Will stock T3 D-Jet run a 2.0 T4?

vwfreek · Post by **vwfreek** » Mon Jun 04, 2007 6:59 am

I just picked up a 1970 T3 Squareback, the body is in good condition, but it is in need of an engine. I've got a 2.0 from a Porsche 914 with 43,000 miles on it out in the shed, and was thinking about putting it in the Squareback. I don't have the ECU for the 2.0 and was wondering if the T3 ECU will work with the bigger motor, or will it run too lean?

raygreenwood · Post by **raygreenwood** » Tue Jun 05, 2007 1:13 pm

I am assuming that you have the intake runners, plenum and throttle body for the 2.0. You will also need to either get an MPS for a 914 or recalibrate yours. You will also need to get the distributor from the 914 as the advance curve is different (easily changeable)...but the position of the vacuum can on the type 3 version of the D-jet dizzy is enough out that it will interefere with teh 2.0 case...also fixable...but it may be simpler to get a type 4 dizzy from a 1.7 or 2.0 (same).
Lastly...if your 70 model had teh pressure switch under the right hand runners...the MPS and ECU are different and the systems are not compatible. Ray

vwfreek · Post by **vwfreek** » Tue Jun 05, 2007 6:36 pm

Sounds like I have most of the parts needed. The 914 engine has the intake runners, plenum, throttle body, and distributor. I basically have everything that was bolted to the engine when it was removed from the car. I don't have the 914 MPS, is that difficult to recalibrate? I also have access to a couple 412 parts cars, would it be easier to take a MPS from one of those?
There is no pressure switch under the intake runners on the Type 3, so I'll give it a try.

One other question. The Type 3 is an automatic, is the 914 camshaft going to be compatible with that? I've heard that you don't want to go too aggressive on the cam with an auto trans. Although I did just put together a 1776cc with a Web 86 cam for my girlfriend's 1969 Fastback automatic with D-jet and it starts and idles just fine and made it around the block under its own power. Waiting on a master cylinder to take if for a real test drive.

raygreenwood · Post by **raygreenwood** » Mon Jun 18, 2007 2:37 pm

The selection of manual or automatic transmission will have very little to do with the camshaft. The only thing that can happen is that if some lumpy wild cam is used...it may alter the vacuum signature enough that the vacuum modulator needs to be readjusted. No biggie.

On type 4's....in this country....there was only one camshaft. With D-jet the camshaft is pretty specific. The MPS needs a certain range of vacuum signature. If you have a complete engine and are planning to use it as is...be sure that the cam is good and the cam is stock...and it will be no problem.
However...it is highly recommended to use a new cam and lifters. Use either a Webcam 73 or more preferably...one from Jake Raby.

Yes...a type 3 MPS can be adjusted to work with a type 4. This level of adjustment is pretty involved. It would be simpler to find a good MPS from a like engine. Even that will need adjustment. Keep your other one you will eventually get it adjusted and will need a spare. Ray