987982

look at this pic. I know Hot bodies and HPI are sister companies and they share parts and crap, and the 21bb (savage engine) is used in the Hot Bodies lightning buggy.

Well, The HB dirt demon is supposed to have a .26 engine, right? Well someone on ebay is sselling them, and it is advertised as a .26 engine, but in the pic, it looks EXCACTLY liek the HPI 21bb engine! And another thing, most engines say "3.5" on the side, indicating the CC's. .21's are 3.5 cc's, so shouldnt a .26 be like 4cc's or something? look at this pic of the HB engine. it says 3.5 right on it!!!!! The heat sink looks the same as the 21bb too, but it says 26 on it instead. I have a bad feeling about this. could it be a rip off? i will never buy that truck if it has that crappy engine in it!

Whats the deal

987982

double post my bad

Ledgendary

My Ofna has the 3.5 on the side as well and it is the .25 so go figure! I think they just used the same crank cases on them??

987982

but wouldnt a .26 need a bigger case than a .21 because of the bigger sleeve?

NitroHolmes

Not necessarily, as long as there's enough room in the case for either sleeve the manufacturer could use the same case for both. It's a cost saver for them, it's not cheap to tool up a production line to make a totally different case so they design it to work for multiple applications. The .26(which has a 4.26 cc displacement by the way) only requires the manufacturer to use a different sleeve. Take a look at the attached pic for example, it's not pretty, but it gets the point across....Both blocks(red) have the sime ID hole bored in them. The smaller displacement engine would use the sleeve(blue) with the smaller ID, the larger engine uses the sleeve with the larger ID. The end result is that the only parts that the manufacturer has to make differently are the piston and the sleeve....that costs a whole lot less than making a whole new engine! Now keep in mind that I'm only speculating here, it very well may be that the guy on E-bay is a crook.....

Easy rider

I don't thinck it's the SAVAGE BB .21 engine!! A lot of engines from different brands look the same.

I once took apart a DELTA FORCE .21 5 port and it looked just te same, both outer and inner part, BUT ...... the HUGE difference was the connecting rod and inner cranc case. The delta force engine has a better (thicker) and more tuned connecting rod then the BB .21 hpi engine. And I know from experience that the flaw of the BB.21 is a bad connecting rod !!

So, don't jump to conclusoins when saying the two engines are the same.

Just my 5 cents.

david.

caseyddr

My Feedback: (13)

he didnt jump to a conclusion, he asked a simple question about something he spotted and didn't know about. And i happen to agree with him that the bb.21 is NOT a very good engine at all.

NitroHolmes

Ah....that last post made me think of something....the cases and sleeves may be identical in the .21 and .26. A longer conn-rod and greater offset on the crankshaft would also yield more displacement. So there's not really any way to tell unless you take the thing apart...

987982

So basically it could be a 21 bb with a different conn rod? Would that improve peformance at all?

NitroHolmes

what I'm saying is it could be either a .21 or a .26. The manufacturer could use the exact same external components on both engines. I don't know for sure if they do or not so I can't tell you for certain what the e-bay guy has......I'm just telling you that it's a possibility it could be either and you can't necessarily determine which one it is by the number cast into the case. Many times, a manufacturer will make a mold with numbers in it that become obsolete later.

Easy rider

Yep,

Go buy the DIRT DEMON and take apart the engine.
That's the only way to know for sure because the same engine case can be used on different engines.
for example BB .21 and force .21 and now also the dirt demon .26.

Not the cheapest way to find out , but the only way I thinck.

david.

1stPlaceRace

All they are doing is boring the case out a little more to fit a larger sleeve and piston. O.S. uses the same size case size in the cv.12 and cv.15, Ofna does the same with the force.12 and force.15 and even the saturn .17 they made for a while. I have discussed this a little bit with a guy who does custom engines for some top club racers in So Cal. I had a os cz .12 done by him 6 years ago and it was super fast, I dont know where he is anymore, when I met him he was a mechanic for team kawisaki's supercross racing team. He told me the only disadvatage of the larger piston and sleeve was a slight dropoff in durability. (fewer rebuilds do to case warping over time)

Cal-Torque

Just FYI The guy selling the Demons on ebay is the owner of www.meganitro.com
From what I've heard and read, he's very reputable. I've sent him (Lance) a few notes myself, and his responses were quick and informative.
The .26 is an accurate description. They use the same 3.5 case; it's bored out with a larger sleeve and piston.
I'm seriously considering a Demon too, but it concerns me that HB is not publishing any specs on the motor... In addition to the bigger displacement, the Ofna/Picco has 7 ports. If HB just went with a 4 port sleeve, then it may be a disappointment.
If anyone buys one, please share all the details!

caseyddr

My Feedback: (13)

was looking at the meganitro site, and im not a big savage fan, but even this made it look cooL!



what a killer body

Avalanche

Actually it looks quite different than the .21 in the savage. The only real similar thing is that it has a purple head.

BUGGIES_R_US

That savage just looks SWEET!!

Lovin it! Damn.. thats just totally awesome.

I'd hate to run it and even scratch that body!!

You guys hear about the dirt demon? Looks good!
ram

987982

I wish the hobby stores would start getting them in stock. I emailed him too and he said that Dirt Demons shipped out on wednesday... If anyone has one in a hobby shop near them, they shoould go check it out and tell us what they think.

I have a feeling that this engine isn't goin to be a real powerhouse. I wonder if HPI is making more parts for this engine than just the case? If they are making the sleeve too, it might suck. Doesnt the BB only have 1.7 HP? What if this .26 one only had like 2 hp...thats hella weak.. maybe this could be why HB's isnt releasing info...
hopefully im wronge here. i was so set on getting one of these, but now i have to wait to see if the engine is crap or not.

caseyddr

My Feedback: (13)

its my persnoal oppinion you guys are expecting way to much outta a RTR engine...

987982

I don't think so...look at the 2.5's they are the most powerfull .15 engines out there, and they come in all traxxas cars. Ofna puts their 2.4 hp force .25 in all their cars. And for a car that costs 500+ dollars (DirtDemon, MGT), the engine better not be a piece of sh**.

caseyddr

My Feedback: (13)

first of all most of the stats you see about HP are false, not total lies, but "what could this engine do on mars while in a vacuum at 0 degrees" type of thing. As for the 2.5TRX, Traxxas made a big hit with there own engine, no other company has been able to reproduce or even come close to a 40000+RPM engine for 100$. And even the TRX2.5 has its massive problems, especially as of late. So again, you guys are expecting to much from a RTR vehicle. Your mainly paying for the Truckanyways, they throw in the radio and engine really cheap.

987982

Yeah i guess your right, I just want the best thing i can get. I don't have a ton of money to spend on a car. the most i would ever want to spend would be around 500 bucks, and i dont want to go buy a 300 dollar engine along with it. I just dont want a 30 mph truck like the savage is stock. I want to go fast. I guess rtr and fast just dont really mix. O well

savageone

The 2.5 is the exception. 2.4 hp doesn't sound great for a .25, either.

caseyddr

My Feedback: (13)

the horsepower isnt all that matters anyways, look at the RB Concepts, they have barely any more HP, most under 3 hp, but look how long there engines last and how fast they are

savageone

What is it that makes their engines faster? I know they're the best, but I thought it was a matter of hp and rpm.

studysession

If you want more speed - keep the stock engine and just regear. It is cheaper a lot of times to replace the gearing and go faster than replacing the engine.

Look at the street cars. A lot of them only have .12's and my TC3 gets over 50-55MPh while others with .12 go over 70MPh. It is all in how they setup their car.

Same rules apply to trucks - but if I am going through the mud and the muck - I have 2 TMaxx 2.5 and 1 OFNA Hyper 7 PBS - I do not want to go 50MPh off road. 35MPh does me fine, the rest is how you drive and your suspensions. I see guys with fast trucks and buggies all the time. They can not even stay on the track. If you can drive well and stay on the track, you can beat the really fast ones every time.