Shooting the breeze. What’s the 1/4 mile time of a 340 challenger?

[wingcarenvy]

Hey guys I just saw this thread. Cool thread for sure. I have been building small blocks and racing them for 30 years and I do have to disagree about the compression ratio comment. The factory numbers were pretty much dead on, its the non hip mass produced rebuilder kits out there that give the dismal compression numbers. For example, my weapon of choice is the 360. They all came with 8.8-1 compression. Every last untouched one I have torn down has had that exact compression. One of the reasons that most motors don't have the compression you think it has ( which I do agree on that part)is the head gaskets. Most rebuilder gaskets are .040 inch thick versus the .015 inch thick factory ones. This .025 increase in thickness is good for half a point alone, then you throw in sunken valves from quick valve jobs and other tolerance stacking and they can be down a full point.

Recently had the pleasure of making some passes in my Challenger T/A. We weighed it on my own race scales and it weighed 3440. It obviously has the six pack aluminum intake and fiberglass hood which your car may not have which will make your car weigh more. My car with BFG 255s on it and a 4 speed had zero traction yet amazingly went 15.90s at 90 mph. Now for the curve ball, it has a stock 318 in it. Years ago I had a stock 340/auto swinger with 3.91s in it and it ran high 13's at 100 mph. None of this really pertains to what your doing but it kinda gives you an idea.


Here is another trick that not many people know about. Take out your stock 727 and replace it with a 999 (otherwise known as a 904) with a low gear set and a 11" converter. I did a back to back comparison on my 12 second Dart with a 360 and it picked up .4 and 5 mph. Not only will your car weigh less but the first two gears will be 2.77, 1.77 and then 1 to 1 for third. Versus 2.45 1.45 with the 727. This little trick really wakes them up and no one will be the wiser. I even did this trick on a stock 68 Roadrunner I had that wouldn't break into the 13s and it picked up .5 seconds and just over 4 mph, I changed the stall too which is why I think it went quicker than .4 I had seen in my small block cars. And yes you can put a small block trans behind a big block.I used a JW ultra bell conversion bell housing.

[kawahonda]

Cool story, thanks!

I'm probably guessing my car is touching the 14s right now after the gear change.

Finally got the challenger on its feet again. Filled the differential up with some fresh gear oil, hand-cranked the u-bolts for the u-joints. Set the axle play around .010".

Took me 1.5 hours to set the play. That was mainly just getting used to my equipment and what constitutes "play". If you yank something hard enough, you'll get a change in measurement.

It dawned on my the play is not something you have to yank on, but simple just the movement of the driver's axle shaft. It should make a "click-in" noise, and a "click-out" noise.

I totally understand the process now. Very easy to do again!

[1 Wild R/T]

That click in/click out should be very minimal.....  You'll see allot more bearings damaged by to much end play than not enough.... Fact is zero end play won't hurt anything....

[kawahonda]

My process:

1) Tighten everything down till there's zero play. I probably over did this, because I was yanking hard and still getting "some" movement (which was not axle movement). Took me an hour to figure this out. There's no doubt my bearings are fully seated because I kept tightening...and tightening.

I used a punch and a metal mallet.

2) Loosen the adjuster about 3-4 notches, or so. Then I went to driver's side and tapped with rubber mallet. Spun drive-line a revolution or so. Checked movement. I found .010" and finally got the "click" action and went "oh...this is what they meant by play!". It's not something you have to seriously yank on, just move the driver's axle back and forth and don't over think it. Went around and torqued the adjuster paw down. Rechecked, and it was at .006" play. Hmmm...so torquing affects tolerance..just like the manual implies....

3) Loosened the adjuster clamp and loosened one notch on the adjuster. Torqued it down again, being that that's the next possible place for the axle to sit. Went to driver's side, tapped it again with rubber mallet, spun the drive-line again, and then rechecked.

4) Ended up about about .009, or .010 after all said and done. Right on the bullseye in many opinions...seems like most agree lower in the range is better.

It's really not a hard science at all after I understand exactly what's going on. The fact that the clip "paw" has to sit in a gap on the adjuster makes this nearly fool-proof if you have even an elementary understanding of what's happening. The only thing I found out is that torquing the paw down WILL lessen the gap. Go a littler bigger at first.

This could probably be done 90% of the time without a dial indicator and still lead to positive results. Once you experience that slight "feel" the first time, you could probably guess pretty darn good from then on out...

I could probably do this in 10 minutes tops now. That includes refilling a beer.

[1 Wild R/T]

Which is why I never understood so many people complaining about the adjustment & instead using the green bearings...

[RUNCHARGER]

You don't even need a dial indicator. I tighten the left nuts, tighten 4 of the right bolts, zero the endplay then knock the adjuster back 5 notches then install the pawl and call it done. You can double check with a dial indicator just to confirm.

[kawahonda]

 

[kawahonda]

She's on her feet again. I'll post updates on the distributor...it's coming back from Ford man's house next week. He does a bang-up job on ignitions...

[Cudakiller70]

What type of grease did you use on your axle bearings?

[kawahonda]

They came greased already. It was a green color.

Green tells me that it's probably a wheel specific grease?

I was initially going to re grease the old ones. I was about to use what I had on shelf:

https://www.amazon.com/Silkolene-Silk-Grease-500G-600025885/dp/B00T6JKLK0

[Cudakiller70]

  Thanks

[kawahonda]

Slowly breaking in my gears. Got about 50 miles on them so far. No burnouts, no chirp starts, etc. I've only driven 5-10 miles at a time. I've accelerated at WOT a few times in second gear for some ignition tuning.

My speedo definitely reads about 5-6 MPH too high. Still waiting on a speedo gear.

Can't really feel much difference over the 3.23's yet....I assume once I can mash the pedal more from a standing start is where the benefits come into play, but cannot do that yet.

No clunks, clanks, rattles, or noises.

I got it out going 60-65 MPH, and heard a faint whine upon deceleration at around 55-60 MPH range. Did a few times and it's consistent. Doesn't seem like a problem, but you can hear it. Only at those speeds, too.

Figured I would monitor it, especially after a fresh oil change at the 500 mile mark.

My TTI exhaust w/ stock manifolds has a drone at 2000-2100 RPM...and only at that RPM. Guess where my 40 MPH cruising speed is now....ha.

[kawahonda]

After doing more research, I reached out to Dr. Diff. According to other forums out there, properly set up rear-ends should make ZERO noises.

Take a look at the video. Right after I move into the right lane I allow the car to decelerate. You can hear the wirr.

https://forum.e-bodies.org/gallery/;sa=view;id=736

[kawahonda]

Dr. Diff said that noise upon deceleration is not normal. They are supposed to look at the video and asssess it.

The sound is about a 5/10 (which is enough to set off alarms in my head). Even my girlfriend remembered hearing it aftering telling her that I don't think my rear-end is "done" yet. The sound only happens at higher speeds (60-65 MPH...maybe higher, don't know yet).

I'm trying to envision how this is going to play out and what is wrong OR what needs adjusting. It's probably pre-load on a bearing somewhere. Does this mean I'll probably have to drop the chunk out again?

[kawahonda]

Took an old timer mopar guy out. He said whatever is there is faint, and the fact that it's still being broke in---tells me to stop worrying and bring it through the proper heat cycles.

Good to get sanity checks once in awhile!