Camshaft specs

[burn_your_money]

Well here it is. Pretty interesting stuff if you ask me. Hopefully we can have some more cams added soon.



BTW that G60 cam would rock the valves off the pistons on an AAZ. Dr. Diesel has a graph showing that one...

[truckinwagen]

hey man, if I sent you an ABA cam could you plot it as well?

-Owen

[burn_your_money]

Sure I suppose. Would you want it back?

I'll try and get pictures up of the setup we were using. It would be somewhat easy to build yourself with just scraps.

[truckinwagen]

depends what the map looks like...

but certainly not before the fall, so you could take your time.

a pic of the apparatus would be great!

[Runt]

I'm curious, you comment that the g60 cam would be valves off pistons, but I'm looking at it in the overlap area, and it's almost exactly the same as the solid lifter cam, so really the issue would only be the amount of the valve lash wouldn't it?  In fact, the intake is entirely along or within the AAZ's white line, so it is just the exhaust side that is a little slower to close at overlap, and ten or twelve thou. should be fixable with a little flycut if need be.  Could somebody explain where I am missing something?

[truckinwagen]

if this could be mapped in degrees of crankshaft rotation, I could model it in autocad to check for piston/valve interference as the piston comes to the top of its stroke.

could make designing(or finding) the best cam a little easier.

-Owen

[burn_your_money]

Here you can see just the overlap. The G60 has just a bit too much.

We have mapped them vs the AAZ piston. I don't have that info, Dr. Diesel does. I'm sure he'll chime in at some time.

The AAZ piston hangs out at TDC a lot longer then the 1.6 piston. The G60 cam *might* clear it.

This is still a work in progress. There are a lot more cams to measure and plot.

[subsonic]

If in the need of science, you need a brand spanking new AAZ cam to graph, I have one.  Never been run.    I would of course perfer to have it back .   I am not using it right now so there is no major rush.  Anyone want to kick in a few bucks to help cover shipping/ ins. back and forth?

[rabbitman]

Hey Burn, I have a topline cam that is perfect except the pulley taper broke off (lets not talk about it though ), needless to say it's useless and is waaaay too embarassing to hang on my trophy wall .

It's off a mech lifter 1.6 head and I think they list the TD and NA heads and cams as the same PN.

If you want it let me know......

EDIT: I don't know what shipping will cost but if it won't be worth it I won't be too hurt.

[Runt]

if this could be mapped in degrees of crankshaft rotation, I could model it in autocad to check for piston/valve interference as the piston comes to the top of its stroke.

could make designing(or finding) the best cam a little easier.

-Owen

Mapping in crank degrees is just double the cam degrees.  After 180* cam, crank starts the second revolution.
Perhaps we could convince the creators of the data to post the raw data (comma delinked or something else simple to keep file size down) and then we could play with it ourselves.   Anyways, thanks for the data and charts, it's nice to see what these cams are actually like.

[truckinwagen]

I would be happy to pay the postage for the cam I would like mapped, and the raw data would be great too.

I could easily build a "test engine" in autocad(either AAZ or 1.6, or whatever stroke/rod length) to check for interference.

all I would really need is piston to head distance(at TDC) and valve recess into the head distance.

that with extrapolating valve lift at degrees crankshaft rotation the interference would be easy to spot.

-Owen

[burn_your_money]

Just IM me if you want the excel file. If you want it converted to crank degrees first just let me know.

I would like to measure the Topline one but I don't think we would be able to without the taper. That's what we hook the degree wheel up to.

It would be interesting to see how much wear the AAZ cams take over time, but I don't really think it would be beneficial. If anyone thinks it is LMK. Probably looking at $40-$60 there and back for shipping.

[Turbinepowered]

I have a MatLab license if we want a graphical representation of piston and valve...

[Dr. Diesel]

I've mapped everything out at a much finer resolution re: piston movement vs valve movement. The G60 cam ruins both the 1.6L and 1.9L engines. Ruins. Especially the 1.9L
In theory, if you had a 1-notch 1.6L with the piston at the absolute minimum projection as allowed by Bentley for a 1-notch engine, and installed a 3 notch gasket, and survived reading this run-on sentence without going blind, then, again in theory, you'd finally achieve piston to valve clearance of about 0.003". (roughly the thickness of a hair) That's on average far less than 1/10th of normal clearances. A normal buildup of carbon on the surfaces would likely spell game over, let alone things like heat expansion, belt tension and timing irregularities. Bottom line is, unless you're doing something to space the head significantly further from the block than normal, (read as, no start in the cold due to low static AND dynamic compression) the G60 cam is a write-off. *edit* Most other older gas engine cams would be even worse, as they ALL have even more overlap than the G60 cam. Newer engine cams might come close, but still don't quite fit. That's without even getting into how you'd turn a gas cam with a diesel engine.
Observe:

This graph represents an AAZ 1.9L engine. The blue line is the piston movement, truncated to avoid an unnecessarily huge graph. The red line is the exhaust valve and the green line is the intake valve. The flat lines of the valve curves represent the valve faces in the closed postion and is accurately calculated in distance away from the pistons at TDC in a best-case scenario engine. Meaning, of all the piston projection vs gasket thickness combinations allowed by Bentley, the largest clearance combo was used. Any other combination would only serve to drive the valves deeper into the pistons.
Conclusion: Crossbreeding ain't gonna work.

[truckinwagen]

from the cam specs for gasser engines that I have read, the G60 is not the most conservative cam by a long shot.

in order to meet emissions, the second gen(OBD2) ABA has lots of negative overlap(time that both valves are closed)

also the euro K-grind(mechanical) has lots(and I mean lots) of negative overlap.

the ABA cam I have(OBD2) supposedly has 7 degrees of negative overlap measured at .5mm of valve lift.
how many degrees are both valves closed(less than .5mm lift) on an AAZ/1.6 cam?


as for connecting the cam sprocket, iw would not be hard to have an adapter machined to fit on the gasser cam nose with a keyway, allowing the taper fit of the diesel sprocket.

-Owen