T1 fuel injected engines vs T1 carbureted engines

I have just bought a 1975 1303S (Super Beetle) in Sweden and it has a

1600 carbureted engine (type AS). In 1975 all Beetles sold in the US had Bosch L-Jetronic fuel injection, and when looking at replacement engines it appears that the long blocks are different for carbureted and fuel injected engines. Does anybody know what the difference is? I am curious since I intend to replace the carburetor with the L-Jetronic. Thanks, Jens.
Reply to
Jens
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the 3/4 cylinder head has the threaded boss for the head temp sensor the FI needs. The shroud and sheetmetal is also different, to accomodate the injector hose location. The intake and breather system are also totally different, but you can bolt them onto a longblock, the main issue is the head temp boss

John Aircooled.Net inc.

Reply to
John Connolly

Major difference is the heads. Valve sizes are different and there is provision for the head temp sensor.

Outfitting an engine for FI will be very expensive.

Speedy Jim

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Reply to
Speedy Jim

Are the valves larger or smaller with FI? What are the diameters?

Jens.

Reply to
Jens

FI exhaust valves were 30 or 30.5mm.

I had a FI 1600 rebuilt once by a local shop back in '87(shoddy job, BTW). They used stock heads (35.5IN/32EX) and what I assume was a stock cam. That thing ran like a POS! I finally stripped off the FI components and went to carbs. You can't win with a "Frankenstein" motor.

Transferring FI components to a non-FI engine is a waste of time IMO. You'll be much happier with the results if you fine-tune a stock carb setup and proper ignition. Spend your dollars there.

RT

Reply to
Raymond Lowe

They made the exh valves smaller (30mm vs 32mm for carb) and the exh valve stems bigger (9mm vs 8mm for carb). This was to increase the heat transfer and keep exh valves from failing at the higher running temps.

I agree with Raymond; adapting a carb engine to FI is probably a waste of time (and money).

If you are interested in experimenting with FI, consider joining ShopTalk forum:

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forum is just for FI folk (or is that "volk"). Speedy Jim
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Reply to
Speedy Jim

The carb engine eventually followed the FI, with regard to valve sizes. Early in the 75 model year VW change the exhaust valve (on the AS & AF) to

30mm. These engines then suffered badly from over-heating (just like the original aftermarket 041)so, by the start of the 77 model they reduced the intake to 33mm. Since then all replacement heads whether for AJ, AS, AF, AE etc come with 33/30 heads. The 9mm exhaust stem, I understand, was to reduce valve guide wear by increasing the surface area to load ratio.
Reply to
Peter

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