1150 cams in a 1100

[Fjbj40]

I just installed 1150 cams in my 83 1100. I put the 1100 gears on the 1150 cams because the 1150 gears did not have the index marks. So I installed and timed the gears as per the 1100 manual, twice. I am getting very little compression. Engine has new OEM rings with deglazed cylinders which are within new specs.

The cam notches on the r/h side of the cams line up like the manual says?

Am I missing something here? Should I have used the 1150 gears instead? It should make no difference as long as the notches line up and valves are adjusted as per spec, correct?

I have aves done plenty of 8 valve engines and never had this problem, this is my first 16 valve engine.

 

[rapidray]

To get the best power, you really need to degree the cams. I would go 103/105 or 104/106 if it is a street motor. Just make sure you check piston to valve clearance but shouldn't really be an issue with cams that small.
Ray.

 

[Fjbj40]

Thanks for the reply Ray,

Once I get her running, jetting and all that extra stuff, I plan on doing cam dial in. I actually have all the required tools to do the 1085 this spring. All I need for the 1100 is a TDC stop.

Ray, my problem, or maybe not, is with the cams at the stock setting, as in the first post, I have very little compression when I turn the engine over by a wrench on the crank. I know the cylinders are tight because before I installed the cams I turned it by hand and there was strong compression, hard to turn in other words.

so should I get lots of compression when turning by hand? I know on every other engine I have ever frigged with I do!

 

[GregT]

Dial the cams before you fire it. In my experience you will have to move things quite a bit to get to the figures Ray has recommended. Plus i suspect there is a major error in where the cams are now.....

 

[Fjbj40]

Greg, I assumed I made an error when I first installed, so I took it all apart and redid it, with the same result! I know that's definition of insanity!

I guess I will have another look, get the TDC stop and dial them in. I have 4-5 months before riding starts anyways. I probably am missing something stupid and simple, usually that's the way it is.

Thanks

 

[Fjbj40]

I am going to get the stock gears holes elongated. Roughly how many degrees should I have them milled?

 

[Blower]

I am going to get the stock gears holes elongated. Roughly how many degrees should I have them milled?

Get a good round file and file the bolt holes about two times wider than original bolt holes. It should be enough for the 1150 cams.

 

[Fjbj40]

Thanks! That I can do, I figured the gears were really hard and would be difficult to file so my buddy was going to mill them for me, now I don't have to bother him.

cheers

 

[blowerbike]

take an old plug and knock the guts out of it and make a positive stop.

 

[Fjbj40]

Made a stop last night.

After TDC was found using the stop, the initial observation is that the timing plate mark was approximately 1/8" away from the "T" mark on the advancer unit. Gonna play with it again this weekend to confirm this observation.

For max power and probably efficiency I can see why this is the proper way to time the engine. Gonna slot cam gears and dial everything in during Xmas break.

 

[Fjbj40]

Well I seated my rings degreeing in the cams

So my final numbers are 104.25 intake and 106.75 exhaust. Gonna try those and see how she performs.

I ended up with those numbers by intake opening 11.5 BTDC @ .050, closing 40 ATD @.050
Exhaust 5.5 BBDC @ .050, closing 39 ATD @.050

So 11.5+180+40=231.5/2=115.75-11.5=104.25 intake

5.5+180+39=224.5/2=112.25-5.5=106.75 exhaust

I found conflicting info so this was done at zero valve clearance.

so do these numbers look correct to those in know?

Thanks

edit, realized I effed up! Redoing ......again!

ended up with intake @ 105.25 and exhaust @ 107
in opens @ 10.5 BTDC, closes @ 41 ABDC
ex opens @ 39 BBDC, closes @ 5 ATDC
both measured @ .050"

 

[Fjbj40]

How do these numbers look in the edited post above?

 

[GregT]

104.25/106.75 will be fine. Close enough for government work....
Only a dyno would notice a 1 degree change in either.

 

[Fjbj40]

104.25/106.75 will be fine. Close enough for government work....
Only a dyno would notice a 1 degree change in either.

Thanks Greg, I actually ended up redoing and it and ended with 105.25 and 107.

This was my first time doing this type of thing. Going to do my 1085 the spring, try and wake her up a bit.

Cheers

 

[posplayr]

I found this helps slot if you are trying to precise.
http://www.thegsresources.com/_foru...-Accuracy-Degree-Wheel&highlight=Degree+wheel

 

[Fjbj40]

I found this helps slot if you are trying to precise.
http://www.thegsresources.com/_foru...-Accuracy-Degree-Wheel&highlight=Degree+wheel

I read that one, I need to get a better wheel than I currently have. I made one myself from an online printed sheet and piece of aluminum.

 

[posplayr]

I read that one, I need to get a better wheel than I currently have. I made one myself from an online printed sheet and piece of aluminum.

With 600 dpi print resolution, I suspect that if the wheel was at least flat and centered you are fine. I insuring proper perspective of teh needle to wheel alignment will probably add much more variability.

My finding was that with the back and forth measurement of one side and then the other of TDC, with a precise reading of the wheel, you developm much more confidence in the measurement and can iterate to the final degree settings much faster.

Sighting down the edge of the razor just takes a lot of variables out of the measurement and therefore improving repeatability (I'll not repeat my analysis here). It is hard to imagine anybody arguing the point, but then again I have to realize there are plenty of people that are insecure enough that they will argue against the most basic principles in defense of their prior practices regardless of what "new" might come along.

No reference to you but rather the parties in the other thread, I just revisited.

 

[Fjbj40]

With 600 dpi print resolution, I suspect that if the wheel was at least flat and centered you are fine. I insuring proper perspective of teh needle to wheel alignment will probably add much more variability.

My finding was that with the back and forth measurement of one side and then the other of TDC, with a precise reading of the wheel, you developm much more confidence in the measurement and can iterate to the final degree settings much faster.

Sighting down the edge of the razor just takes a lot of variables out of the measurement and therefore improving repeatability (I'll not repeat my analysis here). It is hard to imagine anybody arguing the point, but then again I have to realize there are plenty of people that are insecure enough that they will argue against the most basic principles in defense of their prior practices regardless of what "new" might come along.

No reference to you but rather the parties in the other thread, I just revisited.

It was a rather interesting read

My wheel was okay and up to the job. What I did was make the pointer the width of the degree gaps and the wheel was flat enough that the pointer was only about .040" off the surface.

This made it easy to get the readings, actually quite easy.

The only issue was I ended up getting the numbers I wanted but when I looked at the notches on the cams there was a large spread! So I rechecked true TDC and sure enough the wheel moved, this was after Loktite. So I had to redo it.

I am sure I seated the new rings into the cylinders though

Cheers

 

[posplayr]

It was a rather interesting read

My wheel was okay and up to the job. What I did was make the pointer the width of the degree gaps and the wheel was flat enough that the pointer was only about .040" off the surface.

This made it easy to get the readings, actually quite easy.

The only issue was I ended up getting the numbers I wanted but when I looked at the notches on the cams there was a large spread! So I rechecked true TDC and sure enough the wheel moved, this was after Loktite. So I had to redo it.

I am sure I seated the new rings into the cylinders though

Cheers

As I described in the thread, my motivation was the readout accuracy I saw at RapidRay's shop. He was degreeing my engine using his big wheel and had me read off the angles. Then he leaned over and read a number himself and promptly told me I was reading 1 degree off. It became obvious that where you stand can make a huge difference (i.e. 1 deg ) even with the big wheel.

Another subtle factor is that when you measure two angles on each side of TDC and then diffence them, teh error goes up (statistically) by 1.41 again.

So if you figure 1 degree variation for the 18" wheel, that equates to 2 degree error for an 8" wheel and the error you used to move the cam is 1.41 times that or close to a full 3 degree of potential error (+ or - 2 sigma).

It is no wonder that you might have to go through multiple iterations of back and forth (which I experienced as well) measurements trying to figure out where a cam lobe really is if you have such sloppy tolerances.

With the razor I figure it was easy to get to 0.1 deg (1 sigma) and so there was a lot less trial and error getting to the proper settings. Perhaps as an engineer I'm much more aware of these things as it is part of my practiced skill set. Ironically this turned out to be even more controversial than the wheel alignment techniques debates. (the string v.s .the laser).

If you are careful about how you read a piece of wire (or can keep a sharp point next to a flat disk), you can do a reasonable job I suppose. If you have significant distance or less than fine point on the wire, there is really no way to know how accurate you really are as just moving your head a little can make a pretty big difference.

 

[Fjbj40]

I totally understand what you are saying. I strive for perfection, within limitations, on everything I do. I am an aircraft mechanic by trade, I accept nothing but the highest level of success in my job.

The pointer I used is exactly the same width of the degree markings, if you are not looking at it perfectly straight when you take the reading you will see the side of the pointer and not just the front, so you know you are not reading it correctly. Looking straight on you will just see the front and no sides of the pointer, make sense?

For me, it was the best that could be done at the present time. I am sure I will improve my technique on the next one, I will look over your thread again and see how I can use it to improve, multiple ideas are always better than just one idea as long as they are looked at in an unbiased manner.