J

JimB

Member
For you engine guru's out there. I have access to a first runout O320 A1A. Can anybody give me any advice about the sutibality of this engine for a RV7? Thanks.
Jim
 
O-320-A1A is 150 hp @ 2700 rpm, 7:1 compression, conical mount, fixed pitch. It will work fine in a -7.
 
Well, you could probably find several hundred replies on this basic topic buried in here. But, IMO, the 150-160 hp engines suit RVs very well. You'll still be outperforming spam cans dramatically - even with less than 200-hp. Yes, it's true!

Also, the early/original RVs were intended for -320s, AFAIK. So there's nothing novel or new about using them.

I have a 160-hp on my -8 and find it to be just fine. 80-90% of my flying is solo and the tanks are somewhere in the 30-80% full range. This is a good combination for my flying mission.

Who wouldn't want 200-250-hp out front? In my case, the engine deal I found was just way too good to pass up.

One RV angle to seriously consider is indeed the simple, light one. Put a -320 on the front of a light airframe with a coarse-pitch wooden prop and go fly. You'll have a max speed of 200-mph, +/- a few and save a lot of money/weight in the process.

Last, although most hopefully will never have to find out, having the lighter plane will help should you have to make an off-field landing. This is something very clearly demonstrated back in my old RC days. The lighter the plane, the less damage that would occur with a crash. It's just physics.
 
I would consider upgrading it to a 160HP with slightly higher Compression (still a stock configuration for some O-320's) and go with a Sensenich to keep the weight up a little. Should work OK, might have limited baggage weight is some configurations due to a aft-ish CG because of the lighter engine. I don't remember if the O-320A1A can be configured for a CS prop or not, but if it could, a Harzell would help out that situation.
 
thanks for the response guys, I'm a ways away from making the decision but I appreciate your input. I'll start looking into overhaul costs etc. I'm definitaly considering the 160 hp conversion. I belive the A1A has a hollow crank but because of cost I'll probably stay with a fixed pitch.

Speaking of which, does anybody know anything about prince fp composite props?
 
The A1A does indeed have a hollow crank, but it has the wrong front main bearing. It can be converted but it is a VERY extensive conversion.
 
Thanks Mel, extensive modifications usually mean extensive $$ so I'll keep looking. I don't think I want to go with less than 160 hp.
 
Wait. Don't misunderstand. It's a great engine for F/P. The extensive conversion is for constant speed.
 
Prince Props

JimB wrote "Speaking of which, does anybody know anything about prince fp composite props?"


I have a prince prop on my RV8 with an IO360A1B, 200 HP engine. The prop is beautiful to start with. I had a 68-80 on it initially and was just a little bit too fine of a pitch. I talked with Lonnie Prince and told him what I was getting in cruise, wide open, static, etc and he decided to up my to a 68-83 composite P-Tip wihich I now have.
Initial results are much better, although, not as nice as a constant speed prop would produce. However, I'm in at less that 1/4 of the weight of a Hartzell, and 1/4 of the price of a Hartzell and none of the maintanence costs. So..tradeoff's. You bet. I still cruise at 167 knots TAS, 8-5 to 9.0 gph, Solo climb of 1700 fpm. Take off roll is longer that constant speed but not terrible, approximately 7-800' conservatively, so not bad.
I have been extremely happy with Lonnie's service and product.
I even bought the 68-80 prop to have as an extra in case I ever want to just play around home base. Take off's and Climbs are great just a little too many revs in cruise.
e-mail me if you have any other questions about the Prince Prop.
 
I see, I thought maybe you ment the bearing was wrong for the 160 hp conversion. I vaguely remember some 0320's had tha problem.
 
Thanks Jerry the prince prop sounden interesting it's good to hear from someone with experience with it.
 
I have increased the hp on my O-320-E3D to 176 hp with the O-235 front main bearing. I've got 700 hrs. since converting with no problems. Catto 3-blade prop.
 
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Scott McDaniels wrote on the RV List some years ago that if he were building an RV on a limited budget, he would have a 320 with a constant speed on it. So, if you have a good lead on one, seems a good choice. Perhaps one factor to consider is resale value - I would think a 7 with a 360 would have a better resale value, reflecting demand and percieved value, not necessarily better.
Bill
 
C-GRVT said:
Scott McDaniels wrote on the RV List some years ago that if he were building an RV on a limited budget, he would have a 320 with a constant speed on it. So, if you have a good lead on one, seems a good choice. Perhaps one factor to consider is resale value - I would think a 7 with a 360 would have a better resale value, reflecting demand and percieved value, not necessarily better.
Bill
Click to expand...
Don't discount the significant number of people who value the lower power engine. There are quite a few who are intimidated by the additional horsepower/higher achievable fuel consumption and who seek a lower price aircraft. But agreed - the majority of potential RV customers probably desire greater hp.
 
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