'84 1200 engine for a '82 GW

[canuckxxxx]

joedrum » Wed Jul 15, 2015 7:59 am[/url]":2t5lq6nr]
hmmmm surprised ... i would have thought big difference ....hmmm this brings a lot to the table on 1200 mod bikes ..... yes the 11% more oil flow in 1200 quiets the motor down a lot....it also has the stoutest crank and primary chain set up .......great work brian opcorn:

Probably the reason why the 1200 doesn't have huge performance is because of the low compression. if it ever gets up >170psi it will be a fairer comparison. I should also say that, in my test ride, I didn't wind it out so I don't know what performance would be like >5000 rpm.

I'm glad I went ahead and put the 1200 in. Even if the comp. does not come up much there are many benefits of the 1200 over 1100, that you have listed Joe.

I can ride like this till winter then decide if I want to put a new set of rings in it. That is if I can find some...they seem to be hard to find. Can anyone suggest a source. I read somewhere that rings for a '75 Civic 1200 would work. But I cannot find a source for those either.

I'm sure glad I have an '84 engine...it is a true plug and play.

 

[slabghost]

Compression should come up in time. It'll take some running to get there. Power wise there isn't a huge difference in 1200 over 1100. With 1100 cams in it the motor should run very similar to the 1100.

 

[canuckxxxx]

slabghost » Wed Jul 15, 2015 3:02 pm[/url]":2a2friwv]
Compression should come up in time. It'll take some running to get there. Power wise there isn't a huge difference in 1200 over 1100. With 1100 cams in it the motor should run very similar to the 1100.

Makes sense Slab. I'm using 1100 heads and cams so basically I've gained 100cc and lower compression over my old 1100.

I'm still fascinated with the full 1200 package: heads and cams. Still have those 1200 parts and maybe will take another look at this winter. Seems like Honda had a different concept, using smaller valves/ports and lower lift cams but getting big gains in power and torque.

Did a google on how to free stuck rings. There are some interesting ideas. One method I like is to pour some penetrating liquid into the spark plug hole when the piston is on it's way up on the compression stoke. When all air has escaped through rings all that is left is liquid which fills the whole space that's left. I imagine at that point the piston would come up solidly against the liquid. Gentle pressure on the crankshaft forces the penetrating liquid through the ring which should free them up. What penetrating liquid to use...ATF, diesel fuel...?

What do you think of this idea?
Brian

 

[dan filipi]

Good idea.
I'd do that with PB Blaster. It's good stuff.
It seems to 'creep' up metal well so I think it might make it at least 1/2 way around the piston.

Otherwise, put lots of miles on it and I expect compression will come up as the rings loosen.

 

[canuckxxxx]

The one thing I have to do, now that I see hope in this engine, is put new timing belts on. So I will have to take all the stuff off the front again so that would be a good time to try that penetrating liquid thing.

Where can you buy PB blaster?

Brian

 

[dan filipi]

It's available here at most auto parts, I think Walmart has it too.

 

[dan filipi]

I'm a bit skeptical compression will come up.
My reason is usually I read, and I have experienced twice, that compression will be low in only 1 or 2 cylinders then come up over time but I'm hoping yours is the exception and they all come up.

 

[Ansimp]

I wouldn't try the Google thing with penetrating oil as you are working with a flat motor, just run it with ATF and it will surprise you. Plus. 140 psi for low compression motor is okay!

 

[dan filipi]

Ansimp » 3 minutes ago[/url]":2i8nu4ks]
I wouldn't try the Google thing with penetrating oil as you are working with a flat motor, just run it with ATF and it will surprise you. Plus. 140 psi for low compression motor is okay!

Yes but that is quite a bit lower than the 170-180 spec.
Seems to me bigger valves and cam should be higher compression.
Raises a question, what is Joe and Eric's compression running the early 1000 cams?

 

[canuckxxxx]

dan filipi » Wed Jul 15, 2015 4:07 pm[/url]":3ch8xems]
I'm a bit skeptical compression will come up.
My reason is usually I read, and I have experienced twice, that compression will be low in only 1 or 2 cylinders then come up over time but I'm hoping yours is the exception and they all come up.

Latest comp. test shows all cylinders about the same. So, maybe it is unlikely that all rings on all cylinders are stuck the same amount. But more likely that they have all worn out together. I see what you're sayin Dan. :head bang:

 

[slabghost]

I'm with ansimp here. Just run it. You can add 4 oz of atf to the oil too. Being a flat 4 and interference motor I think the forcing of penetrating oil in this motor is very risky. Bigger valves and slightly different timing of the 1200 motor over the 1100 may be limiting compression some. I'd just run it. Mine sat for quite a while and I've been running it with atf in fuel and oil and it just seems to keep getting better. Mine does still have the 1200 heads and cams on it though.

 

[canuckxxxx]

Slabghost, how much ATF to a tank of gas?

Thanks
Brian

 

[slabghost]

4-6 oz is probably best but I just dump a splash in at fill up. This last time I got a bit too much in and I got a big cloud of blue smoke at start up. It clears up after a few minutes but I may skip the atf next fill up.

 

[Ansimp]

How accurate is your compression tester? Evenness in compression to me is more important than actual numbers IMHO.

 

[canuckxxxx]

Ansimp » Thu Jul 16, 2015 3:08 am[/url]":38vo2vct]
How accurate is your compression tester? Evenness in compression to me is more important than actual numbers IMHO.

Good question. :headscratch: I've never checked it against a known accurate gauge. But I do have another gauge that goes to 160 psi. Should have enough fittings to connect them both to the same air source and see what they read.

I could do it all standing at my work bench so it would be like taking a break :smilie_happy:

:thanks:
Brian

 

[canuckxxxx]

Ansimp, here is the setup I put together to compare my two gauges. Again, I have no idea how accurate that big gauge is so test is sort of useless but it was easy to do. The big gauge read 128 psi while my comp. test gauge read 121 psi. So my comp. test might be reading a bit on the low side.

image

• canuckxxxx
• Jul 16, 2015

 

[Ansimp]

How well does your compression tester seal into the spark plug hole? I still think you just need to put on some Ks before you make any decisions.

 

[canuckxxxx]

Caught a bit of a break today. :Egyptian: It's a rainy day here so I decided to put new timing belts on the 1200. Called NAPA; the store I called had 1 belt in stock (NAPA #250070) and could get the other one in a couple of hours. The price...wait for it... $18.79 ea. I was shocked :shock: because when I bought belts for the 1100 in 2012 I paid $56.18 ea. and if you check the usual online sites now they are in the $40 to 60 range.

Anyway, I just went down and got them and got some kind of a discount so ended up paying $13.89 ea.

So if you need new timing belts give NAPA a call.

Brian

 

[joedrum]

yep good time for belt bikes runs ...seems ridable ... time to put new belts on its worth the investment now opcorn:

 

[Ansimp]

joedrum » Fri Jul 17, 2015 4:16 am[/url]":2rs743ah]
yep good time for belt bikes runs ...seems ridable ... time to put new belts on its worth the investment now opcorn:

+1
1200 belts are cheaper down here than the 1100s by at least half :doh: