Subaru E-81 Engine Service Manual

[EDMO 1078]

 

Is your engine a single or dual carb?   Jap carb or Holly? 

Do you think it is time to check or grease those bearings in the redrive? EDMO

Dual Carb the guy who I bought the plane from said they are Bing Carbs (not verified) as I have only just started on taking things apart and am educating myself as I go.

I got five of the six prop bolts out the sixth is frozen in bad enough that the head broke off and the bolt is still in place. As soon as I figure out how to get it the rest of the way off the whole thing is getting an overhaul level going over.

Dave

Soak the bolts in something like Liquid Wrench or a penetrating oil for a few days before trying to force them out.  Getting broken bolts out takes another step that most good machinists/mechanics know about.

The dual carb version was only sold in Japan and has more HP - it would not pass the emissions tests for cars in the U.S.A.   This looks more like an early RFI engine because of the dual carbs.

If it needs bored (I forget .010 or .020 oversize?) either Subaru or VW pistons work, but most of them don't need boring and can be overhauled at home or locally.   RAM is probably best place for professional aviation overhauls.

EdMO

 

Edited 20 Oct 2016 by EDMO

[Dave0415 8]

I had hit it with penetrating oil several time over the five days before the bolt head broke off.  Now I am trying to figure out if the prop mount is just stuck or threaded in.

[EDMO 1078]

I had hit it with penetrating oil several time over the five days before the bolt head broke off.  Now I am trying to figure out if the prop mount is just stuck or threaded in.

Are you talking about the (Warp Drive?) prop hub, or the flange it bolts to?  can you post up a photo and better description of what you are calling a "prop mount"?  The Warp Drive hub just bolts to the flange with 6 bolts - there can be drive lugs on the flange either threaded to the bolt or sometimes the bolts go all the way thru and have a nut on them.   Normally the bolts go into the hub from the front.  Warp Drive has postings on the internet.  That looks like an HP hub, and the bolt circle can be different sizes - I have FOR SALE a HP3-SAE1 for 4 3/8" diameter bolt circle for most small Continental engines, and another HP3-SAE2 for 4 3/4" circle (most small Lycoming).  Rotax uses different "Sillymeter" bolt circles. 

Edit:  Sometimes an impact wrench will jar a bolt loose that you will break trying to loosen with a wrench.   EDMO

Edited 20 Oct 2016 by EDMO

[1avidflyer 1983]

What bolt did you break off?  I see in your third picture of the redrive/engine, that you have the forward half of the prop hub removed.  There is probably a bunch of corrosion around the broken off bolt, between it and the hub.  Can you very carefully tap the back half of the hub free from the prop shaft of the redrive?  If the head is broken off the bolt, and you get the hub off, you may be able to put a vicegrip on the bolt and turn it.  If it's stuck in corrosion, you might just break it off again, and maybe right at the edge of the prop shaft where it will be real hard to get a hold of.  I'm assuming that you broke off one of the 5/16" bolts.  JImChuk

[lostman 198]

I just moved my Stratus engine out into a dry storage locker today. It is exactly the same redrive as you have pictured. The prop is the same as well from what I can see. I have one of the original Stratus engines since it was the one they used for shows. That's the story I got when I purchased it from the builder. I've never seen anyone use two belts though. I can see the logic in it but would worry that if they are even slightly different length (which happens a lot more than you'd think), I would worry they would work up over each other and chew both belts up. I've done a lot of research and never heard of a belt breaking on this type of redrive. All three of my Soob engines with redrives have a different setup. 

[Dave0415 8]

The bolt that broke was one of the six pictured with the safety wire still on them.  They go all the way through to the backside of the pulley on the PRSU.

[EDMO 1078]

I just moved my Stratus engine out into a dry storage locker today. It is exactly the same redrive as you have pictured. The prop is the same as well from what I can see. I have one of the original Stratus engines since it was the one they used for shows. That's the story I got when I purchased it from the builder. I've never seen anyone use two belts though. I can see the logic in it but would worry that if they are even slightly different length (which happens a lot more than you'd think), I would worry they would work up over each other and chew both belts up. I've done a lot of research and never heard of a belt breaking on this type of redrive. All three of my Soob engines with redrives have a different setup. 

Kenneth,  I am almost certain that Reiner Hoffman used two belts to start with - maybe RFI did too?  I think theory was that if one broke the other would get you home - probably bad or un-needed theory tho!   I talked to him a while back.  He had Stratus engine mounts and alternator on ebay and I bought the alternator.   Yes, he bought the dual carb engines too when he started Stratus.    There is a very slight possibility that I may still have his address.

Jim,   My HP hubs take 3/8" bolts.  I didn't see the (3rd?) photo with front of hub off.   Did bolts have nuts on the backside or just threaded into the flange?  Hub should pop off if nothing holding on the front side.   EDMO

OK - now see 3rd photo - looks like bolts threaded into flange.   Ed

Edited 20 Oct 2016 by EDMO

[Dave0415 8]

Thank you everyone for the helpful information.  I will try and tap the hub off tonight.

Ed, You are correct the bolts are just threaded into the flange.

Dave

[EDMO 1078]

Thank you everyone for the helpful information.  I will try and tap the hub off tonight.

Ed, You are correct the bolts are just threaded into the flange.

Dave

I would like to know if there are any drive lugs on the flange when you get the hub off.   So far, none of the WD prop flanges I have seen have drive lugs although most of the hubs have the indentations for them.  EDMO

Edited 20 Oct 2016 by EDMO