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Engine basics => Four strokes only => Topic started by: Douglas Ames on May 13, 2011, 02:17:30 AM

Title: Inverted Saitos
Post by: Douglas Ames on May 13, 2011, 02:17:30 AM
What are the oiling issues and any fuel feed problems with an inverted Saito .40?
I have Brodak's new Corsair which is an inverted engine installation. I don't want to disrupt the verticle CG by mounting the engine upright and a sidewinder config. would require redesign of the firewall/ mount, however I do like Bob Reeve's configurations of his Saitos.
Do you think I would need to drill small bleed holes in the rocker covers for drainage? I would think they would act as sumps over time. This is a future winter project.
Title: Re: Inverted Saitos
Post by: Robert Zambelli on May 13, 2011, 06:00:41 AM
Doug - I have run SAITO engines in every configuration with no modifications and no problems. In general, they seem to run best side-mounted.

Bob Z.
Title: Re: Inverted Saitos
Post by: Bob Reeves on May 13, 2011, 08:35:26 AM
Haven't actually looked at a kit but from the photo it would be fairly easy to change it to a side mount. Depending on how it's designed I would either replace the hardwood engine bearers with hard balsa and cut them off at the front of the firewall or eliminate them altogether. If the firewall is 1/8 plywood, make a duplicate to end up with a 1/4 inch thick firewall and use an RC engine mount turned on it's side. Is the cowl built up from balsa or a preformed part with a cutout for the engine already cut. In either case it wouldn't be too difficult to get the cutout in the right place.

That is what I would do simply because I am completely convinced they do run better side mounted and feel it's worth the trouble, however many have ran 4 strokes inverted and seem to be happy. You just have to make a decision, is it worth the trouble for you?

I wouldn't worry about the vert CG nor would I even think about modifying anything on the Saito but the intake..

I do think the Saito 40 is an excellent choice for that airplane..
Title: Re: Inverted Saitos
Post by: proparc on May 14, 2011, 04:46:24 PM
Just remember, the carb is reverse from a 2 stroke so, it is easier to flood it. As to the actual run characteristic, no difference-a zillion RC Saitos will attest to that.
Title: Re: Inverted Saitos
Post by: Air Ministry . on May 19, 2011, 02:36:06 AM
They all run em inverted in Aus . 56s , 72s , etc .

Turn through backwards to clear wet cylinder to avoid hydraylic lock .
I think Berringer used to lube the cam gar set preflight ?
Title: Re: Inverted Saitos
Post by: Chris Wilson on May 19, 2011, 06:07:04 PM
I have Brodak's new Corsair which is an inverted engine installation. I don't want to disrupt the verticle CG by mounting the engine upright and a sidewinder config. would require redesign of the firewall/ mount, however I do like Bob Reeve's configurations of his Saitos.

It would seem that the prototype was indeed using a side  mounted engine in a profile fuselage so it can't be that bad to do the same with a four stroke.

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