Rebuilding my Sky raiders 1835

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tomz28

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Mar 14, 2021
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Hello guys! I wanted to share my project that i started this winter. I purchase my sky raider that has a 20 year old Scott C. engine. First thing I did was a oil change. It did not look good. so pulled the engine. The trust bearing for the cam was smoked!. wrist pins bushings also pretty. Worst part was the valve spring keepers trying to rip off the heads of the stems. These are mofoco 040 heads. At this point time to start over.

new parts that i have for this build:
new CB 69mm counter balanced crank 2lbs heaver
new scat 5.400 h-beam rods -10 grams lighter
new forged mahle 92mm pistons and cylinders pistons are the same weight but the cylinders are 100 grams heavier each!
new cb 26mm oil pump with outlet cover.
new hd rocker arms/shafts and hardware
new W90 camshaft and lifters new cam is 155 grams heavier even with a aluminum gear lifters are 10 grams heavy each. on the edge to order a cb cam with lightweight lifters witch would be 176 grams lighter
zenith carb 14992b
60x28 prop
compression with .054 deck comes out to 7.9 to 1. i do have some .045 barrel shim if i want to drop it down more

I did order some CB Panchito 044 heads ( 6 weeks out) which is a problem because i have a slick mag and aircraft spark plugs. the new heads are made to use a 12mmx 1.25 thread with a 3/4 reach spark plug. I have not found a aircraft plug yet this size. if anyone has any leads some help would be great! lol I also hope they have the port velocity they claim! at over 300 FPM.

block work:
hoover mods
drilled and tapped the oil plugs
full flow mods
cleaned and opened up the oil drains for the front and rear seals


Looking for a nice remount oil filter mount. i have not found a setup i like yet.

Ill try to keep this post going with updates. the crank is out getting balanced, I hope to have it back this week!
 

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Pops

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All the aircraft spark plugs that I know of are 18mm or 14mm . My 1835 engine has a 7.55 CR with a .060 shims. I can burn 91 no ethanol auto fuel or 100 LL.
The prop should be a mid range prop. My engine turns a Culver 60"x 26" at 3200 rpm on WOT climb out. It's a good climb prop of 1200+ ROC in the SSSC and still cruise 80 mph at 2700 rpm.
Nice Sky Raider.
 

tomz28

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Mar 14, 2021
Messages
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All the aircraft spark plugs that I know of are 18mm or 14mm . My 1835 engine has a 7.55 CR with a .060 shims. I can burn 91 no ethanol auto fuel or 100 LL.
The prop should be a mid range prop. My engine turns a Culver 60"x 26" at 3200 rpm on WOT climb out. It's a good climb prop of 1200+ ROC in the SSSC and still cruise 80 mph at 2700 rpm.
Nice Sky Raider.
thanks Pops! i cant wait to have it up and running. but there is going to be a lot of ground testing before i fly it! lol i enjoy reading your post, very helpful.

So what should i do for plugs and wires?
 

Pops

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thanks Pops! i cant wait to have it up and running. but there is going to be a lot of ground testing before i fly it! lol i enjoy reading your post, very helpful.

So what should i do for plugs and wires?
Could you ask CB to tap the spark plug threads to 14 mm for you ? ( Flanklin aircraft engines uses 14 mm spark plugs) I use the Flanklin plugs.
 

tomz28

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Mar 14, 2021
Messages
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Could you ask CB to tap the spark plug threads to 14 mm for you ? ( Flanklin aircraft engines uses 14 mm spark plugs) I use the Flanklin plugs.
Pops what is the reach on them? i have not told them what the parts are for they might not like them being used for a aircraft. but i might have to try.
 

Pops

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I will measure and get back to you.
I am building a 1200 cc, 40 hp engine to power a generator on NG for my off grid cabin. The noise of an unshield spark plug wires disturbs the pictures on the TV using a VW engine, I'm sure it will do the same on your TV. Using shielded sparks plugs is a must for a peaceful home since my wife loves her TV. :) Unhappy wife, they will understand. Have fun building your 1835 cc VW powered electric generator. If the 10k generator breaks down, I'm sure you can find another use for the engine.
 

tomz28

Active Member
Joined
Mar 14, 2021
Messages
25
how are you guys break in cam and lifters and rings? the rings will be most likely from getting her into the air and putting some load on it!
 
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