YS DZ70 or YS FZ80s Engine
 

Anyone have prop/rpm data for the YS DZ70 engine, particularly with APC 14x7 prop? Also, does anyone have data for the new YS FZ80s engine? Thanks

The DZ 70 is a really strong running engine, I havent ran one with a 14x7 but thinking the rpm will be around 8,800 or so on 20%. I will try to run one this week for you to see ok. The FZ-80 has more power and the engine I would go with but depends on your plane set up and how you want to fly it. The 80 has 3mm more stroke to it. I do know the DZ-70 will spin an APC 11x14 at 11,000 on 50% nitro.

I forgot to add but I run the 14x7 on a FZ 80 in my hanger nine christen eagle but I never tached it. I am thinking it is around 9,500 or so on 20% but not 100% on that number.

Getting the tach data would be awesome. Thanks

Hello i am also interested in comparison DZ70 vs FZ80.

Big adventage od DZ70 is that it can run on low Oil content, as low as 5 or 10%.

Sorry guys i havent had much time to run either engine on the same day to compare them yet. I will try to do that next week as I have a few other engines to run also.

How it is going with tests?

Sorry guys I have been behind on planes and school. bare with me as I will get some numbers soon. What fuel % would you like to see? I have 15-75% nitro I can run?

I think the most popular for YS 30% nitro 20% oil.

Ok I have the engines out of planes as I didnt want to use new ones. I will run them tomorrow on the 14x7 with 30% nitro. I have other engines to run tomorrow also so will make a day of it.

Ok I had the chance to run these two engines and I was surprised by the numbers. Both were closer than I thought. The temp was 64.7F, Humidity was 49.1, dew point was at 45.6, baro was at 29.88Hg and density altitude was at 591.
Both were run with in a 10 minute time span with same prop, same fuel, same test stand and same glow plug and same needle valve(not that it mattered). Both were ran up and I recorded the first rpm number and then a second number with some heat in the engine. Prop was an APC 14x7 and the fuel was 30% nitro and 20% oil. The DZ 70 turned 10,420 and once warm turned 10,290. The FZ80 turned 10,530 and once warmed up it turned 10,410. Both of these were on a header as I didn't have time to install the mufflers. I don't run the mufflers so not sure how much the drop the RPM if any at all.

WOW numbers are impressive for 14x7 APC. For comparison ASP 91 is turning APC 14x6 10 000 RPM here we have 14x7.

Also there is no diffrence in RPM between DZ70 and FZ80. So technology in DZ (direct injection) is awesome. It is worth to mention that DZ can run on 10% oil so more power, less mess, cheaper fuel.

But in case of relability i wil propably choose FZ80, airraptor what is you personal opinion?

IMO I would get the 80FZ. It has the pressurized fuel system and easier to run. The DZ is strong but in the 70/80 size it is a little more finicky to tune. I will someday run a 70FZ on same prop and then a 80DZ and then a ignition on all of them. The 80 is hard to beat for the power it makes with a weight of around 18 ounces. You maybe able to run less oil but I wouldn't do it. The oil does add to the compression some. I have run up to 55% nitro in mine and run 60% in my 115WS engines.

Ok, so FZ version is much easiet to Tune? DZ disadentage is for sure punp which likes to wore out. I am waiting for Yamada to do some DZ80 or sth like that ;)

I am sure you can get one. I will call and see if they are offering it. I would think the DZ 80 should have another 300-500 more over the FZ

Airraptor,

Thanks for doing that comparison. Great numbers for both engines. As for the 70FZ on the same prop, RCSportflyer did a review and got 9,600 rpm (10.1 lbs thrust) on the APC 14x7 with 30% using the stock muffler. I don't think the YS DZ80 exists, but it would be awesome if they offered it.

I have been and still are pretty busy with racing but maybe mid April I will test a DZ 80 for you.

YS has a DZ80?

There is no DZ80, recentrly they presented FZ80 CDI

I will make one out of the DZ 70 parts and add it to the 80. One issue with the small DZ is cooling. since the fuel routing is different from the FZ. The FZ has fuel going through the crankcase where the DZ doesn't. You would be very very happy with the FZ 80. They are around 18 ounces in weight which is about the same as most 55 two strokes with mufflers. A ton of power in them and if need even more just up the nitro some. I have one FZ 80 flying on a Hanger nine Christian eagle thats 10 pounds and vertical is unlimited on the 14x7

I read one of the issues with the dz70 is that it doesn't have the insulator between the crankcase and carb housing like the other DZ engines. So heat gets transfered and can cause fuel to vaporize before getting to injector. Interestingly, I have seen some DZ70s in Japan that have the new DZ 185 red injector type and break-in needle to help keep engine cool.

That would be a cool experiment to see the performance difference. Let us know how it goes, looking forward to know how it turns out.

...

"Prop was an APC 14x7 and the fuel was 30% nitro and 20% oil. The DZ 70 turned 10,420 and once warm turned 10,290. The FZ80 turned 10,530 and once warmed up it turned 10,410. Both of these were on a header as I didn't have time to install the mufflers. I don't run the mufflers so not sure how much the drop the RPM if any at all."

This is interesting information BUT I would point out that Yamada San has emailed me that the FZ80 achieves it's HP peak near 15,000 rpm. This is how to interpret the "practical" rpm range. So the 10,000 range is way down from the HP peak. On the other hand, the DZ is not supposed to be run any faster. Whenever you test and compare engines you can choose optimal conditions for one and hobble the others.

With a 14x8 prop and 10% a Saito 82 and FZ 80 may be close. On a 11x7 prop and 30%, NOT CLOSE. I have not tried this.

NOTE: There is an obscure line in the FZ80 CDI instructions just for me !

Four stroker what are you talking about??????

hello i am from German sorry for my english:
can the FZ 80 turn larger props at the 14 x7 i think to 16" the YS are wonderfull Engines but the RPM over 10000 ist not praktikable for Slower flying scale airbatic modells.
These RPM are good for warbird racing and high speed flying models.
I want to use these Engine for an similar Modell as airraptor but an prop with more diameter looks and works better on these scale planes.