H2AD experience?

Does anyone have any experience/recomendations with the Lyc O-320 h2ad engine? I"ve read that they have a history of cam follower problems. I've been looking for a core to overhaul and have found a few first run h2ad models at very good prices. Would I be spending my money foolishly?

320 H2ad

From my research, the problems should be resolved.
There is still plenty of people around whom remember the issues
There are a few maintenace reccomendations to do.
The firewall forward section at this site has an article.
I plan on using one.

AL Smith
RV 6 Finish
N 495 AB Reserved
KEOS

Yes, the "H" engine should have its problems resolved by now but there is a question about the location of the fuel pump when installed in an RV.

It is my understanding that the engine driven fuel pump is on top of this engine and requires a bump in the cowling.

There is an RV-6A flying around the Charlotte area with this engine and the builder installed two electric pumps rather than have to put a bump in his cowling. I don?t know if he has duel batteries to power the 2nd pump or not.

As always, check with Van's. They should be able to give you some more details.

A friend of mine has a H2AD engine in his RV-6. 1000 hours and no problems. I believe he uses a certain oil as recommended by Lycoming to deal with the cam problem. I know that he does not have a bump in his cowling for the fuel pump but I do remember him changing the top of the engine mount to allow proper clearance.

Dave,
While the cam situation is very much improved, it isn't totally fixed. There is an AD note and requirement to report to the FAA and inspect the cam and lifters, any time you make any metal in the filter. Make sure the engine you get has the T mod or equivalent. This indicates that you have the latest cam and lifter configuration. You want the big lobe cam and large diameter lifter arrangement. This is normally denoted by a "T" as the last digit of the engine's S/N but also could be noted in the engine log if the mod was done as parts of an STC. There is a requirement to use a special oil additive in the engine. This additive is already incorporated in EXXON Elite and Aero Shell semi synthetic 15W50. The engine driven fuel pump is driven in the front left portion of the crankcase and could cause an interference fit with some cowls as the others indicated. I know that you need a special mount in an RV and you must order it special from Van's. The H2AD mount will fit both H2AD'S AND DYNAFOCAL 1 but the regular dynafocal 1 mount, they supply, won't fit an H2AD.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."

H2AD engine

I'm completing the install of a O-320 H2AD in my RV-6A.I kept the front left fuel pump. This required building up the top front of the cowling about 1". The Oil door is also in a different spot. It is almost centered on the back of the engine. See Pix attached.

I'd like to make a correction to my earlier post. I have spoken to my friend and he did indeed have to add a bump on the front of the cowling and he did modify the mount in the centre at the back to give better clearance.

The particular one I'm looking at is a first run with 2500 hrs. The thing i'm worried about is that it has been off an airframe for 15 years. It's been pickled......hopefully properly. I wouldn't want to get the thing and be into it for a crank right off the bat. I'm wondering how feasible it would be to do a home overhaul and be flying behind a very thrifty powerplant. Thanks for the info!

p.s. The seller told me that there's no provision for a mechanical fuel pump on this engine? (C-172) This is contrary to what I've been seeing here?

H2AD cam

The big problem was the cam, that they made small improvements to over the years and special oil additives.

http://www.generalaviationnews.com/...o?-token.key=10408&-token.src=column&-nothing

Just released are new cam and roller tappets (cam followers) from Lycoming. This should put to rest any cam issue.

Other issues are: Baffle are differnt (from Vans baffle kit), mechanical fuel pump pad machined?, fuel line routings, different engine mount (Van's has H2AD mount now), addition of cowl bumps (on some planes depending on how you mount alternator or fuel pump?), different alternator mounting, have to make your own throttle cable brackets.

They also have weird 'siamese mags', two mags on one mount. I think you can use this mag with no problem, or you can get electronic ignition. EI can be fired with a magnetic pick-up off the crank flywheel. Not sure if the dual mag can be replaced by a single regular mag if you want one mag and one EI.

As far as cost and spending money, that is hard to answer. You can buy brand NEW O-360 (180HP) for $18,000. If you can get a low time H2AD running, on the cheap, it could be a deal, but a regular O-320 (like a E2D) would be better for all the reasons listed above. If a run out H2AD core requires a rebuild, I would NOT jump on it real fast unless it was close to free or you are guaranteed that 100% of the components are good. If there is damage to the core it may not turn out to be that great of a deal. Having a solid crank is not bad, but resale of your RV will not be helped by this and the fact "H2AD" is a 4-letter word in the mind of many, deserved or not. I would not worry about reliability but buying a used engine is hit or miss. Caveat Emptor, "Let the buyer beware." Good luck and happy bargin hunting.

George

Motto to think about:

"The agony of poor quality lingers long after the sweetness of cheap price has worn off."

The 172 in our flying club with an H2AD went 3800 hrs. before overhaul. It was flogged daily in hot and cold weather by student pilots and never missed a beat. Never got preheated either, other than a blanket and a light bulb.

I have a H2AD fitted to my RV6 and have had no problems other than needing to fit a bigger oil cooler and shift it to the rear right engine baffle to get oil temps down. Turns out this model engine runs a larger cooler than other o320 models when fitted to the 172 as well. It starts easy and runs great and does about 165TAS at 2500rpm on the f/p metal prop. These engines are also sometimes available at bargain prices due to all the well documented, negative hype that continues to surround them. I paid 2 grand for mine...yes you read it right 2k and it came complete and with full log book history AND 1000hrs to run and didn't come from a wreck. So if your on a budget, ask around, your sure to find one just like I did under a hanger bench somewere that nobody wants!
cheers Graham

Hi Alex

Alex Caldwell said:

You've got me thinking, now that the plane is all set up for the H2AD, maybe I should just look for another one with some time left on it to keep as a spare when the time comes, instead of thinking $16,000 overhaul on this one. Would probably be back flying a lot quicker than the overhaul route as well.

Click to expand...

Thats exactly what I did believe it or not!. I got another one for a spare with 700hrs to run almost complete and with logs for $2500....not as good a deal as the first one but ok compaired to what you would pay for a "normal" 0320!.Look around for a private owner or a shop thats done the Pen Yan 180hp engine conversion to an "N" model 172 and you may find the engine they removed available at a bargain price. The Pen yan company is also a source for used H2AD parts from engines removed for their 180hp conversions. I got a spin on oil filter housing from them(its differant from all other 0320's)in great condition and they're good people to deal with as well.
Regards Graham

From a mechanics standpoint, I'd fly behind an H2AD without a second thought. I think twice before I fly behind a Sube...

I've worked on a ton of them with NO evidence that they are any worse in their current form than an conventional lyc.

H2AD teardown

I purchased a H2AD T-mod first run core with 2048TTSN, new in 1984, removed for time and 180hp upgrade. With all logs back to installation, shipped, it cost me $3500. I tore it down within a month of it's last flight. Lifters were fine, good faces, oil filter had no metal, nothing odd/suspicious in the oil analysis. Upon disassembly, cam looked good, cleanup showed some hairline cracks in two lobe tips, and scratching at one of them removed 0.25"x0.03" x 0.015" deep sliver from the face of the lobe, making the cam scrap.

Case is good, YT by Crankcase Services in OK, crank, rods, gears, all ok, crank at standard and good per SB505 (YT on OH) by Aircraft Specialties.

Having done the research, I was replacing the cam a lifters anyway, and figured in the expense. There are plenty of non-H2 cam/lifter failures out there too . . . the H2 is the only engine you can check without teardown, and people DO check due to the history and AD's.

I also am replacing cyls, since the OH odds (cracking heads) don't look good to me. Complete, I expect to spend $16K and have a 'certifiable' clean OH good for another 2000 hours.

Just my $0.02

Rick 90432

I have an H2AD on my 9A and so far have had no trouble. This engine made it out to Grand Turk Island in the Caribbean and back to Colorado. I purchased it for $5,000. It was built with the T mod and already had the spin on oil filter. When I got it had 780 hours on a factory overhaul. I have put 330 hours on it in two years and it continues to do very well. Burns a quart every 10 hours. Compression checks out in the 76/80 range. Fuel burn is ~ 7.5 Gals/hr at 8000 ft.
I did use the mechanical fuel pump and had to add a bump to the cowl. It starts better than any engine I've seen. I had already ordered the Dyna Focal mount from Vans so I just modified mine. The upper crossover tube had to be removed and "bent" more to clear the accessory case. That is the only difference in the mount. As for the exhaust contact Larry Vetterman directly and tell him you have an H2AD and he will get you what you need. It was not a problem. Bolted right up.
Only problem I had was with the carburetor when the "lead slug" that covers the bolt holes in the bowl came loose and stuck the float during a zero G maneuver.
I inspect the lifters/cam every 50 hours and have not had any issues so far. These engines can be a good deal if you can find one that has been treated well. If mine continues to keep running like it has I think a 2000 hour TBO should not be a problem. Many of these engines were used on 172N models, which most of us have flown behind, before we knew anything "bad" about them.