mark kibort

did both sides get oriented the same?? remember its not a huge deal, but its nice to have the offsets properly for the new engine. (remember, porsche got it way wrong for the stock 2 valve engines).
re-cutting the valve reliefs allow for the proper set up of the engine pistons for optimal rod angles for BOTH banks. again, kind of a minor deal.

so, this is a great deal! anyone thinking of making a 4.7liter become a 5 liter? if so, all you would need is a bare S4 block with no internals.

Landseer

Mark, I'll take pictures in the next half day and post them in a separate thread. Just trying to make-back what I think Jim paid for them, and if they are serviceable. Money will go directly to him.

karl ruiter

I have pretty much been through both US and Euro S CIS systems. As far as I can figure out the only substantial differnece is in the WUR (Warm up Regulator). Do not be fooled by the name of the WUR, it is pretty much the eqivalent of the LH box for CIS cars in that is is were all the smarts reside. It does two jobs: It modifies the fueling for cold start and also, if modifies the fueling as a function of load. It is the 2nd job your are most worried about. Cold start operation is also augmented by a L jet type aux air regulator and injector, but that is totally seperate and some have been removed them without dire side edffect. I can also tell you that a Euro S car will run and drive with a US WUR, although it is known the be curved differently and probaby results in inferior performance.

danglerb

Not a clue, I would stick with the Euro parts unless you learn for sure otherwise. I was suggesting if AFR won't go where you want it, maybe an adjustable regulator would help tune it, but I wouldn't start with one.

karl ruiter

There are two regulators: the system pressure regulator is built into the fuel distributor. As far as I know the system pressures are set the same on all cars, however I think the system pressure regulator can be adjusted somewhat. This plays a similar role that the pressure regulator on a L jet car in that it provides a constant pressure to the fuel meter (in the fuel dist) and injectors. The WUR is a 2nd regulator that is seperate and modifies the peformance of the system for load and temp by providing a pressure that pushes backwards against the fuel meter.

mark kibort

so, this WUR from europe has a electronic control box? you said, like an "LH box for WUR". if so, then we dump that and just use the US WUR, and plumb it in to the plennem as that isnt hard. the euro, is going to be plumed into the head ports for intake in the casting of the heads for fuel and possibly just more air (aux air) to provide more air and fuel on start up.
I guess we will have to see what we got when we pull both engines and see the differerences. However, if the WUR is controled by electronics we dont have, then I guess we can dish the WUR system from the euro and just modify the US version to work. (if possible, or like what we do on the Ljet version of this conversion)

Luis_M

The differences in the specs for the US(.063) and Euro-S(.086) WUR's can be found in the WSM pages 25-6g and 25-6c. Both units have the same warm control pressure ranges, with and without vacuum. The differences seem to be only in the cold pressure curves, so, once the car is warmed up, it would seem that either WUR should perform the same, but the US WUR, with slightly higher control pressures at each temperature, will produce slightly leaner mix during warm-up.

Luis
81 Euro S 5sp

mark kibort

Well, thats not a big deal then. But, the main issue, is, do they use the ports on the back of the heads that feed the intake or exhaust. I dont know about 79 CIS, as Ive never seen those heads. maybe those rear most ports are not even used, but on euro heads, there is a port for air injection that feeds the exhaust ports internal to the heads castings. the US heads for example, have that same port at the rear,but it feeds the intake ports. I dont know if the early 79 US heads have that port, but obviously, the euro heads have it. but those wouldnt be used and could be plugged. I guess what im trying to ask, is if we can just bolt on the US stuff, as it sits on the US car now, and put the new 5 liter and euro top end right underneath it? if the fuel distributor is the same, injectors are the same, then its a swap with no issues affair, right?

karl ruiter

Nope, there is no electronics in the WUR, or indeed anywhere in most CIS systems. The only exception to that is there were a few system modified to use a O2 sensor for closed loop mixture control, but I think that was never done by the factory. You can still purchase an aftermarket electronic WUR to do this, but it is pricy and few do it. Its smarts is all mechanical by vacume and temperature.

Basic overview of CIS:
Fuel comes in from the same pump-filter system you have for Ljet and later cars.
Fuel is regulated to the System Pressure via an adjustable regulator in the Fuel distuributor.
System Pressureis sent through a small orifice in the Fuel distrubutor to the WUR where it goes through a variable orifice and back to the tank. The pressure between the two orifices is the Control Pressure.
System Pressure fed to the injectors via slits in the Fuel Distributor. In the middle of the fuel distributor is the control plunger. It partially covers the slits allowing more or less fuel through them.
The air flap pushes the control plunger to open up the slits and allow more fuel through.
The control pressure works against the air flap, by pushing on the other side of the control plunger to close the slits and reduce the fuel flow.
There is an aux air regulator and injector, kinda stapled to the side of the system, just for cold start. I'm not sure why they felt the WUR was not able to handle it all.

mark kibort

you mentioned, "LH box for CIS cars" so, a assumed that there was some electronics involved. didnt know quite what you meant a couple of posts back

karl ruiter

Sorry about that. I meant the role it plays, not the way it is built.

James Bailey

Control pressure regulator (WUR) is the "brains" of a brainless system...... when one goes South the engine may just barely run...been there done that

Landseer

Mark, is this the way pistons should look when flycut?

RPetty

Thanks!!!

mark kibort

They look great. However when I made them the exact size and dimension as the 2 valve euro piston, they were not quite perfect in position for some reason. maybe some how, the machine shop didnt take into account the larger diameter both times, off by about 1mm. I took a dremel and cut the rest by hand.

What I was also talking about was the offset. half the pistons should have the valve reliefs opposite from each other. In other words, the orientation of the two sides should be different. meaning, there will be a left and a right side bank of piston cut designs. notice how the pistons are all the same for the S3 or S2? this means one side will be right and the offset of the rod will be wrong on the otherside. (the driver side is correct, passenger side the pistons need to be reversed and then notched correctly) not a big deal, but Greg Brown says this optimization gives some engines about 10hp. I didnt do this with mine, but did it with scots, and both made the same hp, but scot had B1 cams, and mine had equal lenghth headers. who knows. maybe its not a big deal. the S4 does this by default, because it has arrows pointing to the front of the engine, while all other, including the 85, have arrows pointing to the exhaust ports.

anyway, those pistons look great. If we hadnt bought a short block, that would have been a good way to go. anyone thinking about a 5 liter bottom end?
buy these pistons, give me a 5 liter bare empty block and Ill match up some rods and a 84 or newer crank and built it up for you!

Here are some pictures of my build of Scots 5 liter euro engine