Chevelle updates

[mockingbird812]

That is one beefy bad boy!!!!!! [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

[Xplantdad]

Looks nice Eric!

[VintageMusclecar]

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.

[Plowman]

That is looking good on the intake ports{the power is on the intake}. All your stuff look's real nice.

[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

[VintageMusclecar]

Thanks guys. I'm trying to get the last few loose ends wrapped up--as soon as I do there will be much more to come.

While the adjustable upper control arms helped tremendously, I'm still fighting a driveline vibration at....um....&quot;elevated&quot; speeds that has to be resolved before the car can see any track time.

Stupid 60&quot; long drive shafts..... [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img]

[VintageMusclecar]

I was going to post a new thread detailing the repairs after the catastrophic driveshaft failure, but that would've made 3 Chevelle threads...which is at least one too many.

So without further ado, here's the new trans for the car:













I had several options on the table to consider after the untimely demise of my Muncie.

1) Jerico 4 speed or 5 speed. (5 speed is based on the Nash/Richmond style trans)

2) GForce 101A 4 speed or (5 speed also a Nash/Richmond style tra... Street 5 speed.

5) Legend LGT700 5 speed.

Several important considerations had to be made (aside from cost, none of which were what could be considered &quot;affordable&quot; Minimal floor pan mods (those done by the driveshaft during it's hasty egress notwithstanding [img]<<GRAEMLIN_URL>>/rolleyes.gif[/img] ) , strength, gear ratios, and availability.

I was first interested in the new Richmond 5 speed as it's now rated for 600 lb.ft where the street boxes are only good to 450 lb.ft. Unfortunately, the Richmond won't even be available until July at the earliest, so I had to scratch that off the list.

The Liberty, GForce and Jerico 4 speeds were eliminated for various reasons, mainly lack of a speedometer provision and shifter fitment issues.

The GForce 5 speed was eliminated due to lack of 5th gear OD along with cost.

The Jerico 5 speed was eliminated due to cost and fitment issues.

The Liberty 5 speed was eliminated due to cost and fitment issues as well.

That pretty much narrowed my choice down to the Legend box. For those who aren't familiar with it, this is the same box that Keisler was selling before they went belly-up. Thankfully the parent company who was actually manufacturing the trans' and components stepped up to continue production.

As luck would have it, Jody Haag (Jody's Transmissions over on the Chevelle forum) just happened to know of the whereabouts of an &quot;exact fit&quot; box for my Chevelle sitting patiently on a retailers shelf. A few phone calls later the trans was ordered and on it's way here.

The Legend box addresses 3 of my needs in near-perfect manner:

1) .069 5th gear overdrive. This effectively reduces the current 4.56 gears down to an effective 3.14 ratio, which means rpm @ 60 mph goes down from ~3300 with the Muncie to 2260. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img] Once the 3.73 rear end goes in, that 60 mph figure will drop down to a lumbering 1850 rpm--the highway equivalent of a 2.57 gear.

Road trip anyone? [img]<<GRAEMLIN_URL>>/cool.gif[/img]

2) As mentioned before, the primary issue which led up to the failure was the OEM 60&quot; long driveshaft. Thankfully, the Legend is roughly 3 1/2&quot; longer than the Muncie, which shaves the driveshaft down to 56 1/2&quot;. (ALSO, with the trans yoke moved back, that <span style="font-style: italic">should</span> allow the use of a 4&quot; diameter driveshaft!) In addition to this, the new Mark Williams billet CM pinion yoke is 1&quot; taller than the OEM yoke which cuts the figure down to ~55 1/2&quot;. That makes a <span style="font-style: italic">significant</span> difference in the critical speed issue with the driveshaft.

Check out the MW chart to see the difference:



3) The Legend box is not only rated for 700 lb.ft, it is also rated to shift up to 7500 rpm, which is impressive for a fully synchronized transmission.

A few changes are necessary to accommodate the new trans--a swap from a 10 spline clutch disc to a 26 spline, the crossmember will need to be re-located slightly, and the speedometer cable will require a little creative re-routing as the hookup is on the drivers side of the new trans as opposed to the passenger side on the Muncie. However, the shifter is in the exact same spot as the Muncie was, which means no shifter hole surgery will be necessary. It even accepts the previously installed Hurst shifter arm.

I hope to get on the install tomorrow. Once it's in I can measure for the new driveshaft and get it ordered.

I'll report back with pics &amp; more info as things progress.

[VintageMusclecar]

Lost two links in the last post, not sure how/why, don't feel like trying to fix it now, may later.

[napa68]

No sheeeeeet? I'll be watching carefully. I am interested in how this thing works when you shift it like you hate it [img]<<GRAEMLIN_URL>>/[/img]

I miss the OD gear I used to have. I do not miss the Tremec shift quality.

Best of luck Eric!

[PxTx]

Looks to be very exciting. I am thrilled to know we'll be getting some honest feedback on this unit.

I've never had to be concerned with drive shaft speeds but it is now on my radar. Careful with 5th gear till you get those 3 series gear in the back! Also looking forward to your comparison of a traditional Hurst shifter to the internal on the Legend box.

Thanks for the update with pics! Shoudl read &quot;Eric Rocks&quot; [img]<<GRAEMLIN_URL>>/youguysrock.gif[/img]