sarpet

Where i can buy long plugs?

1QwkSport2.5r

You can find them online pretty easily. K&B 1L is what comes in the Sportsters from the factory and seem to work okay. I use McCoy MC59 plugs in mine with great results.

Sport_Pilot

Try www.mecoa.com for K&B plugs. Any brand long plug will work except K&B and Enya.

1QwkSport2.5r

You probably meant OS and Enya..?

Mecoa is not exactly a barn burner when it comes to getting parts delivered. It might be more of a pain in the keister if shipping internationally.

Sport_Pilot

Well they make the plugs, who else sells them?

1QwkSport2.5r

What I meant was people wait forever to receive their orders. I've read several posts about people not receiving their orders or having it take a long time to get stuff from them. There's a ton of those plugs on eBay right now.

earlwb

Since you are in Finland, I do not know where you can get plugs. Unless there are some hobby shops there that may sell the glow plugs. I would assume that OS and Enya are possibilities there though. The OS plugs are 3/4 length but they will work OK. I was going to suggest Merlin Glow plugs as they sell direct to the customer. Merlin makes a lot of the other small brand glow plugs too: http://www.merlinglowplugs.biz/
One could use Tower Hobbies for glow plugs too. Plus Horizon Hobbies sells glow plugs too.
I would assume that Just Engines in the UK also sells glow plugs.
You can still buy Fox glow plugs via Tower Hobbies and other sources and they are still in stock. So Fox is still making glow plugs for us.

1QwkSport2.5r

Just for kicks, here's my unrun .45 Sportster (early model). K&B 1L glow plug in the head; plug is flush with the chamber. Also, this particular engine came with a head shim .024" thick - probably to run mucho nitro. I'll break it in without the shim on straight fuel 75/25 for an hour or so and convert it to diesel.

Mr Cox

I like the sound of diesel engines too, but that's the first time I've heard anyone refer to them as a concert! lol

There is no need to run it on glow if you intend to use it as a diesel, that's what one would do on a dedicated diesel engine anyway....

Ebay has been the best place in the past for the KB1L plugs, but with the new shipping policies it might not work in the future. Rossi plugs are a little easier to come by here and they have some really hot ones too. The thread on them is long but their Al-gasket is a little thicker than a copper one.

1QwkSport2.5r

LoL. I didn't catch the typo there.. I'll fix that. .

Considering how long these engines take to break in and the cost of fuel considered, it's far more economical to break in on glow first. Not to mention these engines tend to be rather finicky until broken in good... Besides, the instructions from Davis even recommend to break-in new engines on glow before converting. Not that I always care what the instructions say, but hey...

earlwb

Davis of Davis Diesel Development did put in his instructions (with some of the heads at least), to break in the engine using glow fuel first before switching it over to diesel. At the time I assumed that was for making sure the piston ring was seated good. But in thinking more about it, I agree with 1QwkSport2.5r in that it is quite a bit more economical for fuel costs too.

1QwkSport2.5r

The instructions that came with that Sportster .45 head does say to break-in on glow fuel. They take at least a gallon before they are loosened up enough to take a good needle setting. It would be more time consuming and require a lot of fuel to run it in. If it was a smaller engine, I'd try breaking it in on diesel... Someday maybe.

This .45 I have may just squeak a bit during the first couple runs - it's pretty tight. The extra heat of glow fuel will probably expedite the breaking in of the engine a bit too.

For the Sportster fans/experts - was there as much variation in the finning on the head (length/height) on the .45 as there was for the .65? My pair of .65s, and both the .20 and .28 have cast heads with no additional machining to the head fins. The .45's head fins were machined down after casting. They're consistent in height with the larger and smaller Sportster engines I have. My .65s are very early '90s vintage, unsure of the vintage of the .20/.28. The .28 has a bronze crankshaft bushing, the rest are not bronze bushed.

earlwb

I posted pictures of it back in this thread someplace. But with the 65's they had at least three different heads for them. The early ones had fully finned heads, the later ones had half that much, and the last ones have most all of the fins machined off. I assume they did the same with the .45's too. The problem was cooling, the earlier heads had too much cooling and it affects how the engine runs in the air. On the ground you wouldn't notice it per se. But in the air with the extra air flow moving over the engine, it gets cooled off too much, thus making it more tricky to adjust the needle valve.

1QwkSport2.5r

That makes sense - I remember seeing the photos of the various .65 heads.. Was just curious if they for sure did the same thing on the .45s. The machined fins on the .45 head makes the engine look more refined. I think the as-cast appearance to be a little less refined. I don't think they look cheap though. Function over form is the way to go in some cases.

After seeing my .20 run as a diesel, I'm excited to see how the .45 does. It should be a really nice comparison to the .45 SuperTigre I have.

Hobbsy

My Feedback: (102)

I like this one, I think everybody in the world bought Irvine .53's to Dieselize and he had to keep making more. One time when he was out of them he said he had a prototype that was unused, I bought it just for the cool factor. No pun intended.

The .45 should be a powerhouse and it will look nice.

1QwkSport2.5r

I was recently given a couple more Sportsters from a gentleman that bought a huge engine collection. He gave me a good .20 that should run well - it's used, but not heavily. The other is a .45 that has had a harder life. It's not been run much - it's still fairly tight... But the lower rod bushing is worn out of round and there are two little flecks of chrome missing on the piston. Not enough to be a problem I don't think... But the engine was run horribly lean. The new/used .20 has the later style head without o-ring; the .20 I already had does have the early o-ringed head.

Of my collection of Sportsters, only one (the .28) has a bronze bushed crankshaft. All of the other ones are earlier models with the standard bushing (the aluminum crankcase).

So, I have a pair of .65s (one is new), a pair of .45s (one is new), a pair of .20s, and a .28 (new). I have Davis Diesel heads for the .20/.28 and the .45. The used .45 won't get run without a new rod - which may take a long time to find as Mecoa doesn't have parts for the .45 despite the website sometimes saying they do. Might have to find one on eBay or something.

wnewbury

Just flew my Sportster 45 for the first time in about 15 years. What a great sport engine. Starts, runs, idles, doesn't quit in flight. What a nice engine.

1QwkSport2.5r

What prop and fuel did you use on the .45?

jeffie8696

Merlin plugs are good stuff. My friend Aldon Kelly is the owner and he is a good guy.

1QwkSport2.5r

Merlin plugs are priced similar to the plugs I typically use, so I may give him a call when I need more. My source for Enya plugs went belly up, so I'll need to find another outlet for those at a decent price too.

FWIW, I use McCoy MC59 plugs in my Sportsters which have worked flawlessly. The K&B 1L plugs don't run anywhere near as well for some odd reason. My Jett .56LX came with a 1L in it, but it didn't last long. Piped engines tend to be picky on plugs anyway - so it didn't come as much surprise to me that it went poof so quick. I'll probably try a colder plug in that engine.

jeffie8696

Aldon is always happy to give advise

1QwkSport2.5r

I ran a new to me (used) K&B Sportster .28 in the back yard today. It came in the mail yesterday. This is what she could do.
75/25 methanol/castor fuel, MC59 plug
10x6 APC - 10,770
11x6 MAS - 9,500
12/23 nitro/castor fuel
10x6 APC - 11,100
11x6 MAS - 10,100

Davis Diesel conversion and 31/22/47/2 ether/castor/jet a/Amsoil Cetane boost

10x6 APC - 11,460
11x6 MAS - 10,000

Compared to my older .20, this one is a bit more stout. IIRC, it turned a 10x6 APC at 10,800 on 5/20 nitro/castor fuel and the same rpm on diesel on the same 10x6. Very nice.

1QwkSport2.5r

I ran some more Sportsters today - a .20 that someone gave me recently. I noticed something odd about the .20 that I didn't notice before... It has sub piston induction - oddly enough the other .20 I have has the same deal going on. The .28s don't have it. I also noticed the piston is slightly above the bottom of the exhaust port at BDC. https://youtu.be/_P987sEdLXk

Lou Crane

I also replied to this one from the notice in my email, but have further thoughts.

In the other note, I suggested that you find a way to lift the sleeve - IF the current condition seems to have adverse effect on idle, throttling, top end, heating or whatever. A sleeve-raising shim or gasket would do it, if such were available... Otherwise, if no adverse symptoms, just live with it...


As I recall, however, at least the .20 Sportster has a mid-block - with the cooling fins - between the case and the head. I'm not sure the top of the sleeve has a flange, but if it does, that, finned center piece sets flange height. Makes things much simpler. The surface at the bottom of the finned block is not a high-heat or flame-exposed area.

Cardboard should suffice. IBM computer punch cards were famously 0.007" thick. Modern cheapo 3X5 cards also measure about 0.007", Glazed playing cards measure closer to 0.009" but the filler in the paper might not stand up to the pressure and heat as well as simple paper/cardboard. The 3X5 cards might compress after some running, but I doubt they'd burn or scorch.

If there is a flange, cutting a spacer is a cinch. Remove the finned mid-block. Turn the case-joint surface up. Lay the 'paper' on it and punch the 4 holes for the bolts. An awl dimple is enough... Hold the "cardboard" to the mid block with bolts, Trace around the interior with a sharp X-Acto #11 blade. (The opening in this block is non-critical; just don't butcher it) Reassemble the head, sleeve and case . Trim away any cardboard overhang with the trusty #11 blade, Done! Takes about as long to do as to describe...

If one such spacer doesn't raise the sleeve enough, another one should help... After some running, recheck that the compressed oil-soaked cardboard under assembly pressure is still adequate. If another one is needed, well, you've been there and done that before...

Luck, and keep us informed?

1QwkSport2.5r

The engine runs fine having that tiny bit of SPI, though raising the liner to remedy it will raise the timing slightly as well as alter the opening and closing of the ports - close later and open sooner. I would need to test run the engines with a shim in place to see how much it would alter the running characteristics. By design, these engines have port timing and higher compression ratios for turning big props slow. I'd be afraid that even the thinnest shim would take away a chunk of their stump pulling ability. Experimenting will be the only way to find out. I think brass shim stock would be a good way to go versus using paper that will compress over time and possibly leak. I could go in increments of .001", .002", .003", or .005". Perhaps one .005" to start with and see what happens. The SPI is such a small amount they it won't take much to remove it. Again - the engines run fine as they are, and idle nicely down to 2,100 on diesel. On glow, they will idle down to 2,600 well enough - all while using the stock OEM muffler.

Id be curious if other Sportster .20 owners note the same phenomenon. One of these .20s is the very early one with o-ringed head and the other is the later one without the o-ring. Neither engine uses a head shim.