SAP-180HP pattern K.I.S.S. cookbook


Lou K, this is a good suggestion.

I will make this post a repository for info related to the KISS set-up using standard pump gas, APC props and readily available components for an off-the-shelf powerplant for pattern that anybody can copy and get excellent results. I will occasionally update, edit, add links, etc.

1) [link=http://www.syssaaircraft.com/cart/pc/viewCategories.asp?idCategory=11]SAP-180HP engine[/link], 89 octane pump gas (10% ethanol), [link=http://www.syntheticoildistributor.com/amsoil_2cycle_oil.html]AMSoil Saber Pro[/link] 85:1 (after break-in with dino oil)

2) [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXZ646&P=7]Macs tuned pipe header for OS 1.40RX[/link], available from Tower Hobbies

3) [link=http://www.escomposites.com/petrol.htm]ES 30G tuned pipe[/link]from escomposites.com

4) [link=http://www.siliconehose.com/commerce/ccp11370-870id4-ply-silicone-saej20-compliantgl-c40-087.htm]Silicone turbo hose[/link] from siliconehose.com, 0.870" ID, rated SAE J20 R1, for the coupler, and also Matt (MTK) has had great success with his [link=http://www.mcmaster.com/#5033k43/=7gklvt]Teflon tube coupler[/link] material from McMaster-Carr. Use standard nylon zip ties to secure the silicone turbo hose, and [link=http://www.mcmaster.com/#spring-hose-clamps/=7gloj1]wide-band spring hose clamps[/link] (Part # 7329K15) for securing the Teflon tube.

5) Use a [link=http://www.rcuniverse.com/forum/m_9237216/anchors_9687199/mpage_31/key_/anchor/tm.htm#9687199]1-inch long piece of 0.875" OD aluminum tube[/link] as a spacer between the header and the pipe to minimize direct exposure of the turbo hose to exhaust gases

6) Place [link=http://www.rcuniverse.com/forum/fb.asp?m=9694367]3 or 4 buttonhead screws[/link] near the end of the header and the ES pipe to prevent the hose from sliding off. A couple of zip ties on each end will secure it solidly.

7) The engine can be hard mounted, but for pattern you will probably want to use a [link=http://www.rcuniverse.com/forum/fb.asp?m=9393393]soft 'isolator' mount[/link], making your own as described in [link=http://www.rcuniverse.com/forum/m_6285026/tm.htm]this thread[/link] by MTK. I'm fairly certain that Merle Hyde would be happy to make a soft mount, using the stand-off bolt template supplied with the engine.

8) [link=http://www.rcuniverse.com/forum/fb.asp?m=9607516]Nose ring[/link] and [link=http://www.rcuniverse.com/forum/fb.asp?m=9599410]Static nipple[/link] on the carb ambient pressure reference plate. Eliminates inconsistent engine runs caused by pressure changes inside the cowl.

9) [link=http://www.apcprop.com/ProductDetails.asp?ProductCode=LP15512W]APC 15.5x12W prop[/link] (break-in with something with less pitch). I have tried a bunch of props and there is something magical about this prop with this set-up. The standard APC 16x12 pattern is almost as good, and an acceptable substitue if you can't get the 15.5x12W, which I got from Gravesrc.com

Matt (MTK) is working on some other fuel blends/timing/custom-made prop combinations, but the recipe presented above is proving to be a superb set-up that will work very well for anyone with a pattern-legal (sub 5kg) airframe. Matt is also using a Teflon PTFE exhaust coupler to test its durability and longevity.

Also recommended (to keep things light) is a [link=http://www.syssaaircraft.com/cart/pc/viewPrd.asp?idproduct=35&idcategory=11]Syssa (Tech-Aero) Ultra IBEC[/link] , which eliminates the need for a separate igntion battery and switch, saving about 5 ounces of weight (HUGE!), as well as optical kill switch, all controlled from the Tx. I am also using a [link=http://www.tech-aero.net/plr5-i]Tech-Aero Designs switch/regulator[/link] for the Rx, with a Fromeco Li-Ion 2600 mah, but with the proliferation of LiFe batteries one could use one of these with no regulator. I like the Tech-Aero reg because it has a fail-on switch, so even with a LiFe I might use the Tech-Aero switch/reg for this feature alone.

It seems pretty simple now, but it took a lot of help from Matt, Ed and a few other guys here (including our man from The Land Down Under, Rendegade) to digest, test, distill and finally sort out all of this information to end up with a bulletproof combination.