GT 750 info

[ja-moo]

Just a couple of questions from a total novice - so please be kind ! This mod then replaces the existing rubber carb mounts with three reed housings that take the place of the carb mounts - the the grinding you refer to is to the inside of the intake ? And the pistons need to be modified for it to work correctly - so something like this ?

Thanks !

Novice question are always welcome.

These kits will be for the stub mount cylinders, not the early rubber maniflod type. (As I don't have one of those cylinder banks) The stub will be removed, and yes, the inside of the intake ports are opened up for the reed cage. The cage will have a replacement stub as part of the assembly, so the stock rubber hose will fit. (the rubber tube will be needed to be shortened 3mm.)

The conversion for the MV 38mm Mikuni's will have the flange to bolt on the rubber manifold to fit the carbs.

Does that help?

[oldjapanesebikes]

Clear.

And the pistons would need to be ported - correct ? Also just for clarity - that ball-park price then, is for parts only - no machining ?

[ja-moo]

Clear.

And the pistons would need to be ported - correct ? Also just for clarity - that ball-park price then, is for parts only - no machining ?

Yes the pistons would need "holes" for full duration intake timing. I'm betting boost ports will be needed for full effect.

And yes, that's just the kit price, no machining.

[tz375]

JA, very inventive. Good one.

Let me see if I got this right: The kit will include a replacement carb mount spigot which will mount upstream of the reed assembly. Machining off teh stub and opening up the remaining port will be up to the owner? Yes/No?

And that spigot is to take a stock intake rubber to fit stock BS40 CV carbs? I guess it would also work with much larger carbs with a similar spigot size.

And the other kit will accept 38mm TM/TMX/VM/PJ PWK etc aftermarket carbs or EFI throttle bodies for anyone so inclined to do so.

That should still be easier and cheaper than a full on welded on reed box solution I suspect.

[ja-moo]

JA, very inventive. Good one.

Let me see if I got this right: The kit will include a replacement carb mount spigot which will mount upstream of the reed assembly. Machining off teh stub and opening up the remaining port will be up to the owner? Yes/No?

And that spigot is to take a stock intake rubber to fit stock BS40 CV carbs? I guess it would also work with much larger carbs with a similar spigot size.


I don't have the parts together yes, so it's difficult to explain, but I will try..... One design will have the "stock" stub as part of the casting. There will be a small sleeve that will slip a short way over the remaining extention of the intake casting and be screwed on to the hold the assembly in place. So the stock rubber intake tube slides on the reed block stub casting. The inside diameter of the stock stub and mine is about as big as you can get at 38mm. Installation is up to the customer to do, or get done, as I don't have a cylinder bank that I can actually do a time study for a installation price.


And the other kit will accept 38mm TM/TMX/VM/PJ PWK etc aftermarket carbs or EFI throttle bodies for anyone so inclined to do so.

That should still be easier and cheaper than a full on welded on reed box solution I suspect.

The other kit will have a flat flange instead of the "stub", and fits the mikuni 38mm carb manifold, so whatever carbs fits it. The kit is for hot street motors or roadracers. as huge boxes are for all out drag racing. This kit will be using a modified reed block version of my stage 2 kit for the H2's. I haven't had it dynoed yet, but I did have the assembly flow tested and the flow was good for 38mm carbs. And I would think it would be much cheaper than all the machine work and boxes and reed cages for other conversions.

[oldjapanesebikes]

I'm seriously considering this - my problem is timing as I have way too many projects backed up at the moment, and so I doubt I could realistically commit to it before next summer at the earliest. That could actually be a good thing, as I expect I will be down in your neck of the woods (somewhere around Albuqurque ?) next fall.

Not sure if this helps you JA, but put me down as qualified 'yes'.

[ja-moo]

I'm seriously considering this - my problem is timing as I have way too many projects backed up at the moment, and so I doubt I could realistically commit to it before next summer at the earliest. That could actually be a good thing, as I expect I will be down in your neck of the woods (somewhere around Albuqurque ?) next fall.

Not sure if this helps you JA, but put me down as qualified 'yes'.

Thanks, I wasn't really looking for "definate" preorders, just looking to see if there was "real" interest. I know the GT's are torquie anyway, but I know some guys like to mod them out and still want good torque. I am moving ahead on the project.

And it would be great to meet you! As long as you don't mind a "shop" house...LOL

[tz375]

JA,

FYI, earlier GT750's had much shorter intake timing (5mm difference) and were way more torquey. Later ones lost a lot below 5000. I'd speculate that your reed conversion would bring back the bottom end and allow slightly more at the top end to get a combo that's better than either.

[ja-moo]

JA,

FYI, earlier GT750's had much shorter intake timing (5mm difference) and were way more torquey. Later ones lost a lot below 5000. I'd speculate that your reed conversion would bring back the bottom end and allow slightly more at the top end to get a combo that's better than either.

I noticed that between the 2 cylinder banks I have. The late cylinders will need the bottom of the port lowered to the earlier spec. And yes, the more intake timing (power) the more loss (power) from reversion in the intake track.

I have an old customer with a stock H2 (nice torque) that wanted to try the reeds to stop the surging the H2's have. I sent the kit out and didn't hear from him again. So I called a few months later and asked how things worked out. He said he now calls it his "diesel"...... As he said, when he rides, it's at least 300 miles, so he likes it a bit calmer on the freeway. He went from the stock gearing of 15/47 (3.133) to 16/42 (2.625) and was thinking of going to a 40 rear. He said (of course) it wasn't as peppy, but ran fine on the freeway and take off was good.

So I'm thinking the GT's would do the same, and with porting, be a very fun bike.

[wbm]

Hello

Nice topic ... Reed Valve Reconstruction

Apart from the holes in the piston, piston skirt back.
Does anyone have holes through the inlet (intake port) into the crankcase, crank chamber?

Power Porting with Reed Valve is one thing, the other 360° Intact

Greetings Thomas

[Suzukidave]

Hello

Nice topic ... Reed Valve Reconstruction

Apart from the holes in the piston, piston skirt back.
Does anyone have holes through the inlet (intake port) into the crankcase, crank chamber?

Power Porting with Reed Valve is one thing, the other 360° Intact

Greetings Thomas

[wbm]

Hello

Very good work ....

How long skirt (length piston rear) on the back. If the holes, holes in the crankcase always open?

If there are more pictures to barrel (cylinder)

Edit:

Another example from www. it is von your....Suzukidave.
I just noticed the picture is you, too, had I loaded from the Internet. Do you have the cylinder completely built?

http://draken.gotdns.com/Suzukidave/Bre ... lport1.JPG" onclick="window.open(this.href);return false;

Is this your work....

http://draken.gotdns.com/Suzukidave/Bre ... arrell.jpg" onclick="window.open(this.href);return false;

Greetings Thomas

[Suzukidave]

The two links you posted are not my cylinder but a GT750 based ~1000cc land speed record holder in Australia

[wbm]

Hello Dave
Have YOU also pictures of the pistons?

Greeting Thomas

Hello

Nice topic ... Reed Valve Reconstruction

Apart from the holes in the piston, piston skirt back.
Does anyone have holes through the inlet (intake port) into the crankcase, crank chamber?

Power Porting with Reed Valve is one thing, the other 360° Intact

Greetings Thomas

[tz375]

Dave, with those lower ports, how much of the time are the intakes actually closed? I remember the discussions about AG Bell's suggestion that power porting plus reeds made for more power than straight 360 degree reeds. Presumably those ports make them almost 360 duration.