bjhines Posted October 25, 2006 Share Posted October 25, 2006 I have seen this mount on Pete's site for years... http://alteredz.com/drivelinemods.htm I made my own out of 3/16" instead of 1/4" plate... It was pretty easy to do... I had a local shop shear off 1" and 3" strips 18" long... this makes assembly easy... I cut the neccessary pieces to assemble the mount and beveled the edges to be welded together... I suppose you could band saw the side pieces in one plate with no welds... That would probably be better in hindsight... I was really tempted to punch lightening holes in the sides as well... I decided to leave them alone considering I reduced the thickness of the stock to 3/16"... This piece could get really artsy for someone who wanted to spend some time on it (lightening holes, fancy center web, one piece sides, having it bent on a brake insted of welded, etc)... The design Ron Tyler came up with is easy to put together... and many folks have 1" and 3" stock in the scrap bin... I like the design... It won't crack your crossmember... It holds the rubber in compression insted of ripping it apart... If the rubber does fail the crossmember will catch it... if the entire mount fails it will simply press against the tunnel(It wont go far and it spreads loads)... ----------------------------------------------------------------------- POLY MOUNT #3-1108 The poly mount is an Energy Suspension 3-1108 to fit GM vehicles... It has a plate that comes with it... The instructions state that it preloads the mount... not much though... maybe 3/16" of pull down.. ----------------------------------------------------------------------- Clearance and modifications: This may be different on some cars... mine is a 1973 240Z... The assembly needs some clearance work in several areas... The mount does not fit close enough to the nose of the differential to simply bolt up... I took some measurements and figured I could drum sand the mount enough to get a good close fit without compromizing the integrity of the mount... If you simply stack washers to clear it you may have contact with the lower crossmember.... I will add one 1/2" flat washer on each side between the mount and the nose to get a slight preload on the mount... The holes on the poly mount needed a little grinding to allow the slightly narrower bolts on the diff nose to fit... I glued some clipped washers on them to make it easier to assemble later... The tranny tunnel fits this thing like a glove... you really must grind the outside welds flush on your mount... The muffler hanger inside the tunnel must be clearanced as welll... ... Quote Link to comment Share on other sites More sharing options...
LLave Posted October 25, 2006 Share Posted October 25, 2006 Sweet mount, I think I will have to build one myself... Quote Link to comment Share on other sites More sharing options...
Corzette Posted October 25, 2006 Share Posted October 25, 2006 Now we just need someone to make one for the Q45 short diff and life would be great! Nice job! TErry Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 25, 2006 Author Share Posted October 25, 2006 Ohh... and it weighs 3lbs 3.7oz without the energy suspension mount or the hardware... It took an entire evening to complete ~5 hours with paint dry time... It would take another few hours to actually install it.. no more than it would take to replace the original mount and strap... Quote Link to comment Share on other sites More sharing options...
johnc Posted October 25, 2006 Share Posted October 25, 2006 And, as BRE did, it makes a good place to put a vertical brace from the harness bar/main hoop diagonal through the tunnel to the mount. Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 25, 2006 Administrators Share Posted October 25, 2006 Dang!... may very own 'monument' Good Job. Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 25, 2006 Author Share Posted October 25, 2006 Nice idea John... this was my approach to reinforcing the tunnel in the back... ... Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 26, 2006 Share Posted October 26, 2006 I just finished one too. 1/4 plate is massive overkill. Used 3/16 for the top and 1/8" plate for the sides. The dimensions in Pete's drawing will not work for a 240. The bolt holes that mount it to the body are much closer together. I didn't make separate bolt tabs but just ran the sides straight down and drilled to fit. My whole unit is a good inch nore narrow too. As for the washers, I filed down the bottom of the energy suspension mount to make it conform to the rounded diff. Pretty much had to do this to get the diff up off the crossmember. John Deere green. gotta love it. Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 26, 2006 Author Share Posted October 26, 2006 awwwwwwwww hell... fiddlesticks... dab nabit... I have a 240Z.. I have not mounted this yet... dohhhh... ohh well I'll just redrill a few holes... Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 26, 2006 Administrators Share Posted October 26, 2006 BJ, Don't panic yet. I was about to question Pop... The original mount for Pete P. was built ON a 240Z ('72) and the drawing is a direct reflection of that part. And, if I'm not mistaken, Petes car is also a 240Z. I'm not sure where the discrepancy is. Pop N Wood, what year car is yours? Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 26, 2006 Administrators Share Posted October 26, 2006 I just finished one too. 1/4 plate is massive overkill. Used 3/16 for the top and 1/8" plate for the sides. I look at it this way... a healthy SBC could make 380ftlbs. If you get traction in second gear at torque peak with, for example, a T5 and run a 3.54 butt gear, this equates to approximately 2600 lbs of force pushing up on that mount. Would you jack up your ENTIRE car from that point, repeatedly for 20 years? Overkill? Yeah, probably. Massive overkill? I’m not so certain. Especially if you consider the weight penalty is less then 1.5lbs. I concur though... the 1/8” 'legs' are probably PLENTY sufficient. Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 26, 2006 Author Share Posted October 26, 2006 I just fit the part.. It fits my 1973 240Z just fine.. It also fits one of my 1972 240Z shells... I did not look under the other 1972 yet... granted there are a lot of differences... for instance I cannot find a correct factory tranny mount to fit my 1972 240Z built in january of 1972... It is the early spring style... where I have another 240Z built in June 1972 that has the later style tranny mount... I went through my parts bins and all of the arrestor strap harware I have has the same mounting pattern.. I know I have some stuff from 1970-71 because I have a short driveshaft and a straight rear crossmember for the pushed forward differential position.. I do not have a 1970-71 shell to make sure... Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 26, 2006 Author Share Posted October 26, 2006 hehe.. I literally built mine on my welding table using the measurements only... I tried fitting it to the car after it was assembled and it was perfect... KUDOS to Ron and Pete for making good drawings with accurate measurments... Quote Link to comment Share on other sites More sharing options...
Garrett76Zt Posted October 26, 2006 Share Posted October 26, 2006 I've had mine installed for about a year now, the only problem I had with the install was the top hole for the poly mount was off. I ended up slotting it a bit to get it just right. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 26, 2006 Share Posted October 26, 2006 BJ,Don't panic yet. I was about to question Pop... The original mount for Pete P. was built ON a 240Z ('72) and the drawing is a direct reflection of that part. And, if I'm not mistaken, Petes car is also a 240Z. I'm not sure where the discrepancy is. Pop N Wood, what year car is yours? Yeah, I know Pete's car is a 240 but it is what it is. The item pictured is mounted on the car. Mine is a December 1970. I am pretty sure Petes is the slightly later model that doesn't have the rear hatch vents (for what that is worth). Mine originally had the diff in the pushed forward postion. So maybe they changed the arrestor strap mounts when they went to the pushed back diff. Relocating the holes is a trivial thing. Just put it on the car and take some measurements. I was going to use 1/4 plate, but then I thought about JohnC's words that there is nothing on a Z car that requires 1/4 inch plate. I almost went 1/8 inch plate on top. That cross piece is where all the rigidity comes from, plus the ES mount seems to distribute the pressure over a fairly large contact patch. Anyway you do it will be stronger than the stock rubber mount. Quote Link to comment Share on other sites More sharing options...
deMideon Posted October 26, 2006 Share Posted October 26, 2006 I built one off of the drawings as well and it fit my 78 280Z perfectly... my only problem was that I didn't read the whole thing Pete wrote and tore up the rubber mount that I used Doh! I now have the energy suspension poly mount and no problem at all! Quote Link to comment Share on other sites More sharing options...
bjhines Posted October 26, 2006 Author Share Posted October 26, 2006 I edited the first post and added a lot of content.... Thanks John C. for bringing up one more use for the mount... yet another point for the cage.. and a very good way to stiffen the tunnel... POPnWood had some very good points about the fitment of this mount... thank you very much for the input... I checked fit and added info on clearance based on his points... Ron... thanks for your input!... and Thank you Pete for comming up with the highly accurate measurements... unless they are Ron's original work then Thanks Pete for making them soo easy to find!... As a side note... The mount actually REDUCES WEIGHT... at least mine does the one made of 3/16" plate weighs 4lbs 4.7oz with the poly mount installed... The original hardware weighs 4lbs 10oz ... Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 26, 2006 Administrators Share Posted October 26, 2006 Mine originally had the diff in the pushed forward postion. So maybe they changed the arrestor strap mounts when they went to the pushed back diff. Its looking like that is the answer... the first two years having the forward mounted differentials. Can anyone confirm a '71? then I thought about JohnC's words that there is nothing on a Z car that requires 1/4 inch plate. Exactly... but it implies a solid design in the first place. Said another way... If it needs to be 1/4" plate, it needs to be REDESIGNED. Yes, I'm admitting some substantial improvement could be made with this mount If you knew how fleeting that design was, you'd probably chuckle. Its only strength is that its easy, quick, and cheap. If I were to build another, it would be very different indeed... it would cost 3 times as much, take 10 times longer, and require a machine shop Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted October 26, 2006 Administrators Share Posted October 26, 2006 Thank you Pete for comming up with the highly accurate measurements... unless they are Ron's original work then Thanks Pete for making them soo easy to find!... Drawings are mine... No biggie though. Thanks for the solid write up. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 26, 2006 Share Posted October 26, 2006 Its looking like that is the answer... the first two years having the forward mounted differentials. Can anyone confirm a '71? They moved the diff back in 9/71, or on the 72 model year if you prefer. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.