Jump to content
HybridZ

Cheaper/Easier adapter for CV conversion?


pparaska

Recommended Posts

I'm wondering if there is an easier way that doesn't involve welding or any machining past drilling holes in a flat plate.

 

From looking at the drawings of the adapter that I have on my car, it seems that if you were to take a flat plate of high strength steel about 3/8" thick, and drill and tap 4 holes in it to bolt it to the u-joint companion flange, you could clock the position of the 6 holes for the CV joint in such a way that you could have room to drill and tap for bolts to hold the CV joint to the plate as well.

 

What bothers me about the idea is the proximity of the holes to one another, no matter how you lock the bolt circles.

The other thing that bothers me is running shear loads through the bolted connections with tapped holes.

What do you think?

 

http://members.home.net/pparaska/280ZCVHalfshaftConversion.htm

 

(for others reference to Pete's current setup and hole layout)

 

I can't find the diam. of the 4 holes req'd for the OE stub but in any case here's my thoughts:

My v. first thought is to have it made out of high grade aircraft aluminum and just have it tapped for all holes needed. Use a v. high grade bolt and then I won't be AS concerned with shear thru threaded portion (thinking of how to additionally 'pin' that OE stub on top of the 4 bolts). No time to check my 'guide' to see what spec one can get capscrews up to. I'd back analyze it by finding out spec on OE Nissan bolts and then see if you can't get a higher grade bolt with same strength in it's 'threaded' region. I know aluminum isn't normal use for something like this but it can be stronger than many steels if right stuff is chosen (and pricey but hey, how fast do you want to spend). Bolt hole proximities may be a factor, that's on material strength as well as you say. Brake calipers are held on in threaded portion routinely and OE caliper bolts aren't anything xtreme in strength terms (checked it out when I did my upgrade). If it could be done with steel that could be quite economical and maybe not that heavy if centre drilled out etc? I've been meaning to visit a machining friend to get a CNC quote on some items :-) and if you had a drawing I could run it by him as well. AIR you need about 20 items to make it pay ballpark FYI.

Link to comment
Share on other sites

Guest Anonymous

Yo, Pete

Why are you running around in circles. You don't even have your Z running. I've learned w/ my 68 Camaro always waiting to do it perfect,stronger and faster. Terry Oxdale is running a race prepared Z w/ the option 1 in your list. Race proven and simple. What's the debate. Before I ran into Hybrid Z 1.5 years ago I found Terry's site. Alot of good stuff including power steering and Ford running gear. Why know one has tried too get him on this site is beyond me. Seems like he's been there done that. I've got the turbo axles off a 82 turbo Z,81 Maxima brackets brackets and calipers,(by the way maxima stub axles are the same as 240 Z stub axle plines s w/ 280 Z turbo companion flange bolt holes). Now all I need is money too buy scca'S 5 lug conversion kit too fit my 16x8 Centerlines that were originally for my Camaro.

Link to comment
Share on other sites

Guest Anonymous

So Cal,

 

Terry is on the site...

 

I don't see a problem with Pete wanting his car to be perfect. I am sure we all wish we had Pete's patience to go through all of the R&D he has gone through to obtain his goal. Remember, he has been working on AND researching his project for a long time and we can all benefit. Just be thankful that he does share with us his information. I have only been working on my project for about three months and can not begin to express the appreciation I have for the information Pete has given that has saved me a tremendous amount of time and money.

 

Chris

Link to comment
Share on other sites

Pete, that was my first thought, and try as you may to clock them, bolt holes will overlap.

 

Guys, I think you are chasing your tails. Despite high quality materials and welding, some folks have a problem with my setup just like I have a problem with the other setup that uses 14 bolts. BUT, the bottom line is that both are being used on high HP car, both work and the owners are pleased (at least I am).

 

Ironically, a halfshaft is held together with 8 bolts and a driveshaft has welds on both ends and we ignore those. Anyone using the JTR diff flange for the driveshaft? What makes that any different from what I made? All 3 methods work, pick one. If you have a big torquer or run really sticky tires I would advise using the 280Z stub axle.

 

Scottie

 

------------------

Scottie

71 240GN-Z

http://www.mindspring.com/~vscott911/gnz.html

Link to comment
Share on other sites

quote:

Originally posted by So Cal Z:

Yo, Pete

Why are you running around in circles. You don't even have your Z running. I've learned w/ my 68 Camaro always waiting to do it perfect,stronger and faster. Race proven and simple. What's the debate. Why know one has tried too get him on this site is beyond me. Seems like he's been there done that. Now all I need is money too buy scca'S 5 lug conversion kit too fit my 16x8 Centerlines that were originally for my Camaro.

 

So Cal, I guess you don't know Pete:-) Just because somethings been done and works doesn't mean others want to take a new try at it from another angle. Theirs a few of us (working cars or not) that enjoy hashing out various possibilities as that's something we can enjoy. I also wouldn't assume an item (your take on Terry) w/o having been given that answer. MANY of us have communicated with Terry over the years. As far as your camaro wheels I wasn't aware Mike/SCCA had a 5x4-3/4 kit? His 5x4.5 would not bolt up your 'maro centrelines. No 'debate' their either, Z31 front hubs and redrill your rears for a cheap swap to access the world of wheels.

 

PS I'll take a higher priced aluminum piece with 1/2 as many fittings to come loose over a much heavier iron one with 2x's fasteners any day I have a bit of $. 80hp cars work and so do 500hp so we enjoy improving on some known working items;-)

 

I'm babbling again, time to return to my earthquake analysis calc's.

Link to comment
Share on other sites

Guys, Guys. I have no plan to change anything in that area of my car. I was looking out for everybody else!

 

I get quite a bit of email about this upgrade and alot of people either have issues with the price of having the 2 piece spool type adapter that I have drawings of, or they have a 280Z and don't want to "down grade" the 240Z stub axle and use the 280ZXT companion flanges. Some don't like the idea of welding, but I'm swaying toward that approach as the easiest way to do the swap if you have 280Z stub axles in the car already.

 

I really do think the best way is to just do what Scottie did and weld a slab of steel plate to the u-joint companion flange. I like the idea of fewer bolts to come loose, etc. and the fact that you can gain some endplay as well. I'd just be very careful as to who picked the plate material, welding consumable, who welds and inspects the welds, and overheating the piece. You might want to do a before and after hardness test in the area near the splines to see if any of the heat treatment had been affected, and have that area heat treated back to spec (which I don't know, but you could use the before hardness as a guide). I know you guys probably think I'm a worry wart, but working as a mechanical engineer for the US Navy will do that to ya. They are CAREFUL.

 

Terry knows about the site, and for all I know, he might have a screen name that I just don't know about.

 

Scottie, many thanks for all your input. I figured if just clocking the holes around would have worked, you or Jim Biondo might have tried that first. But I was looking at it on the computer screen real quick and my mind started wondering to that solution as a POSSIBILITY.

 

Some people do fret about welding a plate to the stock companion flange. I'm of the opinion that if the before and after hardness near the splined area of the flange were close, it'd be fine. If a good welder is aware that removing the heat treatment of the splined area is an issue, they could take measures to keep this from happening for the most part and alleviate the need for the testing as well.

 

Ross, I was thinking about shear pins as well. Another option for those that wouldn't want to weld on the companion flange is to provide threaded studs in the adapter plate. Any way you look at it, running shear loads through a threaded part of a bolt is to be avoided and not acceptable in many design practice guide. I know it is done. The larger the factor of safety used in the design, the more forgiving things will be.

 

(Heck, I have a driveshaft adapter that someone made me that's set up that way. I don't like it, but, I'll see waht happens. It seems that I have a rare R200 flange that has the larger pilot diameter of the two designs. So I'd have to make a centering ring up to use the NEAPCO piece.)

 

I'm just throwing out ideas here to help the next guy. Every time I do this I get the people who tell me to just do it the way it's been done and get on with it. Well, Jim decided my path for me by selling me his adapters. But I'm ALWAYS looking for a different way to do things. It's the nature of me, my profession, and my hobby. Sorry to have caused a ruckus. It seems I forgot to put a warning in the post that I was in daydream/ramble mode again.

Link to comment
Share on other sites

So far, I know of 3 methods to get CV shafts in a 240/260/280Z. All use the 280ZX Turbo CV halfshafts (unmodified) and an R200 diff:

 

1) for 240Z (and Early 260Z) stub axles, use the 280ZX Turbo companion flanges with the dust shield swapped with the on from the 240Z flange.

 

2) For the 280Z (or any 240Z/260Z, for that matter) use the u-joint type companion flange and have a custom adapter made to bolt the 280ZX Turbo CV shaft to the U-joint companion flange. This what I have on my car now. Drawings on my website.

 

3) Weld a flat round plate to the 240/260/280Z u-joint companion flange that has 6 holes in it to bolt to the 280ZXT CV halfshafts. This is what Scottie has done. It gives more endplay than the other two options.

 

I'm wondering if there is an easier way that doesn't involve welding or any machining past drilling holes in a flat plate.

 

From looking at the drawings of the adapter that I have on my car, it seems that if you were to take a flat plate of high strength steel about 3/8" thick, and drill and tap 4 holes in it to bolt it to the u-joint companion flange, you could clock the position of the 6 holes for the CV joint in such a way that you could have room to drill and tap for bolts to hold the CV joint to the plate as well.

 

What bothers me about the idea is the proximity of the holes to one another, no matter how you lock the bolt circles.

 

The other thing that bothers me is running shear loads through the bolted connections with tapped holes.

 

What do you think?

 

Maybe just welding the plate one would be the best bet. Or maybe use countersunk bolts in the plate to give the posibility of having bolt shank in both parts, the adapter plate and the U-joint companion flange.

 

------------------

Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com -

Link to comment
Share on other sites

  • 9 years later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...