the 250 GT Competition cars does a fine job of detailing the engine development by the assemblies.

Jeff

 

Yes, it does. According to Pourret the 128D was the basis for the 128LM (the TR engine with outside plugs & 12 ports). I wonder if the block was cast with support bosses in position for the use of either 3 or 4 bolts. Either this or all the 128D's were 4 bolt. As Kare says the inside plug heads have the studs/nuts visible outside the cam covers in the V of the engine.
Can you take a look Julio? There will be either 6 nuts or 7.
I would very much like to know what head configuration is on the 128D which your engine must surely be because the 128LM is the TR engine which you would have noticed immediately because of the outside plugs/12 ports.
Will

 

The last of the 128D was the DF as used in some of the 250 TdF Interims. Outside plugs. I do not know the build differences between the DF and the LM except for 3 versus 6 Webers.

Jeff

 

D.G. Is Direttore Generale, I suppose you already knew this? Hope I am not being an anorak...Regards, Alberto

 

Julio,

I suggest that you compare your build sheets to those of the early TR - see the examples of build sheets for 0766, 0710 and 0728 published in Joel Finn's Testa Rossa book. There are interesting comparisons to examples of 128D build sheets. See also the build sheet comparison charts in George Carrick's 250 California monograph.

The crankshaft of the early 250 TR and the 128D are noted as the same - 128C 12261.

The early 250 TR block is written as 128LM 10612. As Kare notes, you will find the numbers 128LM 10612 cast into the block of a 128D motor (either side of the flywheel timing hole), suggesting it is the same as a TR block - or the numbers are in the base casting even if there are some differences* (I do not know).

From my notes, the 128D build sheet I have seen has for the block a 128C number that is typed over with what looks like 128D 10621 (maybe a typographical error for 10612?), but it was very difficult to read with certainty.

128D motors are definitely 3 studs per cylinder, not 4. The related 128LM 10612 casting number infers 3 studs.

The meaningful difference of the early TR motor would be the cylinder heads 128LM 17265. The connecting rods and camshafts are other differences along with many other peripheral pieces.

The 128D motor typically has heads 128C 17272 evolving later to 128C 17275. If your build sheets have either of these numbers, I would trust that your car has a typical 128D motor. However, if the heads are 128LM, then you would have something special, but I would expect 6 intake ports per head and 6 Webers?

These observations are simply from comparing the build sheets and enough general familiarity with an inside-plug 250 motor, not expert experience, so take it for what it's worth.

*To illustrate how the casting numbers can lead one down the wrong path, the water pump casting numbers in the 250 inside-plug parts book reference an early water pump. The numbers cast on a 128D version water pump are the same numbers as the book, but the pump is different than the earlier version.

 

Are you saying that the early TR heads were 3 stud, or is it that the 128D block can be machined either way?

 

No; I am not saying definitively that a 250 TR motor has a pattern of 3 studs per cylinder - I surmise the possibility given the literal number comparisons and do not know. I have not had the fortune to observe a TR motor disassembled. Someone else will have to answer that one. Not sure of the detail comparisons with the 128DF motor either.

The inside-plug 3-stud pattern is triangular about the cylinder, whereas a 4-stud pattern is rectangular about the cylinder. This would mean that for 4-stud pattern, the same block would have to be designed for enough material in the casting to receive a stud in each of two additional corner positions about the cylinder compared to the 3-stud, to make a parallel stud arrangement. I do not know whether the 128D can acommodate such variations, but 128D motors with 128C heads are 3-stud.

 

The TR engine (128LM) definitely has 4 studs/cyl, as does the 128DF.

 

oeps......

ciao
Oscar

 

I think congratulations are in order to Julio for a spectacular win in the World Cup!
Que viva España!
Best, Alberto