davek9

You should come out to our local 928 OC meeting, on the second Wednesday of each month, we can discuss what your goals are and you could see some examples of what others have done. Please send me a PM and we'll get local club contact to you.

Hope to see you at one soon,

Dave

davek9

so does my Blue '85

mi650

I have the shop trying to track down a Euro engine.

I have another question, but I'm pretty sure the answer is no. Will an S4 engine fit?

GregBBRD

I can't possibly see how a shop can take a 928 engine out, correctly rebuild it, and re-install it for 5-7K.

There's simply too many pieces and too much labor for that to make any sense, at all.

I spent more than that, on my son's engine....with free labor and parts at my cost.

Get an itemized estimate, before you start.....because it has to end up being 2x that number, before you are done.

Hilton

All good reasons to keep it.


Honestly, given the cost and range of options, I strongly recommend you just get a decent re-paint, and enjoy driving the car as-is

The modification trail is fraught with hidden costs and complexity, and if you're paying a shop to do the work, there will be all kinds of issues with trust/communication/stress when the complexity and costs is uncovered and there are any kind of running issues.

If you're determined to go down the modification path, then read on...

As you're considering putting in a Euro motor, and if part of that plan is to take the Euro motor apart and put new head gaskets, then it may be worth considering making a hybrid 5.0L 16V "euro" motor. Using:

Block/crank/pistons from US 85/86 32V 5.0L motor (pistons need flycut reliefs for the larger 2V valves)
Heads/Cams from Euro 4.7L 928S

The trouble you run into is engine management - but you're already facing that with swapping out an L-jet for any variety of Euro. Either you ditch L-jet and use the Euro's setup, or you ditch L-jet and go with aftermarket injection (VEMS, Megasquirt, etc.). Note if you do with the Euro CIS setup, the entire fuel system (especially pumps) will need to be converted to CIS too as the fuel pressures are key to running well.

If you do a search here on Rennlist, there are a fair number of hybrids under discussion - should get you north of 300rwhp. Ducman has a lot of posts on the build of his hybrid for your interest.

Lastly, S4 motor will physically fit - but you run into the same problem with engine management. S3 blocks still have the bosses on the top of the block to work with 16V heads, S4 blocks don't.

mi650

Thanks Hilton, lots of good info.

If I go with an S4, it will be a long block. So, unless I'm mistaken, entirely possible, I shouldn't have to worry about these problems. I'm by no means a mechanic, and it's been 30 years since high school auto shop.

karl ruiter

Another choice might be to put a 85/86 motor and Porken's chip set. Would likely save $2k or so off the cost of the S4 motor that can go towards labor and performance would be similar, I think.

mi650

I can get the S4 for about $2500 + shipping.

mi650

The shop manager suggested I try another oil change before we give up hope. I had used Valvoline High-Mileage synthetic 10w-30. He wanted me to try Mobil1 5w-30, and add a quart of Lucas, then put a couple hundred miles on her.

So I did that, but at the same time I was thinking maybe bad gas. I usually get gas from only 2 stations. 1 here, the other near my house up north. Well, I had gotten gas at a different place. I ran it as low as I dared, got new gas and added a can of Seafoam.

Thursday, we headed north. Within 50 miles, the knock was gone.

I'll probably never know for sure which was really the problem, but it doesn't matter now. She's back to running great!!

Leon Speed

5w-30 is way too thin. Use 15w-50 at minimum unless you only drive it on the arctic circle.

928 at last

For your geography, (Pretty much the same as ours for climate). I'd go 20/50 with sufficient ZDDP. Like maybe Brad Penn Racing Oil.....

mi650

Really, that heavy, in the winter?

I've never used oil the heavy in anything.

928 at last

I haven't had a problem with winter starts at that weight. In the '70s I had a 455 HO Pontiac that refused to turn in -30, but no issues with the Porsche.
Mind you, I haven't tried starting it in that low a temperature yet. It's been fine down to the low single digits Fahrenheit though.

sendarius

Yes, that heavy.

It's not rocket surgery - read the Owner's Manual.

Don't try and second guess what it says - believe me, unless your name is Greg Brown (and maybe a few others), you don't know better than the designers of the engine.

gearz

5-30W will destroy your engine in short order.