52' Type 527 Comp Engine Carburetor Question
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Re: 52' Type 527 Comp Engine Carburetor Question
Thanks gentlemen. I am learning a hell of a lot on enrichment mechanism parts for my Solex 32 pbj carbs.
Trying to stay factory correct on the choke system is becoming quite the challenge.
Trying to stay factory correct on the choke system is becoming quite the challenge.
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Re: 52' Type 527 Comp Engine Carburetor Question
A quick response to Vic's question is simply that as Alan has pointed out it is not a 356 item but fits some other vehicle of the era. There is a partial off line discussion that suggests using one of the other enrichment valves from one of these other applications. I did not keep the responses totally isolated... Perhaps I have started to show my age...
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Re: 52' Type 527 Comp Engine Carburetor Question
All great info supplied here. A further note, the type 527 engine is not a "comp" engine. It is Porsche's first 1500 motor (ignoring the type 502).
People assume because the type 527 has a Hirth crankshaft that it must be "competition" or "super" or similar, but this is not the case. The Hirth crankshaft was Porsche's solution to using a 72 mm stroke in the VW case. And only that. In fact, Porsche competition engines of 1951-52, the type 514, used VW crankshaft/rods on the 1100 and Hirth on the 1500 - so competition was not the driving force behind the Hirth.
So no, 527 motors were not competition and were not supers. As you can see from Alan's jetting info, the venturis for the 40 PBIC and 32 PBI versions of the motor are the same size, leading to roughly similar performance at the same RPM. 60hp.
People assume because the type 527 has a Hirth crankshaft that it must be "competition" or "super" or similar, but this is not the case. The Hirth crankshaft was Porsche's solution to using a 72 mm stroke in the VW case. And only that. In fact, Porsche competition engines of 1951-52, the type 514, used VW crankshaft/rods on the 1100 and Hirth on the 1500 - so competition was not the driving force behind the Hirth.
So no, 527 motors were not competition and were not supers. As you can see from Alan's jetting info, the venturis for the 40 PBIC and 32 PBI versions of the motor are the same size, leading to roughly similar performance at the same RPM. 60hp.
- Vic Skirmants
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Re: 52' Type 527 Comp Engine Carburetor Question
74mm stroke.James Davies wrote: ↑Tue Jan 03, 2023 6:15 am All great info supplied here. A further note, the type 527 engine is not a "comp" engine. It is Porsche's first 1500 motor (ignoring the type 502).
People assume because the type 527 has a Hirth crankshaft that it must be "competition" or "super" or similar, but this is not the case. The Hirth crankshaft was Porsche's solution to using a 72 mm stroke in the VW case. And only that. In fact, Porsche competition engines of 1951-52, the type 514, used VW crankshaft/rods on the 1100 and Hirth on the 1500 - so competition was not the driving force behind the Hirth.
So no, 527 motors were not competition and were not supers. As you can see from Alan's jetting info, the venturis for the 40 PBIC and 32 PBI versions of the motor are the same size, leading to roughly similar performance at the same RPM. 60hp.
- Albert Haefner
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Re: 52' Type 527 Comp Engine Carburetor Question
James is right. Hirth was necessery to get the stroke of 74 in a VW split case, only possible with a closed connection rod crankshaft bearing.
With a longer stroke, the bearing half shell nuts would touch the engine case - only until when an intelligent Porsche engineer invented studs
on the lower half shell which allowed to have the nuts at the upside of the rod. This was the solution!
And then, the Hirth roller crank disappeared even for the later 528 engines. The roller crank always caused problems when used in cruising cars.
Not enough oil with the small pump at lower revs. Same reason is valuable for later carrera engines.
With a longer stroke, the bearing half shell nuts would touch the engine case - only until when an intelligent Porsche engineer invented studs
on the lower half shell which allowed to have the nuts at the upside of the rod. This was the solution!
And then, the Hirth roller crank disappeared even for the later 528 engines. The roller crank always caused problems when used in cruising cars.
Not enough oil with the small pump at lower revs. Same reason is valuable for later carrera engines.
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Re: 52' Type 527 Comp Engine Carburetor Question
*foreheadslap* Thanks for the correction Vic. =)
I'll add that all this development happened very, very quickly at Porsche. At the beginning of 1951 they developed the 1100 race engine (Type 514) using 40 PBIC and a new Fuhrmann-designed camshaft. And almost concurrently developed this into a 1500 engine for Liège-Rome-Liège using the same race components, and almost simultaneously started putting the road version of this 1500 into customer cars, all by the fall of 1951.
So while some engines in the P-30xxx series were race engines, most were street engines in customer cars. Similarly, not all engines in the P-40xxx series were type 528 (1500 Super); some were 1100 race engines.
- Albert Haefner
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Re: 52' Type 527 Comp Engine Carburetor Question
But longevity was not a strength of roller bearings.
They all died early - unless raced with high revs and a lot of oil.
They all died early - unless raced with high revs and a lot of oil.
- Albert Haefner
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Re: 52' Type 527 Comp Engine Carburetor Question
My Suggestion: Never restore a roller crank to re-use it in a car. But keep it as a Beautiful doorstop or deco object in a glass cabinet. Just take a plain bearing one. Much cheaper and no difference in performance.
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Re: 52' Type 527 Comp Engine Carburetor Question
Details about carburetor change:
In German, a drawing is added:
In German, a drawing is added:
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Re: 52' Type 527 Comp Engine Carburetor Question
Thanks for sharing Olivier. I had not seen this version of this document.
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Re: 52' Type 527 Comp Engine Carburetor Question
In 51/52 Each owner of a 356 fitted with a 1500 cc engine received this document. It's a complement of the "glove-box" manual.James Davies wrote: ↑Fri Jan 06, 2023 10:52 am Thanks for sharing Olivier. I had not seen this version of this document.
I know two versions:
-the first one has one side in Emglish, the other side is in French.
-The second one is in German and has one more page.
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Re: 52' Type 527 Comp Engine Carburetor Question
Does anyone have more detailed info on what they are referring to in this paragraph? In the process of dialing in my engine and I have it about 85% I assume it has to do with the transition between the idle and main circuit.
- Alan Hall
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Re: 52' Type 527 Comp Engine Carburetor Question
The stabilizing hole is the hole in the butterfly plate as seen in attached photo.
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Re: 52' Type 527 Comp Engine Carburetor Question
Thanks Alan I appreciate it.
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Re: 52' Type 527 Comp Engine Carburetor Question
I think the carbs would be a 32 mm single barrel Solex Alan The Stable.