Author Topic: Sugden Specials and Nalon Viper  (Read 4890 times)

Offline bp

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Sugden Specials and Nalon Viper
« on: March 25, 2016, 01:38:50 AM »
After 4 years I've nearly finished 2 off Sugden Specials and two off Nalon Vipers.  In fact all that's left to do is to make a couple of needle valve assemblies for the Vipers.
Many thanks to David who provided the EN36a, heat treated and ground the crankshafts for the Sugdens.  I would have added pictures of the Mk 2 Viper, but there was a problem with the camera..........
cheers
Bill

Offline Ramon Wilson

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Re: Sugden Specials and Nalon Viper
« Reply #1 on: March 25, 2016, 07:59:48 AM »
Hello Bill, That's some real nice work - heated and ground crankshafts eh? - cor I wish  ;) What did you use in the Nalons?

I've never been attracted to the Sugden as a design but do know it's a good performer. I have two Nalon cases roughed out (along with two (5cc) ED Hunters) but other things are in the way as usual - you have got the juices flowing though  ;).

Bet they run as good as they look - I'd love to hear how the Nalons perform.

Regards Ramon (Tug)
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline bp

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Re: Sugden Specials and Nalon Viper
« Reply #2 on: March 25, 2016, 08:18:42 AM »
Hi Ramon, On advice from people who have done this sort of thing before I used 4140 steel for the cranks in the Vipers.  It machines very nicely even on my mini lathe. 
I know what you mean about the Sugden, for my money, internally it's like a plain bearing Oliver Tiger, without the Olivers external good looks!!  Because I used a full length bronze bush the weight is about an ounce heavier than it should be at 4.5 oz, still pretty good though.  The Vipers, in comparison are very heavy, the Mk 1 is about 180 grams and the Mk2 (steel fins) is about 195 grams.
Both Sugdens and Vipers "feel" very nice, I'm looking forward to running them!!
cheers

Offline Ramon Wilson

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Re: Sugden Specials and Nalon Viper
« Reply #3 on: March 25, 2016, 09:15:29 AM »
Hi again Bill,

Off the top of my head I have a feeling 4140 is close if not the same as En24t which is what I have used. Yes, it's ideal for the purpose, I've not had one let go as yet  :D

I wasn't certain when I replied earlier whether I had set out to make the Nalons as scaled 5cc versions or as originals. Having just checked them yes they are indeed 5cc. Hmmm? maybe  ;)

Lot's of distractions at the moment and a steam engine to rebuild but possibly later in the year.

Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Jo

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Re: Sugden Specials and Nalon Viper
« Reply #4 on: March 25, 2016, 09:51:21 AM »
They look very nice Bill  8).

Did I mention I have a crankcase casting to make myself a Sugden Special  :embarassed:

Jo
Enjoyment is more important than achievement.

Offline Admiral_dk

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Re: Sugden Specials and Nalon Viper
« Reply #5 on: March 25, 2016, 07:42:30 PM »
Very nice engines  :ThumbsUp: - hope to see a video of them running in the future  :)

Offline rklopp

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Re: Sugden Specials and Nalon Viper
« Reply #6 on: March 26, 2016, 04:37:55 AM »
I built two Nalon Vipers, a Mk I and a Mk II. I love them, in part because they are very LOUD! I like to fire one up on 4th of July in lieu of firecrackers (illegal here in drought country). They are powerful and are finger-bruisers as a result.

Offline billitmotors

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Re: Sugden Specials and Nalon Viper
« Reply #7 on: March 27, 2016, 09:23:23 AM »
G'day guys
I am also building a pair of Nalon Vipers.
 I was wondering if there is any difference in performance between the Mk1 and the Mk2 cylinder engines.
I have made a pair of cylinders for each engine and was wondering which was the best.
Rob.

Offline rklopp

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Re: Sugden Specials and Nalon Viper
« Reply #8 on: March 27, 2016, 11:40:27 PM »
G'day guys
I am also building a pair of Nalon Vipers.
 I was wondering if there is any difference in performance between the Mk1 and the Mk2 cylinder engines.
I have made a pair of cylinders for each engine and was wondering which was the best.
Rob.
I have not noticed a difference between my I and II. However I have not put a tach on them.

Offline rklopp

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Re: Sugden Specials and Nalon Viper
« Reply #9 on: July 17, 2022, 05:17:12 AM »
I built two Nalon Vipers, a Mk I and a Mk II. I love them, in part because they are very LOUD! I like to fire one up on 4th of July in lieu of firecrackers (illegal here in drought country). They are powerful and are finger-bruisers as a result.

I dragged my Vipers out after having sat for close to six years and tried to start one of them. First, I had to free it up, because it was gummed up with dried castor oil - my bad from the last shut-down. Once turning over, the engine would run on a prime but not sustained. I noticed that fuel was blowing back to the tank when choking the intake. Something was amiss with the valve rotor.

Sure enough, the rotor, which I had made from generic black acetal ("Delrin"), was cupped and no longer flat. Apparently some fuel component preferentially swelled the side facing the crankcase. I took apart the other engine, and its rotor was also cupped. The cupping was in the direction such that only the rotor rim touched the backplate and there was a gap preventing the inlet from sealing.

I made two new rotors from linen phenolic, and now the engines run well again. The Motor Boys plans call for "Tufnol," which is phenolic, so I should have listened from the git-go!

Offline Jo

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Re: Sugden Specials and Nalon Viper
« Reply #10 on: July 17, 2022, 06:26:46 AM »
Good stuff Tufnol  :) It comes in a number of types which exhibit different properties ( see attached table  ;) )


Sadly there are very few of the Motor Boys left these days  :(

Jo
Enjoyment is more important than achievement.

Offline Bluechip

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Re: Sugden Specials and Nalon Viper
« Reply #11 on: July 17, 2022, 08:32:13 AM »
Good stuff Tufnol  :) It comes in a number of types which exhibit different properties ( see attached table  ;) )


Sadly there are very few of the Motor Boys left these days  :(

Jo

More info if you trawl around in here:

https://tufnol.com/

Gives all the specific types and applications rather than generic 'phenolic / paper / epoxy' etc.

D.

'Kin hot here already .... wondering how early I can start swilling cold lager  ???  :thinking:    :DrinkPint:




 

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