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0-320-H2AD rocker arms

Greg Dillon

Active Member
I don't know if this is common knowledge but I'll share this bit of info for those of us using this engine. I'm overhauling an H2AD for my RV9A-so far the expensive parts(other than the cam and 2 lifters) are still at new specs-crank, rods, case halves. I was cleaning the valve gear parts at work (I'm a diesel mech) and one of the foremen noticed that the rocker arms looked like Ford 351 C parts. My wife works at an auto parts jobber store so I asked her to bring home a new rocker arm and pedestal for a Ford 351 C --lo and behold the parts were identical . In fact the aftermarket (Sealed Power) rocker arm looked better! So I ck'd the Ford Motorsports website and found that aluminum roller rocker arms can be had that will bolt up with no mods to 351 C heads. I'll be getting a pair of these to test fit-if they work out they could possibly reduce valve guide wear due to less scrubbing action putting side loads on the valves. The big question is whether they will fit under Lycoming valve covers. If not the Sealed Power rocker arms would be a much lower cost replacement for the $25 ea. Lycoming branded rockers. Looks like Lycoming used their head and went with a proven part from a car engine with untold millions in use for their aircraft powerplant. Now if I could just find out who made the lifters for them($160 each ) :eek: I had the undamaged lifters refaced by a machine shop that wasn't afraid of 'Aircraft Engine' parts. Not so with the cam-the welding shop freaked when they saw it was a Lycoming cam--oh well-anybody have a yellow tagged cam for an H2AD? Greg RV9A N4603X (res) (EFI)0-320-H2AD :cool:
 
There is a roller lifter cam package for that engine I have the same engine in my 7 I bought it with 1400 hours it now has a little over 1500 runs great I started buying parts for the rebuild I bought the cam kit New not rebuilt cam roller lifters push rods for $1500 can money give or take on the cost i wuld have to pull the invoice then see what i paid in us funds either way it was a good buy suppose to run cooler and 5 hp gain there is an STC for this kit it will also work for the Tee mod cases

If you woul like more info on this e-mail me and i can get it for you

Ken in maine starting my apint next week
 
On the H2AD engine I would suggest the roller lifter + cam kit if your looking to let it sit for periods of time, otherwise, the H2AD's regularly make TBO if flown weekly.

I would inject a word of caution about using non-lycoming parts in a lycoming, but I'm sure you've already heard it before. Remember the temps will be much higher in the Lycoming engine than in the Ford, and it will be running a much thicker oil that the Ford as well. Consider that before you decide to go with the roller rockers. The "identical" OEM ford part PROBABLY wouldn't be a problem, but you wouldn't catch me recommending it.
 
Lycoming built the H2AD engine specifically for Cessna using many automotive parts so as to build a "cheaper" engine. The parts may or may not be built to automotive standards, but since the idea was to save money, I would guess that they are.
Again, this is pure speculation on my part, and I'm not recommending anything. If you use automotive parts, you do so at your own risk.
P.S. I have run my Lycoming 1000 hrs using an automotive oil filter and we all know that we can't do that!
 
I installed the Ford Motorsport roller rocker arms, checked alignment and clearance from the valve cover--both dimensions are as good as the originals. In racing applications, some guys still use 50wt single grade oil, and the heat factor is high also, so I'm confident the Lycoming environment will be tolerated well. One of the nice things about the H2AD is that a lot of oil is circulated thru the heads, cooling the valve stems, springs and rockers more than other models. This requires a larger oil cooler to remove the heat, so I'll be running an 11 row cooler similar to what the I0 360s require. I was looking at an uncowled 172 with the H2AD engine, and it had an 11 row cooler factory installed. I'm also installing an electronic fuel injection and ignition system, so more heat will be generated due to timing advance and optimum mixture control. A Sam James cowl and plenum will help in cooling also. I'll post updates as I go along.
 
Hi Greg - I'm rebuilding an H2AD as well. Do the ford parts include the fulcrum? Are they stamped metal?

I was originally planning on reusing the old ones, but this may be an option for me.

Thanks!
 
Hi Greg - I'm rebuilding an H2AD as well. Do the ford parts include the fulcrum? Are they stamped metal?

I was originally planning on reusing the old ones, but this may be an option for me.

Thanks!

Any GOOD auto parts store can get you some rocker arm assemblies-I think the brand is TRW.These are the stock stamped steel ones, with pedestal/fulcrum. Ask for ones for a 351C. Any Ford Motorsport dealer can get you aluminum roller rocker arm assemblies. Get the ones to fit a 351C non-adjustable valve train-i.e., hydraulic lifters. you'll have to get some shims from an aviation shop, these go under the pedestal to set your lifter pre-load. You may be able to re-use the shims that came with your engine.:cool:
 
I'm there too

Just starting to buy the expensive parts on my H2AD rebuild, cam, Cylinders. I'm weighing this one, I would love to have the TRW numbers, if you've got them. I'd buy a few and lay them out vs the Lyc parts from my core, ESPECIALLY the metalurgy.
Rick 90432
 
I installed the Ford Motorsport roller rocker arms, checked alignment and clearance from the valve cover--both dimensions are as good as the originals. In racing applications, some guys still use 50wt single grade oil, and the heat factor is high also, so I'm confident the Lycoming environment will be tolerated well. One of the nice things about the H2AD is that a lot of oil is circulated thru the heads, cooling the valve stems, springs and rockers more than other models. This requires a larger oil cooler to remove the heat, so I'll be running an 11 row cooler similar to what the I0 360s require. I was looking at an uncowled 172 with the H2AD engine, and it had an 11 row cooler factory installed. I'm also installing an electronic fuel injection and ignition system, so more heat will be generated due to timing advance and optimum mixture control. A Sam James cowl and plenum will help in cooling also. I'll post updates as I go along.

Hey Greg and someone who 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.
I would like to hear you about your "electronic fuel injection and ignition system" that could be a solution for my case. So, please tell me a little bit more about your "electronic fuel injection and ignition system" .Maybe the best way for me will be a dual electric fuel pump, with dual battery, etc but I need some help to decide what I should to do exactly.
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
 
Last edited:
H2AD fuel pump lobe

I just checked my cam which is wating to be installed in my H2AD case and it does have a cam lobe for the fuel pump. It doesn't look like a "normal" cam lobe as it has muchmore duration than required at the valves. I also know this engine needs the "long arm" fuel pump but ir sounds like you have that. I looked at your pictures and I can't see the cam at all? Let me know what you find out.
Ron Drake
90400
building AcroSport 1
 
I don't know if this is common knowledge but I'll share this bit of info for those of us using this engine. I'm overhauling an H2AD for my RV9A-so far the expensive parts(other than the cam and 2 lifters) are still at new specs-crank, rods, case halves. I was cleaning the valve gear parts at work (I'm a diesel mech) and one of the foremen noticed that the rocker arms looked like Ford 351 C parts. My wife works at an auto parts jobber store so I asked her to bring home a new rocker arm and pedestal for a Ford 351 C --lo and behold the parts were identical . In fact the aftermarket (Sealed Power) rocker arm looked better! So I ck'd the Ford Motorsports website and found that aluminum roller rocker arms can be had that will bolt up with no mods to 351 C heads. I'll be getting a pair of these to test fit-if they work out they could possibly reduce valve guide wear due to less scrubbing action putting side loads on the valves. The big question is whether they will fit under Lycoming valve covers. If not the Sealed Power rocker arms would be a much lower cost replacement for the $25 ea. Lycoming branded rockers. Looks like Lycoming used their head and went with a proven part from a car engine with untold millions in use for their aircraft powerplant. Now if I could just find out who made the lifters for them($160 each ) :eek: I had the undamaged lifters refaced by a machine shop that wasn't afraid of 'Aircraft Engine' parts. Not so with the cam-the welding shop freaked when they saw it was a Lycoming cam--oh well-anybody have a yellow tagged cam for an H2AD? Greg RV9A N4603X (res) (EFI)0-320-H2AD :cool:
Sealed Power Part Number R855 looks like a part that will work. Around $6. including fulcrum. Now, it looks like some online stores selll shims, anybody used these? Also, would anybody have any information on push rods available?
Thanks,
Ron Drake
[email protected]
248-330-1267
 
I just checked my cam which is wating to be installed in my H2AD case and it does have a cam lobe for the fuel pump. It doesn't look like a "normal" cam lobe as it has muchmore duration than required at the valves. I also know this engine needs the "long arm" fuel pump but ir sounds like you have that. I looked at your pictures and I can't see the cam at all? Let me know what you find out.
Ron Drake
90400
building AcroSport 1

yes, I agree I dont have the "normal" camshaft. (no plunger/cam lobe)
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

I would like to buy the correct one for my H2AD, and I?m not sure which is the correct part number.
Anyone could help me?
Where can I find it? new or used in good conditions?

Thank you in advance.
helio
brazil
 
This thread has been quiet for a while, is there any more progress on the use of 351c parts?
 
Also.... Is the roller cam still available??? Can't find anything on the web about buying one.
 
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