My 1200 cams in an 1100I ride report

[dan filipi]

I decided the customizing forum is more fitting for this subject because this mod is totally custom.

Just got back from my 75 mile test loop of mixed freeway, rolling hills and some twisties and I gotta say I'm really liking this mod.

It pulls nice at low rpm.
No BS I'd say a good 20% increase of low end torque judging by my seat of the pants dyno.

One improvement in particular is when riding on a level road the transition into and climbing a slow rolling hill there's much less need to give it more gas. The torque has improved without a doubt.

Another improvement is in uphill twisties. It always felt a bit "off" in power like it was always hard to be in the right gear when coming out of a turn. With the improved torque it's like the gear ratios have been modified.

Another improvement is easier takeoffs from a stop.
With improved lower end torque there is less lugging.

Anyone considering this mod should also consider my bike is not normal by most comparisons.

1. It's got an '81 engine with '83 gears.
2. The rear wheel is 17", stock '83 companion to the '83 gears runs a 16" wheel.

The gearing plays a huge part I think in the results since mine runs at a lower rpm than even a stock '83 engine and gears because of the 17" wheel.
I would love to hear from someone trying this in a stock '83 and stock '81.

I have no comparison to the other cams but this run I got 7 seconds 0-60.
Not great but not terrible, I suppose not too shabby for a full dress bike.
I could have done better but without a tach I didn't want to risk over rev and the clutch slips a good bit off the line.

Disadvantages so far are no mechanical fuel pump and no tach drive.
The left tappets are noisy, the right are pretty quiet.

I contribute this to a few possibilities, break in one and it's running old valve springs and rockers.
On top of that who knows what all these valves have been through. I'm sure I lapped them once but I think a full on head reconditioning would only improve the overall performance and quiet down the valve train.

 

[detdrbuzzard]

what are you using for a fuel pump dan, oh don't forget redline on 1200's is 7500 rpm

 

[slabghost]

Any possibility that you have a mismatched pair of rocker arms? Thanks for this latest report! :mrgreen:

 

[ekvh]

Cool report. I was measuring up the intake manifolds the other day. The 1200 intakes are much smaller than the 1100 or the 1000. I wonder if that would improve or lessen the mod you've done. I have read that the smaller diameter intakes actually speed the velocity of the charge and thus get more fuel/air in the combustion chamber. It would interesting also to see what the smaller intakes would do with the 1200 carbs or with the 1100 carbs.

 

[joedrum]

well im going to find out when funds and time to get my mod done .....ekvh by the way im glad you found the oldwing funny farm here and yes im the senoir typo master of the forum with no close competition at all .....i have two 1200 mod projects going on ...one 1200 with 1200 heads and carbs with 76 1000 cams installed ...and yes the smaller intakes will improve low rpm performance with faster flow down low in the rpm im hoping ....the other 1200 mod is going to have 1000 or 1100 heads and 75 1000 cams and either 77 1000 carbs or 1100 carbs all still up in the air .....cant wait to get them done ....hows your 1200 project coming

great to have you here :mrgreen:

 

[ekvh]

My 1200 is a really slow project for me. I hate the cold so much, and the time seems to disappear quickly. I am trying to get my regular ride ready for the year, an old 77 pretty stock for now. It is almost 50 today, so it won't be long....I hope. After that I have to do some frame repairs and then start fitting the 1200 into either a 1000 or an 83 1100. I enjoy learning so much from you guys, but it keeps changing my plans. I am now starting to think the 1200 in the 1100 frame and gearing will be best. Then fix the 1100 motor and put it in the 1000 frame. The 1100 should be able to handle the revs better in the 1000 frame and rear end. Dan's info on the 1200 cam has my interest spurred in trying the 1200 cams. I haven't got any 1200 carbs, so I'll likely use a set of 77 carbs, but I am thinking of a way to try and reduce the size of the intakes to see what it does on performance. I thought it would hinder, but I am really not so sure any more.

 

[joedrum]

im thinking it will boost the low end torque with smaller runners but will hinder some on top but early cams will boost the top end ....making a nice package all the way around ....will see :headscratch: :mrgreen: and yes the 1100 will be the best gearing match for the 1200 in my opinion....and the 83 1100 is an absolutely the best 1100 motor to put in the 1000 with its final drive and the 83 1100 gearing ....the best ...that will diffinitly deliver the mail with early cams installed in the 83 :mrgreen:

 

[ekvh]

Joe, what did you adjust your valves at when you put the 1000 cams on the 1100 heads? The 1000 has 0.04 for both intake and exhaust. The 1100 calls for 0.04 and 0.05. You also put the 1000 cams on the 1200 head, correct? Is that running yet?

 

[joedrum]

.004 just like the 1000 specs the cam made it more 1000 than 1100 on adjusting ...the 1100 heads have better cam carriers oiling system but esentialy the sae as 1000 heads......yes the 1200 heads have the 76 1000 early cams installed ....im also grafting the the 1000 ignition and fuel pump to the 1200 heads andthat where im at ....when done its going in a 79 1000 that has a 83 final drive already modified in it making the gearing like a 1100 ....it will all hookup to the standard 79 1000 wiring and instruments ..the 1000 ignition has een upgraded to dyna electronic ignition already too ....its close to being done...im going to bench test run the motor before install ....iwish it was done and ready to go .....soon :mrgreen: .... :mrgreen:

 

[dan filipi]

The latest is I've adjusted the left cam in and ex tappets to .03 which quieted the tappets at idle but still clatter as it's revved.
Compression stayed the same at 160.

Next up I'll adjust the right side to the same and take a test ride.

If it's running okay with no weirdness I'm going to leave it like this for the ride April 30 up North with some occasional trips around town before to shake it out.

 

[dan filipi]

Just a short ride around the hood revealed alot of spitting and coughing so the tappets need to go back to .04.

 

[macka]

so how did this mod do over the summer with more riding?

 

[dan filipi]

Unfortunately ive only put on a few hundred miles but Its done really well.
Oddly it seems the more I run it the better it runs?
I think it needs to break in more because as the miles tick away the tappets get louder when they were completely quiet.(this is with ground seats and new OEM springs.

Another strange thing is it did have over 200 lbs compression on the right head, 165 on the left head, now both are 165(?)

Next I need to check tappet clearance to see how its getting on.

 

[macka]

thanks