V-8 Engine mount / vibration isolation |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
V-8 Engine mount / vibration isolation |
drive-ability |
Feb 21 2006, 07:02 PM
Post
#1
|
Senior Member Group: Members Posts: 1,169 Joined: 18-March 05 From: Orange County, California Member No.: 3,782 |
I know most of you guys have Porsche engines but most have a lot good ideas about most power plants. I have a V8 car and from the start my goal was to make it a reasonably comfortable driving car. One of the things I am looking at is adding more engine mounting points. I have a Renegade set-up and am thinking of installing a set of 911 engine mounts where the engine cross-member connects to the body. Thats as I understand the factory 4 cyl is done. Not using 911 mounts but similar. My question is about where the vibration comes from, at what point is it transfered the most. I wonder how much is transfered through the drive axles? You could have a great set of engine / transmission mounts and still get a lot of vibration via the axles. What do you guys think on the subject..? I know using the 911 mounts on the Renegade cross-member will introduce more forward / aft movement but the 911 mounts seem to have a firm hold on my transmission. (IMG:http://www.914world.com/bbs2/html/emoticons/welder.gif)
|
Dr. Roger |
Feb 21 2006, 07:13 PM
Post
#2
|
A bat out of hell. Group: Members Posts: 3,944 Joined: 31-January 05 From: Hercules, California Member No.: 3,533 Region Association: Northern California |
you mean like this and this?
(IMG:http://www.914world.com/bbs2/uploads/post-2-1121286589.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-2-1123045243.jpg) |
marks914 |
Feb 21 2006, 07:24 PM
Post
#3
|
Senior Member Group: Members Posts: 845 Joined: 9-October 04 From: the motor city Member No.: 2,912 Region Association: None |
Hey
I use solid mounts to connect the V8 mount bar to the 914 body. (911 solid mounts) and 911 sport mounts for the trans mounts. The rubber chevy mounts between the block and the engine mount bar will isolate any vibration. Mark I typed the word mount alot in that post. |
rick 918-S |
Feb 21 2006, 07:32 PM
Post
#4
|
Hey nice rack! -Celette Group: Members Posts: 20,451 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region |
Mine is mounted solid. I don't notice any more vibration than my car had stock on the rubber mounts.
|
drive-ability |
Feb 21 2006, 08:21 PM
Post
#5
|
||
Senior Member Group: Members Posts: 1,169 Joined: 18-March 05 From: Orange County, California Member No.: 3,782 |
That in the second picture is what I am talking about. I would however was thinking about removing some of the cross-member to keep the engine at the same height. Have you driven the car with that set-up ?? If so, does the engine / trans move, hit the firewall during hard braking?? or ?? |
||
marks914 |
Feb 21 2006, 08:32 PM
Post
#6
|
Senior Member Group: Members Posts: 845 Joined: 9-October 04 From: the motor city Member No.: 2,912 Region Association: None |
This is what I did. If you use the solid 911 mount, you do not have to modify anything. It bolts right in at the same height. No problems hitting the firewall beacuse there is less movement.
Mark Attached image(s) |
drive-ability |
Feb 21 2006, 09:49 PM
Post
#7
|
||
Senior Member Group: Members Posts: 1,169 Joined: 18-March 05 From: Orange County, California Member No.: 3,782 |
The reason I am asking is because I wish to use the non-solid mounts. I don't think the skimpy block mounts isolate much vibration. They work great but there is still a lot of vibration running down the long cross-member. |
||
marks914 |
Feb 22 2006, 04:00 AM
Post
#8
|
Senior Member Group: Members Posts: 845 Joined: 9-October 04 From: the motor city Member No.: 2,912 Region Association: None |
The chevy motor mounts are rubber, there is no need to use 2 sets of rubber mounts on the same thing (engine). Everything is still isolated by rubber.
Are you talking about the motor munts or the trans mounts? Mark |
neo914-6 |
Feb 22 2006, 09:13 AM
Post
#9
|
neo life Group: Members Posts: 5,086 Joined: 16-January 03 From: Willow Glen (San Jose) Member No.: 159 |
Have you driven your car without the body/xmember mount and it's vibrates too much for you?
The properly tuned V8 revs smoothly. I originally had more "isolation" in the trans mount and Brad changed them to solid. It helped solid shifting. I was told by the conversion designer (Jaide) to mount the bar solid to the body for correct engine placement. You would drop the body if "stock" isolation was added. The engine bar to engine mount is sufficient for isolation. I switched to Polyurethane but I haven't got the car running yet. If you're after more vibration isolation go for it. It will just add some more R&D. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) |
Dr. Roger |
Feb 22 2006, 09:30 AM
Post
#10
|
||||
A bat out of hell. Group: Members Posts: 3,944 Joined: 31-January 05 From: Hercules, California Member No.: 3,533 Region Association: Northern California |
Truth be told, I originally set my V8 up like this. After ONE drive the rubber mounts came off as it threw shifting, engine movement, and ride height off. (Hey, a brother's got to try. Right? LOL...) I would not suggest going this route. Heck, even with my radical cam I'm mor ethan satisfied with the vibration dampening of the motor mounts as they are. If your V8 is not idling smoothly and your not running a radical cam, then you've got other problems. Really. |
||||
Lo-Fi Version | Time is now: 11th May 2024 - 02:23 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |