'84 1200 engine for a '82 GW

[sgq700]

Brian, the camshaft design will not work very well when you try to run solid lifters with a hyd cam, ask any of us old guy's that tried that in the 60's ! it will run... but not very well! just wanted to give ya a heads up to save the problems.. as it is said"if you don't mind=it don't matter" give it a go opcorn:

 

[canuckxxxx]

sgq700 » Sun Jun 28, 2015 11:36 am[/url]":2ohlg4c7]
Brian, the camshaft design will not work very well when you try to run solid lifters with a hyd cam, ask any of us old guy's that tried that in the 60's ! it will run... but not very well! just wanted to give ya a heads up to save the problems.. as it is said"if you don't mind=it don't matter" give it a go opcorn:

Thanks, good to know. I'm going to stick with the OE setup as long as I'm using the 1200 heads.

Brian

 

[canuckxxxx]

OK this might be a game changer: :crying: :head bang: Today I thought I would lap all the valves in using some fine grade valve lapping past. The left head valves lapped in fine; nice even gray bands around the valve head and the seats. But the right head has some serious pitting on both exhaust valves and their seats. :Awe: The black spots are actually pits in the surface you can see they have some depth when you shine a light on the right way. I think you can see near the top where the light is brightest.

pitted exhaust valve seat

• canuckxxxx
• Jun 30, 2015

and the valve also has pitting at the contact band

pitted exhaust valve

• canuckxxxx
• Jun 30, 2015

In addition #1 intake valve would not lap in. I got an even band on the valve but there is a portion on the seat that does not make contact.

I think the pitting is beyond what can be taken out by lapping. I could get new seats ground in but I think that would put the valves in too far.

What do you guys think? Time to start looking at those heads on the 1100? I get 150 psi on all 4, on the 1100, which I know isn't great but those heads are proven runners and might lap in OK. What are bennies of 1100 heads and cams on a 1200 (besides and additional 100cc)?

Thanks guys in advance. :beg:
Brian

 

[dan filipi]

Benefit to be had is bigger valves and intake ports so the 1200 breathes better.
May be a valve to head clearance problem running 1100 cams needing reliefs ground into the pistons.

 

[joedrum]

many brian ...many ...the extra oil flow is now for motor and not on hydro lifters also... thats 11% increase..over 1100 oiling system ....larger ports in 1100 heads and larger intake valves ...simple easy user friendly valve adjustment....ability to use 1000 early cams and c5 system on head or other stemed ignition cams.....discount pistons have to be cutout a bit for clearence...and the bike might be to fast LOL

 

[ekvh]

Again, from the top......do it, do it, do it, do it! Notching the Pistons isn't that bad. See Joe's post on how he did his. Can't get easier than that.

 

[canuckxxxx]

OK guys, if I get in trouble for doing accidental smoky burnouts on the street in front of my house it will be your faults. :smilie_happy:

For the sake of simplicity and economy I think I will stick with the 1100 cams...at least for now. Can always keep my eyes open for some '75 cams.

Thanks for all the help
Brian

 

[ekvh]

I think 1100's might be the best of both, has the larger intake valve, but has different opening and closings to give better bottom end torque and response. Probably better mpg also.

 

[canuckxxxx]

Just thought I would explain why I'm asking for a 1200 head in the Sale/Wanted section.

We are in the middle of our short, but very nice this year, summer and I am doing lots of riding. So I would like to keep the 1100 engine together as long as I can. If I can get the 1200 ready, using 1200 heads, then I can probably put it into the '82 in a week or two. And start it and see if it is going to be a runner. If I do that and find there is something wrong with the bottom end or something then I can put the 1100 engine back in and ride. If the 1200 seems good but I want to try the 1100 heads and 1000 cams then I can do that this winter.

On the other hand, if I take the heads off the 1100 right away, and the 1200 doesn't work out then I need to do a bunch of work to get the 1100 going again.

Hope that makes sense. Just don't want to be under pressure to do the swap fast.

Thanks guys
Brian

 

[dan filipi]

canuckxxxx » 27 minutes ago[/url]"lt23il4]
Just thought I would explain why I'm asking for a 1200 head in the Sale/Wanted section.

We are in the middle of our short, but very nice this year, summer and I am doing lots of riding. So I would like to keep the 1100 engine together as long as I can. If I can get the 1200 ready, using 1200 heads, then I can probably put it into the '82 in a week or two. And start it and see if it is going to be a runner. If I do that and find there is something wrong with the bottom end or something then I can put the 1100 engine back in and ride. If the 1200 seems good but I want to try the 1100 heads and 1000 cams then I can do that this winter.

On the other hand, if I take the heads off the 1100 right away, and the 1200 doesn't work out then I need to do a bunch of work to get the 1100 going again.

Hope that makes sense. Just don't want to be under pressure to do the swap fast.

Thanks guys
Brian

With that plan then I'd do up the right head best it can be by lapping, put it together and run it.
Worst you're out is a head gasket and time. At least that get's you going fast and the compression was okay on that side.

 

[Tom_Charlton]

85 Honda Prelude electric fuel pump works fine and is available at O'Reilly's and AutoZone.

 

[canuckxxxx]

Well, Dan, if I can't find a good 1200 head then I might just put the whole thing on hold and put the 1100 heads on this winter. Just don't want to have to do it too many times. But I would really like to give the stock 1200 setup a good test first.

Another thing I was thinking was that if I go with stock 1200 then I should put the taller 1200 rear drive in. With my '82 now it turns about 3700 rpm at 60mph. I think the 1200 rear drive gives about 3000rpm at 60 mph, which would be very nice. If I put the 1100 heads on it might gain some at the top end but loose a bit at the bottom so the '82 gearing might be better.

What do you guys think about that.

Brian

 

[canuckxxxx]

PurpleGL1200I » Thu Jul 02, 2015 1:47 pm[/url]":2nm1ijji]
85 Honda Prelude electric fuel pump works fine and is available at O'Reilly's and AutoZone.

Thanks PurpleGL1200I, good to know. If I find another 1200 head then I will definitely need and E fuel pump.
:thanks:
Brian

 

[sgq700]

if you do alot of hi-way riding.. go with the 1200 drive, th whole swing arm is a bolt in deal and it gave me 10 more mph at the same rpm the 1100 gera is around 3:08 or so and the 1200 is 2:80! plus the 150/90/15 tire really fills up the 1100 rear fender and looks great!

 

[canuckxxxx]

sgq700 » Thu Jul 02, 2015 3:16 pm[/url]":2gsbqidc]
if you do alot of hi-way riding.. go with the 1200 drive, th whole swing arm is a bolt in deal and it gave me 10 more mph at the same rpm the 1100 gera is around 3:08 or so and the 1200 is 2:80! plus the 150/90/15 tire really fills up the 1100 rear fender and looks great!

Thanks sgq700. If you use the 1200 rear do you have to use the 1200 rear wheel or could I use my 1100 wheel?

Brian

 

[sgq700]

i used the entire 1200 swing arm. wheel. drive unit and brake assy. all was bolt up and go, it does make the bike almost 3 inches longer and will lower the rear about 2 inches due to shock mount location but every thing works great! Your 1100 wheel will not work with the 1200 drive

 

[slabghost]

Could get a 1500 rear wheel and final and brake caliper bracket and mount it on a 1200 swingarm and get a bit taller. Cross that bridge after you get the 1200 in and working right though.

 

[canuckxxxx]

Doing some more thinking :headscratch: (dangerous I know): the two unknowns with the 1100 heads on the 1200 bottom are the condition of the bottom and the condition of the heads.

So I figured I could answer to second question by doing a compression test with and without oiling the cylinders. So I warmed it up and took compression readings.
1. 150 psi
2. 145
3. 145
4. 150

Then I squirted oil in each cylinder and did compression again.
1. 170
2. 160
3. 165
4. 175

So to me that means that the heads aren't bad and the rings are getting a bit tired. Also, squirting the oil in only really gets the bottom part of the cylinder oily so does not eliminate rings leaking completely.

What do you guys think?

Brian

 

[joedrum]

hmmm to me ...the numbers are not that bad ....oil is going to raise compression in old motor thats been sitting ...

 

[canuckxxxx]

As far as the condition of the bottom goes; the PO was trying to rebuild the heads so he must have figured the bottom was OK. Also there is no ridges at the tops of the cylinders and you can still see hone marks on cylinder walls. Also, all piston tops are a medium brown with little carbon buildup.

So I am tempted to take a chance on the bottom end being OK.

So if I assume the 1100 heads and the 1200 bottom end is good, then by far the cheapest and easiest way to go would be to go directly to 1100/1200 combination. I have all the parts I need in my garage right now.

Time to just do it!

Going on a group ride tomorrow, that I am committed to, and after that I start tearing the old beast apart.

Brian