XJ6 & XJ12 Series I, II & III 1968-1992

XJ6 New and Improved Boot-Lid Hinge (concept)

 
  #1  
Old 06-28-2019, 07:15 PM
Senior Member
Thread Starter
Join Date: Dec 2011
Location: Southern Califonia
Posts: 184
Received 57 Likes on 39 Posts
Default XJ6 New and Improved Boot-Lid Hinge (concept)

XJ6 New and Improved Boot-Lid Secondary Hinge (Concept)

Benefits:
1) 45 minutes to install
2) Completely reversible
3) Securely holds the boot-lid open at 71 degrees, 30 degrees more than factory hinge.
4) Very easy to operate

The factory hinge design holds the Boot-Lid open at 30.5" measured from the Boot seal to the Boot-Lid edge. This new design holds the Boot-Lid open at 47" a 50% increase.

Factory Hinge assemblies with weak springs, will get a reduced moment from the Boot-Lid being more vertical, hence the springs become more effective at holding the Boot-Lid open without a secondary prop.

The assembly consists of a new RH & LH hand Boot-Lid to Hinge Bracket attachment, that incorporates a secondary hinge feature. A new 5/16” hole will have to be drilled in each existing Hinge Arm (drilling template provided). A lever locking device is used to lock Hinge at New Angle or Factory Angle.

Current machining quote; (concept SS Hinge/Bracket) would produce a kit for both hinges (including new hardware) for ~$70, plus shipping.

Questions for XJ6 Owners?
1. Are there enough XJ6s Boot-Lid Hinges with weak springs?
2. Are there XJ6 Owners that would value more Boot-Lid head room?

……To justify machining 20 kits. Please way-in….with interest, desired features, ideas, concerns & etc.
If there is enough interest, I will make a prototype out of aluminum to test geometry details.

Thank you, Bill-Jose-Elinor, for illuminating the issue.

Rgds
David



Factory Hinge to Boot-Lid attach Bracket


Jeff's secondary hold-open rod


"Concept" Bracket Hinge combination +30 degrees
 
  #2  
Old 06-28-2019, 07:45 PM
Jose's Avatar
Veteran Member
Join Date: Mar 2007
Location: Florida
Posts: 5,823
Received 1,338 Likes on 1,088 Posts
Default

this is great David! But I want to see it in action. Can you install one in a XJ to see the difference?

in my car, the springs are fine, is that a problem? Not sure I understood the issue with the springs.
 
  #3  
Old 06-28-2019, 10:31 PM
Senior Member
Thread Starter
Join Date: Dec 2011
Location: Southern Califonia
Posts: 184
Received 57 Likes on 39 Posts
Default

Jose,
When boot lid is open an extra 30 degrees, the center of the boot lid weight moves forward toward the hinge pivot point, which reduces the down force on the springs. It is like trying to pick up a 8' long 2" x 4" laying flat on a table holding onto the last 4 inches of one end. If it were laying vertically up against a wall, you could pick it up with one hand. Just eye-balling it, the down force on the springs should be 20-30% less with the additional 30 degree opening. I'll do some graphs over the weekend to get the accurate numbers.
Rgds
David
 
The following users liked this post:
Jag7651 (06-28-2019)
  #4  
Old 06-29-2019, 12:17 AM
Veteran Member
Join Date: Mar 2014
Location: Tehama County, California, USA
Posts: 17,185
Received 3,472 Likes on 2,709 Posts
Default

If this works sign me up.
My springs have all the tension of a wet Kleenex so I'm not sure a mere 30 degrees extra will do the job.

They never did work well, and quit completely after I noticed shiny metal dust on the floor and lubed them. They stopped squeaking but also stopped holding up the lid. Hence the broomstick (which some say I can use for emergency transport).
(';')
 
The following users liked this post:
gcrosby (07-07-2019)
  #5  
Old 06-29-2019, 06:33 AM
yachtmanbuttson's Avatar
Senior Member
Join Date: Jun 2016
Location: Palm City, Florida
Posts: 597
Received 75 Likes on 52 Posts
Default

David - You are a man of ACTION! Wow! Count me in for a set. My springs seem to be fine. Does your concept incorporate the hydraulic piston? Not sure I understood if it did or not. Yes, I'm all for the boot opening up more.

Thanks, Bill
 
  #6  
Old 06-29-2019, 07:49 AM
Senior Member
Join Date: Aug 2017
Location: Cincinnati Ohio
Posts: 412
Likes: 0
Received 226 Likes on 114 Posts
Default

I'm interested. Can't picture where it attaches or how it moves. Looking forward to developments.

One of my key questions is can it be installed by one person or do you need two people to hold the lid while another bolts things up? When I reinstalled my hood I had to round up some neighborhood teenagers to help me.

My springs were tired. I could open the lid and it would stay there until a breeze came along and then it would slowly sink down. The gas strut I used has only 10 lbs of pressure. It doesn't open or even help to open the lid. Just enough to hold it open.

A question for our British fiends: a bonnet is the big piece of sheet metal that covers the engine bay (like an American hood). But the boot is the cavity in back where you put things, right? Is the part we are talking about called the "boot lid"? Americans would call it the trunk lid.
 
The following 2 users liked this post by Yellow series3:
LT1 jaguar (06-29-2019), yachtmanbuttson (06-29-2019)
  #7  
Old 06-29-2019, 04:30 PM
LT1 jaguar's Avatar
Member
Join Date: Dec 2018
Location: Wasilla,Alaska
Posts: 77
Received 18 Likes on 13 Posts
Default

David, I just looked at mine and I would definitely want the boot lid to open more. I only saw one possible issue with the lid hitting the rear windshield if it continues on the "factory" arc. Mine stops about 1" from the glass. If the new hinge swung (is that a word?) an arc larger than curve of the glass or moved the lid farther away from the car, it would work. Thanks for your efforts.
Dave
 
  #8  
Old 06-29-2019, 10:08 PM
Senior Member
Thread Starter
Join Date: Dec 2011
Location: Southern Califonia
Posts: 184
Received 57 Likes on 39 Posts
Default

Dave
Your right about getting the geometry to move the lid away and up from the glass, or at least no closer, while keeping the mechanism simple. It is the challenge, before I try a mock-up bracket/hinge.

Jeff
I think at this point, you will be able to do one side at a time, with a prop under the factory hinge arm.
Thanks & Rgds
David
 
  #9  
Old 07-01-2019, 02:26 PM
Junior Member
Join Date: Jun 2019
Location: East Hertfordshire UK
Posts: 16
Likes: 0
Received 4 Likes on 4 Posts
Default

I would be interested in the brackets as I'm fed up with the lid coming down on my head due to week springs, I have to prop it open with a piece of alloy bar. Hope you can ship to the UK.
 
  #10  
Old 07-02-2019, 07:57 AM
Veteran Member
Join Date: Apr 2012
Location: New York City
Posts: 1,706
Received 857 Likes on 554 Posts
Default

Great idea. The as designed spring hinge setup is heavy and exhibits what I call "spring sing". The spring tends to resonate with road noise, music from speakers installed in the rear shelf and with suspension impacts.

Also factory spring tends to push up the rear of the trunk up which makes a proper shut line difficult to attain. The strut design will push the boot lid back thus making a proper shut line easier to attain.
 
  #11  
Old 07-02-2019, 05:41 PM
Senior Member
Thread Starter
Join Date: Dec 2011
Location: Southern Califonia
Posts: 184
Received 57 Likes on 39 Posts
Default New and improved XJ6 Boot-Lid Hinge

Originally Posted by Nigel.W View Post
I would be interested in the brackets as I'm fed up with the lid coming down on my head due to week springs, I have to prop it open with a piece of alloy bar. Hope you can ship to the UK.
Nigel
The shipping will be $26-43 US.. If you can source two gas struts locally in UK, then international priority small flat rate box would be $26. The kit price would be reduce without the struts included: The lift struts cost $30-35 a pair in US on E-bay.

I am still working out geometry for combination Bracket/Hinge, all the while, keeping it simple. I have fabricated the prototype parts and ordered a set of struts to try... They are 8.5" compressed & 12" fully extended , and come with several different lift ratings (20 lbs to 60 lbs each). Once the prototype is up and running I will figure out optimum lift rating, and will provide the details to see if they are available in UK.
Thank you for your interest

Rgds
David
 
Attached Files
File Type: docx
Strut Details.docx (70.8 KB, 11 views)
The following users liked this post:
yachtmanbuttson (07-02-2019)
  #12  
Old 07-03-2019, 04:07 AM
Junior Member
Join Date: Jun 2019
Location: East Hertfordshire UK
Posts: 16
Likes: 0
Received 4 Likes on 4 Posts
Default

Many thanks David, I would be interested in the complete package with struts and the shipping is OK with me. Looking forward to your results.
 
  #13  
Old 07-03-2019, 06:37 AM
Senior Member
Join Date: Sep 2017
Location: Lincoln Ontario
Posts: 267
Received 52 Likes on 35 Posts
Default

David,
Recieved my new bonnet stay yesterday. Cannot wait to install it!. Many, many thanks, Ian
 
  #14  
Old 07-05-2019, 08:56 PM
Senior Member
Thread Starter
Join Date: Dec 2011
Location: Southern Califonia
Posts: 184
Received 57 Likes on 39 Posts
Default

Originally Posted by David84XJ6 View Post
Dave
Your right about getting the geometry to move the lid away and up from the glass, or at least no closer, while keeping the mechanism simple. It is the challenge, before I try a mock-up bracket/hinge.

Jeff
I think at this point, you will be able to do one side at a time, with a prop under the factory hinge arm.
Thanks & Rgds
David
First attempt at Trunk/Boot Lid extended opening angle.

The first prototype hinge/brackets were from metal angles used for house framing. I took one hour for booth sides (one person), but supported OEM hinge arm and Lid. 13"- 2"x 4" for hinge arm and 37.5-38" "broom handle" for Lid (pic).
Reached about 1/2 of the target angle of 30 degrees (7.5" additional height of trunk lid). Need to adjust new hinge center point an additional 1/2". Confirmed two possible attach locations for 12" gas struts.
Did confirm that OEM springs have more upward force as lid is till forward toward the hinge. Next time with "prototype -2 hinge/bracket" I will attempt to get readings with fish scale.

Major finding: The OEM angle brackets have over-sized holes in every direction for alignment (fore and aft--- up and down-- side to side). I took 30+ minutes to get lid back into alignment when re-installing OEM brackets--- one side would go in and another would go out).
I have figured out a sequence and with two people, it could be done in 10 minutes.
Rgds David



13" 2x4

37-1/2 to 38" prop

First mock-up of Hinge/Bracket (friction knob lock is for prototype only)

OEM opening

13-1/2 degree increased opening ~+7.5"
 
  #15  
Old 07-05-2019, 11:33 PM
Veteran Member
Join Date: Mar 2014
Location: Tehama County, California, USA
Posts: 17,185
Received 3,472 Likes on 2,709 Posts
Default

Speaking only for myself, I would Love the main body of the lid almost completely vertical.
That's probable a pipe dream, but that's my idea of Perfection.
(";')
 
  #16  
Old 07-06-2019, 07:25 AM
yachtmanbuttson's Avatar
Senior Member
Join Date: Jun 2016
Location: Palm City, Florida
Posts: 597
Received 75 Likes on 52 Posts
Default

David - Great job! You have a cheering section from me. Again, getting golf clubs into the trunk without me climbing in is my goal.
 
  #17  
Old 07-06-2019, 12:41 PM
Senior Member
Join Date: Aug 2017
Location: Cincinnati Ohio
Posts: 412
Likes: 0
Received 226 Likes on 114 Posts
Default

Me too. I was getting something out yesterday and bonked my head. Yes, those holes are oversized, when I put the gas strut mount on mine I had to fiddle awhile to get everything lined up and that was just loosening one side.

Do you plan to have the gas struts actually lift the boot lid or do you plan for them (or it) to just hold it open once you manually lift it open? My single strut is 10 pounds and just holds it open once I lift it open. I think you are planning much shorter struts which can be more powerful and will address Elinor's concern of loading from the side.

Jeff
 
  #18  
Old 07-13-2019, 08:17 PM
Senior Member
Thread Starter
Join Date: Dec 2011
Location: Southern Califonia
Posts: 184
Received 57 Likes on 39 Posts
Default New and improved XJ6 Boot/Trunk-Lid Hinge

Originally Posted by Yellow series 3 View Post
Me too. I was getting something out yesterday and bonked my head. Yes, those holes are oversized, when I put the gas strut mount on mine I had to fiddle awhile to get everything lined up and that was just loosening one side.

Do you plan to have the gas struts actually lift the boot lid or do you plan for them (or it) to just hold it open once you manually lift it open? My single strut is 10 pounds and just holds it open once I lift it open. I think you are planning much shorter struts which can be more powerful and will address Elinor's concern of loading from the side.

Jeff
I have re-tried the hinge/bracket pivot point relocated to provide more clearance with rear windscreen. I am now seeing 68 degrees (up from OEM 41 degrees) and 46 inches opening (up from OEM 31 inches). With a household scale, the down ward force at trunk lip was 14.1 lbs down. I hooked up one 12" x 20 lb gas strut and the downward force was reduced to 5 lbs. With both struts installed I expect to see +4 lbs upward force at lip.

Second test addresses weak springs only, without additional opening. I installed one 24" x 40 lbs strut to an existing 5/16 hole in OEM hinge arm. Result was trunk lid open by itself to 18" when the latch was released. I think with two struts, it would go all the way to 31". My trunk lid normally stays where I put it, but does not raise itself at all.

Based on tests today, I will make a small correction in the hinge/brackets and retry with the two 12" struts. I got the lid re-aligned with three adjustments.


68 degree opening with modified hinge/bracket


OEM config> one 24" x 40 lbs strut (aft end not secured...has bracket for two screws)


OEM config>Fwd end attached to existing 5/16" hole in Hinge arm. One strut reached this height with out assistance
 
The following 2 users liked this post by David84XJ6:
LnrB (07-14-2019), LT1 jaguar (07-14-2019)
  #19  
Old 07-14-2019, 06:36 AM
yachtmanbuttson's Avatar
Senior Member
Join Date: Jun 2016
Location: Palm City, Florida
Posts: 597
Received 75 Likes on 52 Posts
Default

31" to 46" is almost a 50% improvement! Way to go Dave!
 
  #20  
Old 07-14-2019, 10:44 AM
Veteran Member
Join Date: Mar 2014
Location: Tehama County, California, USA
Posts: 17,185
Received 3,472 Likes on 2,709 Posts
Default

That means I could actually reach in without banging my head, even with my broomstick holding at maximum!
I'd go for that!
(';')
 

Thread Tools
Search this Thread
Quick Reply: XJ6 New and Improved Boot-Lid Hinge (concept)


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: