Anyone building a 3.6 here?

[TahoeTim]

I ordered a kit Saturday and spent the weekend reading up on the 818. I built two FF5 kits almost 10 years ago. It seems that backorders and powdercoat issues are still around.

However, in my absence, I built a kit airplane. That experience made the FF5 kit issues seem trivial. After all, you can't just "pull over" if something goes haywire. I live in Lake Tahoe at 6500 ft so I upgraded my airplane engine from the stock 4 cyl to a 6 cyl so I MUST throw a 3.6 engine in my 818.

While waiting for posting rights, I have been in contact with Wayne about his harness and brain. I see a few 3.0 builds but no 3.6 builds. why? cost?

Tim

[StatGSR]

I'm sure cost and availability is one reason, and I'm sure those crazy connecting rods that are in the 3.6 and general aftermarket parts availability is another.

also doing any h6 swap guarantees that you will not be doing a "single donor" build which is the primary market for the 818.

[TahoeTim]

Yeah, I understand the single donor concept and have lived it with two FF5 Cobra builds and a wombat vw donor build. I want to mix and match parts this time. Donor pallets seem to be around 9k so that is my "donor" budget.

[Goldwing]

The 818 is still pretty young, give it time. Wayne is the only one I know of to try an H6 and I believe his was a 3.0. Talking to Wayne would likely prove helpful comparing dimensions between the 3.0 and 3.6. I think I remember reading the 3.6 is longer. There is a little wiggle room to slide the transmission mounting point backward with regard to the driveshafts. But, it will require some modding at the rear if shifting rearward is needed. The shift selector is close to the bumper as designed. A few solutions have gained an inch and a half, with BobnCincy highlighting a way to get more by cutting the center diff case down. There are a few threads that talk about the dimensions between the H6 engines to search for that are likely a bit buried now. The case mod is newer. Good luck! It would sound beautiful.

[TahoeTim]

Thanks, I've scoured Wayne's build pages and have been talking to him offline. My ship date is August so someone will try a 3.6 by then.

[Rasmus]

those crazy connecting rods that are in the 3.6

I love the "waaah-huh?" factor. It would seem to put less stress on the rod bolts.

[TahoeTim]

Not as bad as I expected. Being an engineer, I kinda like them.

When you are bored, google Jabiru 3300 offset and you will discover that I am not afraid of a little offset. (have that engine in my airplane).

Crap, I just realized why a $3500 ez36 seems so cheap. My aircraft engine was $20k plus $4k for the mounting kit. The 818 feels so reasonably priced now.

[Xusia]

Hey Tim, I'm a fan of the H6's and will probably do another 818 with one in the future. It seems, however, your main reason for wanting an H6 is power and altitude. If that's true, you would be better served by an H4 turbo. Cost aside, building an H4 turbo to the same power level as an H6 is fairly trivial and straightforward. Also, a turbo engine should provide better performance at altitude than a normally aspirated engine. Of course, you could build up and turbo an H6, but then cost, parts availability, and long term viability may become issues. Also, because building the H6's isn't commonplace, there is not a lot of real world data (i.e. the "path" isn't well known, and you are often relying on the opinion of engine builder).

I'm not trying to talk you out of an H6. Just pointing out an easier, more reliable path *IF* your goals are more power and better performance at altitude.

[Frank818]

The 818 feels so reasonably priced now.

It just doesn't fly yet.

[TahoeTim]

I agree if altitude was my concern - I simply want grunt, the sound, and I am not a turbo fan. I guess my age of 55 hinders my turbo acceptance somewhat. I'm still in the mindset that there's no substitute for displacement. My 6 CYL airplane just sounds so good... maybe I am missing something but here's what I have for a budget so far:

engine $3000
trans $1000
VCP harness and box $2400
New aluminum LCA $300
Ebay steering column $50
FF5 adjustable rear lowers $140
VCP shifter $700

That's $7600 which leaves me $1400 to spend for brakes, bolts, etc and stay under the typical donor pallet package. Having built a FF5 Cobra, I know that I will have to add at least another $10k to the budget. My stuff ends up too pretty and I will try to resist this time...

[Jaime]

I love the "waaah-huh?" factor. It would seem to put less stress on the rod bolts.

Everything important is still in-line, so that design isn't all that radical. I would think it would transfer some of the stress from the upper rod bolt to the lower one, which should promote earlier failure. I heard they designed it that way so the rods can be changed without splitting the cases, not for durability or performance.

[TahoeTim]

Now that you mention it, I agree. On the Subaru forums they said the kink was to add stroke but I don't see a kink at all. If your pulling rod bolts apart, you have bigger issues. My foggy brain is recalling a Cat diesel with a similar rod bolt offset:


http://blogs.cars.com/.a/6a00d83451b...240f970b-800wi

396112394_578.jpg

MUCH higher compression

[StatGSR]

I'm not trying to say there is a problem with the factory rods, only the situation you are put in if you actually wanted to upgrade them.

[TahoeTim]

They are factory forged pistons. I have no plans to up the hp so I am not too worried.

[Xusia]

I agree if altitude was my concern - I simply want grunt, the sound, and I am not a turbo fan. I guess my age of 55 hinders my turbo acceptance somewhat. I'm still in the mindset that there's no substitute for displacement. My 6 CYL airplane just sounds so good... maybe I am missing something...

I hear you. I am also not a turbo fan, and hence I went down this road myself. Again, if HP is your goal, that goal is better served by a turbo H4. If other things are more important, like sound, then an H6 is a great choice. Just realize what you are in for both now (some customization) and later (dearth of upgrade paths).

To use an example you can perhaps relate to, a Ford 335 has more displacement than a 289. But good luck building up a 335 for any reasonable amount of money, or with reliable results. Conversely, you can get just about any HP you want from a 289: TONS of the off the shelf parts. LOADS of people who have been there, done that, and therefore know exactly what to do and what to expect. (In case it wasn't obvious, the Turbo H4 is the 289 in this example)

To get specific, with around $1000-$1200 in bolt on parts you can get a stock EJ2xx (turbo H4) up to the stock power level of the EZ36 (N/A H6). And from what I understand, lag is minimal when sticking with a stock turbo (mine's not stock). Don't forget, this car is light, so you don't need tons of torque to get it moving (this is actually the fact that made me OK with the turbo engine).

You might want to check out the last couple pages of Erik Treves' build thread and watch the videos. You can see just how well the turbo H4 engines work in this platform.

[TahoeTim]

Yep, in my Cobra I built a stock 302 with big valve iron heads. I threw a set of webers on top and it was the best $3k I ever spent. It revved like a street bike.

If it takes $1200 to match the 3.6 hp then my plan is sound. I will spend that extra $1200 on the 3.6 engine. Different strokes so to speak...

[Goldwing]

The H6's have a beautiful sound. The 4 just won't compare in that department. The throttle modulation might prove easier as well in the H6. There are good reasons to go with the 6. After driving a turbo for a few years, I did learn to love the feel of a healthy turbo setup. I have to honor my budget constraints, and I found a young donor, so 4 it is. What kind of kit plane did you put together? If I ever get my medical back, I may go that route closer to retirement. The same medical issue prompted me to sell my Goldwing and start my 818 build.

[TahoeTim]

Goldwing,
I went sport pilot since I am 55 and have afib. The FAA frows on heart issues even though it's never been a problem for me, snowboarding and all.

Look at "new posts" for photos of my plane in the welcome section.

[DruOdil]

A 3.6 sounds great but at 6500' the turbo will make the biggest difference. A NA will loose power very fast the higher you go. A turbo will hold up or just a slight loss compared to the NA. Look at the turbo or turbo's your getting to have that nice constant psi.

[Canadian818]

TahoeTim, you have a PM.

[Wayne Presley]

I really like my 3.0 for the sound! The 3.6 sounds like fun too. The 3.6 has 256 HP stock and with a turbo at 8 psi it will make about 390 HP.

[TahoeTim]

Wayne, Did you receive my email regarding aluminum lca's?

What is the final drive ratio of your trans and would you change it if you were doing it over? lot's of 4.44 finals out there...

[Wayne Presley]

I haven't put enough miles on the car to tell if I'd want to change the final ratio or not.

[flynntuna]

The ez36 has a different motor mount system than the ez30r.

[Sgt.Gator]

The ez36 has a different motor mount system than the ez30r.

It looks like the front center mount started on 2010 Legacys and Outbacks when they added the EZ36.

However No Tribecas have the front mount, all years 2007-2014.

2008 Tribeca:
EZ36 2008 Tribeca Motor Mounts.jpg

[Sgt.Gator]

And anyone thinking of a EZ30 or EZ36 should probably download this service manual: http://phantomotaku.com/SVX/011822-MSA5P0631C.pdf

[flynntuna]

It looks like the front center mount started on 2010 Legacys and Outbacks when they added the EZ36.

However No Tribecas have the front mount, all years 2007-2014.

2008 Tribeca:
EZ36 2008 Tribeca Motor Mounts.jpg

Does this mean the mounts are interchangeable for the ez36 depending the application?

[Sgt.Gator]

Does this mean the mounts are interchangeable for the ez36 depending the application?

I'm not 100% sure. The 2010 Legacy/Outback is the first year of the 5th Gen models and added the 3.6 engine. I'm asking now on the Legacy GT forum why the 5th Gen has the front mount and the 4th Gen does not.
I'm speculating that the front mount was added and the side mounts were redesigned for crash safety reasons, not performance. Possibly the new side and front mount gives better impact protection to occupants than the older side mounts only. Someone on the LGT forums will know.

I'm fairly certain of the safety reason though because even the 2.5L turbo has the front mount in the 5th Gens. Here you can see the mount, and the brace that is added to allow the front mount to connect to the block.

H4 2.5L engine mount 5th Gen 3.jpgH4 2.5L engine mount 5th Gen 2.jpg

I have verified thru Subaru parts that the Legacy-Outback 3.0 engine mounts on the side are the same part number as the Tribeca 3.6 mounts. So I assume they would work on all 3.6 blocks.

H6 Engine Mounts List.jpg

[flynntuna]

Found a thread on nasoic regarding the ez30

http://forums.nasioc.com/forums/show....php?t=1323800

[Sgt.Gator]

On the 3.0 vs 3.6 engine mounts: I thought I would get a good answer on the Legacy forum. I did not get an expert answer. The three answers:

1) The 5th gen powertrains all mount from the transmission not the engine block, that is why the funky side mounts are there. Aside from that the 3.6 should be identical to the 3.0 it replaced on the outside at least.

2) I dunno about "identical" 3.6 from a 5th gen probably doesn't have a spot to attach the older style engine mounts. Probably have to go with the Tribeca 3.6 if you want to mount it in a 818.

3) If nothing else the bosses will be there just need to be tapped and threaded. I doubt subaru changed production of the 3.6 just for the 5th gen. It is easy enough to check for the appropriate bolt holes.

[flynntuna]

I think it might be prudent to have a set of each when installing the engine to see what works best?

[Sgt.Gator]

I'll go by Subaru of Bend and check with my techs there, and have a look. They always have newer 3.6 cars up on the lifts, it should be possible to see if the mount holes on the sides are still there.

[flynntuna]

That will be awesome.

[Sgt.Gator]

I went by the shop. They had no 3.6 on the rack at the time but the tech said he'd watch for one and check to see if the side mounts will bolt on. He knew exactly what we are looking to figure out. He did say the trans mounts differently too, I'm not sure what that means for us.
I have checked into Tribeca engines and trannys, they are relatively cheap and available.

[flynntuna]

The 5sp bolted just fine to my 3.6

[Sgt.Gator]

The 5sp bolted just fine to my 3.6

Great! If you are referring to the above comment about the trans mounting differently, I meant to the car frame, not the engine. But if you have a Tribeca 3.6 you should be good to go if you can figure out how to shorten the 5EAT and make it FWD. Or did you bolt up a 5 speed manual?

[flynntuna]

The engine is an ez36 from a 2011 outback, and the tranny is a 5sp from a 05 forester xt.

[PSUalum1986]

The engine is an ez36 from a 2011 outback, and the tranny is a 5sp from a 05 forester xt.

What model 5 speed trans did you use? Which engine mounts? Any alterations to the car to get it to fit?

[flynntuna]

The tranny is a ty755vw5aa. Out of an 05 forester xt 2.5lt final drive 4.44 1st 3.45 ,2nd 1.94, 3rd 1.36,4th .97 5th .73.
Still researching which engine mounts to use. The tranny mounts are stock. It should fit like the ez30 which has already been done. The only alterations will be a custom exhaust, hopefully the raptor headers will fit without any problem

[Sgt.Gator]

Good News: My tech at the Subaru dealer says the 2016 H6 Outback still has the threaded holes for the old style side mounts, they should work with no problem. So all 3.6 should work with the old side mounts.