Airwurthy

My Feedback: (2)

My engine arrived 2.5 ounces heavier than advertised. Did something change in producution to add the extra weight? By comparison, my jett .35 weighed exactly as advertised on the same scale. Just curious.

bob27s

My Feedback: (19)

Hi,

Thanks for writing....

The engine should weigh somewhere around 17oz fully configured...

What does yours weigh ???

Bob

Airwurthy

My Feedback: (2)

Hi Bob,

I guess fully configured it weighs 19 ounces........engine, muffler, prop nut, glow plug and needle valve. Not a big deal, but I was excited that it was going to be lighter than my webra .50 and have way, way more power. But when I pulled it out of the box I could tell it was heavier, hence the only reason I threw it on the scale.
Skipp

bob27s

My Feedback: (19)

It is heavier than a Webra 50 - but not by a great deal. That also depends a great deal on the muffler choice.

Let me get Dub in on this one.... the two SJ-50 engines I weighed not long ago were both a gram or three under 17 oz - ready to fly. The BSE .46 is just over 17oz I think at 17.3, mainly because that has the thickest crankcase wall. I've never seen any of the small block engines get beyond that, with the exception of some of the developmental/prototype BSE versions.

The 60LX is the lightest of the bunch, aside from the SS40 - since the smaller SS muffler weighs the least.

Do you have a BSE 60LX or a cast case ??

Just for reference, this is the information I have in my own data records...
Webra 50GT (model 1025) data sheet indicates 320g (11.3oz). My notes from weighing one indicate that is about right.
Webra stock muffler, depending on which one you get, is either 105g or 120 grams. I had the fat one, weighed about 4.3 oz.
So, spinner nut aside, this is about a 15.6 oz combo - factor in a spinner nut, and it comes up to around 16.2oz.

The SJ-60L engine only (with the spinner nut) is 12.1 oz (340 g). Muffler is appx 4.4 to 4.6 oz (130g).
This totals up to about 16.7 - perhaps toss in another .2 oz for screws not accounted for ...... and it totals under 17 oz.

Bob

Airwurthy

My Feedback: (2)

Bob,

I have the BSE .60 LX and just the engine with glow plug and spinner nut weighs 14.2 oz.

bob27s

My Feedback: (19)

understood.... thanks for the info. Let me review this with Dub.

Airwurthy

My Feedback: (2)

Bob,


Have you found anything out?

Skipp

jettlag

I have stayed out of this because I am dead out of crankcases and can't weight an engine at the moment. However, I just weighed a brand new .50 and it weighed 16.9 with a nut and washer. This is the way we publish the weights so you can compare with other engines.

However, I weighed a piston and liner and crankshaft of the .50 and .60L and the difference is 10 grams. 1/3 of an oz. All the other parts are the same except the case and it is actually lighter on the .60. This means the difference is less than 10 grams.



dub

Airwurthy

My Feedback: (2)

I understand the publications of weights on your website, and what is included. Bob put out a number there of other engine weights so I just wanted a relative number. I guess my question was.......why is mine heavier than the published weight? Not by a few grams but at least 2 ounces.....

bob27s

My Feedback: (19)

Ok, I will take the hit on this one......

I have a few goofs going concurrently here....

The design is continually improved as new materials become available, and performance/durability improvements are discovered and implimented. Over time, that has caused some weight creep.

1) the weights on the web site were not updated after the last sleeve/crankcase improvements ( well over a year ago )
( crankcase design strengthened, sleeve is slightly thicker at the top - added a bit of weight)

2) the AAC weights are 0.5oz less than the ABC versions of the engines - and I think I posted those

3) Switch to the remote needle valve assembly and some improvements there added a few grams

4) newer sport header and racing header castings and pipe design added some weight to the muffler

5 ) I copied my error and the weights when I created the BSE page

6) The BSE crankcases do weight about about .50 oz more than the cast case, due to some design and manufacturing requirements

7) The 60LX uses the racing header as part of the muffler. I forgot about that calculating engine weight. The racing header includes more internal structures, and weights more than the SJ header piece. So I incorrectly included a SJ-60L weight on the product listing when I added it this past spring.

8) The 60LX has a heavier sleeve - by design - than the SJ-50 or SJ-60L

Clearly I have some work to do here, and I will correct the errors.

I appreciate you bringing this to my attention. Good inspiration for the (somewhat slow) webmaster to get a few updates done.

If you have any questions or concerns, or if you are dissatified with the product, please, call Dub at the shop, and he can assist you further.

As a reference for others reading along, here is some fresh off-the-bench data

SJ .60L ABC with spinner nut 17.8 (as provided)
(with regular nut and washer 17.2)

So yes, the published website weight was shown as 16.8 , and the total airborn weight has grown appx 1 oz over the past 3 years.

SJ-60LX ABC with spinner nut 18.6
(with nut and washer 18.0)

BSE configuration of this engine is about .5 oz more ..... so the reported 19oz is pretty-much accurate.

Bob

Airwurthy

My Feedback: (2)

Thanks for the explanation Bob, that was all I was looking for.

bob27s

My Feedback: (19)

Hey.... no problem at all. Correct info is important.

BTW... Im just down the road off of I-90 a bit.. about 90 min. Any issues, give me a call and I can always cruise on up there to help out.

Bob