Onan engines question?
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Topic: Onan engines question?
Posted By: Tracy Martin TN
Subject: Onan engines question?
Date Posted: 24 Jun 2017 at 10:18pm
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What differences is it in an Onan CCKA,CCKB generator engine and an Onan CCKA, CCKB tractor engine that causes the difference in RPMS 1800 versus the 3600? What internals must be swapped? Any help appreciated. Thanks Tracy ------------- No greater gift than healthy grandkids! |
Replies:
Posted By: M.A.C.K.
Date Posted: 25 Jun 2017 at 4:03pm
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don't hold me to this but there is probably no difference at all, the generator is limited due to the generator head can't turn but so hard. if anything is different it's probably the carb tuning and the governor setup. just my two cents ------------- Mid Atlantic Customs and Klassics |
Posted By: ac720nut
Date Posted: 26 Jun 2017 at 5:36am
| Thought all generators had tapered crankshaft ? |
Posted By: Tracy Martin TN
Date Posted: 26 Jun 2017 at 7:46am
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I will swap out my crankshaft. I thought the cam and governor would be different to gain the RPM's. Rods will swap too. This is what I was mainly concerned with. I need to know about cam ,governor, and timing gears? Tracy ------------- No greater gift than healthy grandkids! |
Posted By: coggonobrien
Date Posted: 26 Jun 2017 at 7:53am
| Guess I didn't know they were differant, I haven't made it far enough with my swap to drive anything with it. |
Posted By: rustydollar
Date Posted: 07 Aug 2017 at 11:23am
The generator engine as you already know uses a shirt stubby crankshaft, some guys will turn the tapered shaft down then cut a key-way to accept a Lovejoy coupler. Machining can be done with out disassembling the engine if you have a large metal lathe. Generator 1800 rpm engine uses ten ball bearings in the governor remove the small spring clip to gain access then remove five of the bearings to obtain 3600 rpm. When reassembling the timing cover make sure the hole on the timing gear with the plastic insert is located in the 3:00 o'clock position. The pin on the timing cover must insert into this hole. Get the pin location wrong the governor will not work. Crankshaft end play tolerances min/max .006 / 012 I've just completed the same parts swap. |
Tracy Martin TN wrote:Posted By: Tracy Martin TN
Date Posted: 07 Aug 2017 at 8:32pm
------------- No greater gift than healthy grandkids! |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 2:32am
The slower running 1800 rpm generator engine requires more mass to facilitate the centrifugal forces required to operate the governor. Centrifugal Governors :In centrifugal governors,
multiple masses know as governor balls, are responsible to revolve
about the axis of a shaft, which is driven through suitable gearing from
the engine crankshaft. Each ball is acted upon by a force which acts in
the radially inward direction and is provided by dead weight, a spring
or a combination of two. This force is commonly called as the
controlling force and it will increase as the distance of the ball from
the axis of rotation increases. The inward or outward movement of the
ball is transmitted by the governor mechanism to the valve which
controls the amount of energy supplied to the engine. Inertia Governor :In inertia governors, the
balls are arranged in manner that the inertia forces caused by angular
acceleration or retardation of the governor shaft tend to change their
position. The obvious advantage of inertia governor lies in its rapid
response to the effect of a change of load. This advantage is small,
however by the practical difficulty of arranging for the complete
balance of the revolving parts of the governor. For this reason
Centrifugal governors are preferred over the inertia governors.
The governor on the right hand side still installed in generator engine has ten balls, one on the left is from tractor engine.  |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 2:46am
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Tracy if your donor engine has the solid one piece main bearings, it would be my advice to change this to the two piece bearing which has the separate thrust bearing. The one piece bearings have a high failure rate. This is the bearing set used to replace the one piece shown below this image. Onan has shims available to adjust crankshaft end play. I discarded the plastic ones staying with metal shims.   |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 8:29pm
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The camshaft from the generator engine are identical with the exception the lobe that operates the mechanical fuel pump may not have been profiled and ground as the gen sets use an electric fuel pump. The valve lifter on he right hand side is new style, I installed the old style as it looks like it may have better oil retention and distribution in the bore. Tool that I made to remove the main bearings.    |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 8:35pm
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If your mechanical fuel pump fails on you this is an easy modification that is much more economical than replacing the pump with an OEM from Onan. I did this modification on a Briggs engine that did not have a fuel pump, drilled a hole into the side of the oil filler tube then brazed a hose bib in place. The hose once installed provided the crankcase pulsations needed to operate the fuel pump. You could make a plate to cover the hole from which the original onan fuel pump was installed then install your hose barb into this plate. You can easily install this type of fuel pump on any engine.  |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 8:50pm
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Generator engine having the tapper turned down to accept love joy coupler to drive a hydraulic pump. Not my engine.   |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 8:56pm
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Electrolysis on main bearing, the fellow from whom I had purchased this generator from had a company that specialized in air sampling. He had the engine rebuilt as a spare, had zero hours on the fresh rebuilt. You can see the bearing deterioration from electrolysis from sitting idle all those years in storage.  |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 9:01pm
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Old style versus new in cylinder heads, the new style has more cooling fins with more surface area also the spark plug has been relocated. I'm using the new style shown on the left.  |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 9:05pm
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You may find one of the two types of spark plugs installed in your Onan engine, I went with the protruded electrode. You may find that the spark plug with the protruded electrode is rather difficult to find, I had to request our local NAPA to order it in. Called yesterday and the plugs were here this afternoon.  |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 9:26pm
This may give you some ideas on how to re-purpose a generator engine. The armature shaft is easily removed using a hydraulic press, the center hole is drilled right through so the shaft maybe cut down in length.  |
Posted By: Tracy Martin TN
Date Posted: 09 Aug 2017 at 9:28pm
------------- No greater gift than healthy grandkids! |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 9:33pm
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Your generator engine may not have an oil filter but you'll find that the base has been machined into the engine block to accept the filter. You just need to drill a few holes then thread two to hold the filter adapter in place. Or you could install a remote filter. Hopefully Tracy will add to this thread once he has started his engine rebuild from donor parts, in the meantime I have an engine to complete and install into my Simplicity Powermax 9020. Let there be fire, tomorrow is engine start up day. This will be a bench run. |
Posted By: rustydollar
Date Posted: 09 Aug 2017 at 10:14pm
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A lot of the parts from the aluminum Onan interchange with the cast iron CCK family. Couple of things that I would like to mention, if the throttle shaft on your carburetor is worn your engine will have poor idling characteristics with deteriorated high end performance. An easy fix is to purchase a bushing kit. A worn piston can be brought back to specks by having it knurled, this was a procedure favored by hot rod racers back in the day. It;s believed that knurling helps to retain oil which in turn better lubricates the cylinders. Most engine shops offer the service. [TUBE]4uzZYPIGbZE[/TUBE] |
Posted By: rustydollar
Date Posted: 10 Aug 2017 at 9:30am
 
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Posted By: rustydollar
Date Posted: 11 Aug 2017 at 11:48pm
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Tracy one more thing, if your using a chrome top ring, your probably better off having an engine re-builder hone the cylinders for you. The final grit used is 400, then if you have trouble with your rings not seating you can use Bon ami powder to assist with break in. Some guys use the break in powder right from the get. Caterpillar Part No.7F5225 Break-in Powder ( Bon Ami ).  |
Posted By: rustydollar
Date Posted: 13 Aug 2017 at 12:49am
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Tuesday another road adventure, according to google maps 3.5 hours from home. I'll be off to purchase another CCK Onan engine that was removed from a Simplicity Powermax 9020, previous owner did a re-power with a newer Vanguard engine. I feel like I'm keeping a personal diary, keeping personal notes to self for future reference. The forum has proven to be a very lonely place. |
Posted By: Tracy Martin TN
Date Posted: 13 Aug 2017 at 12:58pm
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Rusty, you help and advice is greatly appreciated. Most folks take for granted the time and effort to post and answer questions, especially when it comes to pics. Thanks Tracy ------------- No greater gift than healthy grandkids! |
Posted By: rustydollar
Date Posted: 13 Aug 2017 at 10:36pm
Your welcome Tracy, where are you at with your parts swap. The generator engines with cast iron blocks will be identified on the engine tag as 40CCK and 50CCK. I left home at 9:00 am to pick up another Onan engine, a full 12 hour trip. This engine has the heat shield and the air filter that I'm missing from mine. Plus I got the front PTO clutch magnet the rest is toast, still no muffler, maybe eBay. This engine ran when the guy pulled it out of the Simplicity 9020, said it ran rough. I may have found the cause the throttle shaft bushing on the carburetor is badly worn and the friction disks on the electric clutch are toast. I think he may have had difficulty finding a new clutch and this was perhaps the main reason he swapped the engine out for a Vanguard. Most people make the mistake of engaging the clutch with to many engine RPMs, should always idle the engine down before engaging. The implement your trying to run will be stiff from sitting idle for a week or so and will probably stall the engine a couple of times before the mechanicals are freed up enough for the idling engine to overcome. Patients pays off in spades , when your getting three times the life span from your electric clutch over that of your neighbor.  |
Posted By: ac720nut
Date Posted: 15 Aug 2017 at 9:12am
| Gill, thanks for all the details, I have one needing rings in near future |
Posted By: Tracy Martin TN
Date Posted: 15 Aug 2017 at 9:22am
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Thanks for info. It is appreciated. Tracy ------------- No greater gift than healthy grandkids! |
Posted By: rustydollar
Date Posted: 18 Aug 2017 at 10:48pm
I gather your going to rebuild the engine from an AC 720, which is very similar to my 9020. Some of the difficult things I encountered where installing one of the engine mounting bolts and the oil cooler, To get that difficult bolt in the hole I used a telescopic magnet, grabbed the bolt from the side then worked it into the hole. To tighten that bolt had to use a 3/8" ratchet with a flex head. While Pat held the ratchet in place Torqued the lock nuts from the bottom side. Installing the cooling lines on the oil cooler, I removed the fuel tank and the side cover that the oil lines pass through, to get one stubborn line on grabbed it with a pair of pliers then tapped the pliers bringing the oil line into place. The clutch belts, I used a cable come a long to keep the clutch peddle depressed giving me a bit more slack on the v pulleys. Even with the clutch peddle fully depressed the belts are a bit tight to get onto the sheaves. As your working the first belt into place you may have to turn the engine flywheel by hand. With the many do it yourself mechanics on this forum I would think there's more than one way to skin a cat and every mechanic has his work arounds to solve a problem. |
Posted By: ac720nut
Date Posted: 19 Aug 2017 at 5:06am
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I just unhook the clutch linkage and PTO shaft, driveshaft and it allows a good bit of clearance to work belts on pulleys. flywheel belt has to hang on pulley first then you can work other on, I'm not sure how to explain it here but I've found it works best for me. |
Posted By: Gotrek
Date Posted: 25 Aug 2017 at 4:08pm
| I hope you get good use out of that motor. It was nice to finally meet you after years of chatting with you on forums :) |
Posted By: rustydollar
Date Posted: 25 Aug 2017 at 4:47pm
Pleasure was mine, and I'm grateful you decided to sell the engine to me. I'm in my element with mechanical things, chemistry boggles my mind. Pat and I made a few stops today, first to drop off that hub for the cad work, a bit of shopping then two landfills for more shopping on the way home. At the first landfill someone had disposed of an old Evenrude engine, I pulled the carburetor off in hopes of adapting it to another engine. The carburetor won't care if it's a two or four stroke. The pile of cutting edges are still at the second landfill, they look like new. Next trip I'll have some room on the truck. Not sure if its worth your time to make the trip to my neighborhood, but if you want a decent heavy duty cutting edge I'll set one aside with your name on it. Here's an idea for your blade and it's free just pay the postage. I purchased a few Toro lawnmowers from the local gold course the grass cutting reels had small hydraulic motors. A small motor with an eccentric to make some serious vibration would keep snow from sticking onto the blade and chew through ice and hard packed snow. Your tractor has the hydraulics to power the pump. |
Posted By: rustydollar
Date Posted: 25 Aug 2017 at 5:10pm
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Gotreck the Simplicity snowblower would be fairly easy to duplicate, mechanically it's pretty simple. I'll post the gear ratio of the angle drive and the tooth count on both chain sprockets. Angle drive is 1.5/1, small chain sprocket 15 teeth, large sprocket 34 teeth. The fins that make up the auger is called flighting and there are shops that specialize in making it. If you or anyone else on the forum decides to tackle this project I can give more precise measurements. You'll notice that the PTO drive is offset for the mule drive on the front of the tractor.   |
Posted By: rustydollar
Date Posted: 18 Sep 2017 at 2:17pm
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Camshafts used in Onan engines may differ. Credits go to TJ from Onan Parts Com http://www.mytractorforum.com/members/19811-onanparts-com.html" rel="nofollow - http://www.mytractorforum.com/member...parts-com.html The Onan cams with casting # 170-4101 are for the 20HP engines. 170-4100 are for the 16-18HP engines. 20HP cams have a slightly higher lift intake lobe. |
Posted By: Bird76Mojo
Date Posted: 20 May 2021 at 8:56pm
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Fantastic thread here fellas. I have some questions that maybe someone can help with.. I'd like to convert my Onan CCKA in my 616 to a CCKB like my 720 has. I have two NOS shortblocks and will be swapping all of the CCKA parts on to one of them. This is where the questions begin. What will I need from a CCKB to convert the CCKA to CCKB? So far I figure I'll need the intake manifold, (aftermarket) carb, rubber intake boot, air filter housing with lid/clamp/cover, and the flywheel shroud. Are there any throttle linkage parts or governor parts I'll need? You guys all seem very versed in these models so hopefully some of you are still active on the forum. Thanks in advance! GB :) |
Posted By: coggonobrien
Date Posted: 21 May 2021 at 7:46am
| get everything for the throttle linkage/governor. I believe the choke and throttle cables are different lengths as well. |
Posted By: Bird76Mojo
Date Posted: 21 May 2021 at 6:49pm
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I kind of figured they would be needed as well. Thanks for the quick response! I'll put them on the list. |