K&B greenhead .35

Ken Cook Fri Nov 24, 2023 7:31 am

I have a few greenheads. I have the .09, .15, .19,.29 and a older .32. The one greenhead .35 I own is in terrible condition. I mean hacked up.The piston liner is also in poor shape. I came across a .35 greenhead and it had me looking twice at it. First thing I look for is the butchered slotted screwheads. For the life of me, I can never figure this out. WHO DOES THIS? Obtain a properly fitting screwdriver. I see more butchered screws, it makes me sick to my stomach.I find it really detracts the value and appreciation for a engine. Some don't care obviously. Most of these screws are practically unobtainable now. I also noticed that on my example someone broke two screws off in the backplate. HOW DOES THAT HAPPEN? It's bad enough trying to remove one let alone two. I have a cross slide vice in my drill press which is a huge help. Nonetheless, the softer metal always wins and regardless of my attempt, the hole went off center. I was able to substitute 5-40 screws for the now ruined 4-40's.

This engine had NO compression, zero. I looked at it closer and closer and was puzzled. The piston liner didn't look terrible so I looked at the gaskets. Indeed the base gasket was a problem. Next was the head gasket, also a problem and then there was no copper washer under the plug. Having two broken screws in the backplate also proved problematic as it wasn't tight.

I made new gaskets which is a bit of a chore. I don't like fiber head gaskets, they blow out and they're not efficient. They cause poor heat transfer. Metal gaskets are much better. I was able to lap the cylinder and use a Fox .35 head gasket. I glass beaded the cylinder head and used Rustoleum mixed with auto urethane hardener. Not only does this make the paint dry faster, it makes it hard and chemical resistant. Only running will tell if heat is a issue. I'm thinking it will be fine. Worst case scenario, I redo it. I used a screwdriver through the plug hole to paint it. I got some paint on the screwdriver and a wirewheel in the drill press didn't want to remove it.

This is the later version which used a bushed rod on the bottom and a two piece needle valve assembly. This needle doesn't utilze a spraybar. I'm not certain if it was a upgrade offering or it came stock. The needle is visible through the venturi. This isn't a aftermarket needle, it is a K&B needle.

ffkiwi Fri Nov 24, 2023 1:06 pm

Lovely work Ken.I agree with your sentiments early on-there are people out there who should be jailed for being found in possession of tools. I react similarly when I see vice gripped cylinders and fins, or plier graunched prop nuts.

the most extraordinary case I can think of that I'm personally acquainted with was when I was given the carcass-that's the only appropriate word-of a Davies Charlton Rapier 2.46 diesel-the original 1957 greenhead model-not the later 1973 re-introduction. Someone...not the guy who gave it to me-had DRILLED a 1/2" diameter hole through the bottom of the crankcase!!!

The mind simply boggles as to what strange universe the person who did this lived to think that this was a reasonable thing to do. I sent the engine-along with several others that needed work-to Robin Hiern-the Australian speed flier-who was at that time doing engine work as his full time job-with the words "i think this is a complete write off-but see what you can do.."
-anyway he did an extraordinary repair job- made an insert, welded the case and machined down to original dimensions, made a new 'cap' to replace the broken off down draft venturi and several other things to get it back to working order-which it now is. He did manage to assemble it so tight though I've been unable to get the fins off to reanodise them back to the nice lime green they were when new.

If you're not familiar with the Rapier; see: https://sceptreflight.com/Model%20Engine%20Tests/Allbon%20Rapier.html

ChrisM
'ffkiwi

HalfaDave Fri Nov 24, 2023 5:38 pm

Hi Ken,
That is beautiful... Cool

My friend John Cook (probably DNA related ! Smile

) had a Greenhead like that.
Out performed my McCoy RedHead .35, by a fair bit, but luckily I could snag his streamer as he had to pass me ! Cool

Great times, until, mufflers needed to strapped on to those nice engines... Sad

No kidding,
13yr old kids, hand flipping Tornado 10-6s and getting the football field cleared for the 'Longer Lines'... Smile

In the 'Heyday' of the local hobby shop having everything we needed for flying the Cox.049 Cl planes... Cool

Thanks for the memories,
Take care,
Have fun,
Dave

P.S. Chris, your engine knowledge is amazing, I Thank You ! Cool

ffkiwi Fri Nov 24, 2023 5:53 pm

Dave-I have been at this game since I was 8 years old-plus I have a VERY good library, and a more than decent (but not photographic!) memory-plus I own a LOT of engines-and was fortunate enough to grow up at a time-and in a country-where diesels were as common as glows-and grew up with both...and you never stop learning-sometimes even unexpectedly at your own hands....this morning for example I posted a comment on facebook where someone had posted photos of an OS Pet III 099 still NIB and was reminiscing about the earlier Pet models...which inspired me to grab one of my Pet-IIs that is still presentable to post a photo of it in reply. Whilst digging in a box of assorted engines intended for display mounting I had a close look at my Pet-I and discovered to my surprise that contrary to what I had thought it DOESN'T use the same crankcase as the Pet-II-the Pet-II case-whilst clearly derived from the Pet-I, has thicker mounting lugs, thicker backplate mounting points, an enlarged transfer passage bulge, and a longer fore and aft exhaust stack.

truly-you never stop learning in this game...

ChrisM

HalfaDave Fri Nov 24, 2023 7:00 pm

Hi ChrisM,
Back in the Cox heyday here west of Toronto, Canada...
We went to the Library to learn stuff from latest model magazines...
Peter Chinn proclaimed the "Cox TD .010 as the most power full engine in the world yet".
Just after, Man landed on the Moon. Wink

The Local Hobby Shop was the 'cool' place to be...
Well worth cutting lawns and shovelling snow, to spend money there. Wink

The amount of different engines over the decades are mind boggling. Shocked

Thanks for sharing your expertice with us Chris... Much appreciated. Cool

Take care,
Have fun,
Dave

GallopingGhostler Fri Nov 24, 2023 10:16 pm

Great job restoring the K&B .35 Torpedo into a runner, looks really clean and like new on the outside, too, Ken.

I got a used .35 Torpedo, but someone hacked the bottom of the piston skirt in a crude attempt to create SPI. The hack wasn't even cleanly machined. It's got almost 3/32nds of a gap.

The auctions overall want too much for the Torpedoes. I've made do with several .35 Stallions with very good compression.

Ken Cook Fri Nov 24, 2023 10:18 pm

I've always been a fan of K&B engines. I just never use them as much as I should be. I truly love the K&B .61, it's a remarkable engine. In addition, the Sportster series. The Sportster engine line receives a bad reputation from many. The technology in what was supposed to be a inexpensive engine line is amazing. K&B invested a lot of money into those engines and the quality is very impressive. The Dykes ringed .4011 engine is a true powerhouse and is found in abundance for low dollars.

getback Sat Nov 25, 2023 7:34 am

You put a lot of work into getting back to running and looking great order , proves you have a love for the engine .

Ken Cook Sat Nov 25, 2023 8:46 am

It did take some time to clean it and make the gaskets. One thing I can't tolerate is having junk. I want good to perfect examples. So so stuff goes into a box and onto the swap meet table. What most don't understand is that if a engine is incomplete in anyway, it's a parts engine. Needle valves are a big expense, if it's missing, the engine is going to require a immediate $20 or more to put it into service. I deal with control line members who are the cheapest on the planet. I won't say that I have a love for the K&B greenheads, they're cheaply made engines similar to the Mccoy redheads. I just have a bunch of period planes that would utilize such a engine and I find it neat to use them.

rsv1cox Sat Nov 25, 2023 6:44 pm

"Nonetheless, the softer metal always wins and regardless of my attempt, the hole went off center. I was able to substitute 5-40 screws for the now ruined 4-40's."

I feel your pain Ken. I have been there. Best center punch, start with a smaller bit and graduate to proper size and half the time you still get drift to the softer metal. Discourging.

Did you glass bead the case as well? Looks fantastic.

Ken Cook Sat Nov 25, 2023 8:15 pm

Bob, I buffed the case on my buffer. I really don't know what I'm doing with it. My dad made the buffer and I used it many many times but I'm not certain if I'm using the correct buffing rouge. The dark reddish brown rouge works quickly but also loads the wheel fast. Aluminum being so dirty to begin with I think requires a different rouge. I believe the dark reddish brown is tripoli but I have a white bar as well which I didn't try. The K&B case had a lot of flash and craters. I filed them first and cleaned up the case prior to buffing. I ran the engine today. WHOA, it's loud. It was very cold today and it was being very problematic requiring 2-3 times the amount of prime it usually takes. On a Master Airscrew 9.5 x 6 it was taching 13,560 on 10% nitro.

rsv1cox Sun Nov 26, 2023 7:52 am

Generally the lighter the color the less abrasive it is. I have yet to try it on a model engine but you have lit a fuse and set a very high standard. I might tear down Fred's Torpedo engine again and give it a try.

I miss Fred's posts, he still checks in but has very little to say. Freddies SE-5 engine on left.

cstatman Sun Nov 26, 2023 3:15 pm

softer compound, longer time buffing,
with breaks in between, don't heat the metal from friction

I can also recommend using Simichrome polish

lots lots of rubbing and cleaning the abrasive off between rounds on the wheel

lots of soft, clean microfiber towels

rsv1cox Sun Nov 26, 2023 3:37 pm

I remember. You are the authority on this. It's too bad that shiney didn't translate into sales. Pride of posession though.

Bob

davidll1984 Thu Nov 30, 2023 11:53 pm

I just found this little .9 I'm missing the needle unfortunately I think

ffkiwi Fri Dec 01, 2023 3:16 am

davidll1984 wrote:I just found this little .9 I'm missing the needle unfortunately I think

In its day-the mid to late 50s one- of the hottest 09s around-the TD 09 being a good 6-7 years in the future-even by later sport 09 glow standards it was a good performer. I still use them in Nos models

ChrisM

Ken Cook Fri Dec 01, 2023 4:07 am

I see the engine has a Arden glow plug in it too. I have a few new ones and the parts to rebuild one or two.

rsv1cox Fri Dec 01, 2023 7:41 am

Love that little .09 Greenhead. There is one on ebay right now for $69.99 with drilled and broken mounting holes. Too bad, it sucks the value right out of them.

Got a .29 coming. I don't know whats going on with me and this K&B thing, I gave them little notice before.

GallopingGhostler Fri Dec 01, 2023 10:46 am

You got a nice .35 Torpedo coming in the mail Bob, NOS with box and spares nonetheless. Thumbs Up

Reminds me a year ago around this time, I purchased a K&B Allyn .09 Torpedo Green Head for $23 + $12 shipping, that was in NOS condition (hardly run if that) and with "tool drawer head paint chips", signs of mounting without box or instructions and an original Champion glow plug: https://www.coxengineforum.com/t16866-kb-09-torpedo-engine .

K&B .09 Torpedo, left side.

It was in much better condition than the Ebay example you mention, Bob. I know I wouldn't spend $70 for a crashed (broken rear lug) and carelessly drilled out mount hole Allyn .09. Yup, agreed, if it remains unsold at end of bid or BIN cycle, then we know why, seller wanted too much.

rsv1cox Fri Dec 01, 2023 12:16 pm

GallopingGhostler wrote:You got a nice .35 Torpedo coming in the mail Bob, NOS with box and spares nonetheless.

Reminds me a year ago around this time, I purchased a K&B Allyn .09 Torpedo Green Head for $23 + $12 shipping, that was in NOS condition (hardly run if that) and with "tool drawer head paint chips", signs of mounting without box or instructions and an original Champion glow plug: https://www.coxengineforum.com/t16866-kb-09-torpedo-engine .

K&B .09 Torpedo, left side.

It was in much better condition than the Ebay example you mention, Bob. I know I wouldn't spend $70 for a crashed (broken rear lug) and carelessly drilled out mount hole Allyn .09. Yup, agreed, if it remains unsold at end of bid or BIN cycle, then we know why, seller wanted too much.

He sent me an offer of $40 that I must ignore. I don't have the heart to tell him that it's worth $20 or less as a parts engine. But if anyone would like it, just send him an offer of $40.

GallopingGhostler Fri Dec 01, 2023 12:39 pm

Yes, agreed. I'd rather buy a Tee Dee or Medallion .09 in good used condition for that amount of money (which are light and more powerful) than for that parts engine, as you say.

There are other engines in the same displacement class would also work, too.

rsv1cox Fri Dec 01, 2023 6:24 pm

Got it today and well over-packed. He even bubble wrapped the decal. Nice engine that checks all the boxes.

Droobie Wed Jun 26, 2024 7:59 am

Bumping this old thread...I am looking for Torp .35 parts. I have two; one runner that throws my Shoestring around with authority and one with low compression that will only start with the electric starter. I could use at the least a nice piston, but any/all parts considered!

I love these motors, they are way stronger than any of my Fox .35s. I have a really nice Fox I would happily trade for a runner Torp. I find them to start easier, needle more consistently and pull WAY harder with none of the feeble behavior I get from my Foxes.

rsv1cox Wed Jun 26, 2024 2:34 pm

Droobie wrote:Bumping this old thread...I am looking for Torp .35 parts. I have two; one runner that throws my Shoestring around with authority and one with low compression that will only start with the electric starter. I could use at the least a nice piston, but any/all parts considered!

I love these motors, they are way stronger than any of my Fox .35s. I have a really nice Fox I would happily trade for a runner Torp. I find them to start easier, needle more consistently and pull WAY harder with none of the feeble behavior I get from my Foxes.

I will check my spare parts to see what I have. I'll PM you if something you can use turns up.

Where are you located?

Bob

Droobie Wed Jun 26, 2024 2:59 pm

rsv1cox wrote:
Droobie wrote:Bumping this old thread...I am looking for Torp .35 parts. I have two; one runner that throws my Shoestring around with authority and one with low compression that will only start with the electric starter. I could use at the least a nice piston, but any/all parts considered!

I love these motors, they are way stronger than any of my Fox .35s. I have a really nice Fox I would happily trade for a runner Torp. I find them to start easier, needle more consistently and pull WAY harder with none of the feeble behavior I get from my Foxes.

I will check my spare parts to see what I have. I'll PM you if something you can use turns up.

Where are you located?

Bob

Hey thanks! I'm in Southern NJ. My dad and I hang out with the Philly guys frequently.

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