AutoMike

Working with my old 45, I'm trying to pull the piston/con rod out. The rod wont slip off the crankpin backwards like many other motors do. It looks like the wristpin has to come out of the piston first. Looking inside the wristpin, it appears threaded. What will it take to get this motor tore down? Thanks, Mike E.

Hobbsy

My Feedback: (102)

Mike, I think a 6-32 bolt will screw right into the wrist pin, if not then a 4-40, pulling the sleeve out will let you get the rod off also. Have you already pulled the circlip out? Thanks, Dave

AutoMike

Thanks Hobbsy, I've got the sleeve out already but I didnt know where to go from here with the fox engine. Other makes I've rebuilt before allow the rod to slide sideways and off the crankpin but not this one. Also I didnt see any snap ring in the piston that would hold the wristpin in place. After looking at the setup for a bit i figured I better find some help before I damaged something. Should I be able to thread a bolt into the wristpin and with a little heat, pull it out?

AutoMike

Well this is just strange to me. No clip holding the wristpin in place and the pin is hollow but looking down thru it, it looks to be solid at the other end. I cant pull it out and I dont want to try too hard. I need to replace the bearings in the motor but I just cant figure out how to get to'em.

DarZeelon

Quote:

ORIGINAL: AutoMike

...I cant pull it out and I don't want to try too hard.

Mike,


Use a long bolt, or an all-thread, with the appropriate thread for the inside of the wrist-pin, put a flat washer on the end that sticks out and also a nut.

While preventing the rod from turning, tighten the nut against the washer (and the back of the cylinder casing), like a makeshift puller; and it will get this stubborn pin out.


Before using this 'puller', make sure the rod is threaded as far as possible into the wrist-pin.

Hobbsy

My Feedback: (102)

Dar, I wonder if the .45 is built exactly like the .46 and .50, if so I could be more sure of what I said. One of my .50s has a cold rolled pin in the front end of the wrist pin, its crosswise to the cylinder verticle centerline and is not visible until you get the piston out.

AutoMike

I can see something that just may be this very thing as I stare down the center of the pin. Why is it there and do I have to do anything with it before the wristpin can be taken out?

DarZeelon

Quote:

ORIGINAL: Hobbsy

Dar, I wonder if the .45 is built exactly like the .46 and .50, if so I could be more sure of what I said. One of my .50s has a cold rolled pin in the front end of the wrist pin, its crosswise to the cylinder vertical center-line and is not visible until you get the piston out.

Quote:

ORIGINAL: AutoMike

I can see something that just may be this very thing as I stare down the center of the pin. Why is it there and do I have to do anything with it before the wristpin can be taken out?

If this is the case, Mike, You will need to 'coerce' the con-rod bottom end off the crank-pin...

Turn the crankshaft to have the piston at BDC and use a pair of long-nose pliers with padded jaws (or an L-shape Alan wrench), to slide the top of the con-rod on the wrist-pin, as far back as it would go in the piston.

Then, after turning the crankshaft to bring the piston around TDC; unless your fingers can easily unhook it, use that L-shape Alan wrench, to lever the rod's bottom-end off the crank-pin.

The effort should be minimal, as some 'play' is incorporated into the design of these parts, for sufficient lubrication clearance.


If this seems crude to you, I assure you that the engineer that assembled this engine at Fox Manufacturing, in Fort Smith Arizona, used the opposite forces to get this con-rod's bottom end hooked onto the crank-pin... The proof of it not having been damaged is the fact that this engine ran properly afterward...


And, why don't you post some digi-photos as you get along...

AutoMike

I'll give it another go Dar. I just gave up earlier, cleaned what I could with WD-40, re-assembled the motor and gave it a run up on the bench. 20% Wildcat and an APC 11x5 and it was turning mid 13K! Ran good and after 15 mins of run time the bearings felt very smooth. Just old dried caster was gumming them up before I guess. I still need to learn how to take it apart so I can check the bearings better and de-carbon the piston and ring. That castor oil can sure foul things over time. Thanks guys, Mike.

AutoMike

Here's the engine as I reeived it from an ebay seller...

AutoMike

Notice the grey stuff at the carb base and the backplate? I was worried it was JB Weld when I first saw the engine on ebay but hoped it was some type of RTV and thankfully it was. So I had to cut new gaskets, no problem, but the very strong smell of BP Blaster when I opened the box had me saying "oh no". Tearing the engine down showed only light rust on the liner at TDC and around the very bottom and the chanfered edge. Light work with scotchbrite cleaned up the sleeve but I really want to fully tear down the engine, toss in new bearings and a ring and buff up the piston and enjoy the engine in a Goldberg Falcon III I'm building for this spring.

NM2K

My Feedback: (14)

You are going to have one super nose heavy Falcon III with a Fox large case .45 in the nose. Even a light K&B .40 makes that model come out nose heavy.


Ed Cregger

DarZeelon

Quote:

ORIGINAL: AutoMike

Here's the engine as I revived it from an eBay seller...

Mike,


What I meant was photos of your own engine, from the back, showing the con-rod, crank-pin and wrist-pin situation...

...I guess we all know what a Fox .45 engine looks like...

Quote:

ORIGINAL: Ed Cregger

You are going to have one super nose heavy Falcon III with a Fox large case .45 in the nose.

Ed,


This engine, at 12 oz. net, is lighter than the OS.46AX. But it would be better if some items, such as the airborne battery pack, are moved to behind the wing in this Falcon III of yours.

If low nitro (5%) fuel is used, an 8 ounce tank, properly padded, should be sufficient for a 12 minute flight duration (not at full throttle all the time...).
That would also ease the balance issue.

DarZeelon

Quote:

ORIGINAL: AutoMike

....but I really want to fully tear down the engine, toss in new bearings and a ring and buff up the piston...

Mike,


The statement is; 'If it ain't broke, don't fix it'...

As to bearings, Paul at [link=http://www.rc-bearings.com/catalog/product_info.php/cPath/23_77/products_id/60?osCsid=6cce74683ba4810ff24c93f7bd7fd27c]RC-Bearings[/link] has the rear bearing on offer, for $4, with a polyamide cage (Boca wants you to buy the $32 'High Speed' set to get that...).

On his web site RC-Bearings do not offer shielded, or sealed R6-N bearings, however; only the open type.

Hobbsy

My Feedback: (102)

I just got HighSpeed chromium alloy bearings from BOCA for a Webra SilverLine .40 given to me by a friend. 15 bucks, free shipping.

I've had the best luck getting the rod off the crankpin in my Fox .50 at the 1:00 o-clock position near TDC. That puts the piston nearly up out of the block.

AutoMike

Dar, I've got the pics of everything but I'll post them later when time permits. I got everything apart and sure enough, the wristpin is held into the piston by a rolled pin. Front bearing is like new but the rear cant be saved, ring is worn heavy also. Ring, bearing and gaskets shipped from Fox for about $24, cant beat that. Dar and Hobbsy, thanks for your time. Hey Ed, just think, I was planing to use an ASP 52 4-cycle[X(], but I desided to do the plane in vintage colors and carry it over to a vintage engine as well.

NM2K

My Feedback: (14)

-


I love all of the Falcon series models by Goldberg. They fly great, are easy to build and they are durable.

I've built three or four Falcon 56 models, all series one, but I've helped others build later renditions of the Falcon 56. Skylarks too.

My original model with ailerons was the Senior Falcon, powered by an OS Max .58 R/C engine. What a great primary trainer that plane was, even though it was designed to be a competition pattern plane with reed R/C systems. I taught myself how to fly on that model with zero crashes. I had flown single channel pulse proportional before that, on my own.

I'm glad that your setup is coming along well. As others have said, please post some pics from time to time.


Ed Cregger

AutoMike

It took a bit more work than I thought it should, but I was able to remove the piston and rod.

AutoMike

.

DarZeelon

Nice photos, Mike.


As I wrote and as you can see. The bore of the con-rod's bottom end bore is unblemished, even though the builder at Fox exerted as much force to hook it over the crank-pin, as you did to unhook it...


As to the piston and the cross wrist-pin retention mechanism; I know of no other model engine manufacturer who uses it.

Nearly all use fully floating wrist-pins, with just end retentions of some sort.

kersplat

This wrist pin is held in by a roll pin. I don't recommend you try and dissassemble this without the proper holding fixture.

jeffie8696

Just received my Fox .40 today. it appears much worse than yours. And I need to replace the con rod. It is not going to be fun, it needs a lot of clean up but it is a sound engine otherwise.

rcdude7

My Feedback: (264)

I was lucky enough to get a un-run fox 45 from epay once for about $25. The description was bad and the picture was even worse, I was the only one brave enough to bid on it. When I recieved my engine, it turned out to be a beauty.

Mike

jeffie8696

Yea, ditto. I picked up a NIB 45BB ringed . It is an older model with the bump but it really is beautiful. I got it for little more than I paid for my new .40

AutoMike

kersplat, I'm with you on that one. I'm not daring enough to knock the pin out, thankfully I dont need to, sorry jeff[&o].

Ed, I think you and I think along the same lines, how did you know the Falcon Sr. was in my future? If you dont know yet www.earlyrcmodels.com is re-kitting many planes, several of Goldbergs, from a by-gone era and they are laser cutting them to boot, cha ching! I started rc modeling in the 6th grade, 1986, by building a Goldberg Eaglet 50 un-aided, and learned to fly with help from the local club. I admit it, I'm a Goldberg fan and have said many times over that a guy could spend a life time in this hobby and build only Goldberg kits and always have a plane thats fits his needs as he grows. Its a shame that some of the Goldberg line has faded and who knows what will happen now that GP has it, hopefully not what happend to Ace once Thunder Tiger bought them.

Over the years I did the China ARF thing and the China motor thing and have grow just sick of it. I've decided to spend my cash on quality items and thats about the only thing China cant make. Remember back in the days when engine man. advertized quality with words like "Chrome", "Steel" or "Ringed" and there rods acutualy had bronze bushings at BOTH ends? These engines were robust enough and so well backed that they could be pasted from father to son. Now its Nickel or Nikasil, brass and shoddy manufacturing at its best, not in all cases but still all too many. If I buy 20yr old Fox and K&B engines off ebay, I know I can still get parts new from Fox and K&B. How about Royal,Bratt ,Como,ASP,Magnum or even O.S. ?

OK you can have the soapbox back....lol