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Post by weverat on Feb 6, 2018 17:29:33 GMT -5
Usually with the modern aftermarket pistons, if your piston skirt to cylinder wall clearance is .005 to .007 you will have more than enough ring gap.
It is always good to check to make sure you have at least.005 ring gap per inch of bore. Our 440 pistons are 67mm or about 2 1/4" so we need at least .011 ring end gap. I usually wind up with .025 to .035 which sounds like a lot, but with 2 rings it is perfectly ok and normal.
Back in the day, the piston manufactures sent rings that fit with a minimum of clearance, with the thought that we would file to fit. Modern day, here is your rings, and by the way, they have a giant gap!
You could use rings from a piston 1 size over, and then file these to fit more snuggly, but then you would have rings with a lot of tension. I have no problem running a large ring gap.
With the single ring racing pistons, it helps to fit them much tighter.
Yes, I always use B9 plugs in the Cuyunas, only switch to the B8 if you have a problem with fouling.
Try to keep that engine cool, air vented with duct work into the fan, and vented out from under the hood.
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Post by weverat on Feb 5, 2018 19:37:32 GMT -5
Couple more things I have found, wipe your feeler gages clean with contact cleaner and a paper towel as not to get the points dirty.
Cut a slice of white business card paper about the same size as a feeler gage, dampen the end of it with contact cleaner and drag it or snap the points on to it until perfectly clean.
When, and if you get that dam flywheel off, file and sand the key, and the key way so there are no burs or snags. The flywheel goes on first, then tuck the key in there.
The key is only there to locate the flywheel into position upon assembly. The big nut and tapered shaft hold that bitch from turning.
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Post by weverat on Feb 5, 2018 19:25:31 GMT -5
For timing, I disconnect the wire harness from the engine. The connector from the engine has a yellow, yellow w/green stripe, 2 black wires, and a green or brown wire.
The 2 black wires come from the points and go to the kill switches. 1 is for each cylinder, when you touch these to each other it kills the engine.
Hook your buzzer devise to 1 of these black wires to check one cylinder, and the other black is for the other cylinder.
If you have an analog multi meter, it will have a buzzer on it. The digital multi meters have a buzzer also, but they are not sensitive enough, you see there is always continuity to the condenser, so your buzzer is only going to change notes, it will not be on or off. You could use a light bulb and a battery for this, and it would get bright and dim.
Now for the best part, you get to stick your finger in the flywheel in order to hold the little lever into its fully advanced position, as you rotate the flywheel and read the dial indicator to see when it is firing.
1 thousands of point gap will change the timing 5 thousands. Set both points at .014 to .016 to start with. You can move the stator plate to get 1 cylinder spot on.
In order to adjust the other cylinder, change the point gap by a thou or 2 as needed.
It is really nice if both sets of points are around .015 when done. It is normal to have one set at .016 and the other at .014
Your timing can be way retarded and it will still run good, way advanced and you will burn a piston. I use NGK B9 plugs just to be safe.
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Post by weverat on Feb 2, 2018 6:57:22 GMT -5
I am going to Okoboji, Ia. today for a drag race, but I really want to make that reunion maybe next year.
At Waconia they have a Yellow Fever Club (Skidoo), there was a separate Skiroule area, and of course the Johnson Evinrude guy,s always have a good party going on the ice. Those guy,s are really whacked, you should see there hopped up sleds with "Blitz Kits".
We could mark an area for Scorpion, or just all meet at Jack's swap spot?
Take a few pics and give OBJ some shit for me!
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Post by weverat on Jan 24, 2018 15:39:40 GMT -5
Those Eskimo's are really light weight, and would make a good grass dragger. What engine options did they have? Do they have a Donaldson Power Tuned exhaust?
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Post by weverat on Jan 20, 2018 17:28:24 GMT -5
You have to reach your finger in there and move the little arm in order to check the advanced timing.
There is a good explanation of cuyuna timing procedure on here somewhere. The process is a bit hard to explain, some body should make a video.
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Post by weverat on Jan 14, 2018 20:09:05 GMT -5
NitroMan, can you post of pic of your experiment. I tried to do the same thing, sounds like we had similar results, but it can be done. Of course I am thinking of drag racing where we do not want much travel.
I think it would work fine if we were able to lock the front portion of the suspension and only use it as a pivot point, making the whole thing just a big swing arm?
I have a feeling your going to be running one of those Rupps at Willow next summer! I will be your pit man.
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Post by weverat on Jan 11, 2018 18:11:28 GMT -5
Rockwell Jlo Cuyuna engines with angled spark plugs - .083 to .102 I set these at .083
Verticle plug heads as used in the later models .102 to .112
The older style heads ran hotter and burnt pistons, so the timing was set lower
The modern hemi heads can handle the more advanced timing. With this style head I set my timing at .102
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Post by weverat on Jan 10, 2018 17:30:46 GMT -5
If it is an old motor, the fiber that rubs against the cam will wear down, causing the point gap to go away. I think the correct gap is .014 to .016.
More gap advances the timing, as the point gap wears down the timing retards. Which is a good thing because I like to run the timing on the low side of spec.
These motors do not like advanced timing, if your plate has not been moved you should be ok.
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Post by weverat on Jan 10, 2018 6:35:07 GMT -5
Torque values are the same.
When sanding points I start with 400 grit, and finish with 800 or 1000. Then wet the corner of a clean white business card with brake cleaner, snap the points shut onto that a few times.
Usually it does not take much, but I have come across truly rusty points.
The fun part is setting the point gap through the little windows in the flywheel.
Mount the flywheel and key on there lightly until you are sure it has spark, then give the big nut just a little burp with the air impact,do not rattle it down super tight with the impact, just a little.
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Post by weverat on Jan 9, 2018 21:32:13 GMT -5
As long as you enjoy doing it, go for it. I love working on sleds, and admittedly hardly ever ride them.
This old shit gives me something to be thinking about rather work all the time. I actually believe this hobby keeps me from going crazy, or becoming depressed like so many people now days.
You realize when you get that Para-Rail in there you will have a grass dragger! Have you ever seen a Wahl Brothers grass drag suspension?
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Post by weverat on Jan 8, 2018 20:56:29 GMT -5
The ram air is awesome! Great idea and very nice job
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Post by weverat on Jan 8, 2018 17:58:14 GMT -5
Yes, they can be stubborn. You need a good heavy duty puller, and just the right length bolts. Make sure it is bolted on there nice and square, then use a good air impact wrench, it should pop off.
If not, be patient, your pulling on those 3 little 6mm bolts, and you can only thread them into the flywheel about 1/2".
When it does pop loose, you get to fight with the flywheel key, it needs to come out with the wheel. What I am saying is the automatic advance mechanism hangs up on the flywheel key preventing the wheel from coming off.
Upon assembly, the wheel goes on first, then slide in the key.
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Post by weverat on Jan 8, 2018 17:47:19 GMT -5
The rear H works, and I had engineering problems with my custom set up. I think OBJ has experimented with something different back there too, but so far the H is the way to go.
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Post by weverat on Jan 7, 2018 22:25:25 GMT -5
Yes, it needs manifold gaskets. You can get full gasket sets, or just top end sets, they are all over e-bay, and or your favorite parts supplier.
I would get the full kit, that way your all set if you wind up taking the motor apart.
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Post by weverat on Jan 7, 2018 19:27:42 GMT -5
Very nice!, I always liked the red 79 Stings better than the 1980 orange.
In the back ground there is a 4 foot tall gas bottle, looks like for a torch, is it just propane, or is it something you can weld with?
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Post by weverat on Jan 6, 2018 11:34:54 GMT -5
I will use this plate cut free from an old manifold, this way the cylinders are all tied together, no flex. The little one in the picture was built by Charlie, and is probably ok, but it is a tad small, so I am going to build my own version, this way I get to go see my brother
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Post by weverat on Jan 6, 2018 11:22:17 GMT -5
Now I am massively side tracked as ice racing starts in 3 weeks and I decided to campaign the old Red Racer. This thing has been pickled for the last 3 years, while I was dinging around with a Yamaha Exciter in the D stock class, of which I may not run this year, just kind of lost interest for now. It is a great sled, and a great class to run, but I found it to be way simpler to just run 1 or 2 sleds on race day. So the Yami might have to sit out this season. Remember the 6 bolt cylinders I found at Princeton, I could not resist, they are going onto the old 4 bolt Red Racer sled. I will temporarily retire the 4 bolt top end for now, but that set up was legendary. I am using the same exhaust, clutch, and carb. The only change is the top end, so we will see if the 6 bolters are actually any better. Now if I were to plug this new set up into a Sting pipe, I am sure it would be faster, but I have to run the Donaldson in this E Stock class. So the TK 400 engine rebuild is 50% complete, all boxed up, and set aside. The 6 bolt conversion is my focus this week. Today, I am fabricating an exhaust manifold to fit the Double Donaldson muffler, should take all day, and several Heinkins. I have to go to my brothers shop to braze the pipes, and he will get me messed up for sure, probably will have to crash there.
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Post by weverat on Jan 4, 2018 22:15:53 GMT -5
Rene, Did you have to modify the shock mounts to make it fit, did you cut or weld anything?
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Post by weverat on Jan 4, 2018 22:00:14 GMT -5
Stinger Racer, I sent you a pm
Thanks
WeveRat
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