'66 Malibu N/SA - Page 27

Dave Muller · 05-13-2017, 12:08 PM

Quote:

Originally Posted by Mark Yacavone

From my experience , most of these high speed driveline vibrations are shaft related. Usually from not having a 3-4 degree balance between the two angles.

Did you say you still had the mufflers on it?

I would guess it was still almost 90 degrees at 8 pm, and ODA approaching 4000'.

Already been over 100 in the valley.

Yes, mufflers still on. It was warm but not really hot. I'll be double-checking some things a little later today.

Dave Muller · 05-13-2017, 03:10 PM

I don't really see anything wrong with the driveshaft. It pulls back 1 1/16" from fully inserted into the trans. And it's a 3 1/2" shaft. Maybe there's just a problem with the balance? There is room to go even larger on the shaft.

Here's how it looks installed.

There's a little over a half inch of output shaft protruding from the transmission.

Mark Yacavone · 05-13-2017, 04:18 PM

That's plenty big for the shaft.You could use a stock driveshaft in that car.
If you've got time, I'd take it to Phx rack and axle , north of the airport.
See Bernie. Have him check runout and balance. He's the best.
Maybe it's the camera angle, but I don't see any down angle on the U-joint.

Dave Muller · 05-13-2017, 05:45 PM

You can't really tell from that picture.

I just got the slicks dynamically balanced, and the prior job was done with clip-on weights on the inside only. This time they're stuck on in the middle of the wheel.

I have three days, I'll check into that Mark, thanks for the tip.

Ed Carpenter · 05-13-2017, 10:12 PM

We've always bubble balanced our tires ourselves and use stick on weights in the inside (duct tape) for additional security. Never had a problem. The two times we experienced vibrations at speed it was the driveshaft. Have it rebalanced by a shop that can spin it fast enough. I took one to a local shop and had it balanced and still had a vibration. Mark Williams told.md you have to find a shop that can turn it 10k I believe is the number they gave me. I did that and no problem.

Mark Yacavone · 05-13-2017, 11:40 PM

Quote:

Originally Posted by Ed Carpenter

We've always bubble balanced our tires ourselves and use stick on weights in the inside (duct tape) for additional security. Never had a problem. The two times we experienced vibrations at speed it was the driveshaft. Have it rebalanced by a shop that can spin it fast enough. I took one to a local shop and had it balanced and still had a vibration. Mark Williams told.md you have to find a shop that can turn it 10k I believe is the number they gave me. I did that and no problem.

Ed, Usually not a problem. They bubble balance at national meets, of course.
But , if you can get the wheel and tire under the safety hood, it's good way to check for wheel runout or a defective or improperly mounted tire.

Dave Muller · 05-14-2017, 11:02 PM

Here's a couple of pictures from my test session, courtesy of Jerry Hutchcroft, of Roddin' & Racin' magazine.

Ed Carpenter · 05-15-2017, 11:53 AM

Great looking car!

Dave Muller · 05-15-2017, 08:57 PM

I took the driveshaft in to Bernie today and he found .019" of run-out. He straightened and rebalanced it while I waited; didn't even use up my whole lunch hour. I'm very optimistic at this point.

I also hope to have enough ballast in to remove the headers. Oops--I meant remove the mufflers. My fingers type faster than my brain thinks sometimes!

Mark Yacavone · 05-16-2017, 11:54 AM

Dave, You found that rulebook section on ballast for Stock Elim.?

05-13-2017, 03:10 PM	#262
Dave Muller Member Join Date: Apr 2014 Location: Mesa, AZ Posts: 497 Likes: 162 Liked 223 Times in 73 Posts	Re: '66 Malibu N/SA I don't really see anything wrong with the driveshaft. It pulls back 1 1/16" from fully inserted into the trans. And it's a 3 1/2" shaft. Maybe there's just a problem with the balance? There is room to go even larger on the shaft. Here's how it looks installed. There's a little over a half inch of output shaft protruding from the transmission. Last edited by Dave Muller; 07-08-2017 at 05:32 PM.

05-13-2017, 04:18 PM	#263
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,820 Likes: 2,910 Liked 5,129 Times in 1,956 Posts	Re: '66 Malibu N/SA That's plenty big for the shaft.You could use a stock driveshaft in that car. If you've got time, I'd take it to Phx rack and axle , north of the airport. See Bernie. Have him check runout and balance. He's the best. Maybe it's the camera angle, but I don't see any down angle on the U-joint. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

05-13-2017, 05:45 PM	#264
Dave Muller Member Join Date: Apr 2014 Location: Mesa, AZ Posts: 497 Likes: 162 Liked 223 Times in 73 Posts	Re: '66 Malibu N/SA You can't really tell from that picture. I just got the slicks dynamically balanced, and the prior job was done with clip-on weights on the inside only. This time they're stuck on in the middle of the wheel. I have three days, I'll check into that Mark, thanks for the tip.

05-13-2017, 10:12 PM	#265
Ed Carpenter Live Reporter Join Date: May 2006 Location: Dripping Springs, Tx Posts: 2,709 Likes: 186 Liked 520 Times in 132 Posts	Re: '66 Malibu N/SA We've always bubble balanced our tires ourselves and use stick on weights in the inside (duct tape) for additional security. Never had a problem. The two times we experienced vibrations at speed it was the driveshaft. Have it rebalanced by a shop that can spin it fast enough. I took one to a local shop and had it balanced and still had a vibration. Mark Williams told.md you have to find a shop that can turn it 10k I believe is the number they gave me. I did that and no problem. __________________ Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development Last edited by Ed Carpenter; 05-13-2017 at 10:19 PM.

05-14-2017, 11:02 PM	#267
Dave Muller Member Join Date: Apr 2014 Location: Mesa, AZ Posts: 497 Likes: 162 Liked 223 Times in 73 Posts	Re: '66 Malibu N/SA Here's a couple of pictures from my test session, courtesy of Jerry Hutchcroft, of Roddin' & Racin' magazine. Last edited by Dave Muller; 07-08-2017 at 05:34 PM.

05-15-2017, 11:53 AM	#268
Ed Carpenter Live Reporter Join Date: May 2006 Location: Dripping Springs, Tx Posts: 2,709 Likes: 186 Liked 520 Times in 132 Posts	Re: '66 Malibu N/SA Great looking car! __________________ Ed Carpenter 2005 Chevy Cobalt A/SM Race Engine Development

05-15-2017, 08:57 PM	#269
Dave Muller Member Join Date: Apr 2014 Location: Mesa, AZ Posts: 497 Likes: 162 Liked 223 Times in 73 Posts	Re: '66 Malibu N/SA I took the driveshaft in to Bernie today and he found .019" of run-out. He straightened and rebalanced it while I waited; didn't even use up my whole lunch hour. I'm very optimistic at this point. I also hope to have enough ballast in to remove the headers. Oops--I meant remove the mufflers. My fingers type faster than my brain thinks sometimes! Last edited by Dave Muller; 05-16-2017 at 02:02 AM.

05-16-2017, 11:54 AM	#270
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,820 Likes: 2,910 Liked 5,129 Times in 1,956 Posts	Re: '66 Malibu N/SA Dave, You found that rulebook section on ballast for Stock Elim.? __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers