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Can the S4 inlet manifold be physically fitted to the 86 5.0 liter motor?
I'm not interested in the technical flow properties of either manifold, or the pros and cons of either, just if they will physically fit on?
Are the stud patterns the same?
Do the ports line up enough to be ground to a flow correctly?
I want to fit twin drive by wire throttle bodies to an 86 5.0 Liter motor and going in through the side of the plenum would be much easier with an S4 inlet manifold.
You have to grind down the runner mount castings on the side of the Intake valley. Other than that I think that's it
That's great Duncmam82. I can handle that pretty easily.
The next challenge will be to pull the trans throttle position cable without any pedal cable!
I'm going to start another thread for all the other stuff.
If anyone one has a spare S4 inlet manifold, less the throttle body, for sale, I'm in the market.
S3 vs S4 ports are a completely different shape. I know you're not worried about flow, but you _really_ need to not worry about flow for this to be a good idea.
S3 vs S4 ports are a completely different shape. I know you're not worried about flow, but you _really_ need to not worry about flow for this to be a good idea.
Intake gaskets tell the story:
S3:
S4:
You are right Rob, the flow is important, once everything is installed and if I go further with this, the ports would all be enlarged, along with the valves, just as far as I can get them.
Why, just a technical excessive really. I'm rebuilding an 86 5.0 with CAN-BUS style electrical system and modern engine management and I want to use dual drive by wire throttle bodies.
I hate the idea of cold air having to travel all the way to the back of the engine bay, turn around and go forward down into the very hot valley, turn again and go up into the manifold, then turn again to go out into the plenums, where it has to do a complete U turn to enter the intake runners.
I want the cold air to come in the front and turn straight into the plenum/intake runners.
Porsche must have had a similar thought if you look at the intake flow on the Cayenne v8, straight into the front.
Although I'll never try to talk anyone out of science project, consider this:
If you're getting rid of the plastic intake tubes, you'll have room to modify the S3 intake side plenums for throttle bodies. Specifically, add a conical feeder manifold to feed the plenum into the space that is currently occupied by the lback intake tube. I am thinking the "Lehman" intake manifold style conical feeder manifold that has the throttle body:
This would furthermore allow you to replace the S3 T-pipe interconnect with a regular pipe that has the S4 style resonance flappy in it. Figuring out the rpms at which the intake works better with the flappy open vs. flappy closed would give some little extra spice to your science project!
Although I'll never try to talk anyone out of science project, consider this:
If you're getting rid of the plastic intake tubes, you'll have room to modify the S3 intake side plenums for throttle bodies. Specifically, add a conical feeder manifold to feed the plenum into the space that is currently occupied by the lback intake tube. I am thinking the "Lehman" intake manifold style conical feeder manifold that has the throttle body:
This would furthermore allow you to replace the S3 T-pipe interconnect with a regular pipe that has the S4 style resonance flappy in it. Figuring out the rpms at which the intake works better with the flappy open vs. flappy closed would give some little extra spice to your science project!
ptuomov, thanks! This project has plenty of spice. I've long wanted to do a ground up rebuild but there is so much that gets in the way of such a task.
Then I started reading Carl's [flyvmo] fantastic work and up popped an 86 5.0 32v car in a real bad way, just teasing me and I lost control.
I started with the idea of going into the sides of the 86 plenum, well into the front first, but to do it without welding might be a big challenge and I don't know if the material they are cast from can be welded? The S4 manifold being screw on plate sided got me and they have larger ports to start with.
I want to bore the motor to at least 5.4, hopefully bigger, so larger ports and valves will be essential.
The DBW just plugs so nicely into the new engine management boxes so easily. My current favourite is the Link G4+, which gives me 2 E throttles, 2 O2 sensors and 2 knock sensors plus heaps of other stuff.
I'm a long way from there though.
You have to grind down the runner mount castings on the side of the Intake valley. Other than that I think that's it
Well, here is an 89 S4 manifold on my 86 S engine. It fits like me and mum! No mods at all. Even the port sizes aren't as different as the gaskets would suggest.
Now to make side plates with the electronic throttle bodies on them. The challenge looks like how to get to the manifold to head bolts if it is all preassembled on the bench, or, how to get to the lower side plate bolts if the side plates are fitted after the manifold/injector rails.
The valley is going to look lovely and clear because I don't need the water bridge or the water pump with the electric water pump.
Careful. The water pump is an integral part of the tensioner system in the 928.
It would be difficult and unwise to remove it.
Yes, you are correct. The last electric water pump conversion I did, just the impellor was removed.
This time it may well be the same but I'm certainly looking at a plate with the timing belt idler on it.
04-15-2016, 04:08 AM
86 to 87+ 5.0L Inlet manifold interchangability?
