Cam specs?

[Craig]

I think that this has been covered before, but I can't seem to find the thread, I'm just wondering if anyotone knows when the cams are supposed to open the valves (in particular the exhaust cam) and if possible the lobe centres and separation angles?
Cheers Craig

 

[frank]

craig

which cams?
(ps any sign of that package)

 

[rlees85]

http://www.micra.org.uk/showthread.php?t=9790&highlight=camshaft

that any good?

 

[Craig]

Ideally the 1.3, but the 1l will also be helpful - I have Tomei cams, but hoping that knowing the specs of teh std ones will help my mind-calcs.

I sent you a PM - did you not get it?

Basically, I got one package throught form the 10/10/07 (not from you) but still no sign of your package, I know that our postie is prone to putting the package on the alcove by my doorstep so I hope that he didn't do this with your package and then some-one nabbed it (not that it would be of any use to them anyway) I must say that it is rather frustrating as I want to have a good play with your package (ooh er) but there's no sign of it - did you send it standard parcels?
Craig

R. Lees - I've seen that, sadly it doesn't help with the timing of the cams, I seem to remember lowrider posted old fashioned timing measurements of a set of cams that could help, but can't seem to find the thread.
Craig

 

[frank]

craig

nme are 254 duration 8.35 lift 17/57/57/17 timings if thats any help.

first class rm our kid!

 

[Craig]

Wohoo, finally came today - was postmarked the 15th, so only 16 days - thanks Royal Mail.....
I've sent thepayment so you should a 'proper' official member soon enough
Craig

PS, thanks for the specs - I couldn't find that thread when I searched.
Craig

 

[frank]

thats great,thanks craig.

 

[Craig]

Ah, updated already - thanks for the collectors, thet seem to be made exaclty the way I was planning on doing them.

With reagards to the actual topic title, I found that I already had much of the info, apparently the lobe centre agnle for these cams is listed below - is this going to be ATDC, or some other measurement that I will have fun trying to figure out?
Craig

 

[frank]

craig

ideally you need the inlet fully open angle i think, then use a dial guage and protractor disc to set it, i,ll take a pic of one if you want ! (theres a disc in my garage somewere)

 

[Craig]

Wpuld have helped had I included the specs!

CG10 Solid
In: 196° 5.59 98°

Ex: 196° 5.59 98°

[FONT=&quot]　[/FONT]
CG13
In: 222° 7.46 111°
Ex: 222° 7.46 111°
Z10
CGA3 Solid
In: 222° 7.94 111°
Ex: 222° 7.94 111°[FONT=&quot]　[/FONT]

Tomei:

Duration
(degree)​

Max Cam
lift[FONT=&quot]（[/FONT]mm[FONT=&quot]）[/FONT]​

IN/EX​

Max valve
lift[FONT=&quot]（[/FONT]mm[FONT=&quot]）[/FONT]​

Cold valve
clearance
[FONT=&quot]（[/FONT]mm[FONT=&quot]）［[/FONT]±0.01[FONT=&quot]］[/FONT]​

Lobe center
angle
(initial)​

Base
circle
264​

8.35​

IN​

8.05​

0.30​

110​

φ32​

EX​

8.00​

0.35​

115​

​

(Although the PonProcam is listed as 256 degree - maybe this is duratoin at the valve?)


I'm mainly interested in when ex. valve shuts to help me DIY a manifold, but it would be nice to know how the cams are normally set up as I'm looking to get some vernier crank sprockets, but to do that I will have to machine the sprockets.
Craig



Hmm didn't cut and paste as I would have liked, you mean something like htis?
http://www.alcester-racing-sevens.com/cam_timing.htm

 

[frank]

craig

filing the locating dowels worked ok when i advanced mine 10 deg, its an option ?
pic of disc to follow, its got setup info printed on.
lobe center is the key to setup

 

[Craig]

Yeah, I'd rather have something a bit more precise - I have a spare set of sprockets that I might do some maths with so that I can do smaller advancec, but I reckon taht I will ruin it all.

Just googling and I see that lobe centre is measured ATDC, lovely.
Craig

 

[frank]

http://i44.photobucket.com/albums/f47/TomEA/pict0025.jpg

protractor disc

 

[Craig]

Ah, I will have to invest in one of those then - any idea if the cam profile is likely to be symmetrical?
Craig

 

[Soixantaine]

A good read with excellent chapter on cam timing.

S

 

[Craig]

Interesting, I have pored over A.Bell's Haynes book, but it is a bit dated and more applicable to big yank motors, will have a look for that on eBay.
Craig

 

[Antony]

try the haynes 4 stroke tuning manual.... its an engine builders bible.

craig.... are you doing this to "THE" engine

 

[Craig]

Hmm, I could do, but I'd rather wreck my own engine than give it to someone as I think it's a bit of a bodge , maybe I could get something to work after playing with belt-verniers hmmmmmm