GT750 reed intake idea's

[Buffalo-guy]

Makes sense to me Kris. All too easy to distort aluminum with welding heat. I have a friend who is an aircraft welder and machinist by trade who I have convinced to help me with this madness. Did I see some horsepower hiding in that cool reed block? Either way, your expertise in this kind of thing is far beyond most, so your take on it is good enough for me. Maybe some of the others has an idea. Thanks, and cheers.
Fred

[durgam]

Ill put as large as a chamfer as I can around the outer profile. This will lessen the amount of heat needed to get a good weld.

Im worried that the plate will be a bit large for the limted space we have. I would like to see the 12 degree angle made into the plate. This will shrink to size of the 'Mouth' of the box significantly.
Anyways, Richard, or if anybody else is ready to mock this up on a motro to check fitment, it will be ready shortly.

[two-stroke-brit]

nice going dugram, i am watching this thread with great interest.
mark

[tz375]

Kris, you are right that the hole should be at 12 degrees to match the manifolds/reed boxes.

I can do a mock up on this set of machined barrels on the bench and confirm sizes etc.

[tz375]

Kris, I managed to miss the point you were making and it only just sunk in. Yes that is a good idea to change the design to build the 12 degrees into the plate rather than the box.

That would also potentially make the box suitable for an H2 Kawasaki and that improves the return on investment.

I wander if it's possible to machine the block at 12 degrees and go from there. I'll have a look at that possibility

[Suzsmokeyallan]

Hi Kris, thats looking closer to the end product for sure and I know how the time can go by with other commitments.
BTW how about making the front of the block also with a bolt on flange and an o ring groove for sealing. Doing this would mean you only need a plate welded onto the cylinder block and drilling the holes to match the pattern on the blocks you made.

[tz375]

Allan, that is the design - the reed box bolts to an adapter plate which is welded to the back of the cylinder block. Is that what you are asking or were you suggesting something different?

[tz375]

I needed a break yesterday so I played with some more numbers on reeds. The picture that appears to be emerging is that with any "normal" level of tune, the Arctic Cat reeds are almost a match for the much larger Polaris reeds and in the real world, I suspect they may be better.

At more extreme levels of tune with welded and machine transfers huge boost ports etc fat pipes and >140HP, the larger reeds appear to come into their own.

Of course this is all theoretical and would need way too many tests to substantiate, but the bottom line is that Arctic Cat reeds should be capable of supporting all the power a GT motor can possibly make.

Now we need to get back to the v2.0 design

[Suzsmokeyallan]

No Richard i meant external bolt flanges incorporated onto the frontal edge of the reed box. This way once the plate is welded to the cylinder block you simply align the boxes into their final location and drill and tap the plate, then screw the boxes on from the outside.

[tz375]

Allan,

Something is getting lost in translation. the boxes bolt up from outside on the lower surface and from the inside on the upper surface. the uppers are on the inside because the angle of the boxes makes it difficult to have screws on the outside.

The flange approach already requires a much deeper cut into the water jacket than a weld on approach increasing the probability of water leaks into the intakes.

I'm guessing that your mind may be creating a mental image that mine isn't capturing.

[Suzukidave]

Last post to this thread was in July.. has anything happened after the last post in July ?

[water cooled]

I learned that you can get a GT750 to 120 RWHP without reeds.....

[Suzukidave]

And a big thumbs up to you too Kevin but the reed intake setup really shines in a road race or super street motor that other wise would loose the bottom end due to intake porting .

[water cooled]

Hi Dave,

I understand....I guess I was just being a wise-ass! I suspect I will need a reed motor sooner or later. I might have to start with a different block though. Im not sure yet. Most of the fastest H2's have a reeds setup.

[Suzukidave]

I guess it will be great when Kris runs his reed motor so we can see if all this work pays off .. I figured you already knew about the reed benefits but i thought i would add that for the guys following along as i see this topic has 6000+ views