Gearhead Thread

[Tomahawk]

Until this weekend, I had no idea this shtein existed, but I'll do my best to explain.

Some crankshafts have a 4 speed pilot bearing installed...I don't know what the farg for, but I'll assume it's for a manual transmission since the automatic TH-400s are 3 speed. This bearing prevented the "nub" (the protrusion that fits into the crankshaft) on the new torque converter (TC) from fitting into the crankshaft cavity. The old TC fit because its nub was machined to leave a protrusion that fit into the hole of the bearing.

Crankshaft (in engine with pilot bearing still installed)


Old crankshaft...notice it didn't have the bearing in it (replaced years ago because of a spun a crank bearing)


Stock TC (stall is probably 1,500 rpm to 1,800)


New TC (stall is 2,200)

[Tomahawk]

 

[Tomahawk]

When the engine gets dropped back in, it'll look like this the picture below. The pic was taken after I blamed the new TC on the mess so we put the old one back in. Not satisfied with the solution, I had to pull the engine again to get to the bottom of this...otherwise I'd be driving the Carcharodon right now. A test fit up proves the new TC will fit now the bearing has been removed...why it was a 1/4" steel (or maybe the material is effUschwarzium) instead of a much thinner brass or bronze, I'll never know because I'm never going to ask anybody about this bullshtein again.

[Diomedes]

effushwarszium, lol

thanks for the breakdown

[Tomahawk]

This is what it looks like with the better converter installed...so much better:

[Diomedes]

So I don't get it...the preformance difference is what?  Engine stalls at a higher RPM?  What's good about that?  Or is all this trouble just for looks (not that I can't understand that)?

[Tomahawk]

The engine doesn't stall; the stall converter (only in automatic transmissions) decides when to deliver the power to the wheels, or "flash". It really depends on the combination of your vehicle (such as vehicle weight, rear end, camshaft, etc.) on where the ideal stall is, but its purpose is to keep your tires from spinning until your engine reaches the ideal rpm in the torque curve.

One end (the ends shown in the bigass pictures I posted of the stall converters) of the torque converter attaches to the flexplate which in turn is attached the crankshaft. The other end slides over a keyed spindle in the transmission, and cannot be seen in either of the pictures shown of the engine. Don't get me wrong, I buy shtein for looks (see the billet aluminum water neck), but this is a pure performance upgrade.

[Diomedes]

So now the threshold for the power to actually transfer to the wheels is higher than it was, meaning when it hits, you're further into the power band.  Faster starts.

Drag racers must use even higher stall converters.

[Tomahawk]

Correct...having only .460 valve lift (Intake and Exhaust) with the stock 1.55 ratio, a duration of 223/230 (In/Ex), and a power range from 2-5k my cam would be considered mild by a drag racer's standards.

As a comparison (my cam is the top row, a street/strip cam is the second row, a comparable to stock cam is the third row, and a full out race only cam is the last row):

       Lift                  Duration @.050        Power Range     
Intake   Exhaust       Intake   Exhaust
.460       .460            223        230              2-5k
.478       .475            228        247              3-5.5k
.440       .468            205        215              1-4.3k
.573       .601            270        284              4.5-7k

Just throwing this out there in case it helps interpret the numbers and how seemingly small changes in the numbers can have a substantial impact (drilling a couple tubes out in my carb by 0.05" made a world of difference in the idle quality after upgrading the cam)...the cam manufacturer says my cam is 25 HP better than stock, the second is 30-40 HP higher than stock, and the comparable to stock one is about 10 HP more than stock.

[Tomahawk]

She breathes!! Didn't want to fire at first...coil wire wasn't tight and neither was the sonofabitch 5 cylinder wire. Still didn't want to go so I dumped some stupid 87 octane gas (only time she'll see something so pedestrian) in the carb and she fired right up!

I'm tempted to skip out on the float trip tomorrow so I can get it all dialed in, but it's one of the few times I get to wear my awesome hat.

[Diomedes]

There will be women in bathing suits, right?  The car can wait.

[Tomahawk]

On the road again! Some Garage Gnomes switched the 7 and 2 plug wires on the dizzy, but after that all is pretty good....gotta dial in the opening rate of the secondaries on the quadrajet.

[Diomedes]

dreamy

http://www.speedhunters.com/2013/07/a-station-wagon-unlike-any-other/

[smeags]

the gearheads around the corner from me just finished up on a car just like this. drives by my house every day. sick car.



have to stop them and find out what's going on under the hood.

[PhillyPhreak54]

Do they have mullets?