2.5 Air Cooled Combi Engine?

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Tony Z
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Re: 2.5 Air Cooled Combi Engine?

Post by Tony Z »

Do you realize that your car has been lowered? It is lower than stock, so you’d do well to just get it back up to where it should be.
Bigger tyres are likely going to rub and cause problems

The 411 engine is nearly unbeatable as far as low down torque and reliability goes. Get it running properly before you even consider putting in a water cooled conversion that needs revs before it makes any usable torque or power.
If your carbs are screwed and you have some cash to spare then look into converting to fuel injection. If the engine has blow by and end play then have it rebuilt by someone who knows what they are doing.
That gearbox is capable of taking a lot of abuse. If it isn’t giving troubles then change the oil and maybe repack the cv joints with new grease


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Re: 2.5 Air Cooled Combi Engine?

Post by sean »

Have you looked at the size of an inline watercooled motor? How on earth would that fit into the engine bay?

I agree with Tony, start with what he is suggesting.

If you are considering a 2l golf engine, stay far away. They are really horrible engines.
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Re: 2.5 Air Cooled Combi Engine?

Post by retrovan »

If you thinking of doing the motor, start with carbs and exhaust, then heads, then up your engine to 2l pistons and barrels

Lift the suspension and fit smaller wheels, Place air breather into cab to stop dust at the intake, and if you can find a Bosch fuel injection, go for it.

This will be a hell of a lot cheaper then changing to water cooled, and it will be a great rally car.

Just remember dust is an air cooled engine killer so the most important thing is to maybe upgrade to a big truck Donaldson filter system.

And if piped into the cab, you will have a 2nd stage cleaning system, as if you can breath, the car can breath.

OMO

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Re: 2.5 Air Cooled Combi Engine?

Post by Dawie »

Which engine do you have at the moment?
Last you had a very tired basic carbed version with missing cooling ducting.

The basic 411/412 like yours came with a carbed 68hp engine, top speed of 145 km/h as per vw.
The 1700 fuel injected "LE" version had different camshaft and compression ratio, 80hp, and 160 km/h top speed.

The VW type 47 car (also called "porsce 914"), came with either 80hp 1700 or 100hp 2L.
1976 Porsche 912E also used the injected type 4 2L engine. By the way the 411/412 Variant is VW type 46, two door sedan type 41, and 4 door sedan type 42.

The type 4 car's gearbox have it's selector shaft right at the bottom, same as Porsche 911. The type 4 gearbox is unique and share no parts with other cars. Five speed transmissions from 911's have and could be used in type 4 cars, special mountings must be made.

Type 4 variant use shorter diff ratio than 411/412 sedan version. Direct 1:1 4th ratio (instead of 0.89 or 0.93 of beetles), and shorter 3rd than type 3 or 1 cars. Overall ratio in 4th similar to 1200 beetle. So the short-stroke 1700 revs high while gears multiply torque. Overall ratio in 1st gear might feel a bit tall in the sand, so dont load any more weight in the car than absolutely necessary.

The 2L kombi version ony do 70 hp. It has smaller valves than the 1800 kombi.

The leader of the Orange convoy of the Netherlands soccer supporters have a modified 2L type 4 in his orange baywindow. The so called "Camper special", about 115-120 hp, combined with shorter diff ratio from a 1600 kombi to help compensate the large 15" x 225 or 215 tyres.
They travelled across Africa, to Beijing, and toured from northern Usa to South America.
Things like front suspension, bump stops, etc broke. Apart from a fuel pump relay and an experimental aftermarket fuel injection (mis-programmed), the type 4 never missed a beat. This included storming sand dunes in the hot Sahara at full power to maintain momentum. (There he once broke the front supension hitting a dip not seen).
Some of the watercooled vehicles on that trip overheated, suffered permanent damage, and needed to be towed.

Since the early 70's type 4 engines have been sucsesfully modified by experts around the world. Okrasa/Oettinger and others in Germany, some specialists in the Scandinavian countries, Australia, etc.

The type 4 engine was once described as a "fool's trap".
"Fool's trap" as in:

There are no short cuts to take. No fiddling around by some guy who refuses to read and follow the proper procedures. As in many cases have been destroyed by over-torqueing the oil strainer cover's nut. Or rocker arm nuts. (Which have a tiny torque limit). If engine is allowed to severely overheat by allowing hot air recirculation- Caused by- Missing cooling duct (411/412), or missing tinware or engine seal, (kombi),
Then aluminium piston skirts collapse because they expand inside cast iron cylinders and gets squeezed. Then became smaller/undersize once cooled down. Causing compression loss/ oil use.
Same with valve seats. If heads are allowed to severely overheat, the valve seats will loose their correct interference fit because of different coefficient of expansion/ different materials. Choosing valve seat material and correct installation procedure/interference fit/ preheat head/ freeze seats is best left to someone with good type 4-specific experience. Too large interference fit can also cause harm.

An engine only have to severely overheat once to be permanently damaged. Aircooled engines dont overheat by themselves, they are caused by someone's actions to overheat.
Do'nt assume anything- (While doing fault-finding).
"Things should be as simple as possible, BUT NO SIMPLER THAN THAT."
"If something can go wrong, it will go wrong" (Murphy's law).
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Re: 2.5 Air Cooled Combi Engine?

Post by Dawie »

Remember that off the tar, traction is your friend.

Traction and low unsprung mass is a significant advantage of rear engined cars. So much so that in the 60's, a standard 1200 beetle could beat cars like the 6-cylinder Ford Zephyr and achieve the overall win of the East African Safari in Kenya.

Those solid axle leaf spring cars suffer from axle tramp on bad roads. Especially on corrugated/ sinkplaat surfaces. Around a corner in the dirt, those jobs handle like a piece of soap.

Under those circumstances, you do'nt need a lot of power to win them.
Do'nt assume anything- (While doing fault-finding).
"Things should be as simple as possible, BUT NO SIMPLER THAN THAT."
"If something can go wrong, it will go wrong" (Murphy's law).
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Re: 2.5 Air Cooled Combi Engine?

Post by mhsmuts »

I should perhaps mention the 1700 fitted has seen the end of its life, major sump pressure and low compression. Also carbs are very badly worn.



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retrovan
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Re: 2.5 Air Cooled Combi Engine?

Post by retrovan »

Sounds like bad dust intake results,

Need to ensure this is sorted next engine.

May be able to get away with piston barrels and bearings and you good to go.....

Oh, and a carb or fuel injection redo.

Herman
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Re: 2.5 Air Cooled Combi Engine?

Post by mhsmuts »

Herman I suspect we started with a tired motor..

If fuel injection is considered, would you say the k jetronic system or a hybrid alternative?

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Re: 2.5 Air Cooled Combi Engine?

Post by retrovan »

mhsmuts wrote: Wed Aug 12, 2020 8:23 pm Herman I suspect we started with a tired motor..

If fuel injection is considered, would you say the k jetronic system or a hybrid alternative?

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Would say the original system will be better suited to the engine, but an Hybrid would possible be easier to find and to afford.

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1968 Fastback 2Lt.type4( Red)
1972 Low Light Bay Panel Van 2Lt type 4(White)
1975 Fleetline Panel Van 1914cc (Aqua Blue/White)
2019 MeFusco Beetle Truck
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