4agze 20-valve twincharged project update with pictures


Here is an update to the 20-valve project. It is now using the imported 20-valve block with oil squirters. The cylinder bores have been honed, the pistons cleaned and re-ringed, new bearings, gaskets and seals. I am using ARP head studs and main studs to hold the engine together. The 4AGE head stud kit comes with (5) 5-inch studs, and (5) 4 1/4 inch studs, plus nuts and washers. For the 20-valve it needs (10) studs of 5 1/4 inch length. ARP makes 5-inch studs, and 5.7 inch studs. I don't think that the 5.7 inch studs would have worked, because there is only 3/4 inch of threads on the ends, so I used the 5-inch studs from the 4AGE kit, and ordered 5 more 5-inch studs. I have the head and crank installed now. Here's a picture of the engine right before the head went on.

And the modifications needed to the Cometic head gasket.

There are 4 small water passages in the 20v head that the 4agze doesn't have. I drilled 4 small holes in the places indicated in the squares.

Here is a picture of the water piping that I made. The original 20-valve water pump inlet pipe interfered with the supercharger, so I made this using a 4agze water inlet pipe and the 4agze thermostat housing. On the 20-valve the thermostat housing was on the back of the head. I don't think there will be room for it there.
You can see how tightly the water pipes hug the block. It leaves room for the supercharger inlet pipe right underneath the big water pipe.
The 2 small open ends are for connecting the heater core. Yes, I will have heat this time.


_________UPDATE__________
This waterpipe setup does not work well for several reasons - so don't duplicate this in your car!! One reason is that the thermostat is in the wrong place. It needs to be connected to the outlet on the exhaust side near exhaust port #4. The inlet to the water pump goes to the lower radiator hose, and make sure that the water pump is the highest point in that hose. If you loop it 'up and over' the supercharger or anything else that is higher than the waterpump, you will have a big problem with air trapped in the system right there. Waterpumps just don't push air. An air bubble there will cause coolant to NOT flow, and you will overheat. The coolant port on the intake side needs a small hose connected to the waterpump inlet. This will allow air bubbles to go to the head, to be pushed out the outlet on the exhaust side and to the top of the radiator. Also this will allow coolant to flow when the thermostat is closed. The water bypasses the radiator, so it should be 1/2 inch or smaller. I will have to post some pictures of what I have now for the cooling system, it seems to be working well.
Update July 8th 2005. All belt-driven accessories are affixed to the engine and tightened. Belts and front covers are installed. A heatshield is welded to the header, Ford EDIS spark plug wires work fine on the 20v if you bend them straight, and trim the boot. Air filter is installed. The flywheel has just been resurfaced, and a plug for the distributor hole has been ordered (Thx Kwanza and Rix86 for the research)


The turbo is bolted down tight, and the drain is connected with a new gasket

Braided steel line is used for the turbo oil supply and oil pressure sender. The knock sensor was converted to bolt into a smaller hole, since its original location behind the supercharger was blocked by a water pipe.

The original wastegate actuator was blown, and the internal spring was very weak, only allowing a few PSI of boost before exhaust pressur just blew it open, so it was tossed in favor of a Volvo 10 psi actuator. The spring in the new one was so freaking stiff, that the wastegate bracket would bend more than the wastegate lever would move. I got second, identical wastegate bracket, and welded pieces of it onto the original bracket for much better stiffness, and improved the geometry a bit while I was at it.


The engine is virtually done, I will buy an ACT pressure plate to work with the Centerforce disk for a clutch. I like the centerforce disk for its high friction coefficient, and I need the all-rpm clamping force of the ACT Presure plate. The Centerforce would change clamping force with RPM and would not let me shift quickly at high RPM. The clamping force was really soft with the centerforce, so I don't think it will stand the extra horsepower I hope to have now. It never did slip on me, and I can say it is a good clutch to about 200 hp, but I don't think it will take any more.
----------Update october 2005----------
Here are some pictures of the intake system. I already removed the throttle plates and shaft. Boy, that opens up the intake runner doesn't it?

Here are the stainless steel 48mm intake velocity stacks I got from CBPerformance.com I spent a whopping $6.50 each plus shipping for them. :)
I welded the stacks and the bolts securely to a thin metal bar. That way I can tighten the bolts that hold the plenum to the ITBs without them spinning, and there is no way a bolt can loosen up and fall into the intake. (remember my twincharged 4agze was taken out by a loose piece of metal in the turbo..)
Here is a good reference to how big the intakes are on the silvertop 20v engine. If it wasn't for the funny shape of the intake where it meets the head, a golf ball would fall right thru it.

Here is how the parts go together...

The red parts are all aluminum and pretty light weight. I have red tape on them so that they don't get scratched while I am working with them. I will polish them in the future.

I would have liked a little more headroom for the velocity stacks in the plenum, but this will work fine...

I still need this to be welded. I can't do this myself.
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20 valve page 3 - it runs!