Hobbsy

My Feedback: (102)

I recieved a new head for my Irvine .25 from AJ today and it works and looks great. The top picture is idling at 3,000 rpm, the lower pic. is full throttle at 11,750 rpm. The prop is an APC 10x5, yes I actually used an APC, for the first time ever. The 11,750 rpm is not the max rpm attainable, I got 12,100 at one point but the engine would wander between 11,900 and 12,100, I reduced the compression 1/8 of a turn and it settled at a rock steady 11,750. I think a lower idle is doable with a little tinkering. The thing actually started while I was priming it with my finger over the carb. The fuel was Davis ABC mix and the muffler is a Davis in cowl. The engine is going to be on its side on a Sig LT 25. Thanks again AJ, good job.

Hobbsy

My Feedback: (102)

I was hoping that some of you would comment as to whether I should try a larger prop or just keep it as is, it works so well that I hate to mess with anything. I ran about 16 oz of fuel through it, which took a long time, no fuel or oil got passed the contra-piston which is at about the mid point of its travel, it takes me about three minutes to get the equipment and engine back inside, by then the engine was only warm to the touch and the muffler cold.

ajcoholic

My Feedback: (10)

Hey glad to hear it.

If it is running that well on that prop why not fly it and see how it performs in the air. You can allways try something different later on.

AJC

AMB

AJ ran the OS10 fp with your head zinger 8x4 davis abc 12000 idle about 3900 SUPER will go in my 54" inch cub with a 9x4 should do an easy 10000 very happy you made it happen, have not run the others yet Sundasy the day run and fly too martin

ajcoholic

My Feedback: (10)

Well thats great too! I didnt hear from you guys so I didnt even know they arrived...

Been very busy, the last two weeks went by in a blur. I am hoping to go run some engines today myself, and get a plane ready for the upcoming week. Our field MAY be ready for flying very soon...

By the way I have a question for you two - I have one plane (an enlarged Cleavland Viking, powered by an old PAW 15) that I use for flying A Texaco. I havent flown it for a few years and was getting it ready to go recently, when I noticed the fuel tubing (the really flexy stuff that Eric Clutton sells) is rock solid! Never had that happen to me before. Weird stuff. I have a pinch off device to kill the engine, so I will need to replumb the lines as the tubing is too hard to pinch now

Talk to you guys later..

Andrew

Hobbsy

My Feedback: (102)

AJ, the only time so far that I've had the Tygon get hard is when I changed the engine on my BTE Flyin King from a K&B 100 with a Davis head to a Saito .80 and didn't change the clunk line to glow fuel tubing. That was really regrettable because my beautiful FK ended up going down through some pine trees backwards. The soft black fuel tubing has never gotten hard. Every time I look at the Irvine 150 I come closer to the conclusion that a Diesel head is a must.

AMB

AJ hit the hardware store and see if they have any weedeater or chainsaw gas line thats what I use if you can get a small enough
diameter for the paw only hitch not flexable enough for clunk line
maybe small diameter vac hose (automotive) for the clunk?? martin

AMB

Hobbsy prop sounds fine like that Davis in Cowl muffler have to pick i=one up for mine mounted sidways I woulf guess an 1x6 would give you 9500 or a little better martin

jessiej

Hobbsy, my only comment on the prop is to keep all body parts well clear of that APC!

That sure is a handsome engine.

jess

NM2K

My Feedback: (14)

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If my left thumb and forefinger had heads, they would both be shaking them vigorously in agreement with your statement. And they went into the APC from the backside at idle. Unbelievable damage to both digits some years ago. APC's are great props - and excellent meat clevers too.

Hobbsy

My Feedback: (102)

Not to worry Gents, I never fly APCs, it will fly with a Graupner on a LT 25 kit I Have ready to cover.

Hobbsy

My Feedback: (102)

Martin has an Irvine .25 deezel now too.

AMB

Yup just got about a week ago graupner 10x6 grey prop 10600 idle about 3000 quiet great transitions no load ups I did not spend a lot of time since had other non engine tjings to do but quite sure it could have been tweeked to 11K with a little time with the compression and carb needle playing martin

AMB

Yup just got about a week ago graupner 10x6 grey prop 10600 idle about 3000 quiet great transitions no load ups I did not spend a lot of time since had other non engine tjings to do but quite sure it could have been tweeked to 11K with a little time with the compression and carb needle playing martin

Ldalmas

I converted a tt25 pro and got 11000 to 10800 with a apc 10x6 10000 with a 11x4 and 9000 with a 12x5not as strong as the irvine but quite good,
Laurence

AMB

These engines are pretty close as diesels the apc props will run a little faster than graupners sort of looks like a dead heat to me on preformance I have 2 TT25 pros in a twinstar but do not remember the numbers the heads are Davis props 9x7 wood zingers I am thinking of going to 9x6 3 blade MAS or equiv martin