25 HP and 36 HP Outside differences ?

[Flavio]

Hello
Is it possible to see some diferences beetween the 25 Hp case and the 36 HP one, or are they equal from an outside view ?
If there are some diferences could anybody post some pics ?
Thank you very much for any help
Regards
Flavio

[RareAir]

The case itself? Or the parts that go on the outside? (shroud, fuel pump, oil filler etc....)

If you looking at a very early 25hp, early cases were made of Aluminum. Later VW added Magnesium for extra strength. The coloring is obvious if you find an Aluminum case. Here's the one out of my '47

_________________
1947 Typ 11a
1954 Typ 117
1956 Typ 151
1959 Typ 117
1959 Typ 265
1961 356B
1966 Typ 151
1966 Typ 241

[Flavio]

Hello. Thanks for your reply. I mean the case itself. When the magnesium was added by VW is it more dificult to see the diferences ?

[Ivan Fuller]

If you are going to use a 36hp case you should try and find an early one that does not have the cast threaded lug on the genarator stand that holds the later style oil filler. I'd say this is the most notable visual difference between a magnesium (elektron) 36hp and 25hp case, also the early cases do not use the later part numbering system.

[johnshenry]

[Flavio]

By phone I have speak with the person that has the good 25 or 36 HP case and he told that the case have the cast threaded lug for the oil filler. So, it seems like a 36. He also sent me the parts numbers : the rigth side is 111101102 A and the feft is 1111011101 A. Can you give some more info with this ?
Thanks

[johnshenry]

What is the serial number on the case???
_________________
John Henry

'57 Deluxe
'56 Single Cab

[spectre6000]

[Zwitterkafer]

X2 on the serial number being the best indicator.

Another clue:

The small raised area onto which the s/n is stamped is longer left-to-right and more pronounced on the 36 hp version.

Be aware that there exist factory replacement 25 hp cases with 36 hp appearance and 36 hp upgrades, but still with the 25 hp cylinder bores in the block. In this case, (pun intended) measuring the cylinder bores is the way to tell.

H.
_________________
"Criticism comes easier than Craftsmanship"
- Zeuxius, 400 BC

[Flavio]

You mean that the cylinder bores have diferent diametres ? Which are ?

[Zwitterkafer]

Sorry, I won't be able to measure and post on this before Monday.

Anyone?

H.
_________________
"Criticism comes easier than Craftsmanship"
- Zeuxius, 400 BC

[Flavio]

Ok Zwitterkafer.
I'll wait for the measure. All this is because I want to built a good 36 HP. The person who has the good case lives farway from me and all the talks about the case have been done by phone.
I have an used but still good Mahle 36 hp cylinder set. The cylinder part that inserts in the case has a diameter of 81.8 mm. Regardind this, I imagine that the bore in the case must be a litle bit bigger (82 mm ?).
If the person's case has that measure (82 mm) can I assume that it is a 36 Hp Case ?
Thank you

[Zwitterkafer]

fnribeiro, you are correct.

36 hp case openings = 82 mm dia
25 hp case openings = 80 mm dia

Sorry for the delay; I could only measure them this morning.

Cheers,
H.
_________________
"Criticism comes easier than Craftsmanship"
- Zeuxius, 400 BC

[Flavio]

Ok Zwitterkafer. Thanks for your care.
The person who has de case phone me and says that the openings have 80 mm. So, it´s a 25 HP case.
He also says that I could open the bores for 82 mm., but I believe that is not suficient for transforming a 25 Hp case in a 36 HP case. There must be some other internal differences. I think I am going to tell him to forget the possible business with me.
Best regards

[Zwitterkafer]

Yes, there are other internal differences; the 36 hp have more internal ribbing for rigidity, and at some point the oil galleries had some refinements in the area of the pressure relief drillings. While a converted 25 hp would work, (some people here do that on purpose to circumvent buying expensive 25hp pistons & cylinders) it would be better to start with the real thing, freeing up your seller's 25hp for someone else in need.

Good luck,
H
_________________
"Criticism comes easier than Craftsmanship"
- Zeuxius, 400 BC

[Flavio]

Once more, thanks for your very good help.
Best regards

[SplitPersonality]

Bringing up an old topic here....have been doing some searching, but...

- What is the last engine serial number on a pure aluminium case? (feb '51 is it?)
- What is the last engine serial number on the 25hp engine?
- What is the last engine serial number on a "cast gen stand" engine?

[L378]

[SplitPersonality]

L378 - thanks for your inputs!

The picture (pasted below) in your attached link pretty much answers 2 of my questions, I see.

Now - when did they stop the shiny alu case?...January-1951?

[L378]

from progressive refinements engine section page M9

Jan 19, 1951 chassis# 1-0225 376 & 20-09 065 unit # 272 061 Crank Case Now: made of electron Formerly: remelt alloy

So 1-19-51 is the date

The exact date of the cutoff for the 25 page M 19
Dec 21 1953 Chassis # 1-0575 415 & 20-069 409 unit # 695 282 & 695 356 & 122-019 888

I think that covers it as I see the end of 36 hp production listed in the above photo.

So my question remains