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EXP10 to EXP119

Jake14

Well Known Member
Very impressed with the increased performance of the EXP119. Wondering if anyone has looked into converting the old EXP10 engine to the EXP119. unless I'm missing something, the core engine stays the same with a new exhaust and intake system. So installing the new Vetterman exhaust system, new cold sump, intake tubes, and new higher-flow servo would be the main changes. Also the variable cooling flow exit. The cold sump may not provide much performance increase, so keeping the old one may be an option if it doesn't interfere with the new exhaust system. Modifying the lower cowl for the new exhaust system should be feasible and would avoid re-doing the fitting, hinges/fasteners, paint etc.
The new servo is priced around $2.5k, but I don't know the cost of the exhaust system or cold sump. But an extra 10kts and much improved climb might be worth it :)
 
I've done this

Vans and Lycoming offers a kit to accommodate this conversion. Conversion requires new sump, new intake tubes, new FM-200 servo, new exhaust, cowl flap, new lower cowl, etc. PM me if you want to discuss in more detail.

Thanks!
 
Thunderbolt 390

So, what is the difference between EXP119 and my Thunderbolt 390, its placarded at 220HP. Curious
 

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Do the intakes need to be changed because of the location of Van's dual exhaust or is the shape or size of the intakes partially responsible for the increased HP?
I have Vettermans dual exhaust, cooling flap, and modified lower cowl and wonder if I would be looking at changing just the servo, spider, sump and snorkel or if intake tubes are required to be changed.
 
Great, didn't know there was a kit already...Have any of the folks implementing this posted any performance data?
 
Does the Thunderbolt crew ship a dyno sheet with it? And which intake manifold do you have?
.


Dan,
As far as I can tell, just regular forward sump. No dyno sheet. Wander where they get their HP ratings? Trying to figure what the difference is between EXP119 and what I have.
 
Bill, I have no clue as to the "EXP140" designation.

The primary difference relating to HP is an intake manifold with a flange sized for an RSA-10.
 

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Also mine has EXP140 on the placard. Do you know the difference?

My 'EXP119' came with EXP344 on the data plate.

I queried this as my approval authority needed to know the engine spec.

I got this from Lycoming tech support:
According to my experimental build worksheet, the difference between the EXP 119 and the EXP344 is the ignition system. The EXP119 comes with traditional slick magnetos, 1 impulse and 1 plain. The 344 comes with 2 variable Lycoming EIS units.

So I presume your 140 designation is specific to any options that you specified.
 
Thunderbolt 390

Bill, I have no clue as to the "EXP140" designation.

The primary difference relating to HP is an intake manifold with a flange sized for an RSA-10.

Dan,
Certainly not the cold air sump you described. Maybe Thunderbolt division is a little rambunctious with their HP ratings. I also have a PMAG and a Slick, so Mr. Alberry is most likely correct about EXP140 designation.
 

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Dan,
Certainly not the cold air sump you described. Maybe Thunderbolt division is a little rambunctious with their HP ratings. I also have a PMAG and a Slick, so Mr. Alberry is most likely correct about EXP140 designation.

Do you have 10:1 pistons by any chance? I haven't see any IO-390 with standard compression rated at more than 215 hp.
 

That's a nice blog with lots of pics of the conversion process. However, the summary at the end says "Zero performance change measured. In fact, my power, fuel flow, RPM settings yield exactly the same results as before, per the performance table I built before the engine modification."

I suspect Van's claimed performance improvements with the EXP119 and new cowl are probably optimistic because most customer-built RV-14s with the original engine/cowl performed a bit better than Van's published numbers...I think the original numbers came from their prototype RV-14A before it had all of the intersection fairings, if I recall correctly. But anyway, the increased power and reduced drag should at least provide a measurable improvement, so it's surprising that 'E' didn't see any improvements after all the time/money spent doing the upgrade.
 
That's a nice blog with lots of pics of the conversion process. However, the summary at the end says "Zero performance change measured. In fact, my power, fuel flow, RPM settings yield exactly the same results as before, per the performance table I built before the engine modification."

I suspect Van's claimed performance improvements with the EXP119 and new cowl are probably optimistic because most customer-built RV-14s with the original engine/cowl performed a bit better than Van's published numbers...I think the original numbers came from their prototype RV-14A before it had all of the intersection fairings, if I recall correctly. But anyway, the increased power and reduced drag should at least provide a measurable improvement, so it's surprising that 'E' didn't see any improvements after all the time/money spent doing the upgrade.

I, on the other hand, have seen improvement and the one that I could measure easily was my top speed. Granted on two different planes but they were both built by me and very similar to each other.
Since I am not a racer and rather conservative in fuel burn, I personally don't think the performance gains are worth the extra fuel it drinks.
Another observation, if you live in a warmer climate, you may run into oil temp issue even with the cowl flap open. The exit air area is not as good as the standard cowl.
 
……if you live in a warmer climate, you may run into oil temp issue even with the cowl flap open. The exit air area is not as good as the standard cowl.

I’ve actually been thinking about incorporating the Anti-Splat cowl flaps into the -119 cowl to insure proper cooling.
 
I’ve actually been thinking about incorporating the Anti-Splat cowl flaps into the -119 cowl to insure proper cooling.

Another option that you might want to consider, is to use their oil cooler shutter in the tunnel cover. I did experiment by removing the gear leg fairing and I saw a noticeable difference and have been thinking of creating/built a shutter for that area.
 
Another option that you might want to consider, is to use their oil cooler shutter in the tunnel cover. I did experiment by removing the gear leg fairing and I saw a noticeable difference and have been thinking of creating/built a shutter for that area.

Not a bad idea!
 
Not a bad idea!
I am experimenting with some other ways but need to wait till warmer weather is up on us. One of my aim is to be able to remove it if it didn't work without having to do much work and touching the cowl would be the last option since it has been expensively painted.
 
I, on the other hand, have seen improvement and the one that I could measure easily was my top speed. Granted on two different planes but they were both built by me and very similar to each other.

What were the top speeds of your 14A with original 390 and your new one with the EXP119? And can you also share the density altitude, manifold pressure, rpm, and fuel flow when the respective speeds were noted?

Thanks,
 
What were the top speeds of your 14A with original 390 and your new one with the EXP119? And can you also share the density altitude, manifold pressure, rpm, and fuel flow when the respective speeds were noted?

Thanks,
187k and 191k (with the cowl flap open) respectively. I don't have the density altitude handy, but that was WOP and at 2650R.
My EXP119 drinks about 3 more g. (around 20gh) full power at see level, compared to 16.5-17G for the standard which had FM150.
 
Typical cruise data

Mehrdad, do you have cruise data for say 24 squared and density altitudes in the 8,000 to 10,000 ft range for your 2 different 14 airframes? TAS and FF?

Anyone else? Is there another thread that this is posted?

E is one of the most detailed builders and data collectors I have met. It appears that anyone thinking of making this conversion should review.

Thanks
 
Mehrdad, do you have cruise data for say 24 squared and density altitudes in the 8,000 to 10,000 ft range for your 2 different 14 airframes? TAS and FF?

Anyone else? Is there another thread that this is posted?

E is one of the most detailed builders and data collectors I have met. It appears that anyone thinking of making this conversion should review.

Thanks

I had with the old plane specially when I was doing testing with different ignition timing values and when E had shared his. But I have a poor discipline in keeping record.
I have access to the old plane and will try to run those test but the weather right now seems very unfriendly towards flying.

My 14 with the standard engine did very well in X-country when LOP. I would burn 8G @161-162k stop to stop. I had tuned the injector nuzzles as well as I have done with the EXP119, but the EXP119 does not do LOP nearly as well.
 
My 14 with the standard engine did very well in X-country when LOP. I would burn 8G @161-162k stop to stop. I had tuned the injector nuzzles as well as I have done with the EXP119, but the EXP119 does not do LOP nearly as well.

How do you mean? The EXP119 is capable of making more power because (if I understand it correctly) it breathes better. So if you climb up to say 8000', wide open throttle, and lean until it runs rough, it might be reasonable to expect that your original 390 could be leaned down to 8 gph but the EXP119 minimum fuel flow would be somewhat higher (because at WOT it's getting more air).

There's been lots of discussion about how much speed difference there is between the two engine models and FWF packages, it would be really interesting to know how they differ in terms of efficiency. So for example if you set up each airplane at the same density altitude (should be available on your EFIS), wide open throttle, and lean until fuel flow is 9gph, what is the difference in TAS? Or, lean until you get the same TAS and compare fuel flows. The EXP119 cowl is supposed to be lower drag (at least when the cowl flap in the tunnel is closed), so that installation should be a bit faster at the same fuel flow, or have a bit lower fuel flow at the same speed.
 
How do you mean?

Mark,
My flying altitudes that I**go LOP are usually above 12K and* mostly between 14-17.5K.* At those altitudes, the EXP119 will start stumbling very shortly after the peak, I can do about 20-25F LOP and this has to do with the nozzle*size.* I had the same issue with the standard engine (FM150) but not nearly as bad but I was able to reduce my nuzzle size down to .024 which allowed leaning even at or above FL180.I have reduced the size of the nuzzles down to .026 range on the EXP119 and have helped but not nearly as much.*
Now, I could go to the smaller size, perhaps to .025 but any smaller than that, I would need a higher pressure fuel pump for when I am at sea level.* *More cost and at this point, I have stopped where I am.
Hope this helps clarify my earlier comment.
 
LOP performance data

It appears builders are willing to spend a decent amount of money and a lot of time to improve the performance of their airframes in this case RV-14's. I've tried to glean performance data from the posts but seems what people "feel" their performance is and screen shots there is some ambiguities. Is there a post that documents with data needed to understand "typical" performance data ROP and LOP? I struggle getting decent LOP performance. (In terms of TAS) Today on a cross country back home my numbers were:

2,400 rpm, 6,500 FT 69 F OAT both ROP and LOP, 7 knot tailwind component (Used in the miles per gal calculation)

LOP:
24" MP, 155 TAS, CHT 320 F, EGT 1,360 F 24.8 miles/gal, 7.7 GPH

ROP:
22" MP, 166 TAS, CHT 360 F, EGT 1,370 F 19.8 miles/gal, 10.2 GPH

Is 11 knots typical LOP airspeed loss? I really don't want to cruise over 24 " mp even if possible and above this altitude probably not. I get better performance higher but similar loss LOP if not more TAS due to lower MP's possible.
 
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…….(snip)

LOP:
24" MP, 155 TAS, CHT 320 F, EGT 1,360 F 24.8 miles/gal

ROP:
22" MP, 166 TAS, CHT 360 F, EGT 1,370 F 19.8 miles/gal
………

What’s your fuel flow GPH? What’s your fuel pressure regulator set at? What’s the duty cycle on your injectors? I think Roberts fuel pressure recommendations are too low and I think bringing it up closer to about 45 psi works better and reduces duty cycle.
 
ROP vs LOP

There are two methods of running LOP (1) constant ignition timing and I would expect about a 8-10kt loss at 50LOP. At 20BTDC. (2) Advanced timing during LOP. for me advancing the timing to 28BTDC at 50LOP recovers about 1/2 the speed loss. Side note: a baseline of 23BTDC yields better results ROP and reasonable results LOP. It is a very good compromise, if you choose to not have two curves.

To help compare, the following info would be helpful:

1) How much LOP by either EGT or fuel flow?
2) What are your ROP and LOP ignition timing settings.
 
….(snip)

2) What are your ROP and LOP ignition timing settings.

It looks like Dwight is running the EFII S/32. That system has linear timing advance/retard based on manifold pressure, not so much as ROP or LOP.
 
It looks like Dwight is running the EFII S/32. That system has linear timing advance/retard based on manifold pressure, not so much as ROP or LOP.

Are you saying it has a single curve based solely on MP? If so, it has to be a compromise on one or the other side of peak. If there is a override function, I would advance the LOP ignition or one would have to accept the speed loss. Another option would be to fix the ignition to 23BTDC, which is a very good compromise for the IO-390.

I run mine at 20BTDC for takeoff, 23BTDC below 25MP from 100ROP to 25LOP, 28BTDC from 50LOP to 100LOP and 30BTDC when leaner than 100LOP. In truth, I run 23BTDC and Peak for the vast majority of my cross country flights, just because. All these numbers are for an angle valve 390. I have no experience with parallel valve timing values.
 
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