Combining a 77 and 78 engine to make one.

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elslimdiablo
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Combining a 77 and 78 engine to make one.

Post #1 by elslimdiablo » Tue Oct 17, 2017 8:48 pm

I have a 77 gl1000 engine that had a broken ring score up the cylinder wall. I also have a 78 engine that appears good. (I have not opened it up yet to check it out though)
I know to use the cams, upper valve train and carbs from the 77, but is there anything else I need to swap over? Thanks- Slim
1977 GL1000
1977 RD400
1975 CB360T(in the family since new and restored)
1961 T20 Tiger cub SL
1959 T20 Tiger cub S
03 Shadow Spirit 750

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ritalz
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Re: Combining a 77 and 78 engine to make one.

Post #2 by ritalz » Tue Oct 17, 2017 9:04 pm

The rear engine cover if you want to retain the kick starter.
Al

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1976 Goldwing 'Grocery Getter' Sold
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elslimdiablo
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Re: Combining a 77 and 78 engine to make one.

Post #3 by elslimdiablo » Tue Oct 17, 2017 9:12 pm

Yea, that's already on the list. Are the timing marks on the cranks the same?
1977 GL1000
1977 RD400
1975 CB360T(in the family since new and restored)
1961 T20 Tiger cub SL
1959 T20 Tiger cub S
03 Shadow Spirit 750

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wingrider
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Re: Combining a 77 and 78 engine to make one.

Post #4 by wingrider » Tue Oct 17, 2017 10:18 pm

The timing marks will be slightly different between the two years.
2002 1800 Wing
2001 Valkyrie Interstate
1978 1200 EFI Wing with Motorvation Coupe Royale sidecar
1977 1200 Wing cafe/bobber project
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ericheath
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Re: Combining a 77 and 78 engine to make one.

Post #5 by ericheath » Wed Oct 18, 2017 12:48 am

Ignition timing marks have five degrees difference. 75-77 is 5 BTDC and 78-79 is 10 BTDC.

Mechanical advancers are different, keep the one with the 77. (371)
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
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elslimdiablo
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Re: Combining a 77 and 78 engine to make one.

Post #6 by elslimdiablo » Wed Oct 18, 2017 5:30 am

I think I'll swap the crank assemblies to keep things where they should be.
1977 GL1000
1977 RD400
1975 CB360T(in the family since new and restored)
1961 T20 Tiger cub SL
1959 T20 Tiger cub S
03 Shadow Spirit 750

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ericheath
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Re: Combining a 77 and 78 engine to make one.

Post #7 by ericheath » Wed Oct 18, 2017 7:45 am

That makes it a pretty big job. If you want the five degree mark, just cut the distance between T and F in half. Others here have used a chisel to score a line in the crank.
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi

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pierce
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Re: Combining a 77 and 78 engine to make one.

Post #8 by pierce » Wed Oct 18, 2017 8:43 am

I think using the earlier crank and pistons, the whole shebang is a good idea. The end of the 77 crankshaft has the addition of the Kickstart mechanism. Not just the rest case.

I would also switch out the tensioner to the 1200 to reduce chain rattle.

If you are fairly mechanical, and time to yourself shouldn't take more than a day with prep.

Complete gasket set, ebay 120 maybe. Order used tensioner off eBay, a few dollars. Oil, oil filter, plugs and new coolant , belts and permatex gray to seal the case. Good to go for around 200.

See you in a few hundred thousand mies.
1976 GL1000
1978 Gl1000

elslimdiablo
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Re: Combining a 77 and 78 engine to make one.

Post #9 by elslimdiablo » Wed Oct 18, 2017 8:55 am

I already have the 1200 tensioner and will be taking some of the winter to get the job done. Im also thinking of getting the valves and valve guides done in the 77 heads for piece of mind. Thanks guys!
1977 GL1000
1977 RD400
1975 CB360T(in the family since new and restored)
1961 T20 Tiger cub SL
1959 T20 Tiger cub S
03 Shadow Spirit 750

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delling3
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Re: Combining a 77 and 78 engine to make one.

Post #10 by delling3 » Wed Oct 18, 2017 9:03 am

Not wanting to hi-jack this thread, but I have a question reflecting my ignorance here. If the idea is to swap the crankshaft from engine 1 to engine 2, do you use the bearing shells from the donor engine, or the destination engine? Does it matter? I know that there are different bearing sizes. Is the size based only on the crank, or just the crankcase, or both?
delling3

Current: 1978 GL1000 - JUNE 2017 BOTM

Previous:
2006 Kawasaki Concours: Sold
1995 Kawasaki Concours: Crashed/totalled.
1976 GL1000: LAST RESTORATION, sold
1981 Honda CB900F Supersport: 3rd restoration, sold.
1979 Yamaha XS-750F: 2nd restoration, sold.
1982 Honda FT-500 Ascot: First (only) new bike. Family forces sale.
1973 CB500 Four: First restoration, long gone.
1972 Suzuki TS-100: First bike, sold.

Only dead fish go with the flow . . .

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CYBORG
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Re: Combining a 77 and 78 engine to make one.

Post #11 by CYBORG » Wed Oct 18, 2017 9:17 am

The "size" is in every engine. Back in the day called blueprinting. Both crank and rod bearings are Matched to the block and the crank. By color of the bearings. The difference in size from color to color is very small,......but different. The marks on the block are the factory determined colors for each block/crank combination.
Just changing a crank and block combination from one engine to another might work, as the differences between colors is very small, but defeats the original intent of the factory, and could limit the life of the engine
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200

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CYBORG
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Re: Combining a 77 and 78 engine to make one.

Post #12 by CYBORG » Wed Oct 18, 2017 9:21 am

If bearings were readily available in all colors, a factory fresh engine could be built. But in my experience, they are not. If you can find a source for all different color bearings, let me know. I have been looking for a long time
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200

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robin1731
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Re: Combining a 77 and 78 engine to make one.

Post #13 by robin1731 » Wed Oct 18, 2017 1:29 pm

A whole lot easier to just mark the crank you have.

Even if it all took the same bearings it would be a lot easier to mark the crank. Swapping it all out is a lot of work just to have the timing marks in the correct location.

.
1975 GL1000 parts bike (parts for sale)
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
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elslimdiablo
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Re: Combining a 77 and 78 engine to make one.

Post #14 by elslimdiablo » Wed Oct 18, 2017 2:01 pm

I measure out engines when I pull them apart for rebuild to see what it will need. I will use plastigauge to check the crank bearing clearance and go from there. I would like to retain the kickstarter if possible, but if things don't measure up in the swap, then I'll just have to do without. ( not a deal breaker, just love the idea of a kicker)
1977 GL1000
1977 RD400
1975 CB360T(in the family since new and restored)
1961 T20 Tiger cub SL
1959 T20 Tiger cub S
03 Shadow Spirit 750

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delling3
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Re: Combining a 77 and 78 engine to make one.

Post #15 by delling3 » Wed Oct 18, 2017 9:33 pm

From my first reply, I know that engine bearings are basically unobtainium. Once you pull a motor apart and start into plasticgauge, the assumption is that you can get bearings. Not so (at least for now) with 4-cylinder wings. I would lean towards using the bottom end of your donor engine as-is. Unless you have already confirmed that it needs a full rebuild. Then I might start looking for another donor. That's me, YMMV. I had a '76 with a kicker, and now have a '78 w/o. I would prefer to have it (for emergency use), but on the 'Wing they ain't very user friendly, and I don't think I would tear down a motor just to have a kickstarter. I would simply swap the top end/valve train, and mark the flywheel. Robin and Cyborg are far more experienced than I, and unless I mis-read their replies, I think they agree. In any case, good luck with your project!
delling3

Current: 1978 GL1000 - JUNE 2017 BOTM

Previous:
2006 Kawasaki Concours: Sold
1995 Kawasaki Concours: Crashed/totalled.
1976 GL1000: LAST RESTORATION, sold
1981 Honda CB900F Supersport: 3rd restoration, sold.
1979 Yamaha XS-750F: 2nd restoration, sold.
1982 Honda FT-500 Ascot: First (only) new bike. Family forces sale.
1973 CB500 Four: First restoration, long gone.
1972 Suzuki TS-100: First bike, sold.

Only dead fish go with the flow . . .


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