BrickitSAM

Hello, one of my friends recently gave me an old Webra engine, it says its a 6.5ccm engine, I have looked it up and it seems like webra seems to make good engines and this one still has GREAT compression. I'm not really into RC planes so I was wondering if it would be possible to mount it in a car? I have read that plane engines are designed to run at a certain RPM and stay there while RC car engines run at all ranges of RPM, would that effect anything? I will have to replace the carb I know that, it's seized after "not being run for 10+ years" from what my friend told me, also will have to make a custom cooling head.
So the main questions are
Is it a good engine?
Will it work in a RC car?
Any help is greatly appreciated
https://imgur.com/XB3al0B
https://imgur.com/EhzHAHo
https://imgur.com/jAN3IUI
https://imgur.com/eUuGPPk
https://imgur.com/jo1z2hM
Thanks,
BrickitSAM

Hobbsy

My Feedback: (102)

Sir, that is loop scavenged engine, if if you look it will have a baffle across the top,of the piston. A great engine in its day and would still make a great airplane engine . It's not really a high rpm engine. It will have a piston ring too.

Here is a test of it. http://sceptreflight.com/Model%20Eng...2040%20RC.html

BrickitSAM

Thanks! that was very helpful, I might try to get it running, the info said it's good for 5% nitro, and 20% oil, I don't have any fuel like that. Are there any more reasons airplane engines don't work well in cars I did not mention? I'll take it apart and see what the insides look like, the piston looks to be in good shape from the exhaust port.

aspeed

They need a heat sink head to cool properly in a car. There is no prop flow when it idles. If you can get a clutch on it, and it physically fits, it should be ok.

1QwkSport2.5r

And a .40 is way too big for most cars on the market. You would be much better off selling that Webra to an airplane pilot and buy a proper RC car engine. Seriously.

Hobbsy

My Feedback: (102)

I have one of those that needs a piston.

BrickitSAM

Yea, that was my primary concern, cooling, would have to either make a custom head or buy another cooling head and make it fit the other, I don't think finding a clutch would be very hard it would just be finding the right clutch spring tension.
That would work, I would feel a little bad about doing that but I'll just ask him, maybe I could get into RC planes
Would you be interested, the piston in this one looks like it was ran lean from my little experience, its a red-brown color on the top, my pistons in my TRX and cen engines were a yellowish grey like they should be. I'll try to clean it up, whats the best way to clean an engine? From what you can see in the pictures is a tiny bit rusty.

aspeed

You can clean the outside with LA Totally Awesome cleaner which is at the Dollar Tree stores in North America. I don't know where you are from. Just spray it on and let it sit for a couple minutes and use a toothbrush or brass brush and it will look nice. The insides I use acetone. Either way, I would spray some WD 40 or something to stop oxidation. I don't see a muffler, but ya, you could make a plane for it!!! It adds another couple dimensions to it compared to cars. You just can't pull over and think when you are moving.

Hobbsy

My Feedback: (102)

PM me a price without clean up and I'll think about it.

BrickitSAM

I'll try that, it does come with a muffler, I forgot to take some pictures, it does not have a pack-pressure port though, looks like there used to be one put it was taken off.
Ok, I really don't know what these engines are worth, I'll hand onto it for a few days and work on it a bit, try to get it running, I have some traxxas junk fuel that I'm using until I run out and buy the "ingredients" make some home-brew, would that work?
[Edit] I'm also thinking of making a custom RC, most likely a buggy, custom chassis plate, 2wd, using 1/8 driveshafts to handle the large engine, I'll have to see what that would cost compared to just selling the engine and working on my t-maxx

1QwkSport2.5r

The top of the piston should be a med-dark maple syrup color. Darker than that and it was run a bit lean. Heavy black carbon was run too lean. Clean or light tan means it was run rich. The color of the fuel can influence this, but even blue fuels will leave the piston a honey or maple syrup color if they were tuned properly.

Also - aircraft engines will easily get ruined if run on car fuel. I'd not advise using Traxxas fuel anyway, but that would probably be the only one you might eek by with due to its high oil content (16%). Most likely it has way too much nitro in it for the Webra engine though. Get the proper fuel for it even if it's just a quart if you're gonna try to run it.

BrickitSAM

Yea its a darker maple color, I'll take some pictures in a bit, I usually run my engines a little lean to have a longer lifetime on the engine and I don't need blistering performance out of my t-maxx

BrickitSAM

Ok I wont run it on that then, I just took the backplate off, its a pretty good condition just some old oil on it, the inner bear looks to be seized, its not moving at all, and the front section (I don't know the real name) is not moving either, I tried using some vice grips on it and holding it in a vice without much pressure but I don't want to warp anything, also the piston sleeve is not coming out, I tried a zip-tie through the exhaust port and moving the piston up and all that did was cut the zip-tie in half, have any pro ideas?

1QwkSport2.5r

Heat it up real good - this should loosen it up well. Soak in some acetone to loosen up the bearings. Rinse thoroughly, dry well, and oil it. Being a ringed engine, the ring is seated to the liner. Don't needlessly disassemble it if the bearings are smooth after cleaning and oiling. Removing the liner will upset the ring seating and require some careful running to re-seat it. It's usually best to free everything up and run the engine to determine if anything needs to be done.

And lastly - DONT use vice grips or other malicious tools to turn the engine over! This includes putting the engine in a vice as well! Tool marks will turn off a lot of potential buyers (should you decide to sell it) as this will show inexperienced hands have had hands on it and may cause other damage to the engine. If you're not sure what you're doing, ask questions first.

BrickitSAM

Will do, yea I was very careful not to scrape anything, I did put 1 very small scratch on it and I think someone else had already tried judging by some other marks, I'll just soak it on acetone, the front bearing seems to work well, there is some buildup in the engine, where the crankshaft and the piston rod and behind the cam
Also the seals are very hard and I think they are shot, I'll just leave it on the back plate to not risk tearing it.

jaka

Hi!
The bearings has to be replaced! No use trying to clean them! They are rusty and rusty bearings are replaced not cleaned!

1QwkSport2.5r

Nevermind.

BrickitSAM

Here are some more pictures of the engine
https://imgur.com/a/DHptK
How exactly do you embed images?

1QwkSport2.5r

I couldn't get the images to load before, but I could now. That engine is in rough shape. I apologize to Jan for my previous comment. That engine needs a lot of work to be serviceable again.

aspeed

The outside looks really nasty, but inside looks better than a lot of motors I have got from swap meets which worked well. Some had 1/32" of black carbon on the head and piston. They were actually touching. Exhaust ports carboned up so bad that the liners would not come out.

1QwkSport2.5r

Yeah, that thing is gonna probably need the crockpot soak overnight, new bearings, and may as well put a new piston ring in it and hone the cylinder a little. Carb will need new o-rings most likely.

aspeed

I would check the rod and make sure it moves on the wristpin, flush it out with fuel, and fire it up. Maybe get the toothbrush and some LA Totally Awesome soap after it seems ok. Maybe that is just me, but inside looks nice, and, well, it was free. I have seen worse bearings that worked well, as long as the cage is good. The car fuel is a bit low on oil content. Has the carb got unfrozen yet? Often they seize up, but can be unfrozen with fuel and/or heat. I have some that will seize up after a week. Ten years is only a bit worse:-) I take the locating screw out after a soaking so it doesn't get damaged when pushing on the horn.

BrickitSAM

Yea it is in rough shape, soak it in LA totally awesome? dilute some water or just 100%? Yea the engine definitely needs new seals and the carb needs a new O-ring, how would I remove the sleeve? blowtorch the case and pull it out? the rod looks to be in great shape, the outer bearing seems to be in great condition, the carb is totally seized and I think I can see a little rust in the sliding part (Forgetting the real name...)
I'll get some airplane fuel, anyone know of any quarts that will work?

aspeed

Full strength, just spray it on the outside and use the toothbrush. I wouldn't bother with the overnight soak, or crockpot. Then rinse and oil it after. A hair dryer on the carb after a soaking in fuel or acetone, carb cleaner, laquer thinner, whatever is handy. Then carefully turn the barrel until it is free, with the locating screw out. Clockwise is best as the screw loosens if you go the other way. Carefully though, don't break the arm. Use a 10-6 prop or so to run it on a test stand. You may need to make paper gaskets up.

aspeed

Full strength, just spray it on the outside and use the toothbrush. I wouldn't bother with the overnight soak, or crockpot. Then rinse and oil it after. A hair dryer on the carb after a soaking in fuel or acetone, carb cleaner, laquer thinner, whatever is handy. Then carefully turn the barrel until it is free, with the locating screw out. Clockwise is best as the screw loosens if you go the other way. Carefully though, don't break the arm. Use a 10-6 prop or so to run it on a test stand. I would leave the piston and cylinder in for now, and the carb o ring too. Just fire it up after the carb is free.