Kasama upgrade header for Hatori .90 series pipes

[jsenicka]

Quick write up on a very nice piece of Kasama kit. I run Hatori pipes on my OS91 engines. Love the power the SB18L makes on the CSPEC and SZ. Not so happy how easy it is to strip out the threads on the floating head mount.

When I was last in Grand RC a few weeks back picking up the second Kasama Srimok head for my #2 Raptor 90, Ed mentioned Kasama was coming out with a replacement header for the SB-16, 17, 18, 19 series pipes. Since I had a header with 2 stripped bolts on my R90SE, I asked him to order me one.

I got the first unit Grand RC received from Kasama this past Friday and it is cool!!!

Overall nice machining. Looks to be a bit lighter than the stock unit.

http://www.helifreak.com/attachment.php?attachmentid=49321&d=1211848538

The unit is intended to have the mounting bolts for the can brought in from the back and locked with red locktite, and then use M3 locknuts to secure the can itself.
http://www.helifreak.com/attachment.php?attachmentid=49322&d=1211848538

The coolest part is how well ported the exhaust inlet is as compared to stock. You can also see how the back is milled down a bit to allow clearance for the M3 bolts to come in from the rear.

http://www.helifreak.com/attachment.php?attachmentid=49323&d=1211848538

These units should be in stock at Grand RC next week! I hope to have mine installed late this week in time for the Helis Over Tidewater event next weekend and will update how it effects performance.

[jsenicka]

Available now

OS
http://www.grandrc.com/inc/sdetail/136618

YS

http://www.grandrc.com/inc/sdetail/136619

[jblanch999]

I've gotta ask if you made the trip from Virginia to the bay area only to visit GrandRC? I have to say that it would make sense, I think it's possible Ed has about the best selection in the cali, I don't know about the country. . . Maybe though.

He definately needs a bigger shop.

[DavidH]

The Kasama header will result in torque loss.
Mr. Hatori makes the opening in the header the size it is for a reason. If you measure the opening in a stock header, it is the same size as the exhaust opening.
I have used Hatori exhausts for nearly 20 years. I have modified headers the same way Kasama did as for the opening. I have tested them side by side. All in all, I have found the stock header and opening always performed the best.

Here is a post from another person. So you can see that I am not the only one that has achieved the loss of torque.
Quote
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The hatori manifold matches the exhaust port on the engine,the Kasama doesnt.
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This is not correct. The Kasama looks like its port matched. The hatori 19 has been tuned with the stock exhaust port that appears smaller than the engine port.

If you enlarge the stock port you will loose a lot of torque and hence the value of the 19. I did back to back flight testing with a stock header versus a modified (ported) header and the power/torque loss was noticeable.

Charles


David

[jsenicka]

jblanch999, I live in VA, but work for a company based in the Bay area. I am in the Mountain View area every few weeks and can usually miss lunch to feed my habits. The customer service at Grand RC has pretty much made it my "local hobby shop"

David H, I do not have a 91SR to test, or any SB19 pipes. The unit pictured is for the OS engines (assuming SB17, SB18 or SB18L pipe). Major difference in exhaust port layout between the OS and YS. I plan to fly side by side on one of my two ships with SZ power and see if I get any gain or loss.

As of right now I have not tested, so I can only comment that I think the mounting is far better.

[DavidH]

I have tried the stock header and modified header side by side on OS engines. The modified header had less torque than the stock header. The engines need a certain amount of back pressure to perform at there best.

David

[Ivan]

Haha. I made a backing plate for he stock header which has more meat for the threads. I asked if something like this would be feasible, since I could make them and sell them for less than half the cost of a new header, and the bowyz at runryder told me I was stupid for mentioning it since no one ever strpis those threads out.

I guess since tis part has a Japanese name on it it will be a great idea and people will start stripping out their threads just to have a reason to buy it. go figure.