Page 1 of 1

RC8b4 nitro kit questions

Posted: Sat Mar 08, 2025 11:39 pm
by treystoys
Figured this would be ok here, since we don’t have a designated 1/8 scale forum…I think!?!

Got a couple of quick questions about this car, but first I wanted to share the back story cause it’s pretty cool!

So a few months ago I met a younger than me guy that lives a few houses down. He happened to stop out front when my son and I were running rc cars. By chance it was when I gave my Halsey kit it’s one and only test run with all its 80s era electronics. Anyhow, he stops out front and says “hey is that an rc10?” Short of it was he had seen us running cars a few times, and he said he was also into rc cars, and had a few AE trucks that he usually ran in his backyard just messing around. So we wave now when we see each other, and we’ve talked a handful of times since. Just friendly neighbors with a hobby in common.

So I’m actually in the middle of building a pretty big wooden fast electric rc boat, and was up early today leaving to go to the hobby shop to pick up a few things. I see the neighbor and his wife, and wave as usual and drive past and then see him waving me down in the rear view. I back up a bit and see him carrying what I immediately recognize as a team associated rc buggy box. I thought cool, he wanted to show me his new toy! So he reaches the truck and we exchange pleasantries, then he says hey, would you and your son like to build this? I’m like sure, what do you want for it? He responds with “nothing, a few friends and I bought a bunch of these off eBay a few years ago, and this one’s been sitting in my trunk for almost a year” he tells me him and his wife just bought a lot in a neighboring state and between work and them building a house he just doesn't see him having time for it. I tried offering him money and he didn’t want anything, even said he had a couple other items to go with it and would bring them by later. The other items were an upgraded bearing kit, a really nice set of turnbuckles, and two bodies! I asked him again about money and joked about him forgetting how much this stuff cost, and he said no, he’d rather see us build it and see it running at some point! I thanked him and had little Trey do the same, and we picked him up a gift card for a popular local restaurant this afternoon for next time I see him.

I have to say I have never built or even run a nitro car, so this’ll be new to us. I did have a nitro boat in my 20s and a Zenoah powered larger boat, but that was the extent of my “fueled” RCs.

My question is as far as engines go, can I do something on the lower price side? I was looking at an SH engines with a pull start and tuned pipe kit, very budget priced, or I see LRP has a motor alone for in the $140 range. Both of those are pull start and I know they are considered “sport” motors, not really racing, but this car will likely only ever be run around the neighborhood. Also what types of fuel can I use? Again trying to keep the cost low, but I don’t want it to be a complete headache yet if I have to tinker with it some, I surely won’t mind.

So that’s that, I thought I’d share the story! Kind of a rare occurrence that a $600+ kit gets handed to you unexpectedly! Pretty neat! And If I hadn’t just started this boat build I maybe would put a bit more funds into the rc8, but for now, Trey and I will get to building it and see what I can do about putting together a budget power package for it. Any tips or suggestions with motors or stuff I’ll need, I’m all ears!

What I know I need…
.21 engine and tuned pipe (hope a pull start will work)
Fuel (type or percentage??)
Some extra glow plugs
A glow plug heater
Tires and wheels
Switch harness and I’m guessing a small (2s ?) lipo battery

Thanks for reading guys!!

Trey

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 1:03 am
by mtbkym01
Wow that a cool story.

The B4 is definitely a “Race” kit, and depending on the engine mount that it comes with may dictate whether a pull start engine will fit. I recommend getting the best engine you can afford, it will be a much more reliable engine, and will be less frustrating without doubt. OS XZ-B .21 or Reds R5R (Both non pull start) are great reliable engines.
Glow plugs will depend on the engine, whether it has a standard or turbo head.
For a .21, I would recommend 25% Nitro fuel, should give you a decent tuning window. Get a good brand that is available where you are located, and stick to it to minimise having to retune.
Wheels and tyres will depend on your running surface, they are generic in 1/8 so any brands will work (I like Hot Race).
A decent glow igniter is important, particularly during run it (The Mugen Seiki glow igniter is the best I’ve used in 15 years).
I would just get an extension lead rather than a switch, and plug in your 2S RX pack direct (eliminates a potential fail point).
If you do go lipo RX pack, make sure your servo’s are HV.
Always run a rubber band around your carb to act as a throttle return spring incase you ever lose battery power to reduce the chance of a run-away.

Hope I’m not telling you how to suck eggs with above advice. Enjoy the build and keep this thread updated.

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 1:11 am
by RC10th
That's pretty cool, great story !!!

Just check the instructions to make sure a pull start motor will fit.

Fuel would be 20% - 30%. The lower the nitro content the larger the tuning window, so maybe start with 20%

Tuning will change slightly from day to day depending on conditions, it even could change throughout the day if the morning is cold and damp to hot and dry later in the afternoon



Welcome to nitro :lol:

Nitro isn't all that hard, you'll either love it or hate it.

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 9:40 am
by Elkcycles
If you prefer, they are absurdly simple to convert to electric. Otherwise, I second the vote for an OS or LRP engine.

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 10:20 am
by treystoys
Thanks for all the great info guys! I thought about just converting it, but thought it would be cool to just build it as is. I think my son will appreciate it! Just hope it does t start another out of control hobby segment for us 🤣

I brought the instructions with me to work today, so at some point I’ll try and figure out if pull start is even an option. I was kind of sticker shocked with some of the .21 motor prices! But that was just what a main decided to show me as an opening search 😳 I know that LRP has a few “sport” models, I guess there are others, I will revisit that later.

I woke up this morning with a resurfaced memory lol. I did build a nitro rs4 probably 20+ years ago. It was a 2speed with a .12 or .15 race engine. I basically built it tuned it then sold it. I had a bump box for that, but it went with the car.

Thanks again guys, I’ll update as I progress with it.

Trey

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 5:13 pm
by treystoys
So there’s no specifics in the manual that says pull starter or not. I’m guessing there are decent pull start .21s or similar? Just trying to go about this as practically as possible. I see that the back of the blocks on the pull start motors have a larger flange and that one of the drive shafts can cause interference even on a standard motor, but i think it angels to the front not back. Are there other alternatives to the pull start and bump box? Like a drill attachment? Am I thinking right that one of the manufacturers used a starter similar to that? Kind of a hand held shaft starter?

Thanks guys!

Trey

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 5:24 pm
by GoMachV
Looks like lrp sells an inexpensive 3 port with pull start (amain, around $130), and they have an optional roto start for it. I'd be tempted to go that route, pull start first and if it has issues try the roto start. With the roto you should be able to clock it into a position that clears.

Re: RC8b4 nitro kit questions

Posted: Sun Mar 09, 2025 11:50 pm
by treystoys
GoMachV wrote: Sun Mar 09, 2025 5:24 pm Looks like lrp sells an inexpensive 3 port with pull start (amain, around $130), and they have an optional roto start for it. I'd be tempted to go that route, pull start first and if it has issues try the roto start. With the roto you should be able to clock it into a position that clears.
That’s the one I think I was looking at. I will do some more digging into it. Would there be a pipe preference for just running up and down the street? Or a particular type of plug? And so the roto start? Is that what I was thinking of like a drill type starter?

Re: RC8b4 nitro kit questions

Posted: Mon Mar 10, 2025 2:12 am
by GoMachV
roto start is the drill starter you are thinking of.

As far as pipe and header for that, just find a good budget RTR setup, I dont think you will find much for gains just bashing. The SH pipe combo is on backorder but should be perfect if you can find one.

Re: RC8b4 nitro kit questions

Posted: Mon Mar 10, 2025 6:57 am
by treystoys
Ok thanks, good info!