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This thread is dedicated to any modifications I do to Gramps (the 78 924 non turbo). The picture above is a bit of a beautiful joke (photo credit: the interwebs), however, because I don't plan on making Gramps into a "Giant Killer"... he's more of an everyday sportscar, but some things aren't quite up to snuff IMHO.
First project on the go isn't suspension or brakes or engine or anything like this. It's the heater fan. These early fans aren't good enough for heavy defrosting of windshield, let alone defog the side windows. I figure if I can't see then I can't drive.
The heater fan hasn't the best reputation and I found the body had several cracks in it. Repair: I'm going to patch it up so it was better than before, but here's the "hot Rod" solution that I'm hoping will work:
Extending the 5 fins by about 25%. Riveted & glued on with a strong bonding agent. I'm excited to try it!!
Yes the fan works better & there is not any extra vibration/noise. I also bypassed the variable resister (or whatever you call the dash level control for fan speed) & plugged in the ground directly to the fan motor & that made a big difference in fan speed. Now when ever the key is on then I have full fan power. Will probably install a switch for that. I don't like the cable/control set up. The whole heater set up is crap.
Lately my preference for engine performance is torque. Lower rpm hair pin turns is what I've been dealing with and rallye style driving has captured my imagination & desire. And torque is nice to kick the back end around.
Since I have two cars (Gramps and Wilson) that I drive a lot, I notice where each car shines. Gramps is far easier to get into & out of. His seats are factory '44 Recaros. So nice. His engine is a far cry from the 2.5 litre though. So I've been exploring some options.
In a nut shell (I'm running out of time this morning & must go to work):
I have 944 2.5 engine parts; enough to consider placing the Porsche 2.5 in place the 2.0. I am considering converting the mechanical CIS fuel injection system from Gramps to the larger engine. What sort of job would this be & what are the results?
The back of my mind worked on it & the search engine confirmed: The 1979 928 model was CIS & look at the CIS injector on what appears to be a 2.5 head. It is possible the injector could be a true bolt in.
There are several other aspects that need research for the conversion I'm thinking off. Such as clutch/bellhousing/input shaft/ign/engine mounts/harness adaption, etc.
Common belief is the n/a CIS can be used for a built 2.0 (150-160 hp). Well that's stock 2.5 territory.
My exploration into the swap will reveal more. If you've already done this research then feel free to post the info. In the end I think I'll just rebuild the stock 2.0. (It's leaking and someone appears to have stripped out all of the allen bolt heads from one end to the other). Nice
Or I might put the Motronic ecm & harness in with the 2.5. Right now Gramps is finally parked on the street & Wilson the white 944 finally gets some well deserved garage time!
If I rebuild him I will try to bump the compression to 11.5:1, I will regrind the camshaft on the bench with common hand tools & perform my first port job and get the flywheel lightened. Probably add what? 20-25 hp? All for pretty cheap. But will it last? Will it work is the question.
Regarding the cam grinding, I'm referring to making the base circle smaller. When googling I found this and was impressed by the fellows answer... the very long answer... although not all applies to the Porsche engine. https://answers.yahoo.com/question/i...9000014AA0T8uQ
Not trying to be discouraging by any means, it would be a cool project, I don't know if it's ever been done. Definitely in for results. Also, I looked at the 928 runners at some point for an ITB idea I had but they won't clear the hood when you have a 2.5 in the engine bay. I bet you could mod the 2.5 injector bungs to accommodate CIS injectors pretty easily. You could install the warm up injector near the throttle body or something.
Hey Noah.. Why not buy the turbocharger from Michael that he's not going to use and spin that up with an electric motor? That ought to move some REAL air through the heater core..LOL..just teasing..!
no need to touch the head unless you are shooting for 200+hp.
it flows fine stock.
cam is what the 944 needs to make more power. good luck with that, but didn't you have a hot cam before??
CIS is a fascinating and beautiful system but a real PITA to maintain and parts are hard to find nowadays...
compression adds some "snap" but it isn't a huge power jump...i'd be surprised if going from 9.5:1 to 11.5:1 got you more than 10hp at the crank.
but 10 here and there....
Originally Posted by Noahs944
If I rebuild him I will try to bump the compression to 11.5:1, I will regrind the camshaft on the bench with common hand tools & perform my first port job and get the flywheel lightened. Probably add what? 20-25 hp? All for pretty cheap. But will it last? Will it work is the question.
Dear Noah: I would grind the cam journals on a lathe to insure the same dimensions..AND some cars use the cam bearings to determine a lot of the oil pressure in the engine..although Porsche is probably different. You will have to get some special bearings to insure the proper fit to the camshaft once you go there. Watch the C/R as to what your local gasoline will support w/o knocking...Don't need to buy a Cometic head gasket if you don't need it.....jus sayin..
06-06-2016, 03:52 PM
Gramps unleashed
