mark kibort

which motor do you have? is it twin Dizzy? or single dizzy CIS?
either way, the 4.7will bolt right on to whatever you have up top. heads, cams, the works. obviously now, that it is apart (when its apart) you should put the bigger heads and cams on . later you can adapt the newer Euro S intake stuff on to it. CIS or LH, whatever you have

hopwood

If he has a 4.5 it must be the single dizzy 240bhp motor.

Go-carter

Quite right, single dizzy 4,5l 240hp. M28/01.

Thanks for the input. I have a single 3" today, so I guess I'll just stick with that, and try to get some new headers. A powerdyne is on the schedual this season, also..

Go-carter

Sooo... Going to pick it up on monday! So in the meantime, I have som other questions.

The 4,7, which eventually will be equipped with a S/C... What is a good exhaust size for it? Today I have a 3" all the way, was wondering if that's enough, or if it's better with for example dual 2 1/2", or dual 3" or if single 3" like today is enough?

Go-carter

I'm ordering things from Pelican now. What would I need, other than new valve stem seals, nuts&washers for the head, and head gaskets? First time I ever rebuild a engine(other than swapping compltete heads)

Other things I should do when the engine is out? Give me a full list now I'm thinking ofc wash and clean the entire engine bay, clean up the new engine, perhaps fresh up the paint on it.

GlenL

I'm unclear on what work you are planning to do to the engine. Drop in a complete engine?

Go-carter

4,7 block, with 4,5 head? Atleast that's my initial plan, as the donor engine has LH, and my current has CIS. And this also brings me to another question, would it be possible to fit my 4,5 spider, to the 4,7S head? Or is spider bigger/different? Guess I'll just have to try when I get the engine. The 4,7 head has anyways a bent valve, so I guess I'll just stick with the 4,5 head unless the 4,7 is in exceptional condition.

GlenL

The 16V heads will accept the same intake manifolds.

So you will not be taking apart the engine block, just swapping on the heads and other top-end parts.

You need the PET or PDF version of part catalog to assemble the list of parts you want to replace. You can find the PDF on the real Porsche website. Start with 2 4.7l head gaskets, 8 intake manifold gaskets and 2 water cross-over gaskets. You can re-use the head bolt nuts and washers.

A good time to replace the thermostat and any bad looking hoses. I'd make sure to get that short one between the block and the heater valve.

I suggest taking your time, getting it apart and assessing what you've got.

pjburges

Don't mean to hi-jack the thread - but would the tubular steel headers from a 944 work as an upgrade? They'd bolt right on for the passenger side,

But on the drivers side perhaps you could cut them up near the flange - rotate them around, stick a collar on and weld the pipes back up?

944's have a "tri-y" 4 into 2 into 1 and they definitely seem better than the 928 cast-iron logs. Anyone tried it?

Ad0911

A 4,7L block with 4,5L heads? Does that really work? It could be a most interesting option for me too. What hp would this setup produce? I now have the 4,5L EURO camshafts but could perhaps change to 4,7L S EURO camshafts.

Go-carter

Well, it seems to me that it will work, based on the feedback I'm getting here. I'll find it out on monday

Go-carter

Picked up the engine today. When I cleaned it up, i noticed something special: it's a M28-12 ?! But with twin dizzys??? How do I know if the engine is a Euro or US? Suppose it's a Euro, but still... would bring peace to my mind to know its 310hp, and not 200-ish... Also suppose the head is changed, as the M28-12 engines are all K-jet, or?

Trip..

https://www.928gt.com/t-928engine.aspx

Here are your block numbers. Looks like an Euro S Automatic to me with 300hp.

I would think US motors would be pretty rare in your area. But I guess anything is possible.

Iwanna928

Well you want to use those heads and cam's for sure to make more power. Runners , TB are all bigger!

Change of plans, rebuild your 4.7L euro motor!

Then again if you are boosting you would perfer the 79 cam's and sell the euro cam's to someone to off set costs!

Rich9928p

What you have as a donor motor is a Euro 1984 - 1986 motor, the 310 HP engine.

1. The heads have larger valves.
2. The cam's are more radical

To transplant the newer engine, you'll need a 25 pin Euro LH fuel injection controller and EZF spark controller and MAF (if that is not included with the donor). The EZF requires a vacuum input from the engine. You will need the full under-hood wiring harness AND the in-car central electric. This will take a lot of work, as the may be wiring issues to mate the newer 1984-1985 central electric to the existing plugs.

Or, what would make this much easier, use the donor engine sans intake manifold and throttle body (spider) and find a 1980 - 1983 Euro S (M28/11 or M28/12) intake manifold and throttle body that will mate up to your CIS. Your existing CIS system will flow plenty of fuel.

My 1979 Euro 928 track car was upgraded this way (using a 5-liter block) and runs well. It still uses the original 1979 CIS system.