Setting cam timing

[Sheep]

Guys,does anybody know of a good link/page etc on the step by step job of setting your cam timing using a degree wheel/dial indicator etc...I have had a read through one or two sites but they seem to go into to it way too deeply.Getting the tdc set with a piston stop i am confident in doing,its just the cam timing itself I need to get to grips with.

I am planning on fitting slotted sprockets to maximise my stock cams potential and i want to swot up on it before i do it..(efe engine).Also,all the sites I did see seemed to be USA based and everything was measures in inches,is this the industry norm or is it down to personal preference?

 

[KATANAMANGLER]

Try This

[Sheep]

Fantastic...cheers mate.

[markfoggy]

Forget the piston stop, there is a lot of dwell at TDC so is easy to be 2/3 degrees out, which is a country mile. 

Big old dial gauges s/hand are great for dialing in a timing wheel for exact TDC. Cheap as chips on the bay of thieves as nobody wants old Imperial stuff. I'd explain how, but too late in the evening for that malarky. Get a good metric gauge to find the cam lift points, if you can find one with a selection of screw on pointers/tips, all the better as space can be tight getting a good reading and long tips can help.

 

[KATANAMANGLER]

22 hours ago, markfoggy said:

 

Forget the piston stop, there is a lot of dwell at TDC so is easy to be 2/3 degrees out, which is a country mile. 

 

Isn't that precisely why the positive stop tool is used initially to set TDC on your degree wheel? You measure the travel both ways then using the  degree wheel readings you calculate true TDC. Which is when both the conrod and the  piston are at TDC.  Then you  set your wheel to true TDC and everything else is set from there and the positive stop tool is no longer required.

[vizman]

On ‎12‎/‎5‎/‎2016 at 10:46 PM, markfoggy said:

 

 I'd explain how, but too late in the evening for that malarky.

 

so why not reply at a more convenient time instead of a mix of nonsense and stating the obvious?

[Gixer1460]

On 06/12/2016 at 11:20 AM, KATANAMANGLER said:

Isn't that precisely why the positive stop tool is used initially to set TDC on your degree wheel? You measure the travel both ways then using the  degree wheel readings you calculate true TDC. Which is when both the conrod and the  piston are at TDC.  Then you  set your wheel to true TDC and everything else is set from there and the positive stop tool is no longer required.

Exactly! If you don't understand the principles behind the theory then how will you know what to set the cams to? You can set them to what Suzuki designed them but is that what your engine spec wants? Single cam engines are relatively simple in that the lobe centres are fixed but with double you can move both around and still have the same centreline angle sbut with totally different responses - something to think about!

Edited December 7, 2016 by Gixer1460
spelling

[Sheep]

Cheers guys...

Yesterday a did fashion a stop from an old spark plug and threaded bar and it works a treat.

I am not ready to do the timing until the new year as i have yet to get the barrels bored etc but i just want to do my homework first.

I took the head off last night,labelling and bagging everything methodically which was pretty straight forward (cars/twins i am used to but my first multi bike to this extent).

Everything looked normal albeit a little oil wetting #3 piston top.Very little bore ridge evident but may still go bigger!!

I have all the dial gauges,feelers etc..just need a degree wheel.

[Reinhoud]

You don't need a degree wheel to determine your TDC.

 

Assuming your fly wheel cover is off and fly wheel is visable.

- Make a pointer and mount that in one of the bolt holes, make pointer so that it's close on top of the flywheel, make point on the pointer.

- Take piston stop and turn that into spark plug hole

- Turn fly wheel to one side till piston hits stop.

- Mark with marker on the fly wheel where pointer is.

- Turn fly wheel the other side till piston hits stop.

- Mark again where pointer is on fly wheel

- take a ruler and mark the center of the 2 marks, this is your TDC.

 

- Off course it's all about how accurate you do this.

 

My experience, as long as you set everything on the stock marks it's ok, I didn't notice any difference after dialing in. (trying to improve stock setting that is)

 

[KATANAMANGLER]

Depends on whether you intend to spread or close the centres. increasing valve overlap is desirable for top speed. Reducing valve overlap will , broadly speaking, give you more low down and mid range. I think of it more of moving power rather than generating more.

I had my 1230 engine set at 105 degrees intake 108 degrees exhaust and it was very different from what it is now 109 intake 109 exhaust. the current  wider centres  ( reduced overlap) has the power biased to bottom and mid range, at the cost of top end. That suits me and where I want the power.

I have never diialed in the standard cam timing but I guess every little bit helps. 

I found this article invaluable from a theory point of view.

[Sheep]

I was reading an article only last night on lobe centres.This article explains it pretty well,and has a pic to boot lol....

[KATANAMANGLER]

Yeah pics are good for us air cooled boys who don't  read good 

[clivegto]

[clivegto]

This is what I use, sorry about some pages been the wrong way up.

[vizman]

do not scale off drawing

[markfoggy]

Sorry guy's I'm working about 67+  hour weeks so not getting to do a lot of lateral thinking. Of course cam stop is fine as a determining method, just not to be confused with the TDC positive stops that used to drop into the cases of older 2 Cyl engines or the sort of TDC locator's that you can buy from motor factors that you could screw into the plug hole of a GSX engine and then wonder where all the accuracy went.

I'm still a gauge man as a point of working principle, because I would never rotate an engine in any direction but firing. 2 points here, big end and little end float, though tiny, should always represent loaded condition and if you have the cam chain tensioned, reversing the direction is liable to give erroneous results at best and a positive invitation for the chain to jump a tooth when you are not looking.

 

 

[markfoggy]

I love this old Batty Gauge that cost be not a lot.

It's a push through type, big button on the end of the probe is ideal for most pistons. Set it at a nominal depth and find a rough TDC set gauge to zero.  Turn crank until it stops registering, counting the turns and a figure in thou. Turn the crank round and count turns and thou on the way back up. Reset outer ring to half distance in thou, check on next crank revolution and then fix timing wheel and a solid pointer.

Job, Jobbed.

[vizman]

how does that gauge attach/fix itself to sit true in the spark plug hole or a fixed position ?

[markfoggy]

Oh I just bolt it into a magnetic clamp and fix a piece of steel gauge plate across the rocker box gasket face. I then use the same magnetic clap to get a Mituyo onto the cam lobe, though I have not used my gauges on a GSX so haven't drilled holes in the right place yet, but you can usually just get away with one random hole.

Last one I did was a GSXR with loony tunes internals and an untested set of cams so had to be careful. As it goes the cams were a little tame and I was clocking the cams a bit at the time, so had to be careful. If anybody has a set of silly cams for an XRO engine lying around I could put them to good use.

That is a normally aspirated XRO type/spec engine, before the mods go spitting feathers BTW. 

 

[markfoggy]

Hmm, just thinking, not sure you lot have seen this yet, Is OSS, engine stand by GIA.

[Reinhoud]

When I was busy with the turbocharger on my bike some told me to experiment with the cam timing, so I did..

Result, didn't matter if a made the overlap bigger or smaller, it lost power, throttle response was crap, and on boost there was hardly any difference.

Bike ran at it's best on the stock timing, but maybe others have different experiences.

 

 

[vizman]

i would've thought stock/mild cam more suited for street forced induction....but then i've never had anything but stock on my (street) turbos.

[Captain Chaos]

AFAIK "hot" cams with big overlap are a waste on supercharged engines, because of the overlap a lot of boost is lost.

[Blower1]

I have stock EFE cams in my supercharged EFE, intake 109 / exhaust 111. Throttle response is good and so is torque from idle to redline.

[Leblowski]

I am running 108/110 on my oilcooled 1216 tried a lot of diff settings.

108/110 was best in keeping torgue until 8000 rpm i wanted a nice steady torgueline as long as possible

All other settings i tried where worse, it all depends on what behaviour you want.