Hi guys...I need to pick your brains please.
 

I'm considering putting a 914 engine in my 1967 912. Is the 1.7 and 1.8 engines the same stroke as the 2.0. Can I just put bigger P&C's on a 1.7 or 1.8 and achive the same power as a 2.0. Is the VW pancake bus motor the same engine and are all the above wet sump motors.What sort of HP can I expect
from a modestly built 1.7-2.0 with Webbers and tuned exhaust.Are these motors notorius for dropping valve seats and if so, how do I defeat that problem. Any information or help in my deciding to build this would be greatly apprecated.Thank-you gentleman.

The 2.0 motors have a strocke of 71mm, while the 1.7 and 1.8 have a 66mm stroke.

If you do the necessary machine work to fit 103mm pistons and cylinders on a 1.7 or 1.8, you can easily make more power than the 2.0 motor.

The VW Bus (72+) has a Type IV motor, which is very similar to the four-cylinder 914 motors. It is not the same, however. There are differences in the cam, and differences in the case (including the oil filler and dipstick). The 2.0 914 heads are better than any other Type IV heads, while the 2.0 Bus heads are among the worst for performance. The 1.7s seem to have the most in common between 914 and VW motors, while the 1.8s are fairly similar and the 2.0s are somewhat different.

A "modestly" built 2.0 can get you into the 120 HP range without a lot of fuss. This assumes a good set of headers (Kerry Hunter, Eurorace, or CFR), an aggressive cam, higher compression (8.5:1 or so) and so on. That's just a ballpark guess, though--there are a lot of details that can make or break the engine.

None of the 914 engines are as notorious for dropping valve seats as the 2.0 Bus is. However, it is not unknown, particularly in 2.0 914 heads. When the heads are overheated, the seats tend to come out. This can be cured by using different material valve seats (the original sintered metal doesn't expand with heat, while the aluminum head does), by carefully machining them, and by never overheating the motor. And, of course, all of the cracks that tend to form should be cut out, welded up, and the surfaces re-machined.

--DD

Check out the "Type 4rum" at shoptalkforums.com, there are many knowageable type 4 people on there. I am installing a 1.7 from a 914 into a bettle with a 915 transaxle from a 911SC. 2.0L cranks and rods have a huge core charge on them (getting scarce I guess). 1.8L heads are the most popular for performance. I would like the longer stroke also, and will probably have my crank offset ground to the 2.0L 71mm stroke and go with 103mm pistons for 2365cc. A reliable 150hp should be easy depending on cam, valve size and carbs. In a 912 you may be better off using a bus crank and 210mm flywheel as the 914 flywheel has a recessed clutch assy. that may cause problems with your transaxle. Good luck

Why are you putting a VW engine in your 912???? Instead of putting a VW engine in rebuild the 912 engine. The Porsche gods are begging you to reconsider your decision.

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Joshua Harrison
1968 912 Coupe

Josh, the main reason is that I bought it without one.It cost a kings ransom just to buy something that "runs" let alone rebuild it.Don't get me wrong, I'd love to have a 912 in it but, it just seems past my financial reach. Thank-you all for your comments and shoptalk leads. Very informative!

Check out my buddies page. He's got a 2.4 914 engine built in a bus case. I know, Bus case?!? He bought the motor that way. and he didn't want to use up the original 912 motor doing Drivers-Ed and Autocrossing.

http://members.home.net/jecole/912_24.htm



[This message has been edited by Conrad W Peden (edited 03-10-2001).]

Hello

Just to remember the factory used the 914/2,0 to make the 912 E.

Grüsse

The larger engines, with correctly built engines are actually just as reliable as the 2.0...

My favorite is the 2270, it drives great, alot of torque, and is very reliable.

Check out my site at www.aircooledtechnology.com The 2270 is my hottest selling engine, the 96 bore is the way to go...The 78 stroke crank is a great addition to it.

There is a guy on the 911 rennlist... www.rennlist.org that is looking for someone to take the drive train on a 912....go there and search the archives...he is using body parts...