993 cam tower swap on 3.3
02-13-2004, 04:19 AM
#2
RL Technical Advisor
Rick:
You'd need the 3.6 cam chain boxes, tensioners, ramps and everything to even attempt fitment on a 3.3.
3.6 engines do not have external cam tower oil feed lines like the 3.3 and earlier engines do, its incorporated into the chain box assemblies.
I've never actually tried to do this so the above info merely reflects most of the differences. It many not even be possible due to case differences.
You'd need the 3.6 cam chain boxes, tensioners, ramps and everything to even attempt fitment on a 3.3.
3.6 engines do not have external cam tower oil feed lines like the 3.3 and earlier engines do, its incorporated into the chain box assemblies.
I've never actually tried to do this so the above info merely reflects most of the differences. It many not even be possible due to case differences.
02-13-2004, 11:42 AM
#3
Rennlist Lifetime Member
Actually you can do this with the 3.3 stuff. You need to tap the cam tower or accept the banjo fitting. The main oil feed is in the case, however the secondary line on the 3.3 is not present. Rather than running an additional line off of the main you can use the old style housings and line with the updated cam towers and retro the lines. Not that difficult really. All you really need is the cam towers and rockers. The 964/993 housings use a bridge, the location of the cam housing is the same, the difference mainly was the jacket into the cam housing was not tapped, rather smooth with an O'ringed tube that meets a bridge to the chain housing. The major difference is the chain housing which moves the outlet out to the end. This makes the tube on a solid bridge possible. No more hose. So the 3.3 chain housing can be used, just swap cam towers and a little work and you are there.
02-13-2004, 12:15 PM
#4
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Thank you for the information. It's still a little foggy in my mind, but it's probably the kind of modification that is clearer with the parts sitting in front of you. I guess that I should be looking for 993 cam towers rockers and valve covers!!!!
To think...limited valve adjustment, and on a 3.3 turbo!
Rick
'78 930
To think...limited valve adjustment, and on a 3.3 turbo!
Rick
'78 930
02-13-2004, 03:11 PM
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I would think that you would have to swap the cams to 993TT as well. I think the ramping profile for hydraulic cams is differant than the mechanical style used in the 930's. I would be wise to also check the cam journal sizes too.
02-14-2004, 11:38 AM
#6
Rennlist Lifetime Member
Oops, sorry about that. You will need the cams, the profile IS different for the ramp up. I assumed we knew that was part of the deal. You will need rockers, lifters, screws and rocker shafts. Sorry for not being clear. The journals are the same size. In fact, the 964 cam tower was used on the later pre 964 cars. When they showed up on the 964 car the hole for the feed was not tapped for the old style and was bridged. Position was the same though. The 993 showed up with a different cam housing, yet everything else remained the same in regards to fitment. So you can see the puzzle and how it all fits. One of the things you will notice on the 993 cam tower verses the 964 is an extra stretch of surface area that has the EGR port in it. It ports through the head on the 993 and through the am tower then out the rear and the back to the pump. These holes go no where in a retro conversion and in fact hang over and sealing portion of the head. The towers still seal up it. You can blow through the port holes in the back though. Not a function issue. You can have the cam tower welded up, but it is not necessary. I would plug the top port just to keep junk out. I will take some pics of the difference of you guys would like.
