From industrial to road engine

[malsteph]

I have adquired recently a 633-1 industrial engine. Despite looking bad on the outside due to poor storage conditions, it is remarkably clean inside. No play in the crankshaft nor the rods. It looks almost new.

I would like to convert it to a road engine. My understanding is that the following needs to be done:

Harder springs (industrial ones are apparently softer)
Piston & cylinder for street engine (I will put 86mm from AA).
Carbs, manifolds and linkage, (I have dellortos DRLA 40, Weber IDF 36 or Solex 40 PII) so what would be best.
I have a Monza exhaust and J tube.

What else should I do without opening the case?
With the orginal camshaft, heads and the modifications as mentionned above, what kind of performance can I expect?


My understanding is that this would basically be a 912 engine but with a softer camshaft.

[foamcar]

I am not very familiar with the industrial engine aside from external appearances. I would do a search on the 356 Registry site(bad search feature there, but can use google with a few keywords and works better). There ahs been considerable discussion on converting these on the Registry forum. I would check out those cam specs vs. say 356 C or SC, as with those big carbs you may be disappointed. Also, heads may not be compatible with AA pistons due to different angle(22 degrees vs 30 degrees or something like that). Ports in the industrial heads may not match your intake manifolds. Might be worth getting a good set of late(C, SC 912)heads which will have good valve springs, rockers, etc.

Good luck.

[Jacks]

Fat head (cast) lifters can be a problem.
_________________
Jack Staggs
Actual name

[malsteph]

The engine is a 616/33-1 from 1964.
It turns out it take very little to convert those to a decent road engine as most parts are identical to 912 and late 356. Case is 912 type, cranckshaft and heads are identical to a 912/late 356. Only the springs need to be changed for harder ones as they are not able to cope with higher revs.

There is virtually no hours on the engine and the rockers, heads and pistons need only a very light cleaning to get back to new.

I have ordered already a set of 86mm from AA Performance to get the engine to 1720cc and a compression of +/- 9.2. (Industrial from this era have 1680cc and compression at only 7).

I tested 2 different sets of carb manifolds and clearly one fits better than the other. It will take very little effort to match them to the heads

As I have quite a few 356/912 engine parts at home, it will not be difficult to change the fan shroud, clutch and exhaust.

I do not know about the camshaft. Some say it is identical to a C cam, others say it is "softer". I will start the engine in a month or so and I will see. If it accept to rev higher than 5000, then it is a standard C cam. Otherwise there will be little to expect above this.

I did not take photos but made and will make videos of the disassembling/rebuild process. I will try to post this once the engine is running.

[DWildrick]

Below is what Harry Pellow had to say about some of these engines back in 2003. Based on this, you may have overlooked the fact that the pushrods are "skinny" and less durable than street engine pushrods. Also, you may need to rework the flywheel, if you have the one with the original industrial engine ring gear.

Plus, as Jack Staggs pointed out, the lifters are cast iron and brittle, not intended for high revs as you intend to subject them to with the AA big bore kit plus large carbs.
Nevertheless, it's your motor and your money. Good luck.

[Subject: Re: REASONS AND INDUSTRIAL MOTOR WILL NOT DROP IN A 356
From: "Marc Bertels" <[email protected]>
Date: Wed, 24 Sep 2003 21:02:56 +0200

Here is what Harry said about these engines...


Ken Daugherty wrote:

>Harry, I have opened up some more boxes. This time industrial motor =
>components. The fan housing tag reads: Typ 616/33-1; motor nr 48902xxx; =
>Baujahr (model) 1973; Dauerleistg.max.PS 43,5; Drehzahl (rpm) 3000; =
>Funkentsorgrad (?) N. It has a magneto system with the 12V generator. I =
>have the original muffler ( with some repairable rust) and the funny =
>flywheel and starter. But no bellhousing. I will probably set it up with =
>a standard 356 flywheel just so I can run it on a stand. My plans are to =
>use super internals so I can use the motor, less industrial accessories, =
>in a 356 later if need be. This will be a fun project, long delayed. =
>

Dear Ken:

You have one of the LAST Industrial Engines, made in 1973 (four YEARS
after the last "real"
912 was made.

These have an Engine Number in the 48 MILLION range, and were mostly used
by the Swiss Military only 2 weeks a ye
Your engine should have a Case Casting Number > 121,000, which is 1000+
beyond the last 912, and of course a Type Number of 616/33-1.

As you noted, it has a Scintilla Magneto, a 12 Volt small diameter
Generator, a Flywheel with Ring Gear Teeth perpendicular to the "normal"
direction, requiring a starter that comes in vertically (but the massive &
heavy Ring Gear can be removed, leaving you with a 180mm flywheel with
Virgin, unused clutch surface).

Internally, it will have a 356C crank (a nice Standard), a Late-model Case
(Almost Always a Perfect Standard! But you gotta change the 2 lower Engine
Studs), primo 912 Rods, a 356C Cam, the bad Cast Iron Cam Followers
(replace them), excellent C/912 Rockers with OPEN Oil Squirting Holes,
skinny pushrods (replace them too), flat-topped, low-compression 85mm
Pistons with Cast Iron Cylinders, and really nice 912 Heads with weak
(VW-like) valve springs (replace) and 356C non-Sodium filled exhaust valves
(replace with sodium-filled ones).

And all the Major Internal Parts will be like-brand new- stored for 30
years just for you!

Once you overhaul them, replace the inferior parts, balance and blueprint
them, you will have an engine that will perform well in either street or
Race trim.

Just like Jerry Seinfeld's engine in his 1958 Speedster, as that's what
he has now!

Keep the 356 Faith
Maestro]
_________________
Dave Wildrick

[malsteph]

Thank you for the message.
The pushrods are not of the weak type, they are identical to a late 356 or 912 type.

The lifters should not be an issue as the engine will not rev higher than 5000.
Due to the heads having a volume of 60cc, the compression ration will stay low (around 8 vs 9.3 for a normal street engine). Therefore there is much to bet that the engine will be happy between 3 and 5000 but no more than that.

I am including new springs in the heads to replace the original ones. But the ones I will be using have a similar strength than a street engine type. The efforts on the pushrods & lifters will not increase dramatically.

Cast Iron lifters are no too brittle and many street engine use them. But it is not good to use them at high revs or with very strong springs that are puting to much effort on them.

[Jacks]

[malsteph]

At what speed / rev did it snap?

[Jon Schmid]

Listen to Jack--he knows his stuff! Also, if possible get ahold any information the late Harry Pellow put out regarding these engines--he wrote about them frequently because they were his "favorites" and he had a lot of tips to give. Basically these engines were designed for static applications (starting jet fighter planes, for example) so they were meant to run at a nice constant speed like 3000 RPM. Hence the cast iron followers, lower compression, less robust valve springs, magneto ignitions, and even crank starters among the items making them "different" from the auto engines. As you know they also only had the single carburetor/manifold set up. As basic engines they were/are great, but to put them in a car the changes mentioned above must be made or they won't last. One more time, listen to Jack, he knows what he is doing--I have to drive 80+ miles round trip for any service and it's well worth it.
Good luck--do it right and you'll do all right.

[malsteph]

Hello,

Some news. A friend of mine had a problem with his engine builder and needed an engine to compete in the French rally "Neige et Glace" for his 356 of 1954.

http://www.zaniroli.com/neige-et-glace

with only a week to go before the race we decided to take the chance and we changed the pistons/cylinder, cleaned-up the heads, changed the springs etc to convert the engine for road use.

We could not split the case so the engine is for the rest stock including the cam followers. Carbs are solex 40 PII, exhaust is stock. Dizzy is a Bosch 022.

The only caution has been to stay under 5000RPM. It is a rally that is 90% on snowy and icy roads. It is not a full speed rally but a regularity challenge. 35mph can be a challenge under these conditions.

Well the 356 performed well and ended up 6th overall and best in class (cars prior to 1965).

Oil looks fine after the race with no metal chips or particules whatsoever. I will keep it as it is for the time being. But for sure if I decide to get this engine into a full road configuration, I will change the cam followers.

Thank you for your support and advise.

[jootman]

Do you have to split the case to see what cam followers are in?

[Jacks]

No
_________________
Jack Staggs
Actual name