Chevelle updates

[earntaz]

Ya' need to drag that "tech" under the velle' and let him change it ...

[VintageMusclecar]

Here's the original 10 spline disc that was installed when I first built the car. Note the even wear pattern across both friction surfaces.

Flywheel side:



Pressure plate side:



Here's the new disc I just took out, the one that slipped like hell. Notice anything..."unusual" about it?

Flywheel side:



Pressure plate side:



Bear in mind that the original clutch had less than 75 miles on it and never once slipped. The flywheel and pressure plate both look good, no unusual wear. There is a slight heat spot on the flywheel now that wasn't there before, but I don't think it warrants resurfacing.

Waiting to hear back from Jody for his opinion before I button this back up again. I'm <span style="font-weight: bold"><span style="font-style: italic"><span style="text-decoration: underline">reaaaalllly</span></span></span> getting tired of looking at the underside of this car. [img]<<GRAEMLIN_URL>>/thumbsdown.gif[/img]

[cook_dw]

What type of break-in procedure was done on the clutch that slipped?

[VintageMusclecar]

None was specified. I did ask.

[novadude]

I know Ram says &quot;no break in required&quot;, but that seems counter to what every other clutch manufacturer recommends. I would think that any new clutch needs to &quot;bed in&quot; for a few 100 miles or so, just like brake pads don't provide full pad contact right out of the box.

Having said that, I could only wait about 50 miles before &quot;testing&quot; my organic Centerforce disc. I'm not patient enough for 500 miles of &quot;grandma-style&quot; driving. [img]<<GRAEMLIN_URL>>/wink.gif[/img]

[VintageMusclecar]

I'm getting a crash course in clutch tech 101 on this project.

I've had several stick cars before this, but none were anywhere near this power level--maybe 400-ish tops. That said, I've never once performed any sort of &quot;break-in&quot; procedure on a clutch, I've always taken it out and hammered on it...never once had one slip, even a generic parts store unit. I've had a couple that chattered a little, but I've always just chalked that up as being part of the game with a stick.

What threw me with the 2nd disc (the one I just took out) was how it let go when I rolled into it in 1st gear. Even with this power, easing into it from a roll with a 4.56 screw in the back in 1st gear, I wouldn't think it should slip under those circumstances. Maybe if it'd been a somewhat aggressive launch, or hitting it from a roll in 2nd or 3rd I might expect it. Upon removal, seeing how it was only making contact in the center half of the friction surfaces explains to me why it slipped.

FWIW, I didn’t do any break-in with the original Powergrip setup and it held fine. It seems a bit odd that something designed primarily for racing use would require a break-in—I’d imagine most people install them and take them straight to the track.

At any rate, the new clutch is in (and my back is <span style="font-style: italic">out</span>! [img]<<GRAEMLIN_URL>>/frown.gif[/img] ). I still have to mount the shifter and bezel, but that's about it. We're supposed to get another break in the weather later this afternoon, so with any luck (and assuming my back cooperates) I'll try to get the car back out for a bit today.

[earntaz]

Good luck Eric ... you've had your share of issues with your Velle' ...

[cook_dw]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: novadude</div><div class="ubbcode-body">I know Ram says &quot;no break in required&quot;, but that seems counter to what every other clutch manufacturer recommends. I would think that any new clutch needs to &quot;bed in&quot; for a few 100 miles or so, just like brake pads don't provide full pad contact right out of the box.

Having said that, I could only wait about 50 miles before &quot;testing&quot; my organic Centerforce disc. I'm not patient enough for 500 miles of &quot;grandma-style&quot; driving. [img]<<GRAEMLIN_URL>>/wink.gif[/img]
</div></div>

That is the process I have always followed. 100 miles break-in varying rpm from 2500 to 3000 to 3500 to 4000 and finally 6-6500 shifts after the 100 mile break-in.. Only clutch that I am aware that does not need a break-in is the iron disc race style clutches. The only Ram clutch setup I had success with were their twin disc systems. I hope you get it straightened out.

[Verne_Frantz]

The last time I replaced the clutch behind the '09 I used an OEM '69 Corvette 11&quot; pressure plate with a woven disc. IT had those little fibers sticking up all over it so I figured it wouldn't hold as designed until those wore off. I didn't want to waste time driving around for many miles before they wore off so I put it in reverse, set the parking brake, revved it up and rode the clutch until there was plenty of nasty smelling smoke everywhere. That break-in took about 30 seconds and the clutch has never slipped or failed with many miles after that including 4000rpm launches with slicks.
All I can say is that &quot;it worked for me&quot;. [img]<<GRAEMLIN_URL>>/scholar.gif[/img]

Verne [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

[VintageMusclecar]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VintageMusclecar</div><div class="ubbcode-body">Time for another quick update:

As I mentioned in this post of the 496 dyno thread, I was on the hunt for another pair of rectangle port closed chamber heads before the 496 had even cooled off from the last dyno pull.

Within 2 weeks, our own Joe Smith came through with a good pair of 840 casting cores.

I had originally intended to send them to the same porter who updated the 462 heads on the 302 project, but he politely declined as he's trying to get away from working on iron castings (esp. big block Chevy units) in the interest of sparing himself from further back aggravations. Can't say that I blame him.

At any rate, I asked him who he would recommend I send the heads out to, and without hesitation he advised Chad Speier of Speier Racing Heads.

After discussing my goals with Chad, he agreed to take on the project. I just received the news that Chad finally had the chance to get started on them, and he posted two sneak peek pics on the Chevelle site (and on his Facebook page as well)

A <span style="font-style: italic">little</span> chamber work:



Getting started on the intake ports (click the link, the pic won't embed here for some reason):

https://scontent-iad.xx.fbcdn.net/hphoto...amp;oe=559F4566

More info as it becomes available. </div></div>

Heads are done. [img]<<GRAEMLIN_URL>>/naughty.gif[/img]



Flowed on a 4.310 fixture. 1 7/8 pipe:



I'll format some numbers later for comparison's sake, but suffice it to say Chad knocked this one outt'a the park. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

*edit* Here are the comparison numbers to an unmodified set of 840 heads with 2.19/1.72 valves to Chad's work:

Speier Racing 840 heads vs. unmodified

--Intake#2---before/after--Intake#4--before/after---Exhaust before/after
----.200-----133.9--151.7--------------134.3--147.5------------100.5--123.4
----.300-----208.5--218.9--------------209.5--215.8------------124.4--164.5
----.400-----234.3--264.8--------------256.5--276.5------------145.9--187.9
----.500-----257.8--292.8--------------272.4--307.6------------162.0--210.7
----.600-----274.1--322.3--------------292.7--332.0------------177.6--231.3
----.700-----271.8--324.8--------------291.7--342.8------------177.3--249.8
----.800-----273.6--340.0--------------292.1--354.0------------178.2--260.4