Hammerhead .21

[Hammerhead]

I finally got it wet.

If you want to see more of the developement stages of this rigger, you will have to go back a few pages in the forum to the "Hey Hammer thread"

It runs fast, and corners like a dream.

I got it broken in this weekend. Still need to get a little more speed out of it to be competitive, but I'm confident that it will be easy with a little prop and turn-fin work.

 

[TimD]

Bad link Marty.

Tim.

 

[Hammerhead]

It sure was Tim-san. I will get her fixed.

http://members.jcom.home.ne.jp/0418787901/DSC07046.JPG

Try this one!

The sponsons on this are Roadrunner sponsons. They didn't do my rigger any favors, so they are in the garbage now. I made a pair of my own sponsons, and it ran like a dream.

 

[TimD]

Hi Marty-san,

That looks beautiful! Once again you have out done yourself!

Tim-san.

 

[Hammerhead]

The picture in the link is the HH.21 with the RR sponsons.

I haven't painted the sponsons that I made, yet. I just ran them with sealer on them. Had to make sure the worked before I got crazy with the paint, you know.

The guy wants 60 bucks to paint my new sponsons to match my tub.

The new ones are just typical Hammer-Cut sponsons.

Thanks for the compliment. I will try to get a pic up with the new sponsons soon.

Hammer

 

[TimD]

Hammer-san,

Is this your first Mac? They love to rev so maybe use a little less prop than your other engines.

Tim-san.

 

[Hammerhead]

Yeah, Tim. This is my first MAC. I'm extremely satisfied with it. I am having a 1445 and a 445 worked for me right now. They are a bit smaller than the 447 that I'm using. I will give them a whirl on Sunday.

I sent some close up pics of the engine room and the transom to Wade Swatzell to have him post for me. Hopefully he will have them up soon.

I found that the MAC .21 hates it if you get the pipe even a millimeter too short.

It just stops reving up at all.

Hammer

 

[TimD]

Hammer-san,

What pipe are you using? A smaller diameter prop will help probably help with the shorter pipe too.

Tim.

 

[Hammerhead]

I'm using a Macs marine tuned pipe. I first tried the Macs normal marine pipe which has even less volume. It was worse. It might have to do with the silencer that I have on the stinger, but there is no getting around that. Rules are rules, you know.

I haven't cut the Macs marine down as short as the normal one, I think I can still get it down about 5mm more. That will bring it to 21.3 cm from the plug to the weld. Actually the Macs pipes don't have a weld mark. but to where it would be if it had one.

What do you think of the 1445. I don't know anyone who has ever used one. Do the turn well?

 

[shoboat]

Hammerhead,

That will be a GREAT PROP try cupping it from 3.2" to 3.7" max. Another

would be an H-4 pitched the same way. Pipe I would try, the AB nitro pipe

with a muffler on it. We have found this to be a GREAT PIPE. Another would

be a OPS 3280 pipe very similar.

Good Luck,

Mark Sholund

Props-4-U

 

[TimD]

The 1445 pitched up would be "the Benchmark prop!" They are good.

The symptom you describe is something I have seen with Mac's products pipes - they aren't that great set up short. A CMD pipe should be better for you.

I'm running a Novarossi in my 21 rigger so my setup varies a quite bit from yours. I'm using the low volume Mac's pipe about 12mm longer than you and I'm using a modified H10 prop (Props-4-U) with 3.6" cup. A stock 1445 with that length would see it "over-running the pipe" at 3/4 throttle or more - more prop and it stayed on pipe.

Come on MAC21 guys - give Hammer-san the right pipe / prop info!

 

[Hammerhead]

Thanks for the info Mark and Tim.

The problem for me with using another pipe, is that the only silencer that is being produced right now that will keep me in regulation with the JMPBA rules is the TRK series made in Japan. (Kind of a Monopoly) These silencers have been designed to be used exclusively with Macs pipes. If I were to use another pipe, the silencer probably wouldn't fit it. Since I live in Japan, it is really difficult to test fit before purchase. I could end up spending enough money on other pipes to build a whole rigger before I find one that works right. I don't like cutting up pipes just to make things fit, either. The TRK silencer that you will see in the picture a few posts back, is glued onto the pipe with Epoxy-Patch (LOC-TITE).

It is a perfect fit.

I will try the cup on the 1445 since I already have one.

Thanks, Hammer

 

[TimD]

Hammer-san,

What is the noise limit? Is it measured in dB?

 

[dave roach]

Hammerhead

Boat looks great. prop/ try a new abc 1714 or a 1716. I'am running a blackjack 21 with a mac and the prop is a 1716 great speed and good handling. I'am going to try a 1718. Brad chirsty The builder of the blackjack is running a mac and the 1718 prop.

 

[Scott Schneider]

Mac .21 and you say you like RPM, use the Nova rossi .21 nitro pipe at @ 8 1/8 to 8 1/4" plug to weld.

Should see @ 29 to 31K with 45 to 60% fuel and with the right prop load.

You will need to make a muffler, but that pipe is SWEET !!

Good luck. Scott

 

[shoboat]

Dave,

I hear that the 1718 is sagging a little in the corners for Brad? We have found

the 1716 to be GREAT also. If you run a Nova Rossi try a 2014 they are getting

even better performance.

Thanks,

Mark Sholund

Props-4-U

 

[wswatzell]

Hey hammer, I haven't checked my email in the past couple of days, I'll post those pics tonight for you.

As far as the silencer to pipe fit problem, what if you sent one of the silencers to someone who had a variety of pipes to test fit it on, & report back to you. If I had a bunch of different pipes, I would offer, but I only have 1 .21 pipe, & it is a Nova Rossi pipe.

 

[wswatzell]

here are the pics from Hammer

pic 1

 

[wswatzell]

pic 2

 

[Hammerhead]

Hey Tim! I tried a Stock 230 it was faster. It seems to wind out better than the 447 and it's top speed seems to be quite a bit faster. Still haven't finished working me 1445, yet. Maybe be this weekend.

Hammer