love-my-V8-280Z Posted February 13, 2004 Share Posted February 13, 2004 I went and bought the steel to make my JTR mounts, I copied the pages from the book and used them as a stencil. Well it turned out so bad I gave up and just ordered there’s. Well today I also had a lot of confusion when trying to follow the directions. The copies in the book have two problems. One when I placed my new brackets on there picture they were a LOT different. Also they labeled both brackets as passenger side and told you to turn to page (whatever) to see them installed and they have the wrong page number. I was able to figure it out, its no big deal but if they had taken accurate measurements when making the diagrams I would have not wasted $25 on the metal, 2 hours making them wrong and probably not spent the $80 on there hardware.. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted February 13, 2004 Share Posted February 13, 2004 Most likely you had a bad parallax error on the copier you used. Some photocopiers use a camera type lens to snap a picture of the subject being copied. That will distort the image pretty badly for dimensional applications. Just photocopy a ruler and compare the image to the original to get the jist of this. Better off to use a copier that scans, or your computer scanner if you have one. Quote Link to comment Share on other sites More sharing options...
wheelman Posted February 13, 2004 Share Posted February 13, 2004 I don't think it was a bad copier. I looked at copying the pages before I made my mount plates and found the measurements listed in the drawings do not match the drawing. Just to verify I remeasured the drawings for the plates last night with a caliper and they are wrong. The largest deviation was 1/16th inch and the smallest was almost 0. All of the dimensions varied from the listed value though. These can't possibly be precision drawings, especially the way they are printed. After I measured mine the first time I decided I would just cut and drill based on the values. I didn't get it perfect but it's a whole lot better than the drawings. I also haven't mounted mine yet so take that with a grain of salt, I may find out they are way off. Ken W. Quote Link to comment Share on other sites More sharing options...
love-my-V8-280Z Posted February 13, 2004 Author Share Posted February 13, 2004 I know its not the scanner, as I had said I bought there mounts and placed them on top of there print and its not a huge difference but plenty enuff to screw you over. with the holes of in different dirrections you would have to ream them out a lot to make them match... Quote Link to comment Share on other sites More sharing options...
spdsk8r Posted February 14, 2004 Share Posted February 14, 2004 Terry, On my first two conversions, I coppied straight from the JTR manual (first edition) and made my own, they fit right on. Must be later editions have gotten changed. Sounds like you are just about ready to install. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted February 14, 2004 Share Posted February 14, 2004 It's been a while since I looked at my JTR book, but I dont remember it indicating that the drawings were to scale and could be used as stencils. I do remember it providing the measurements for you to use. I'll double-check my copy when I get home. Quote Link to comment Share on other sites More sharing options...
love-my-V8-280Z Posted February 14, 2004 Author Share Posted February 14, 2004 I have read the book cover to cover and no it does not say "use these" But it does draw them each on a seperate page, very miss leading. And they are only off a small %. I believe when they drew them they were accrate. I'm assuming they became distortated when they went to print. And for the most part, I only made this post so others don't make the same mistake I make. Quote Link to comment Share on other sites More sharing options...
Michael Posted February 15, 2004 Share Posted February 15, 2004 Back when I thought I’d be using a small block (around 1998) I ordered the JTR book, 6 th edition. The frame mount drawings are in some places off by about 1/16 th, as already mentioned. As-drawn, some of the bolt clearance holes are maybe 0.030†off from the listed diameter. But I just used the listed dimensions, some calipers and a machinist’s scale, transferring the dimensions to sheets of aluminum (I used 6-series aluminum at the time) - at it was straightforward. A couple of years later I realized that I wanted to use a different engine, and mount it directly to the frame rather than to the steering crossmember. Most of my engine mounts ended up in the trash. Quote Link to comment Share on other sites More sharing options...
Guest Bob L Posted February 18, 2004 Share Posted February 18, 2004 It's generally a bad idea to scale a drawing. When I'm machining something, I always assume the drawing is not to scale unless I made the drawing. My recollection is that the drawings in the JTR book were unambiguously dimensioned. Quote Link to comment Share on other sites More sharing options...
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