Mike J

Okay, in this installment we will be exploring the inner depths of the SAI passages. Its actually a pretty simple system except its loaded with turns and twists (yes, pun intended). I thought I would try to capture this while I am cleaning out the old passages...

So I tried to mockup what the SAI total route looks like (yes its hokey but hey its for education purposes! ) Here we have the two banks of heads with the cam carriers attached. The position of the heads are the same as if you are looking into the engine compartment with the hood open, i.e. Piston 1 is the left front. The air pump is mounted under the manifold and is connected to both cam carriers via piping. The intake of the air pump is just behind the air filter. The air is run through the rubber hose into the pump. The pump output goes through a one-way valve and into a splitter. We will see this in the next picture...



This is the view from the back of the engine. The pump feeds into a splitter which directs air into two tubes, one for each cam carrier.



Here is a closeup of the splitter...notice the left hand feed pipe is connected to the top of the cam carrier. Inside the cam carrier is a cast distribution tube that allows the air to be directed to each of the exhaust ports.



Here is the left hand bank. The air tube runs just ahead of the back sheet metal to the back of the cam carrier on the rear of the engine.



So here is a cam carrier off the car. I put some stiff wire into each SAI port so you can see the angle of the drilled hole....on both my carriers the rear-most ports were almost entirely plugged...its a bit curious that both sides are the same.



Okay, here are some closeups of the each of the air passages. This is piston 1, ie the one the farthest away from the air source. Notice the cast passage that runs from the access hole to the access tube that runs parallel to the valve cover.



Piston 2, similar to Piston 1.



Piston 3, rear most. You can see the threaded access hole on the upper right corner. The castings of the access tube can be seen clearly on the corner of the casting.



Here are the heads with the same stiff wire showing the angles of the SAI ports. On my heads they were actually pretty clear all the way from the top to the base of the cam carriers.



Looking from the top you can see the angle difference between the SAI tubes in the heads vs those in the carriers. Since they are connected together the air actually has to change angles in mid stream as it travels from the top of the cam carriers to the exhaust port.



Two of my ports were quite plugged so I used a small drill but to cleanout the crap. Quite a bit of carbon was carved out with the bit (with no metal). The material is a hard carbon material and actually loaded the drill a bit so it was very crusty and hard.



Here is a clearer shot...



I then cleaned up the outside portion with my drmel tools and a very small bit..again the carbon material is very heard!



And then with a liberal use of brushes to cleanout the access tube...again lots of black carbon gunk....



After cleanup here is that the tube looks like that runs inside the cam carrier.



And nice clean ports............



Cheers,

Mike

C4S_fan

Mike, great photos and very educational.

Thanks showing me all the bits on Saturday... an unbelievably educational experience.

jnor10

Nice job Mike,

Forgive my un-environmentally PC comment, but when I looked at the first shot of your setup, my initial response was "wouldn't it be great to get rid of all that crap".

Anyhow, got that out.....

I'm enjoying the comphrehensive reviews your doing, great job!

Jeff N.

InTheAir

Very neat.

Too bad we couldn't have tested some SAI unclogging cleaners on those ports before the drill out. Given how hard it was, I'd be surprised if we have any cleaners that could ~really~ do the job completely.

Ben in Plano, TX

Mike -

When my motor was apart we had a machine shop bore out the passages a bit larger than stock to lengthen the time to the next clogging event. You may want to do the same.

Ben

tam993

It would be interesting to see on the passenger side cam tower the path of the port that goes from the top where the SS pipe feeds the first cylinder to the head.
In other words is it possible to get a wire down from the place were the air feed pipe connects down into the cam tower where it meet the cylinder head. If it's possible to work through that opening that would have made things easier on the end two cylinders. Understand what I'm asking for?


As far a chemicals that work, I've tried just about everything :-)) soaking the crap with B-12 chemtool seemed to be the most effective. When the ports cleared the carbon came out like sand.

The fush thing works but next time I'd drop the engine..... going on week 3. One last port to clear.

chris walrod

Great write up Mike, thanks for taking the time to do so! Must have been an overwhelmingly(<--is that a word) great feeling while drilling those passages..

Thanks for the update..

pcar964

Great writeup Mike, learning a lot here...

Don Plumley

Great stuff - thanks for the effort to document this project!

jnx

Very nice job, thanks for sharing.

swmic

Mike,

We really appreciate the time you are taking to put all this together for us!

ibdavid

Mike, thank you mucho! Good stuff.

Lorenfb

Check here ( www.systemsc.com/pictures.htm ) for additional info.

Mike J

I did not do that but there was nothing unique about the material...just black carbon. I might even be able to scrounge up some as I keep cleaning. I will see what I can get...

Cheers,

Mike

Mike J

Yup, was thinking the same thing. There looks like enough meat to enlarge the hole a bit anyways...I will certainly look at that..

Cheers,

Mike