Ahoy, a match to port

[Philthy]

Before I bolt my intake back together, does anyone have any advice on gasket matching the intake and the head? Is it worth it in a motor that will probably not see anything more than an exhaust/catless y-pipe and maybe a bigger throttle body?

Since the valve covers are off, it'll be super easy to make sure the valves are closed, but I'll still use the play-dough trick to keep the poo out and tape over the ports I'm not working on.

Also, what are the horns in the intake? Several people have said to remove them, but I can't imagine Yamaha had several thousand extra horns laying around and decided the best way to get rid of them was to put six in each of our motors.

And finally, any thoughts on polishing and gasket matching the exhaust ports. Shine those babies up so the exhaust flows all smoth and fast.

 

[Off Road SHO]

Before I bolt my intake back together, does anyone have any advice on gasket matching the intake and the head? Is it worth it in a motor that will probably not see anything more than an exhaust/catless y-pipe and maybe a bigger throttle body?

Since the valve covers are off, it'll be super easy to make sure the valves are closed, but I'll still use the play-dough trick to keep the poo out and tape over the ports I'm not working on.

Also, what are the horns in the intake? Several people have said to remove them, but I can't imagine Yamaha had several thousand extra horns laying around and decided the best way to get rid of them was to put six in each of our motors.

And finally, any thoughts on polishing and gasket matching the exhaust ports. Shine those babies up so the exhaust flows all smoth and fast.

Troy,

Personally I don't think all of that is worth it in the scenario you describe.

The horns are inside the side tanks of the plenum. They act as velocity stacks with the rolled edge about 3/4" away from the flat side of the tanks. Smooth laminar air flow is a good thing in a normally aspirated motor, but the horns become a hindrance under forced induction.

Tom

BTW, are you a proud papa yet?

 

[Philthy]

Not yet, but in the next couple days. We just got back from an ultra-sound and the baby measured kinda big sooo, we think she will be induced either tomorrow or Friday, but we haven't heard for sure from the doctor yet. My Grandma and sister were both born on the 6th though, so I woulnd't be surprised if it was this Saturday.

 

[Rav]

Troy,

Personally I don't think all of that is worth it in the scenario you describe.

I think that it's worth it. You get a big hammer and whack it. Or was that when you change a clutch?

Rav.

 

[nik97]

Troy, I just gasket matched my heads/runners and ported the runners a bit on Monday(I was bored). I can tell you that it was well worth it and I noticed a difference. I would do it especially since you already have the motor out and the intake off. Here's how I kept the shavings out of the chambers: cut a shop rag into 6 equal pieces. Take two pieces and stuff them down the port and over the valves. Pour a but of motor oil on them just enough to saturate them. Then, stuff two more rag segments in and pour oil on them. Do this till' you have all 6 oiled up segments in the port(s) for each chamber. Then, lightly bolt down the gasket over the port you are working on using the bolts that hold the crossover section of the intake on. Go to work with the dremel and match the port to the gasket and carry the opening down about 1.5". After you've done all six ports, remove the rag segments slowly. Remove one segment at a time and stick a vacuum cleaner in the port after each removal to suck up the excess shavings not stuck to the oily rags. By the time you get to the rags at the bottom of the port, there should really be no shavings.
Now do the runners. I didn't use rags on the runners since I could just wash them out afterwards. Make sure you use the same corresponding gasket(bank) and glue it down so it's evenly matched to the locating pin holes(you should be able to tell roughly from the carbon buildup where the gasket goes). I removed a pretty good amount of material about 3" deep into the runner and smoothed it out a bit.

I would polish the exhaust ports for sure! Might as well, it's free and the motor is at you convenience. I'm all about the free or next to free mods(also known as Dooleyville mods ).

 

[Philthy]

Cough, ack, spit...

Mkay, intake is now gasket matched. Basically, I'm not sure it was worth it (of course, the motor is still not back together yet) but here's what I found, at least on my motor.

1. It's a LOT of work, even with the motor out and on a stand. The head is made of some sort of super unobtainium aluminum that takes a lot of sanding wheels to work through, about 1.5 per cylinder. The intake is made out of cheerios by comparison.

2. Aluminum dust gets everywhere. Especially in your nose. This does not impress the ladies. I used Nik's rag trick, well, actually, underwear I was gonna throw away, but whatever. Since my valve covers were off, I made sure the valve was closed, then bolted on the valve cover, duck taped up all the holes and other cylinder's runners, inserted the oily underwear (gross) and then made a little play-dough plug. I screwed down the old gasket and got to Dremeling. Cleaned it up with some compressed air and then repeted 5 times.

3. On the intake, the primaries can be opened up quite a bit. The secondaries all already matched pretty close. On the heads, both ports could be opened up significantly. I think the heads presented the restriction, so maybe this will end up worthwhile.

Anyway, it ended up costing me some oil, 3 pair of underwear, 11 sanding drums and a few feet of duck tape. Let's hope it was worth it.

 

[nik97]

I'm convinced that it was well worth it. Since you haven't driven the car in a while it may be hard to observe a difference from how you remember it. Needless to say, it should run like a champ for sure.

 

[Philthy]

Yesterday I finally got back out to the garage for a bit and found a few more places that could use some matching. Between the primary runners and the, um, big air-holding tank thingus whose name I forgot because I am sleep deprived is a port that can use some clean up. There is not a lot that can be done to the secondaries because the butterflies and rubber hoses do most of the connections. Anyway, I've got another pack of sanding drums and if the little one decides to sleep, I'll get back on it.