progress on the banshee...

[Shaun41178(2)]

would like to read some kill stories soon.

8 lbs you should be around 350 whp so it should roll out. Mine does.

[ericjon262]

would like to read some kill stories soon.

8 lbs you should be around 350 whp so it should roll out. Mine does.

comparable build N/A have put down about 275 to the tires through a FWD getrag with a pretty nice torque curve as well. I've gone to about 1/2 throttle a couple of times, and it gets pretty fun until the maf coupling blows off.

[ericjon262]

well, I got fed up with trying to make the stock bracket do what I wanted, so I ditched it and the stock alternator and began whipping up a bracket of my own design, so far, it's looking decent, but I still have quite a bit of work to do. the new alternator is off of a 2003 gmc safari w/4.3 v6. it's dimensionally very similar(slightly smaller case.), but it mounts with bolts parallel to the axis of rotation of the rotor instead of perpendicularly. I chose this alternator because it will be easier to mount imo, I'll post pictures when I take some later tonight.

The trick is still going to be making the tensioner work, which is proving to be more of a nightmare than expected.

[ericjon262]

still a work in progress, but it's coming along nicely.





a couple of pics comparing the two alternators. you can see that they are pretty much identical except for the mounts.





sorry about the crappy pics. I'll try to get better ones with daylight...

[ericjon262]

still don't have better pics of the "new" alternator in daylight, but the new low mount alternator is about halfway done. still need to get the tensioner mounted, and add some bracing so it won't flex under load.

[Shaun41178(2)]

:yawn:

[ericjon262]

:yawn:

are you not entertained?

[ericjon262]

the promised pictures of the "new" alternator in daylight. also, in case I didn't already say it, I am only using this JY alternator as a mockup, it will either be replaced or rebuilt as necessary.







and here's some more pictures of the new alternator/tensioner bracket.





installed:



right now, there are two big things left. the tensioner is currently through bolted to the bracket, for the rear bolt, that's fine and good, for the front, it's a no go as it hits the nut hits the block and doesn't let the bracket sit flat. to combat this, I'm going to weld a stud to the bracket and have the nut on the opposite side. the other thing, if ti wasn't clear in the "installed picture, is to make a mount for an idler pulley above the tensioner. other than those to big-ish things, I'm also going to add a few supports to limit the amount of flex the bracket can see. I'm pretty happy I've been able to make this work with "wear parts" that are all available off the shelf, without having to be modified for installation, so if I blow and alternator, or tensioner, a quick stop anywhere should be able to yield a replacement.

[ericjon262]

so at this point, the bracket is about 80-95% done, seems pretty strong, the only thing I'm concerned about is belt wrap on the crank pulley. right now, it looks like the best I'll be able to get is about 180*. I'm gonna give it a shot and see how it does, if it squeals like a stuck pig, I'll try a few ideas I have.

In other news, I'm also working on converting the valvetrain to a full roller, adjustable setup. on a 3500, there are a few problems to overcome to make the conversion.

1. no guideplates available. I've got a solution I'm working on for that now though.
2. no conversion studs in long enough to make me happy, I've got about 25mm of threads in the head. the longest conversion stud I've seen only extends 20 mm into the head, which would be ok if it would be threaded directly into the head, but there's going to be a custom guideplate in between the head and the stud, which will further reduce the thread engagement. if it was in iron, I would have no worries at all about it, but going into soft cast aluminum, it's a spot where overkill is underrated. Thankfully, I have an extra set of heads I can use to test fit components on.

[ericjon262]

I test mounted the new alternator bracket, looks pretty good, just hope belt wrap isn't an issue.

in other news, I made up a quick drawing of an idea I have that would allow me to use fully adjustable rockers on my 3500, assuming I can find studs that will work...



the stock pedestal mount rockers have a groove that aligns the rocker to the valve, my thought, if the groove is good enough for the pedestal, why wouldn't it be good enough for a guideplate. nobody makes guideplates for a 3500, and because the valve are canted, a off the shelf guide won't work, as the angles won't match up.

Thoughts?

[The Dark Side of Will]

Is the pushrod centered on the groove where it passes through the plane of the guide?

[ericjon262]

Is the pushrod centered on the groove where it passes through the plane of the guide?

yes, but I gave this more thought and see a potential problem, the pushrod is not inline with the lifter, so as the lifter rises, the pushrod is going to act as a lever, with the guide acting as the fulcrum, so to minimize the effects of this, the guide will need to be positioned as close to the pushrod cup on the rocker as possible to minimize the effect on geometry. the best solution would be a shaft mount setup, but I don't think packaging will allow for it. the next best thing is a pedestal mount, as the lever action of the pushrod will be minimized because the fulcrum(guideplate) will be removed. downside to the pedestal mount, is that they can't be adjusted to obtain optimal geometry.

[The Dark Side of Will]

Can't aftermarket pedestal rockers be shimmed to get good rocker geometry?

Also, how much lift & valvespring are you running? How much RPM are you intending to turn? With roller tipped rockers, super correct rocker geometry isn't nearly as big a deal as it used to be.

[ericjon262]

Can't aftermarket pedestal rockers be shimmed to get good rocker geometry?

Also, how much lift & valvespring are you running? How much RPM are you intending to turn? With roller tipped rockers, super correct rocker geometry isn't nearly as big a deal as it used to be.

with a stock 1.6 rocker, I'm over .570 lift intake and exhaust. up to .640+ lift with a 1.8 rocker. the springs are pac 1518. with the guideplate, the roller tip on the rocker will receive thrust loading as the valve cycles. the only way to minimize the loading will be to get the guide closer to the pushrod cup. the only way to eliminate it, will be to manufacture a pedestal to the exact height needed, which shouldn't be too hard, but not a cake walk either.

as for shimming, maybe, but I don't see how you could shim what I'm working with.

[The Dark Side of Will]

I understand what you mean by using the guideplate as a fulcrum and the pushrod as a lever.

It sounds like you don't have any options but to use pedestal rockers. BBC's have canted valves as well, so there may be something in that market that could help you.

Are any other V6/60 guys running the cam setup you are?
I would think that if rocker geometry were a problem, people would be wearing out valve guides and/or bending valve stems with similar setups.

[Shaun41178(2)]

I'll have to check my cam specs from Ben but I think mine are over .500. I know I have them in my build thread but I have two different quotes. I am using 1.5 crane full rollers with Gen 2 guideplates.

[ericjon262]

I understand what you mean by using the guideplate as a fulcrum and the pushrod as a lever.

It sounds like you don't have any options but to use pedestal rockers. BBC's have canted valves as well, so there may be something in that market that could help you.

Are any other V6/60 guys running the cam setup you are?
I would think that if rocker geometry were a problem, people would be wearing out valve guides and/or bending valve stems with similar setups.

any others using the same cam? yes and no, superdave was running a similar lift cam on his car, but his car, and engine IIRC, have both been sold and are gone. I don't think it's crazy far off right now with the stock rockers, but it can't be ideal with the added lift as it would have been stock. need to take more measurements. I'm getting ready to put it back together with a set of stock rockers for the time being.

I'll have to check my cam specs from Ben but I think mine are over .500. I know I have them in my build thread but I have two different quotes. I am using 1.5 crane full rollers with Gen 2 guideplates.

gen 2 guideplates don't fit 3500 heads without machine work. I'd rather not pull the heads if it can be avoided. pulling the valve covers has become much easier now with the remote alternator mount though. now I can change rockers out without removing anything but the covers.


at this point, I think I have three options if I want to go full roller, option 1, machine a pedestal that will allow for the fulcrum to be shimmed up to correct deficiencies in geometry. make a guide that holds the pushrod right at the cup on the rocker as close as possible, or three, find a rocker that fits the stock pedestal and live with any imperfections in the geometry.

[The Dark Side of Will]

Is something wrong with the stock rockers?

[ericjon262]

well, not really, I'm just looking for ways to put a higher ratio in to get more out of her... it is low on the priority list though.

got the rest of the valvetrain back in and torqued down. re-installed the bits of cooling system that had to be removed to pull the rockers, and re-pressurized the cooling system. this time it performed much better. still not as good as I would prefer though. over the coarse of about 30 minutes, I lost about .75 psi, compared to the 1 psi per minute I was experiencing earlier at the same pressures before all this work. some of the pressure loss could be the compressed air cooling as well, so tomorrow, I'm going to fill the system and pressure test again.

I also finalized the alternator mount. I still need to extend/re-route the wiring to the alternator, and get a slightly shorter belt, hopefully I can find one 1/2" or so shorter, that will probably be perfect. I'm not as worried about belt slippage as I was before, I did some quick math using very conservative numbers, and determined that the crank has more than double the belt contact area as the alternator, which would be the major load on the belt. the only other load is the water pump, is has about the same belt contact as stock, but on the smooth side, so way less contact area than the alternator and crank. it should be fine. in doing the low mount alternator, I also now need to remount the coils, as they won't fit with the front valve cover on the back, so tomorrow, I'm going to mount them to the firewall of the trunk.

[Shaun41178(2)]

stop wasting time figuring out how to get full roller rockers on. Instead of wasting all that time and money to get the hp out of it that a roller would give, turn the boost knob up 1lb and make up the power that way.