MJD

My Feedback: (1)

I was rooting through my half-A prop box last night, I have one of those combat props with a hangar-rash ding on the leading edge, but out past .020 diameter. I could stick it in an envelope. I'll post a pic here if I remember tonight when I get home.

hllywdb

The smallest of the F2D props I am finding are in the 85mm (3.3") pitch which may work, but I would have to whittle it down a bit to get decent rpm. I am thinking of shaved piston/bored out venturi, polished crank, and CP's idea of pressure tapping the case to start. Just trying to come up with a 2nd TD to experiment with and a few pistons. You can find cylinders on the bay but no pistons or cranks. I should have started this 15 years ago

lfinney

My Feedback: (44)

adding a ounce of hoppes #9 gun cleaning solvent, was the hot trick, when I ran TD .020, and slimmed down revup props..I think that their are carbon props available now...I used two head gaskets...never blew a plug..ran cox red can fuel or hotter

hllywdb

An oz of hoppes to what? A pint of fuel?

MJD

My Feedback: (1)

Here's my FG combat prop with the damaged part trimmed off and the other blade to match. Tips need dressing. Very light, nice thin blades.

Now I just gotta find the specs.. these are the other prop that Larry Driskill offered at the time, this one and the one with the CF strands. Where I put the specs..

hllywdb

That looks promising. I found a site somewhere in Europe that sells combat props that are a 70mm pitch which is around 2.75 I think. But I'm not sure they ship stateside. Larry doesn't have any cf props on the site anymore.

MJD

My Feedback: (1)

These are 1/2A size, so they have to be lighter than the F2D props. This one is somewhere in the 2.6" - 2.75" pitch range I think. I have a doubt you'll be able to run much more pitch than that and get anywhere.

hllywdb

You may be right on that but if I can get the motor up over 25k it should be plenty interesting at this size just to keep tracking it. Any idea of the manufacturer or US source for it?
I've been tied up getting my daughter's car ready for paint this weekend, short story she let her boyfriend drive it which resulted in yours truly replacing a fender, door, and welding a quarter panel on. One of my flying buddies is letting me borrow his shop to shoot it in this weekend. He has 2 daughters as well so he knows the drill. So I haven't made much more progress on the plane other than trying to locate another engine and spare parts to tinker with and trying to track down props.

hllywdb

Got a chance to get a little more done. Started the "D" tube planking with 1/32". With less than 1/16" between the spars, I opted to just run a bead of Ambroid between the spars rather than try and cut webbing that small.

Was thinking more on the TD mods, has anyone tried to drill and re-tap a 020 intake to take an 049 TD venturi and spraybar? Might be smart to start with one of the aluminium intakes. This would also allow for a KK or Texas Timers fine thread needle too. Since there is not much room to hog out an 020 venturi, the 049 TD makes sense. Think it would be too much? I could always restrict it a bit if needed.

combatpigg

My Feedback: (3)

I think a TD.049 NVA sounds like a good idea. It will look like a 1150 Dominator sitting on top of a 283.

hllywdb

Ha! That's exactly my first thought CP. I figured an 1150 works fine on a small block as long as you launch at over 5K. Since there is no throttling to deal with it should work OK.

combatpigg

My Feedback: (3)

Will the velocity stack clear the prop..?
I installed a TD NVA on a Norvel engine with the oval shaped carb casting. The difficult part was carving an oval shaped plug, then drilling and tapping it. The threads cut almost all the way through the filler plug.

hllywdb

I think it will. Worst case I can re-angle it when I drill it out and machine it 90 degrees to the hole. I don't think the angle is critical to the air flow. I could always make a small ram air cowl out of fiberglas, use a couple of pee wee needle springs and make a "Shaker" hood. I wonder if Edlebrock makes chrome glow head covers?

combatpigg

My Feedback: (3)

Funny how the conversation shifts. Before looking at your post I was looking at Hilborn injection systems on Ebay. The going rate is about $6,000....!
A little too much for me, I was just curious how much it costs for the old mechanical system now a days.
They want $10,000 for a 8-71 blower, so $16,000 for the package. Of course if you get into unlimited tractor pulling, you'd need 4 of those set ups plus 4 in reserve as spares.

hllywdb

It's crazy how much stuff has gone up. In 1978 a 671 was $800 for my 351 and that included the intake, belts and pulleys. No wonder the kids are hopping up Nissans and hondas today instead.

combatpigg

My Feedback: (3)

I'm hot rodding a 65 Ranchero right now with a 351W. I remember those prices back in the 1970s. Some items haven't gone up all that much. The Ranchero is a masochistic project because these early uni-body cars are horrible to restore. I even had to remove the cowl to patch the "rain gutter" panel underneath it. I'm about 14 months into this one and it's been about 14 months since I flew any toy planes.
The 351 will need a hood scoop and I've been mulling "shaker hood" ideas.

aspeed

There was a Thunderbird with a blower and a Buick V6 or something that had one. You can find those at swap meets for a couple hundred (I got one of each for my 32 Ford which I have kind of abandoned) . Totally different setup, but I saw a guy with the Ford one in a little 4 banger that went ok. The .020 just needs the venturi drilled out a bit and a remote needle. These intakes are really on different ends of the spectrum.

lfinney

My Feedback: (44)

a ounce of Hoppes #9 gun cleaning fluid per pint of cox red can racing fuel or the equivalent fuel

hllywdb

aspeed, there's not a lot of room to drill it out without getting into the fuel ring. What remote have you used on a 020? Remember I am going to go with CP's suggestion and put a pressure tap into the case.

Ifinney, thanks for clarifiying

aspeed

I am not sure they are still available, but KirnKraft had a remote needle. 128 threads per inch. Most were used on the .049's but they would work fine on an .020. Just have to open the needle on the motor and use the remote, or plug up where the the needle sticks out. The venturi is pretty small to fiddle with on the little guys. I was just playing with my new .010 and was kind of cautious of just flipping the thing, and my job was machining small parts for a few decades.

MJD

My Feedback: (1)

Aren't the product engine press-fit spraybar assemblies fine thread?

aspeed

I can't say for the .020 because I don't have one, but the Cox .049 ones are #4-80. That is really pretty fine for anything but a bladder. Someone else had a short needle assembly which could maybe be made into a remote. Texas Timers or Doug Galbreath? The KirnKraft one was just a regular 128 tpi needle with a piece of 3/32" brass tubing soldered on where the hole was. It would be very hard to solder without filling up the hole and ruining everything though.

MJD

My Feedback: (1)

I have a KK TD .049, and it has what looks to be the same fine thread needle as a product engine (plastic backplate), so I am guessing it is a product engine NV assembly press fit into the TD spraybar assembly. I've run product engines on bladders before, worked okay.

aspeed

They all will work ok, the 128 maybe a bit better. The TD has a ratchet, and one click is a lot on a big venturi with high nitro and a bladder. Anyway I checked a Surestart and it is #2-80, a Babe Bee is #4-80 as well as a TD. A KK is #2-128. A #2 is .086" nominal dia. and a #4 is .112" dia. The spec. is a couple thou. under nominal. Looks like my KK needle is bent too.

Barrymartin

Ok, bought the router bit cleaned out the glue, most of it so far. And im worried im going to go too deep. So far im about .045 deep, but i bought magnabraid Which is only about .020 thick. I feel to get the gains nice and true i still need to go a bit more. After primer and paint, with no filler...