bought an hb, made in germany motor. it's a .15 and feels like it has no compression. this is a lapped piston engine i think. guy says it only runs castor fuel and needs to be broke in for two hours. it sure don't run very good on regular 15 % cool power. i say it's worn out. he says no way. but the motor runs real hot and won't hold an rpm. acts like some engines i have had that were worn out and ready for a new piston and sleeve. didn't build any compression on two tanks of fuel i ran through it on a test stand. can't keep it running steady enough to put it in a plane thats for sure. has a perry carb. is this engine a ...relic.....like the old fox lapped piston engines of the 60's and not up to moderen spects like os,super tigre, thunder tigre etc...........thanks for any input guys..............RON

I have an HB .15 that I purchased in 1984. So I don't think they are from the 60's.

Mine did not need a two hour break-in. In fact I think I probably ran a couple tanks through it and called it good. I actually used mine in a 4WD truck, and it was a beast in that application. The truck was designed for an OS .10 and so the HB was a 50% increase in displacement (no replacement for displacement, heh-heh) and I was frequently destroying the gears in the transmission with this engine. But when it ran, holy smokes it would literally leap off the ground when I punched it.

HB .15 is a good engine. Yours sounds worn out or just plain abused.

I hate to say it but........

Running a lapped engine on cool power will kill it, the hot running is from friction. Lapped engines need castor for lube. It can be a pain finding castor only fuel for sale, I know, but it is a requrement for engines like this.

I agree with rcdude7. Some time ago I was doing a test run on an old lapped piston engine and accidentally used a fuel with 20% all castor but luckily I was monitoring the head temp. When the temp started to soar past 300F I had a DUH moment. I filled the tank with the 25% all castor I meant to use and then all was sweet .

Fox and one or two other companies make a fuel with more than 20% castor so wait until you can get some of that before running it again, it may still be OK.

You might buy some Castor Oil and up the oil content ( a test) See if it acts better with the more oil. Then you might invest in a different fuel. I run mine on 5% nitro and either 20% Castor or 22% Castor/ Synthetic Blend. HB's like low nitro content. The HB 15 is a great engine if there is any of it left. I hope you still have a decent engine.

As stated previously, Cool Power is a killer for lapped piston engines. I ran Power Blast 12.5% nitro that had a good bit of castor oil as the lube. I forget what the ratio to synthetic was, IF there was synthetic at all.

If the case is in good condition and everything is present, it might be worth it to replace the sleeve and piston and start all over again. I have over 20 of these engines. That might tell you how much I love them. I've never found another .15 that is as light, runs so well and handles as much like a pattern sixty as the HB .15. If you want to see some serious screaming, put a 7x4 on it, not that it won't pull more prop, but it sounds like a rabid Rossi with the 7x4 up front.

The engine is an easy hand starter and will out last its owner if castor oil based fuel is used.

I learned how to fly inverted in control line using a Fox .15X. There is absolutely no comparison between the Fox .15X and the HB .15 R/C engine. None whatsoever. Parts for the HB .15 can be bought from RJL/MECOA in California.


Ed Cregger

Dito on the fuel, all castor is essential and environmentally friendly too (vegetable based).
If you're lucky you have just mated the surfaces and when it gets the right fuel it may run fine (I have seen that happen on a similarly abused Enya engine). In the worst case you have worn it out and it needs a new piston and liner.

Great engines, about the same weight as an OS 10LA, and with the firewall mount you will end up even lighter...
Perry carbs have great fuel draw, just be very gentle on the low speed regulation.

Hi, I have two of these both needing front housings due to crash damage. Mecoa is out of stock on these housings and have been for years. Do you have another parts source or do you yourself have any spares of this housing? Even one would do for now. I also have an HB .25 and an
HB 61.
Thanks

Sincerely,

Richard

Richard, the reason that I have over 20 of these engines in the first place is because of the scarcity of parts. I still have yet to inventory what I have, to be honest with you. I wish I could be more helpful.


Ed Cregger

SIGmakes 20%and 25% all castor fuels in 5 and 10% nitro. Iuse it for lots of stuff, bushing engines, break in, old well worn engines, etc.

thanks for all the info guys. i didn't like the idea of using all castor fuel. i used it years ago, but like the castor syn blend i use now. i sent the motor back to the guy, bouught it on r/c universe of course. he said he would send me a refund, because i didn't like it. it's just me. i can't see spending more money on fuel besides what i have. the motor is going in a powered glider,electric now, and thought how about a nice .15 to power it. i should have bought a os fp......or la or even a thunder tiger 15, but bought this relic...instead. yeah parts are avail from mecoa 45.00 for a piston and sleeve, just ain't worth it to me. there is nothing wrong with it except no compression. it also only has pdp porting i believe. it's sent back now so i'll look at something now,i'm the wiser................thanks..............RON

There is/was nothing wrong with that "relic" engine apart from the fuel that you have feed it.
Perry directional porting (PDP) is a good thing, but I don't think it is available on the .15, only the .21 and up came in that hotter version too.

Well, there is some good info to be had here in this thread. The leason is: Don't run a lapped piston engine if you don't want to use the right type fuel in it.

Some people on this board swear by synthetic lube as the superior lube choice, but most engines will benefit from at least some castor in th mix. Some will cringe when I say I even run some castor in my YS fourstrokes

It also depends upon the type of synthetic oil too.


Ed Cregger

gee ,i thought that castor fuel went south when fox engines did ,but there still around. i learned something from this too...............thanks.......sincerely...RON

Some of the Enya range are still made with lapped pistons which can be a trap for the unwary.

Have you ever heard of engines having a "green" piston?

Some of the old OS lapped piston engines came through with loose pistons that actually "grew" into the proper size needed. I am not kidding.

I have broken-in several HB .15 engines. None of them had fuel with pure castor oil lubricant. I was blissfully unaware of that need, but I used to add lab grade castor oil and nitromethane to my fuel, except for pattern engine fuel. That I did not want castor in because of the mess and the very heavy flying schedule of those models.

Anyway, get some fuel with some castor oil in it, or add some castor oil on your own. Be aware that these engines need to be ran in slobbery rich. When you can run the engine peaked out (minus a few hundred rpm) for a minute, then you are ready to lean out the mix a bit. You have nothing to lose except some time and some fuel. Unless you're stupid enough to try to fly the engine through break-in. I've been that stupid on several occasions.


Ed Cregger

Well, this is an old thread, about an old engine, but I need some advice.
Ireceived a brand new, in the box, HB 15 (clean foam, instructions, etc ) as part of a package of stuff I got from a guy that has been carting it around for years. He is one of those people that bought RC stuff long ago, never flew successfully, but kept all the stuff. It is sort of a time machine ... it has the purchase slips with it.
At any rate, I'm pretty much into gas engines, or small electric (big at the field, small at home), and will probably sell this engine.
Is it a collectable, or were they so common that it does not have much value?

The HB .15 is a special engine to me. But, even to me, it is not worth a lot of money.

When you consider that most .15 size engines of yesteryear came from the factory with an air bleed idle circuit as opposed to HB's superior Perry/Perry clone carb, it is no surprise that the little .15 handles more like a pattern 60 than the miniscule .15 that it really is. In other words, it idles and transitions more like its larger brethren than its equal sized cousins.

I have about twenty or so of these engines. However, I'm always in the market for more of them, should someone wish to part with theirs. I'm warning you up front, I'm a cheapskate.


Ed Cregger

They are nice engine, old-school but very light and with the integrated radial mount it is perhaps the lightest .15 there is. They need full castor (i.e. the fuel of the time and will be ruined by the modern synthetic car fuel for instance). Used ones are therefore not worth very much, as you don't know what you get, but NIB ones go for about $100 I guess on ebay.

Isn't there a 28 or 29% all castor blend as well? Specifically for use with Fox Stunts and the like. I think it's called Duke's Fuel.

Iskandar

Fox Superfuel was / is the one with 29% Castor...
Duke's fuel was a bit lower in oil...IIRC it was around 25%?

Fox engines are still being manufactured today, as is Fox fuel too.
With lapped pistons you need to use castor oil, more modern lapped piston engines can do well using a blend of synthetic and castor oil, but are best with 100% castor oil. For a new lapped piston engine you need 25% oil, but it can be reduced in a broken in engine. Old timey engines can use upwards of 33% castor oil in them, with 25% being the minimum. A old well used mapped piston engine needs 25% castor oil at the minimum and you do not clean the piston and cylinder either as the old varnish is actually helping improve the compression. If you ran a fuel with 100% synthetic oil through a old varnished up lapped piston engine, it will remove the vanish and the engine will loose all of its compression and you can't put the varnish back on by then, it is too late.

I think the little HB .15 engine was one of the sweetest engines in its time. A modern .15 runs circles around them, but the HB .15's were just such gooid runners though.

Cool Power fuel is Ok for use in a modern plated cylinder ball bearing engine, but never use it in a older lapped piston bushed crankshaft engine, it will quickly destroy the engine.
You likely ruined the little HB .15 doing that.

Thanks to all for the replies.
Just to clarify ... I am not the original poster, and my engine has not been run, nor has it been in the vicinity of synthetic oiled fuels.  It is NIB.  I've been in the hobby since 1967, and ran lots of lapped engines on castor.  I agree with all the advice.  I still use Byrons on modern engines to keep castor in the mix although I know it would not work in this application.
OK ... so onto eBay then.
And to Ed, who identifies himself as a cheapskate ... me too!  I got this engine, two of the ugliest .40 size trainers I have ever seen, an OS Max 40 and a K&B 40, for the trainers, old S48 Futaba pin type connector servos for the planes, several illegal transmitters, some on AM, a new roll of monokote, AND a bunch of odds and ends which are obsolete ... for $40.  Charity on my part to a friend who was cleaning his apartment.  i figure this engine and the monokote are the only items of value.  The high wings are going to be made flyable, taken to a deserted field with my flying buddy and ... well, lets simply say we will return with good video for our club banquet.
  
Thanks again!

I think many if not most brands offer a blend with at least some castor. I run a bit of castor in everything, and all castor in some.
Some brands don't tell the buyer what the oil type or content is. I don't buy those now, though "back in the day" it was common for fuels th list neither oil or nitromethane content.


jess