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**bszopi** · 02-05-2005, 12:29 PM

RE: Cam phasing?

I'll see if I can find the pics to explain it more. They are on here somewhere....

**Doubt_Incarnate** · 02-05-2005, 01:25 PM

cool, i was tinkering in DD2K and it seems if we can do a centrifigal retard in the cam gear we could first advance the cam for a slightly better lowend than base, and make it retard like 10-15 degrees overall at 4500rpm to boost the topend.

i know its just the dd2k thing, and yes, "some people say that im a dreamer..."

if you can make it compact enough mechanism in the cam gear so it just bolts on, and strong enough, it might be worth developing. just wishing to try more things i dont have tools for, yet...

**geoffinbc** · 02-05-2005, 03:34 PM

On the new engines oil pressure is delivered to either side of the phaser attached to the end of the cam. It just advance or retards the cam based on the computers commands.

On a pushrod motor all you can do is advance/retard the cam timing. On a DOHC motor the intake and exhaust can be controlled seperatly thus you can adjust overlap aswell.

**bszopi** · 02-05-2005, 05:43 PM

Ok, got some new pictures in the gallery.

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http://www.60degreev6.com/modules.php?set_albumName=2006-Pushrod-Engines&op=modload&name=gallery&file=index&include=view_album.php

Both the 2006 3500 and 3900 have cam phasing. You can see the controller on the front of the engine. Looks like it might almost be integral with the timing cover. If you look at the 3900 cutaway drawing, you can see more of the internals of the cam phaser.

As far as adapting it to older engines, not really practical. You'd probably need the whole engine, harness and PCM in order to utilize it. I'm not even sure if a high end standalone would be able to control it correctly.

**Doubt_Incarnate** · 02-05-2005, 11:51 PM

in honda land they have a swap, called "mini-me" i belive its for the d-series only, it involves swapping a v-tech head to a non v-tech motor/setup. all theyt do is make use of an rpm activated switch to turn the v-tech solinoid on it to controls oil pressure in the valvetrain.

much differnt than the hondas, i like it better, honda uses actuall moving pins, more parts.

as oil flows in it just tweaks the cam one way, or the other, depending on which side its alowed into. sort of like a hydralic cylinder, fluid from one side to the other and the movment happens

**speedvisioncavalier** · 02-07-2005, 12:17 PM

the honda mini-me swap is very close to what the 660 hybrid swap is. they take a D15 or D16a6 bottom end (88-91 civic SI, CRX) and put on the top end from a VTEC D16z6 or D16y8. the head breathes better than the original one, mostly due to VTEC, and gives about 1000 more rpms of useable powerband.

just like the 660 hybrid (which usually runs off the old MPFI ECM), they usually make the new mini-me hybrid run off the old ECM, which doesnt have provisions to activate VTEC. therefore they need something to tell the VTEC solenoid to activate, so they make it simple and use an RPM switch. then you can use a SAFC or something to enrigch the fuel maps at the upper rpms to compensate for the extra airflow, or you can try to hack the fuel maps to accomplish the same thing.

**Doubt_Incarnate** · 02-07-2005, 01:25 PM

i wonder what the feasability of a centrifigual retard mechanism would be. i played around on dd2k and on a 3100 you can (supposedly) get much more top end by retarding the cam after 3500rpm. do you think its a waste of time to try such a thing? it would have to be a custom cam sprocket with all the mechanics on it, weights, levers, and springs. the faster it spins, the wieghts pull the levers out wich rotate the cam to retard it at the required rpm. i think it can be made to fit under the stock cover, or maybe have to mill it a little where the sprocket is for clearance.

**speedvisioncavalier** · 02-07-2005, 05:36 PM

if you want inspiration for how to phase a cam advanced or retard, you should try to copy the methods OEM guys do it. no one is doing it with mechanical means. its all done electronically on the cam sprocket.

**Doubt_Incarnate** · 02-07-2005, 07:08 PM

thats alittle beyond me. putting a dumb mechanism on a disc is one thing, trying to controll it from a stationary point is little boggling to my mind.im open to ideas though, any suggestions are to how this can be done? simply.

**geoffinbc** · 02-08-2005, 12:39 PM

You would need to copy the weight mchanism in an old mechanical distributor.

This would give you a basic idea. However you are going to be haulted by several sizing and technical issues.

Also go and get a new cam and pshser mechanism and see how the cam, phaser and gear are oriented.

In the end go get a nice cam with a 112* LSA and good duration to get big flat torque curve.

**Doubt_Incarnate** · 02-08-2005, 01:30 PM

i'll have to price the stuff, but it does look like its part of the timing cover. i guess its just to house everything. is the motor out this year? next year? i dont want to walk into the dealer asking about stuff that they have no idea what it is.

i drew up a model of what needs to be done for such a mechanism. the only problems i see as of yet are tuning the springs and weights to keep it stock until it needs to move. then i kinda wwant tit to move rapidly. if i can find the old escort cam gear i have i'll be able to make something out of it. i think. just needs to spin it up to about 1500-2000rpm. i guess i can use an electric motor and a belt to do that. assuming i ccan make the parts, or maybe pirate some from something else, i'll have a working visual model.

but then my family is not so family like recently, most of my projects are on hold as i try to relocate away from them since all they do is ask 20 ?'s and get mad at me when i don't know the answer. "if its not bore x stroke, cam, awd, tubo, nos, or dohc. i cant help you dad, sorry". probably be selling intake/heads/tb and whatever parts i have and dont need.

**bszopi** · 02-08-2005, 02:13 PM

Damnit, I was looking at a PDF from Powertrain last night that had a picture of the cam phaser outside of it's case, but I can't find the PDF for the life of me now!! I'll have to check my history when I get some and see if I can't find it again. Give you an idea at least of what GM is using.