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Need Advice on 0-320H2AD

M

medic311

Active Member
I am looking at a pretty sweet deal on a 1st runout O-320H2AD 76 series (<$2800 complete - no prop strike 1900TT) (no "T" mod done). I have reviewed the AD's and understand the cam issue and I have some questions since I am totally new to this.

Are there a lot RVs flying this model? I see tons of 172N models with tons of time but does this come at a huge expense to maintain these engines?

Is it hard (i.e. expensive) to fulfill the AD?
Is it worth buying a 1900TT engine only to have it OH in a couple of hundred hours.
Since I will be using this in an RV4, I can rebuilt it myself and have my progress followed by an AP/IA right?

Are the dual mags in a single case a real issue?
Can I do light aerobatics with this model?
Am I better off with a different model?

I've read some great threads on lycomings in general but I hope to find specifics on this model.

Any suggestions would be great. Thanks.
 
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O 320 H2ad

I choose the same engine for my project.
See Randall's narrative in the Firewall forward section
http://www.vansairforce.net/engines.htm
The single mag is used on many other engines, so I see it as a
non -issue.
There is a company in Canada that is producing a roller cam.lifter
kit if you desire.
The fuel pump is in a non=standard location, with fire sleeve it should be fine.
Auto Gas is not an recommended option for this engine. The engine mount is standard. Van's Baffle kit is usable but you will need to customize some pieces.
There a others that are flying that should add more information.
I would go the same direction again.
 
Alschief said:
The single mag is used on many other engines, so I see it as a non -issue.
Click to expand...

Yes, but... there's always a but, right?

I've flown hundreds of hours behind these -H2AD engines, along with other dual mag/single drive engines in Mooney 201s, Cardinal RGs, etc... and for the most part they were reliable and trouble free. But, I once had a bad day instructing in a '79 C-172N; the mags were fine but the single drive gear failed. I was able to limp back to home base, barely... it's been 18 yrs and I don't recall the exact failure mode, but the mechanic said the single drive gear setup was coming apart. I'm not sure if it was the gear drive in the accessory case or the gears in the magneto case... either way I thought it was pretty lame to have two mags disabled by a bad drive.

This might've been just a freak occurance, one in a million type of failure, who knows. In the 18 years since I've flown behind these mags with no more trouble, and every night there are Piper Navajos/Chieftains out hauling the mail with these mags... but ya never know, it might happen again someday.
 
One mag one EI

jbDC9 said:
Yes, but... there's always a but, right?

I've flown hundreds of hours behind these -H2AD engines, along with other dual mag/single drive engines in Mooney 201s, Cardinal RGs, etc... and for the most part they were reliable and trouble free.
Click to expand...
Easy mod is install a single mag and use a crank triggered EI for the second ignition. I think a single mag is a bolt in replacement. Just a thought. Besides your story I did read of one NTSB accident caused by the dual pak mag design.
 
0-320h2ad

Answers to your questions:Vern's opinion
Q:Is it hard (i.e. expensive) to fulfill the AD?
A: Not necessary according to most engine guys i've consulted with. It is very easy to monitor cam/lifter wear since you can easily remove lifters and observe cam lobes without splitting the case. As pointed out by others, there is a new roller lifter/new cam kit available that eliminates the need for T mod.

Q:Is it worth buying a 1900TT engine only to have it OH in a couple of hundred hours.
A: That depends on the actual condition of the engine when you buy it. If it has been flown often, cold wx starts have been aided by a sump heater or heated hanger, it may join others of its type which have repeatedly gone 3000-4000 hours such as the powerline patrol and fish-spotters who used H engines. If it has not been flown often and has excess wear now,it will not get better.

Q:Since I will be using this in an RV4, I can rebuilt it myself and have my progress followed by an AP/IA right?
A: Yes. Experimental means just that.

Q:Are the dual mags in a single case a real issue?
A: No problem. In fact, mine starts better than any Lycoming I've ever started. Get your mag overhauled by a good shop and it will serve you well.

Q:Can I do light aerobatics with this model?
A:It is no different than any other non-aerobatic Lycoming engine. Note: most RVers do not have 'aerobatic' Lycomings. I do everything but snap manuevers in my 6A.

Q:Am I better off with a different model?
A: That depends on your finances. The price you quote may allow you to get airborne considerably sooner. There will be prejudice when resale time comes along from others who have the same questions you have asked. Certainly a newer/more HP engine capable of using a CS prop would produce greater resale and performance. Again, that is all a question of ecomonics.If this price engine allows you to fly this decade, jump on it.

Q:Any suggestions would be great.
A: >On the RV-6A, Vans sells a special engine mount that has the top rear member arched slightly to allow the engine to fit. Many' RVers have modded the standard mount themselves. Ask for that mount when you order your finish kit. Should you re-engine later, other non-H Lycomings slide into place.
>The recommended oils must be used. They have an anti-scuff additive mixed into the oil.
>The H2AD is still listed in the Lycoming lit as current production model still available new from Lycoming. Parts are relatively cheap.
>Because of the forward fuel pump and the never-machined prop gov pad on the front (no-you cannot add CS prop to this engine unless you use an electric/non aerobatic prop) ,The cowling front may need to be built up slightly. Some use 'bumps' on the top cowl front.
 
H2ad

I Have a H2AD IN MY rv-7 i BOUGHT THE ENGINE FOR 3500 BUCKSWITH 1400 HOURS ON IT, IT WAS NOT A T MOD ENGINE AND FROM WHAT I HEAR THE T MODS STILL HAD PROBLEMS

When I bought the engine I was able to remove the lifters and check them out they were all fine the comp was good there was no metal in the strainer or filter

I sent the mags out to Maxwells in FL and ended up replaceing them with model 3000 which elimated the 500 hour AD for inspection and when I replace the mages I also installed a new coupler for the drive

I have since flown 100 hours on the engine and just did my third condition inspection all is fine

I have the vans mount cost 50 bucks more the baffels are no harder to do on this engine as it was on a 180 hp lyc

I'm in the process of painting my plane now and at this time i have orded a james plemum with the rings i'm not sure how they will fit becasue of the fuel pump and govenor pad, I will be starting that next week on the firts trial fit It looks like I can do it

Yes you have to mod the top cowl to fit two bumps worked great and most people never even notice the bumps

I have not been disapponted with the engine sure if money was not a problem or I would wants payments I would have 180-210 hp with cs but money is a concern this has worked out great yes if i ever sell it it will not be worth as much(?) but i have less in it

Fuel burn solo 2100 rpms cruise about 165 mph 6.5gph Two people some baggage full throttle 2500 rpm 9gph

I have started to buy some engine rebuild parts for when that time comes buy alittle at a time makes it easy I have the roller cam set up(got a good deal last year from canada)

RV-7 fuse painted in maine
 
Hey Guys.
maybe someone here could help me,
I just have bought a H2AD for my low-wing plane. So, I decided to buy a fuel pump p/n LW-15399 from my part catalog Lyc_pc-122.pdf.
After buy it from spruce, I had a big suprise at installation time, because I cant see nothing to move the arm of my fuel pump, I just see a hole whithout the camshaft extension to move the fuel pump.
I cant see installation details in the catalog and I am worried about it.
Any help will be very grateful.
Regards.
Helio
[email protected]

ps:
please see what I see in my O320-H2AD fuel pump location, and tell me understand why that:
http://www.ppxdf.com/h2ad/image_1.jpg
http://www.ppxdf.com/h2ad/image_2.jpg
http://www.ppxdf.com/h2ad/image_3.jpg
http://www.ppxdf.com/h2ad/image_4.jpg
http://www.ppxdf.com/h2ad/image_5.jpg
http://www.ppxdf.com/h2ad/image_6.jpg
 
Helio, I tore down a H2AD last year. Pics are here: http://picasaweb.google.com/pilotandy/RV9AEngine#


You might want to pull the lifters to check for wear, and you might get some more clues while doing so. I believe there was at least one (maybe more) aftermarket cams for this engine. One was for a cam/lifters that used roller bearings. It's possible that these cams might not have had the pump actuator. Hopefully someone else can chime in with better info.

My engine is a stock t-mod 320-h2ad with no surprises, so that will perhaps offer another data point. Comparing my pics to yours, it seems like you should definately be able to see the fuel pump lobe.

To pull the lifters, remove the valve cover, remove the stamped rocker(keep track of shims!), remove the pushrod, remove the shroud clamp, remove the shroud, and you should be able to get the lifter to slide right out. You can use a popsicle stick to grab at the edge and pull it out if it doesn't come on its own. Be sure to keep them clean, and put them back in the same place you pull them from. Once out, you can inspect the lifter face as well as the cam lobe by looking down the lifter bore with a flashlight. At the very least this might tell you if you have one of the roller lifter kits, and also what condition your lifters/cam are in.
 
ppxdf said:
Hey Guys.
maybe someone here could help me,
I just have bought a H2AD for my low-wing plane. So, I decided to buy a fuel pump p/n LW-15399 from my part catalog Lyc_pc-122.pdf.
After buy it from spruce, I had a big suprise at installation time, because I cant see nothing to move the arm of my fuel pump, I just see a hole whithout the camshaft extension to move the fuel pump.
I cant see installation details in the catalog and I am worried about it.
Any help will be very grateful.
Regards.
Helio
[email protected]

ps:
please see what I see in my O320-H2AD fuel pump location, and tell me understand why that:
http://www.ppxdf.com/h2ad/image_1.jpg
http://www.ppxdf.com/h2ad/image_2.jpg
http://www.ppxdf.com/h2ad/image_3.jpg
http://www.ppxdf.com/h2ad/image_4.jpg
http://www.ppxdf.com/h2ad/image_5.jpg
http://www.ppxdf.com/h2ad/image_6.jpg
Click to expand...

Since this engine was installed in Cessna 172's, they didn't use (or need) a fuel pump so the plunger will not be there. In order to add it you will have to find the right plunger, split the case and install the install it.

Rather than going thru the trouble, I would suggest you consider going to dual electronic ignitions with dual electric fuel pumps. Forget the mechanical pump altogether. This is the route I've taken with my Rocket.

Personally I think the H2AD is an excellent engine, there is one in a C172 that lives in a tee hangar behind our home, and it went 3800 between overhauls, in a flight school airplane that got whipped on a daily basis.
 
rocketbob said:
Since this engine was installed in Cessna 172's, they didn't use (or need) a fuel pump so the plunger will not be there. In order to add it you will have to find the right plunger, split the case and install the install it.

Rather than going thru the trouble, I would suggest you consider going to dual electronic ignitions with dual electric fuel pumps. Forget the mechanical pump altogether. This is the route I've taken with my Rocket.

Personally I think the H2AD is an excellent engine, there is one in a C172 that lives in a tee hangar behind our home, and it went 3800 between overhauls, in a flight school airplane that got whipped on a daily basis.
Click to expand...

Dear rocketbob
Could you, please, give more details about your "dual electronic ignitions with dual electric fuel pumps".
My H2AD is equipped with dual Mags Bendix D4RN-3000, instead of D4RN-2021. So, At first I am thinking to buy just the dual electronic fuel pump? What do you think?
 
H2AD fuel pump plunger

I just took my freshly overhauled H2 crankcase, and a new fuel pump, and the old (scrap) cam, and it looks like no plunger is required. There is definitely nothing in the parts book. The arm runs on the cam lobe.

I bought a 2046 TT H2 core, Tmod, from a 172N, NDH. It went through 2 independent (different A&P's, in different states, one seller paid, the other buyer paid) pre-purchase inspections in 5 hours, both noting 'no cam wear' . It was flown another 10, then upgraded to a 180hp O360, a common 172N upgrade.

I tore it down, noted a clean cam, visually perfect. After having the cam cleaned up, I scraped at the #3 lobe with a fingernail, and out popped a fingernail sized & shaped divot. Neato. New cam, $798 at airsuppliers.

Otherwise, the entire engine looks great. Crank dialed as new.

I'm going mech + elec boost on fuel pumps, my engine had the D3000, which I have had rebuilt. BTW, the 500 hour/5 year inspection still applies, how I read it. It's going to be a full-compliance engine, which where new is required and then some. New Lyc cyl, which is the big $$, at $1260 each if you ask factory cyl nicely. Std 320 jugs are ~$1000.

I'm also going with an Ellison. I'll do the single mag/elect ign swap at the first 500 hour mark - let the finances recover a bit! Vetterman has an exhaust for it. It's a 7/16" prop bolt motor. It's a 8.9:1 compression(you may see it as "9:1"), so 100LL is a must. I flirted with LC pistons - from the book info, the 8.0 -320 pistons should work, but nobody has done it that I could find. The Skytec LS starter fits nice, the plane power boss alternator mount looks like it will fit good on the stock mount.

The guy I bought it from is a A&P, having built 2 RV's both with H2's. He firesleeved the fuel lines, ran over the top and down the front ('cool side') from the collator to the pump to the carb.

Just my $0.02, YMMV. Rick 90432
 
thank you rocketbob

Before I decide setup my Electric fuel pump I wonder hear you if you have heard someone install a mechanical fuel pump in the vacuum driver, as showed in the picture below
http://www.ppxdf.com/030.jpg

I remember I saw it before, but I have no idea if it is a good idea or no.
I definitely don't want to open my engine to install a plunger there. Then I should to install a dual electric fuel pump in my carburetor engine in this case.
 
ppxdf said:
thank you rocketbob

Before I decide setup my Electric fuel pump I wonder hear you if you have heard someone install a mechanical fuel pump in the vacuum driver, as showed in the picture below
http://www.ppxdf.com/030.jpg

I remember I saw it before, but I have no idea if it is a good idea or no.
I definitely don't want to open my engine to install a plunger there. Then I should to install a dual electric fuel pump in my carburetor engine in this case.
Click to expand...

I believe you could install a Romec or Titan gear driven fuel pump there I believe... no need for vacuum if you have electric instruments.
 
rocketbob said:
I believe you could install a Romec or Titan gear driven fuel pump there I believe... no need for vacuum if you have electric instruments.
Click to expand...

Thanks again rocketbob,

You have switched on the light at the end of the tunnel, And I am happy hear you again.

I see this one at Aircraft spruce
http://www.aircraftspruce.com/catalog/eppages/romecfuelpump.php
I am trying a difficult contact with them in order to buy the correct one.
My carbured lycoming O-320-H2AD is not there, and maybe those fuel pump are for high pressure, so that is another way to run...

I see here some others
http://www.aircraftspruce.com/catalog/pdf/Kelly Aerospace Fuel Pump Application Chart.pdf

You help is always welcome.

regards,
Helio
Brazil
ps
I have found nothing about titan
 
Please post back here with what you find Helio. If someone does make a pump that mounts onto the vacuum pad, it would eliminate the need for H2AD builders to add the pump blister to the forward part of their cowls (providing they don't need a vacuum pump).
 
The Romec pumps are adjustable, so you can set whatever pressure you want. If it doesn't adjust down to the range the carb needs, is just a matter of changing the spring on the relief valve.
 
rocketbob said:
I checked the pump I have, and it won't fit on the vacuum pad.
Click to expand...

Thank you so much my friend.
I did phone call to aircraft spruce and they told me that they have only the Quick Kits for those models.
http://www.aircraftspruce.com/catalog/eppages/romecfuelpump.php

Today I just got a ROMEC RD7790 in good condition (it was in oil stocked).

This romec fuel pump RD7790 is used in carbured continental engine>
Now I am checking the pressure necessary in the carburetor, reading the overhaul manual of those engine ( http://www.ppxdf.com/romec.pdf )

I hope is not necessary to install any valve for pressure adjust since it is not easy make a return to tank in my case.


regards
helio

btw.
do you remember what model of fuel pump did you check?
 
Last edited:
I have flown some hours using my ROMEC RD7790 AT vaccum PAD.
At Beginner I did not change the spring on the relief valve and I was flown too much rich, because the pressure was about 12 psi at minimum regulator.
Then, I changed the spring on the relief valve for a soft one, and now I am flying at cruise with 2 psi.
In the take-off and landing with the aux pump on, the pressure go to 6 PSI.
(a litle low in my opinion)
I am thinking changing the spring again, to reach at leat 4 or 5 PSI without the aux pump on.

when the aux pump is on, I imagine it will reach 9 psi.

Thanks in advance for any suggestion, or advise if I am walking in the right direction

Special thanks to rocketbob. :)
 
Helio, 2psi at cruise, 6psi on takeoff is fine. I think you're good to go. I'm glad my suggestion worked out for you. The Romec pump is a much better pump than the diaphragm-type pump IMO.

For the benefit of H-engine owners, please post some pics of the fuel pump installation.
 
That's great news Helio. I just got my engine back together and I have been thinking about getting the Romec pump.

Where did you find yours? I'm having trouble locating one.
 
rocketbob said:
Helio, 2psi at cruise, 6psi on takeoff is fine. I think you're good to go. I'm glad my suggestion worked out for you. The Romec pump is a much better pump than the diaphragm-type pump IMO.

For the benefit of H-engine owners, please post some pics of the fuel pump installation.
Click to expand...

Today, in the morning I tried increase a little more the pressure, because in the 800 RPM the engine was stopping.
Mine Romec RD-7790 is not new, and the AXLE broken.
I was in the taxi to go to take-off once more.
I dont know why it happened. I will open it soon to check the internal parts.

I have got another fuel pump.
this is Thompson TF-1900
No need change spring. I can adjust to any pressure from 0 to 12.
I adjusted mine to 6 PSI, same pressure of the aux pump. so, when the aux pump is on, the pressure keep the same 6 PSI.
I liked this one.!!! because it is simple, no need change the spring and I think it is more reliable.
This one is not new too. ?!
Tomorrow I am going to fly and I will post my opinion.
hope someone can add any suggestion.
sorry my poor english ( I speak portuguese here.)
These fuel pump I got here in Brazil with a old friend mine.
see some pics here
http://www.ppxdf.com/romec_thompson/
 
TF 1900

Hi wounder if you could help, ive just purchased an over hauled TF1900 fuel pump to install on my h2ad.
On the pump we have the 1/4 npt inlet and outlet fittings but we also have 1/8 npt fittings on the pump, do you have any thoughts what they are for. john.
 
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