NORVEL TALK
01-29-2005, 07:42 PM
#1
NORVEL TALK
Hi y'all....been tinkering with an old style AME, the object is to get a good runner for diesel and throttle. The original case and crank combo feel super, no wobble in any axis but nice and free. I can flick the prop with fuel for a lubricant and it spins easily for a couple of seconds. The P/L set is a AME REVLITE replacement as well as the rod. After doing a trial fit /assembly there was a noticeable pinch at TDC, but there was also a pinch at BDC too[
]! I pulled the backplate and the pinch went away, hmmm....the back side of the piston skirt was touching the backplate, so I took a dremel grind wheel and cut a slight bit off the piston skirt. Now a trial fit feels good, there is very little turning resistance until you hit TDC. With an APC 6x3 and 30% nitro it put out 19000 and 7500 at idle with an old G MARK carb. The next thing to try is diesel with a 7x3 APC but I couldn't get it to run. Either the head needs the o-ring replaced, or I need to get some fresh 1/2A blend fuel. I want to get a baseline with the stock rod [on diesel] and then with my beefy "diesel rod".
]! I pulled the backplate and the pinch went away, hmmm....the back side of the piston skirt was touching the backplate, so I took a dremel grind wheel and cut a slight bit off the piston skirt. Now a trial fit feels good, there is very little turning resistance until you hit TDC. With an APC 6x3 and 30% nitro it put out 19000 and 7500 at idle with an old G MARK carb. The next thing to try is diesel with a 7x3 APC but I couldn't get it to run. Either the head needs the o-ring replaced, or I need to get some fresh 1/2A blend fuel. I want to get a baseline with the stock rod [on diesel] and then with my beefy "diesel rod".
01-30-2005, 01:31 PM
#3
RE: NORVEL TALK
Here's another engine that has been on the junk pile, a G MARK .061. It has a P/L like a COX and came with a clamp on muffler and carburetor. I don't have any numbers to quote but it was a dog, a good running dog, but never-the-less a dog. Problem is the crank shaft broke. I vaguely recall ANDYs' mention about crank swapping, so I did a quick look and found a NORVEL crank with a slightly smaller shaft dia. and length. I made a bushing out of mild steel to fit the NORVEL shaft and then milled the front of the case back to where a thrust washer rides on the crank snout. The stroke seems to be just right! The last details will be to finish the venturi and do a ball socket[:'(]resetting. After that it will be interesting to see what it tachs!
01-30-2005, 02:47 PM
#4
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RE: NORVEL TALK
ORIGINAL: combatpigg
Here's another engine that has been on the junk pile, a G MARK .061. It has a P/L like a COX and came with a clamp on muffler and carburetor. I don't have any numbers to quote but it was a dog, a good running dog, but never-the-less a dog. Problem is the crank shaft broke. I vaguely recall ANDYs' mention about crank swapping, so I did a quick look and found a NORVEL crank with a slightly smaller shaft dia. and length. I made a bushing out of mild steel to fit the NORVEL shaft and then milled the front of the case back to where a thrust washer rides on the crank snout. The stroke seems to be just right! The last details will be to finish the venturi and do a ball socket[:'(]resetting. After that it will be interesting to see what it tachs!
Here's another engine that has been on the junk pile, a G MARK .061. It has a P/L like a COX and came with a clamp on muffler and carburetor. I don't have any numbers to quote but it was a dog, a good running dog, but never-the-less a dog. Problem is the crank shaft broke. I vaguely recall ANDYs' mention about crank swapping, so I did a quick look and found a NORVEL crank with a slightly smaller shaft dia. and length. I made a bushing out of mild steel to fit the NORVEL shaft and then milled the front of the case back to where a thrust washer rides on the crank snout. The stroke seems to be just right! The last details will be to finish the venturi and do a ball socket[:'(]resetting. After that it will be interesting to see what it tachs!
I think there may be time for you to build a .0490088 Norvel. Here's the shopping list: AME .049 piston and sleeve, AME .061 crank, .061 rod, and then do that fillin'/cuttin' stuff to turn it all around and make it a rear exhaust.
01-30-2005, 08:56 PM
#6
RE: NORVEL TALK
Well I guess I could have found something better to do with my time[&o]...... The old G MARK runs but it could only manage a wheezing 15K today. I found the piston to head clearance to be .030", so I cut the head to bring it down to a more universally accepted .008". I also lower the liner a couple of thou to restore some of the lost pinch. The engine has pretty good "pop", but acts like it lacks pumping action. Oh well, at least I have a solid foundation to work with, to see if experimentation can bring about some results. Some carefull comparison between a TD liner and this liner should reveal something?
