Subaru power

[nickzeringue]

I know it won't "qualify" as a mini, but I'd like to use a Subaru to push my rig. My uncle has a 4 cyl, 1600 cc Subaru sitting in his shed. Or I can get a 2.2 4-cyl for about $1000. What kind of reduction is best, what prop, and what ratio, for each powerplant, if anyone knows?

I also spoke with Chuck today about the 40 Kohler, as far as reduction ratios and prop selection; top speed isn't important - low end push and not getting stuck are my main considerations. What kind of props work best on the 40 Kohler? What about if I were to go with a 27 kohler?

NJZ

[Papee]

When working with an "unknown" engine, something that hasn't been done before I would go with an adjustable pitch prop so you can tune the prop to what the engine needs. The 1600 is pretty close to the vw boys so maybe something like what they are using would work for that. Still I would rather have the the ability to fine tune the prop.

If you want to make torque from the small engines you would have to go with a reduction drive. The smaller Kohler you mentioned would not have the power to prevent getting stuck with direct drive. Even with the redrive a smaller motor will only make so much torque and would not make a good motor for any out of the water use such as running trough some mud.

The smallest combination in my opinion for what you are look for as in your description, would be one like Chuck puts on the mini Pro line with a reduction drive. I get away with no reduction drive because my boat never leaves the water except for the occasional stuck on a sandbar deal if I run across one that is to wide. There are only my opinions for what it's worth.

[Spyda-Ryda]

I've seen people fit the ea82 motor with a rotax 4:1 gear and a 4-blade warp drive prop. The only problem is that you need to or you need someone to build a bell-housing to adapt the gear to the block. That set-up performs pretty good on a Spyda hull. I've also seen photos of other types of gears that have been manufactured for subaru motors. Several of the aviation guys use subaru motors as an alternative.

[av8or]

I have a subaru ea-81 I used on my gyro that I am going to be using on an airboat in the future. It has an amax redrive 2.1 to 1 turning a tennasee 66x32 prop. Always got me in the air quick. Used a vw rabit radiator for its better cooling. Made my own intake manifold to reduce restriction of air flow and changed the carberator. Enlarged the exaust manifold for better flow as well.

John

[Spyda-Ryda]

Nick where do you live? If you don't mind my asking..... Last name Zeringue, I'm guessing somewhere in LA....

[av8or]

Tried to down load a pic of my ea-81 ready to set in a boat, but it didn't work

John

[nickzeringue]

Yeah, spyda-rida: I live in Thib, LA and do my airboating in Terrebonne Parish near Houma.

What is the ea81? Is it the regular 1800cc model? With the ea82 being the DOHC model? What model is the older, 1600cc engine?

Could a belt-reduction, such as the one used on Chuck's Mini105, be used to get 2 or 2.5:1 reduction on the something as powerful as the Subaru?

I know all about bellhousings... My immediate family has 5 mud boats currently.

Nick

[Spyda-Ryda]

yeah, the ea81 is the 1.8L model
ea82 is the 1.8L DOHC model
ea71 is the 1.6L model

As far as the belt drive goes, you'd probably be better talking to Chuck. I'm not familiar with the type that they use. I would imagine that it would work though, since a subaru and the evo should put out about the same amount of horespower. Would just have to see about adapting it to your motor. Any of your mudboats built by Boats by Kirk in Des Allemands? Kirk is my cousin. I just got off of the phone with his son Kerwin. He was saying that the guys running small airboats around here with subaru motors weren't very efffictive in the marsh. There are only a few guys running them that I know of. They are running the same rotax gear boxes the we are running. They use some type of bell housing or adapter to mate the box to the block. I think those guys are running the ea82 motor. I actually thought about using that same set-up, but... I didn't like the weight to power ratio for an airboat. Even though the rotax motors cost a lot more, the power to weight ratio is much better. Although, I did opt to use the "Super 1600" subaru motor on my custom surface drive mudboat.

[nickzeringue]

Yes I know Kirk well. He works on my brother's Toyota-powered rig. I would trust him to build me a Subaru powerplant for a small airboat. My plan is to build a mini, something light that even a 40 kohler could push, but overpower it with a Subaru, approx twice the hp and torque. I don't see how it couldn't run well.

Seems like a belt-reduction would be lighter than a rotax gearbox (and cheaper) and also gives you about 6" of offset so you can mount your engine a good bit lower.

How do I get in touch with you to talk shop on the phone?

Nick

[Spyda-Ryda]

Yeah....You'll have twice the torque and hp, but you'll also have twice the weight too. You can ask any airboater and he will tell you that weight is of the utmost importance. What model of motor do you have, or which one were you thinking of going with? What are you thinking for a hull? Have one in mind yet? I'd definately get in touch with the guys that are already running boats with subarus and get some info from them. Possibly see if you can convince them to take you for a ride. When I started building my mini, Kirk was telling about a subaru powered airboat that was for sale. For a good price too! If you decide to build one of your own, as far as a hull goes, I'd recommend looking into Air-Tech Inc. in Reserve, LA. With the weight of the motor in mind, I'd go with the wide hull for more stability. Kirk would be a really good person to talk too, he's an expert when it comes to subaru motors & fiberglass. He's been in the buisness for a very long time. He has some good prices on motors too! And yes, I'd keep the center of gravity (the motor) as low as possible on any application. Basic rule of thumb, your prop tip can be no more than 4" below the top of your transom. Any more and you'll be resticing your thrust.
By the way have you heard of Gator Airboats in Houma, LA. I have heard their name mentioned a few times, by random people, but I can't find any information on them. I'd like to go and check out their boats and operation.
How old are you, if you don't mind me asking? I'll be in Thibodaux and DesAllemands this weekend. Hopefully doing some work on my boat. I wouldn't mind BS'n with you about the boats if you're interested in building one. Or you can send me a private message with a contact number and I'll call you as soon as I get a chance. Just let me know what would be the best time to call.

[av8or]

this is an ea-81 used as an atv.....lol

[chuckitt]

How fast does that Subaru powered Nissan run. Never seen one powered that way before. Engine looks good.
Chuck

[Spyda-Ryda]

Looks good! Do you have any more photos?

[av8or]

we will see if these load

[Spyda-Ryda]

That's a good looking set-up! You said you built the intake yourself? That's neat! How's about your belt drive reduction? Did you custom build it or buy it? If bought, who's the manufacturer? What is the ratio?

[av8or]

Chad,

The redrive is made by remax out of Australia. It is a 2.1 to 1. The intake and exaust are made of chrome molly. The muffler is off of a cherockee 6. All ya really hear is the prop wash. When on the gyro all ya heard was the prop wash and the main rotor, if I did a dead stick landing it was just a woshing of the main rotor. The prop is a Tennasee 66 x 32 pusher with a polymer leading edge. Any other questions, just fire away and I will try to help.

John

[River Rat]

Awesome looking set-up.
Bet it has some nice upper RPM power with those long intake runners Maybe a little sleapy a low RPM?

Seriously, what kind of RMP do you turn that engine?

[av8or]

The normal cruise I used was between 2500 and 3500 rpms

John