Sundance 6g72 "3.0 turbo build thread"(N/A DYNO SHEET pics inside)

[shayne]

not neccessarily, now i could totally be wrong here, but i just looked at a junk 3l head. and did some reading on roller rockers, by nature a roller acting on a cam lobe even in a lifter bore like a v8 where the lifter travels up and down the contact area between the roller and the lobe does move back and forth hence why with late model v8's have such a long lifter to support the side loading created by factory cams that have a fast ramp up to peak lift. while the 2.2/2.5l rockers do "float" but they cant move significantly fore and aft or else you would have wasted valve guides and destroyed lifters in short order with side loading. by nature an eccentric cam lobe acting on a roller, especially when the roller moves in an arc by itself as the cam acts against it also dictates that the imaginary measurement from the center of rotation (rocker shaft) to the point of contact (where the roller contacts the cam lobe) moves to create both a shorter distance and a longer one thus changing effective rocker ratio.
im not saying that it is significant, but it does affect the ratio. which is also why i think some people got mixed up trying to figure out the rocker ratio. this could be a good thread all by itself..

[Ondonti]

You are just talking about the contact patch of the roller moving from one side of the lobe to the other and thus touching a different part of the roller. I think that is taken into account in the camshaft design. You can always compare partial lift with a little eyeballing and temporary marking. I really only care about the maximum lift for clearance issues and the standard duration numbers. My hot cam was ground based on a 1.5 ratio and we certainly do not have a 1.5 ratio so my cam is more like a 230+ duration cam @ .050 and that is probably why I killed retainers when used with stock length valves on a stock head.

I wish we could get a lot of things back from B-M. Love the ebay coilover FAQ. So much good stuff in the Valvetrain thread. I didn't save all the links I ever found for retainers and locks. Still no time to work on that stuff. I assume that Frank has ALL the backups, but its an intellectual ownership issue.

[shayne]

exactly, plus rocker ratio is only ever calculated based upon the active ratio at peak valve lift. And thathats why im wondering if one of the reasons why we the different cam lobe lsa between cylinders.

[Reaper1]

Well, with a little time and an Excel spreadsheet the ratio could be easily documented though the entire valve cycle. If it does in fact change through the cycle instead of the cam profile taking the effect into account, that means that the ratio will be vary with larger cams as well vs. stock. If that is the case, then that means the only true way to get actual valve lift and duration numbers is to throw the cam in the head and measure it, document it, and then extrapolate from there.

[shayne]

the difference of ration was insignificant from my old stock cams (oddly which are the ones now being used in this very build seen here after being checked and reground) and the cams i have now resulted in very little change. i remember it being in the .00x range. my comment in passing was mostly due to how for periods in the cam acting against the rocker results in a rocker ratio that changes a bit and is even different from head to head on the same motor. the rocker ratio to be thinking about is the measured 1.62:1 and also making sure to check if with the valve retainers installed wont smash into the valve guides at max lift.

[Sundance 6g72]

well i got the motor to run today with the new cams.


My boost gauge was sitting close to 0.. not much vacuum. It needed me to help it idle for a while before It would idle on its own. Took me forever to get it to start. seems like my dizzy was off a tooth? I remember taking a picture of how the dizzy should sit when its at tdc with the cam.. i have to find it though.


I need to get a timing light because I have no idea what my real timing is right now. Even with it running in questionable shape, it idles like it wants to go fast. It sounds alot meaner and rougher than before.

[Sundance 6g72]

Okay so the picture I thought I had has been deleted.

Anyone want to set their motor to tdc and pop off their cap and take a picture??????

[Force Fed Mopar]

At TDC on the compression stroke, the rotor should point roughly straight to the back of the engine.

[bakes]

i dont remebering the rotor point straight back i remember it point a the # 2 intake
bolt
http://www.justanswer.com/dodge/3soj...rt-timing.html

there is a pic on half way down the page that shows this

http://www.google.ca/url?sa=i&rct=j&...67209915118716

[Sundance 6g72]

thanks for the link

Hello, I was looking at your pics and actually the timing was not off before you removed the timing belt and when you say that the rotor was pointing to number 1 plug, I'm assuming that you meant that it was pointing to the number 1 tower on the cap, labeled #1, Correct? The reason that I am saying nothing was off is because the distributor cap is a crossfire type cap, meaning the actual terminal inside the cap does not line up with the plug wire position on the outside of the cap. So when you said it was pointing to number one, it was actually halfway between the number 2 and 3 terminals. The pictures you sent with the timing marks lined up (factory marks) everything is in the proper position for reassembly including the rotor, number 1 terminal inside the cap is at that location... I'm posting a drawing of the 3.0l dist cap that demonstrates this:

I FORGOT ABOUT the whole 'crossfire cap' type deal. Ill have to check it out tomorrow.

[Sundance 6g72]

So the dizzy was off by a tooth. Fixed that and it fired up quick. Idle like junk but I got that squared away.



8-10psi feels like 15psi on stock cams. I was never able to get crazy torque steer on 8psi until the cam swap. Injector duty cycle goes over 100% at 10psi (11.3afr)

I think the cams did a great job. Now im out of injector on even less boost.


I forgot how crazy this car is. I cant belive I drove it on a daily basis EVERYWHERE before I got my CTS.

[Vigo]

Sweet! Maybe a bit too much cam for my van.. my 3000gt might like them. Good stuff either way.

[Sundance 6g72]

does not seem to have hurt low end power as much as you would think... but its alot lighter than your van.

[c2xejk]

The stock cams are VERY mild, so it is hard to go too far...

[Vigo]

My 3000gt currently weighs more than my van, but that'll change once i put the full interior back into the van.

The van will be roots-blown so it would probably run fine lugging at low rpms with those cams, but id be primarily concerned about their effect on cruise mpg (roots blower, yes i know..lol) since im gearing it to cruise at ~2200 rpm.

But i anxiously await more feedback. Anything on 3.0 cams being tried out is exciting to me.

[Reaper1]

So the dizzy was off by a tooth. Fixed that and it fired up quick. Idle like junk but I got that squared away.



8-10psi feels like 15psi on stock cams. I was never able to get crazy torque steer on 8psi until the cam swap. Injector duty cycle goes over 100% at 10psi (11.3afr)

I think the cams did a great job. Now im out of injector on even less boost.


I forgot how crazy this car is. I cant belive I drove it on a daily basis EVERYWHERE before I got my CTS.

Man that thing sounds AWESOME!! Congrats!

The stock cams are VERY mild, so it is hard to go too far...

Well, there are a few things you have to watch for. Lifters not being able to take up the ground base circle, retainers hitting the valve stem seals, and the tips of the rockers putting too much pressure on the outside of the valve tip, giving it side loading. Brent has the trial/error experience with this stuff and can comment more expertly than I can, but I think it's all in his "Junkyard" build.

[Sundance 6g72]

dont expect a bunch of information yet, i dont have the time as of right now.. but its a start.

[c2xejk]

Well, there are a few things you have to watch for. Lifters not being able to take up the ground base circle, retainers hitting the valve stem seals, and the tips of the rockers putting too much pressure on the outside of the valve tip, giving it side loading. Brent has the trial/error experience with this stuff and can comment more expertly than I can, but I think it's all in his "Junkyard" build.

I was talking purely in terms of idle and low-end torque qualities of the cam. That was my understanding of Vigo's concern about the cam.

If we want to talk about what it would take to run a specific cam grind, that is a different topic.

Ed Kelly - www.kmperformance.com

[MC#4]

I love when you update this thread! It always motivates me to work on my car more. That exhaust note is sick!

[Ondonti]

Clearances are one thing but I do agree it is hard to go too far with cams performance wise.

My big cams with a 1.5 ratio rocker got maybe .5 to 1 mpg less driving to work, if that. Stock ecu, stock timing, stock heads, Holset setup. Oh boy the top end is not the same without them. Wished that rocker setup was not flawed or that I had clearances on that stock head cause I do not like vss replacement with head on motor in car.

What base fuel pressure you running and what size are those injectors again? I was out of fuel at about 12-13 on MS2 and my 47# injectors but I was spraying a load of 100% methanol. I think that was with pretty low base pressure because I was not happy with low pulse width performance (idle, junky modified injectors with bad spray pattern). Amazing how much farther a RRR will take you on small injectors as long as your fuel pump can hang, especially when you are running gasoline and not E85.

BTW i was shocked about my MPG performance because I was certain that being forced back to stock cams was going to give me some amazing MPG gain. It did not. I couldn't believe it since my cruising rpms are all in the low 2000 range which a big cam should destroy efficiency at.