RE: engine converstion help. need real tech help
the engine displacement is the swept volume of the piston in the cylinder, from the bottom to the top of it's travel, it is a simple calculation using the diameter of the piston and the length of the stroke (distance from the top to the bottom of the piston stroke)
Posted on: 11/17/2009 8:21 PM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9261320

RE: No more neoprene in my tanks!
I would imagine that they force flow the filters or wash the felt very well before they release them for production, I'm sure there are exceptions to this
Posted on: 11/3/2009 3:46 PM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9225559

RE: optional fuel pulse port on walbro
[quote]ORIGINAL: Super08 If you still have the old carb just take the cover off of it and install it on the new carb. [/quote] exactly what I was just going to post, it's all of 1 screw...
Posted on: 11/2/2009 12:58 AM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9221735

RE: WD40 as after run oil?
hobbico ARO is marvel mystery oil, which is ATF plus a couple things...
Posted on: 11/1/2009 8:51 PM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9221190

RE: A PISTON QUESTION
looks to me like they polished it...
Posted on: 11/1/2009 3:23 PM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9220464

RE: small gasser
dug a bit further into the 13cc engine, figured out the reason it didn't run for the previous owner is the external pulse line was cracked, easy enough this thing is a pig weight wise with stock ignition, 3lb 10 oz without a prop adapter! will trim it further to get rid of all ignition related components and trim rear crank stub. estimate of about 2.5lb on gas/glow on an external comparison it is identical to the 16cc, so the 16 is probably a bored version (or the other way around) which would make the 16 about an ounce lighter, the 16cc is .1" bigger bore and no bar in the exhaust port (similar to the difference between a homie 25 and 30), exhaust pattern is the same wierd offset thing, same muffler, the 13 has a wierd 45* intake adapter thing which is why it has the external pulse, will get pics up later.
Posted on: 11/1/2009 2:50 PM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9220399

RE: servo help
yeah, I'd say either that or 3mm which would be easier to find...
Posted on: 11/1/2009 11:29 AM by Author "rangerfredbob" in the forum "Speed - RC Gas Boats"
http://www.rcuniverse.com/forum/fb.asp?m=9219968

RE: small gasser
just acquired a 13cc echo engine, it's set up with a point so it isn't very new... I'll see how light I can get this thing... probably get on that tomorrow. it looks just like the 16cc but with a 1" bore and a 1.01" stroke, it's downfall is probably the bar in the exhaust port
Posted on: 11/1/2009 12:42 AM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9219117

RE: T-Maxx help
the 3.3 will DESTROY the stock driveshafts (would require a bunch more money to upgrade all of the stuff to handle the engine), if you are new to RC, get something easier to put in than doing a conversion, the OS .18 CV RX-S is by far the easiest engine that's more power to install in a pro .15 maxx, $120 on Tower Hobbies right now, about the same power as a 2.5, really wakes up the maxx... the OS is easier to tune than a 2.5 and will hold it a lot longer, comes with a nice air filter too
Posted on: 10/31/2009 11:24 PM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9218952

RE: what is this any ideas
on the carb, the cover with the 4 screws, take that off and see if the diaphragm under it is pliable or hard and stiff, it's it's pliable it should run, if hard get a rebuild kit D20WAT or K20WAT at a small engine shop. before trying to start it I would take the spark plug out and give a shot of WD40 or something into the hole then go ahead and try to start it up.
Posted on: 10/31/2009 11:05 PM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9218915

RE: what is this any ideas
looks like a conversion with all those rough cuts. with the green housing in the back I was thinking the old green machine 25cc ish engines, then I went out in the garage and looked at mine and it's a 3 bolt starter housing with the ignition on the prop side...
Posted on: 10/31/2009 1:02 PM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9217688

RE: DA engine ignition unit
[url=http://www.rcuniverse.com/market/item.cfm?itemId=565152]THIS[/url] should work too, might have to change a couple things but I'm not sure
Posted on: 10/31/2009 11:52 AM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9217542

RE: small gasser
got the 18cc together and it is 3lb 1oz on mag itnition, that is everything including exhaust and prop, I believe the echo 16cc will be heavier (has a secondary coil) but will trim it down to see, and the stihl was 2 lb 10oz set up for gas/glow (mag wasn't possible with it's setup). if the mag is too heavy, I have 4 RC EXL ignition modules on their way to me :), or just go gas/glow, I believe I'll have better luck with gas/glow on one of these smaller engines than my modified 32cc mac I tried before. I know I had a 18cc set up on gas/glow before (cylinder was shot) that was at a flat 2 lb set up on gas/glow which is lighter than an RCGF 20cc on CDI, but still a lot heavier than the RCGF 15cc (but I like the $7 price I have into this engine better than the $230 for either of the previously mentioned engines) I'm only about 200' ASL so performance is about as good as it gets
Posted on: 10/30/2009 1:25 PM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9215216

RE: Walbro carburetor compatibility.
I make my own out of gasket material from the auto parts store, it's $3 for enough material for a couple hundred carb gaskets... most of the time I can just reuse the gasket that came on the engines I'm working on
Posted on: 10/29/2009 1:38 PM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9212418

RE: Walbro carburetor compatibility.
all walbro carbs use the same 2 bolt mounting pattern for all of their carbs up to around 100cc I believe, there might be a slight difference in the location of the pulse port in the carb but I don't think that's on very many of them. I have around 30 weedeaters and chainsaws ranging from 16cc to 55cc and they all have the same pattern
Posted on: 10/29/2009 3:42 AM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9211531

RE: Homie differences
ended up with another homie 25 with the one piece crank, this one is on a curved shaft no clutch, the fan/starter schroud is different from any I've seen, instead of the 1" spark plug guard, this one is about 2", the bottom of the schroud protrudes down so when you rest the thing on the ground it rests on that instead of the fuel tank, has a plastic back plate with a steel heat shield over the plastic sheld. Subtle but different.
Posted on: 10/29/2009 2:49 AM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9211490

RE: small gasser
ok, bringing this back up from the dead... got the USL up and going better (well, haven't taken it up since I kinda broke it, full span ailerons at full travel are VERY TOUCHY!!! lesson learned), on EI, I had it good and programmed a few months ago with air brakes, flaps and dual rates then accidently deleted the program (wanted to kick myself), haven't figured out how I programmed it again but got it functional now, will hopefully take it out on sunday if it doesn't rain... got to thinking again and want something smaller for ease of transportation, and just because I want to do it... I'm looking at the 40 size ultra easy stick that's on ebay right now for about $75 shipped for the ARF, going to watch them and see if I can get one for cheaper. they have a bit over 600 inch wing area but I figure with the right setup and a really light engine it could be done for the engine I'm thinking either the 18cc poulan, the 16cc echo, or the 19cc stihl. The poulan is easy and I have 3 of them (one already 95% converted), but am going to try to get all set up so I can judge their weights as I figure any of them would have enough power. I'm going to try to get a serious engine conversion operation going on over the winter, I have a bunch of engines and could use some spare cash for my projects, see if I can get some of the people I fly with into flying gas conversions for cheap...
Posted on: 10/29/2009 2:38 AM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9211485

RE: Walbro carburetor compatibility.
pretty much any walbro will bolt to the engine, biggest thing to look for is one with the same venturi diameter, there's a list of carb sizes with part numbers around here somewhere...
Posted on: 10/29/2009 2:15 AM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9211464

RE: Killed rear diff on my maxx?
if you broke one stock one, you'll break another. I would suggest getting an aluminum diff cup with ring gear that has 3mm screws instead of the stock 2mm, Kimborough used to make one that was fairly cheap (like $20 for the cup and $10 for the ring gear) but that apparently isn't around anymore... I did a quick googlel search and found other options for around $45...
Posted on: 10/26/2009 9:03 PM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9204475

RE: Walbro carb tuning problem
ok, I'm assuming you started with 1.5 turns out on both needles, and did this start out as a new chainsaw or a used one? did it run before you converted it? it kinda sounds like you have the needles unbalanced being that far off, the low speed passage could be plugged. this topic would be better suited for the engine conversions forum, but since I'm here I'll help if I can Chainsaw carbs are generally sized very well for airplane use. if you hadn't already done so, adjust both needles to 1.5 turns out from stop, if that doesn't work, try 2 turns out. according to walbro you are supposed to tune the high end first and work your way down in engine speed. If you are still having issues, your fuel pressure could be too high, under the cover on the carb with 4 screws is a little lever, bend that down just a little ( like .005") and that should help.
Posted on: 10/26/2009 3:56 PM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9203620

RE: up grading pro .15 t maxxs
get a kimborgh aluminum diff cup or however it's spelled (google it), that way you can properly shim the spider gears (get a new $9 diff rebuild kit too). the diff cup is an aluminum version of the stock piece that uses bigger screws for the ring gear and will be more rigid to take more abuse. I have one in my maxx, but haven't abused it enough yet
Posted on: 10/23/2009 10:40 AM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9195823

RE: t maxx diff input yokes don't fit
yeah, that part is always a pain in the rear... take a file or something and remove a bit of material that goes against the bearings, that should help. I think only the 3.3 diffs are any different than the older ones, pro .15 and 2.5 diffs are all the same (apart from softer ring gears on very early pro .15 maxxes)
Posted on: 10/21/2009 11:10 PM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9192388

RE: HOLY MOTHER OF..i never saw nutn like dis
Helical gears are stronger, they most likely use straight cut gears in racing because there are no thrust forces involved in straight cut gears, and racing uses custom ratios, and straight cut gears are MUCH easier to machine (think about it). Helical gears are used on cars because they are stronger and quieter, more contact time on each tooth, most cheap cars use straight cut gears in reverse (if you stand around in a parking lot, you can hear the winding noise they make) because they are cheaper, no one drives in reverse long enough to complain about the noise. the reason that broke was probably a combination of that bent shaft and the design of the gear, all of those lightening holes in the ring cause areas for stress concentration (places to break), that and the large distance between mounting holes. Helical gears have side loads due to their design, put a lot of torque against them and they will push to the side pretty hard, throw in another issue like the bent shaft and things can go bad... it probably wouldn't have broken if the gear adapter piece was a full circle instead of a cross.
Posted on: 10/21/2009 8:54 PM by Author "rangerfredbob" in the forum "RC Giant Scale Cars"
http://www.rcuniverse.com/forum/fb.asp?m=9192014

RE: Rowena - Dolmar 60CC?
it should have the same bolt pattern as most other carbs, what's the venturi diameter? I might have something in my parts drawr I'd give ya for cheap... I have some old Tillotsons with very large venturis compared to most conversion engines I do...
Posted on: 10/21/2009 3:37 PM by Author "rangerfredbob" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=9191286

RE: up grading pro .15 t maxxs
the cheapest driveline upgrade for the pro .15 maxxes is the old style 2.5 drivelines, they are nearly twice as beefy as the old pro .15 ones, going to the 3.3 shafts requires more parts... pretty much anything for any of them will fit on yours other than the transmission from the 3.3 maxxes and the axle carriers everything is interchangable. if you are wanting them to be more stable, get the new suspension arms and turnbuckles the TZ engine you mention is a rear exhaust slide carb, which would mean a different exhaust pipe and a throttle linkage conversion, just to warn you, the CV RX you put on the other one is about the easiest swap you can do...
Posted on: 10/20/2009 11:00 PM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9189743

RE: Easy Vee Trials
hobbytown's never know much about anything that line is a return to the fuel tank, the vent line is different, that is the one you want to go to the film canister
Posted on: 10/18/2009 11:38 AM by Author "rangerfredbob" in the forum "Speed - RC Gas Boats"
http://www.rcuniverse.com/forum/fb.asp?m=9182664

RE: firewall mounted servos
if you really feel the need to use the ring type coils, radio shack has them as transformers in a pack for about $10 for a handful of them you just have to remove the wire from them... I did that to get rid of a little RFI from using one digital servo in the tail... it helped a little, but reworking the throttle linkage did more...
Posted on: 10/15/2009 1:40 AM by Author "rangerfredbob" in the forum "Gas Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9174546

RE: New to nitro Need Help !!!
a few more notes, there isn't exactly a neutral setting, the centrifugal clutch on the engine allows the engine to idle without the truck moving. You are correct, with the throttle moving past the neutral position the brake is applied, there is also a possibility that the throttle trim on the transmitter needs to be adjusted, adjust it to a point where the engine is at idle and the brake isn't applied. The idle should be adjusted to a point at which the engine idles reliably and the clutch isn't engaged. There is a idle adjustment screw on the carburetor that just moves the throttle barrel position at idle, the other two are mixture adjustments.
Posted on: 10/12/2009 1:50 AM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9165753

RE: New to nitro Need Help !!!
it sounds like the clutch spring has broken assuming the idle is as low as you can get it. go to traxxas.com and look for the parts breakdown for your model, the clutch and transmission should be the same on pretty much any nitro stampede, but they have the manuals for all of their models new and old.
Posted on: 10/11/2009 10:58 PM by Author "rangerfredbob" in the forum "Traxxas Monster Truck forum"
http://www.rcuniverse.com/forum/fb.asp?m=9165366

RE: winter storage for engines
is it an attached garage? if so, shouldn't be an issue, fuel might even be ok next seaason (but you could mix it in to your cars gas tank in small doses to get rid of it) tygon fuel tubing is known for hardening if left out of fuel, same with carb diaphragms, stick some stabilizer in the fuel, run it enough to get it in the carb and leave it with half a tank, should handle fine, that's more than most people do for their chainsaws and weedeaters.
Posted on: 10/11/2009 9:24 PM by Author "rangerfredbob" in the forum "Speed - RC Gas Boats"
http://www.rcuniverse.com/forum/fb.asp?m=9165035