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/e...olumn&-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." :)