H2AD > D2J (plus GI275 EIS)

Nathan Miller

Nathan Miller

Pre-takeoff checklist
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Nathan
I understand the upgrade to a D2J from the H2AD is a popular conversion, though sadly I only found two threads on it and they're both 10+ years old.

I've been mulling over the "DeltaHawk" STC by Penn Yan. I don't like using that term, since apparently there's a new diesel engine out there by the same name. So, I'll refer to it as the D2J upgrade :)

1979 C172N with the Lyc O-320-H2AD, of course. T-Modded. Engine is 10,000TT and 3,900SMOH (and the major was 30 years ago this summer). BUT - filter and sump screen are clear and the oil analysis is favorable... Cylinder #2 developed a crack during a touch-n-go. We debated about majoring our engine, given the high time. But the lead time and downtime is a killer. My partners and I put on quite a few hours. Plus we just took on a new partner and he's anxious to get this returned to service. (Poor chap - the crack happened on his maiden flight with his instructor! Yikes!)

Without further ado - Who all has undergone the H2AD > D2J conversion? Penn Yan estimates the labor would be between 25 and 30 hours. Was this your experience? What parts need to be sourced in addition to the D2J? Baffles? Exhaust? Starter / Alternator / Mags (though I'm assuming those would be included as part of the major(?)). Oil Cooler? I'm absolutely going to have new fuel and oil hoses made up and firesleeved, etc... let's see... I understand a new oil door needs to be installed, due to the dipstick / oil filler being in a different (and thankfully far more convenient) spot.

We are also trying to budget for a GI275 EIS. Should we bother with fuel flow? I believe we're springing for RPM and oil temp and pressure probes.

The lead time for an overhauled D2J from Penn Yan is effing stupid - like 12 months. They couldn't even be bothered with putting our name on a list - they simply said "get back to us mid-summer". Yikes! I have yet to call around to other shops.

I used to have a 1983 C172P with the D2J. I loved that beast.

So, the plan is to bandage up our tired H2AD while budgeting and acquiring a D2J to replace it. I'd love to hear experiences from 1) those who have undergone this conversion and 2) those who have experience with the GI275 EIS. Thanks
 
Nathan Miller said:
We are also trying to budget for a GI275 EIS. Should we bother with fuel flow? I believe we're springing for RPM and oil temp and pressure probes.
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I would. Fuel flow is useful information and I think the sensor is incremental cost. EGT and CHT are also useful to have in the log files.

Nathan Miller said:
So, the plan is to bandage up our tired H2AD while budgeting and acquiring a D2J to replace it.
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Have you ruled out a 180hp upgrade?
 
Nathan Miller said:
Yes. One partner had the 360 in his airplane and it was hard to start (cold or hot) and the marginal speed upgrade wasn’t worth the extra fuel…
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Well that's very strange. The Airplains 180 conversion I flew was certainly no harder to start than the 172 O320's I've flown. IO360's can be cranky to start, especially the 200hp angle valve versions but not the carburetor parallel valve 180hp versions.

You're right that the 5-ish knot increase isn't much, but it sure climbs a lot better. And the gross weight increase comes in rather handy (nearly 1100lbs on the 172M-180).
 
It’s been a while so trying to recall between 160:and 180 conversions. Consider Ignition Switch “jumper” unless you are going with dual impulse coupled mags
( option) . Whether you relocate the battery hold- downs 1/2 inch or 1 inch will still take time. Tach swap / remark required per STC?

Those hours MIGHT work. IF the shop has done this before AND has any parts and hardware on hand. A project seems to have inertia. If it stops it takes a lot to get going again. And all bets are off.

The O-360 should not be harder to start than a 320. Of course; dual IC makes just about any engine start easier.
 
I think the 160-180 conversion is more popular than the D2J conversion? I could be wrong?

My buddy had C172N with a Great Plains 180 that he had rebuilt from a insurance auction.I worked on it and didn’t like the battery and magneto arrangements. I had to move a mag to get the battery cover off. There were a couple things I didn’t like 30 flaps.
I did the research couple years ago for my 1980N.

You got a H2AD with 10K TT and 3900 since last major overhaul? Really? I am impressed 1900 past TBO?
Is that right?
 
Disclaimer…I am a happy H2AD owner.

Why do you want to replace it if it has been such a reliable motor. Dual mag?

I Researched the D2J conversion couple years ago. The STC is not cheap and there is a lot of work to do it. Like said above. IMO way more than 30 hours.
There is a very rare and expensive air duct needed for the new oil cooler that gets moved the firewall. Moving the battery is no easy task.
So many other details there is no way one could do all of it in 30 hours.
 
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Gary Ward said:
Disclaimer…I am a happy H2AD owner. Why do you want to replace it it it has been such a reliable motor. Dual mag?
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That. (Dual Mag). And since the H2AD had such a short run, I understand parts are getting harder to find (more than the usual supply chain crisis). Also, the D2J doesn't have a 50 hour AD that basically prevents me from changing my own oil. Bummer I can't sign off on that AD ...

The reputation of the H2AD is no longer deserved, IMHO. Especially since nearly every motor has been "T" Modded. Much like the Pontiac Fiero, though, they worked the bugs out in 1984, but the reputation for its pyromaniac tendencies stuck and eventually killed it off in 1988. That being said, the H2AD name does shrink the prospective market a modicum when we go to sell.

I can see me majoring my current engine (more precisely, overhaul/exchange)... I'm 50/50 whether or not to OH/Exchange the H2AD or upgrade to a freshly majored D2J.
 
Nathan Miller said:
AD 80-04-03 R2
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I read most of it, I don't understand why a AP must do it, change the oil. I am always open to learn new things and don't want to be breaking any laws. My AP was in and out during all my engine work. He was there for first start up and helped me to put the clys back on the old motor. He did all the safety wire.

I edited this^^^
 
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Agreed. I only became aware after my A&P asked “oh, you just changed your oil? Cool! Who signed off on the AD?”


never thought of that. I just thought it was PM. Which as the owner/pilot, I can do. What I don’t have the authority to do as the owner/pilot is sign off an AD :(
 
You didn't mention, but be sure you know what they'll give you on a core exchange, could be a significant difference between engines that aren't the same.
All else equal, if I were to go to the trouble and extra expense for a conversion, I'd go with 180hp.
 
Gary Ward said:
I read most of it, I don't understand why a AP must do it. I am always open to learn new things and don't want to be breaking any laws.
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The AD does not say that an owner can sign it off. I am not surprised at this, since actions beyond adding the additive LW16702 are required for compliance.
 
Yes my core had to be the exact same engine and the core charge was $16000. The engine had to be complete, have a genuine lycoming crank and rods and have run within 12 months. I sent it back and about 3 months later I got my 16K check back from Airpower with void written on my personal check.
Mondster I still don't understand. I realize only a AP can sign off a AD. Please help me understand this. As we all know the additive is in the aeroshell 15/50. Is it a one time sign off? What other actions need to be done? TIA
I edited my post above, I meant why does a AP have to change to oil on a H2AD?
 
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Gary Ward said:
I still don't understand. I realize only a AP can sign off a AD. Please help me understand this. As we all know the additive is in the aeroshell 15/50. Is it a one time sign off?
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It also requires inspection of the sump screen and cutting open and inspecting the filter. It is a recurring AD, unfortunately.
 
Nathan Miller said:
It also requires inspection of the sump screen and cutting open and inspecting the filter. It is a recurring AD, unfortunately.
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Thanks, of course the filter get's inspected every oil change. I have to ask my AP about this!!
From reading that AD again, it pertains to motors built before SN L-6182-76? So I don't think it pertains to my newer motor? I printed that AD out and will discuss with my AP.
IMG_1106.JPG
 
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Gary Ward said:
Thanks, of course the filter get's inspected every oil change. I have to ask my AP about this!!
From reading that AD again, it pertains to motors built before SN L-6182-76? So I don't think it pertains to my newer motor? I printed that AD out and will discuss with my AP.
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The replacement of exhaust springs and lifters applies to SN's prior to L-6182-76 but it appears the inspection of the filter and sump screen (and LW16702 additive) apply to all SN's. But keep me posted after you speak with your A&P. My reading comprehension isn't what it used to be :oops:
 
I agree with preceding applying to all s/n and lifter configurations.

Actions are required at every oil change not to exceed 100 hrs.
 
Nathan Miller said:
The replacement of exhaust springs and lifters applies to SN's prior to L-6182-76 but it appears the inspection of the filter and sump screen (and LW16702 additive) apply to all SN's. But keep me posted after you speak with your A&P. My reading comprehension isn't what it used to be :oops:
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Your reading comprehension is correct. There is no terminating action for the filter/screen inspection and using the oil additive.

What is somewhat vague is the intervals at which the inspections need to be performed and the additive added. Basically it should be performed every 50 hours but inspections should not exceed 100 hours. That part of the AD could be written better.

Edit: What is interesting about the recurring part of the AD in question is that there is at least one other similar AD which requires oil filter checks every 25 hours and investigation if any metal is found. In that case it is considered to be preventive maintenance.
 
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Nathan Miller said:
AD 80-04-03 R2
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FWIW: this is one of those unique ADs that has been the topic of a lot of discussion over the years. Given there is no applicability statement included in the AD, technically it falls to the authorizations provided by Part 43 on who can perform certain sections after the initial compliance of the AD. AD paragraph (a) is an AP. Paragraph (b) can be performed under Part 43 Appx A(c) and subsequently signed-off by a pilot with a reference to the AD. This task would be no different than following any appropriate Part 43.13 reference a pilot would use for oil/filter changes on any other engine. There is an AMOC for paragraph (b)(1) that allows the use of certain oils vs the Lycoming additive so thats no issue either. However, if any metal is noted then its back to an AP territory just as if metal is found in a "normal" oil change. I've heard that several owners took it a step further and obtained an AMOC to cover para. (b)(2) as well but never saw one personally. So whether a pilot can perform/sign the recurring paragraph (b) tasks usually falls to the determination of the person performing the task as the AD doesn't allow it nor prohibit it. A classic gray area.

Nathan Miller said:
I hope people aren’t going 100 hours between changes
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FYI: There's actually a Lycoming bulletin that allows extension of the oil change to 100 hours provided a certain unleaded fuel is used. Its also the reason the AD para. (b) states "not to exceed 100-hour intervals." This extension does not include the filter which remains at 50 hrs. However, per the AD AMOC on the use of certain oils if the owner wishes to extend to 100 hours they need to replenish the oil additives at the 50 hour mark regardless. Isn't this fun.;)

https://rgl.faa.gov/Regulatory_and_...9e66ed8e8625792e005e3f4d/$FILE/NE-06-31R5.pdf
https://www.lycoming.com/sites/defa...for Engines Operated on Unleaded Fuels_0.pdf
 
My AP looked at that AD and agreed that there is no provision for the pilot to sign that off. He will be involved in my oil changes from now on. Thanks for the education.

but what a PIA. I more understand why you want to get away from a H2AD.
 
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Gary Ward said:
My AP looked at that AD and agreed that there is no provision for the pilot to sign that off.
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Bummer. I was hoping for better news. Though, asking your A&P, as impeccable as his ethics may be, does raise some questions about foxes and hen houses :D

bell206 might be on to something ;)
 
I have a '77 C172N with an Air Plains 180HP upgrade. I love the 1,100+ pound useful load and the extra power. When alone in the plane, I will usually see 1,100 fpm climbs on standard days. I also have a Garmin GI275 EIS. You definitely want fuel flow and don't forget to budget for new digital fuel senders.
 
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