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| Warren’s Isuzu-based COLD +401 with SR20DE http://www.locostusa.com/forums/viewtopic.php?f=35&t=11601 |
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| Author: | Warren Nethercote [ September 18, 2011, 6:56 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Bremms, Thank you. I had seen enough comments on engine mounts in other builds to make it clear that I should take care in this area. Even so, I was concerned about the open outboard side of the mounts. The open face allows easy access, but would it invite structural instability? As a result I added brackets to stiffen the open face, especially on the left-hand mount which is quite tall (see photo). Perhaps this stiffening is unnecessary, given that the gearbox mount has a saddle located on a transverse member that should resist fore-and-aft movement of the engine (he said hopefully). |
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| Author: | Warren Nethercote [ September 25, 2011, 8:23 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
In the end I only used the 1 1/2 inch flat-bar gearbox mount as an aid to locating the final gearbox mount. I changed the design to use some 1 1/2 x 1 inch, 1/8 wall (heavy, but not a bother for such a small item) tube as shown in the first photo. It seemed a lot simpler to utilize tube than to weld all sorts of stiffeners onto the flatbar .... I've also relocated the T-tube that was interfering with the cooling water inlet on the engine. To avoid welding in a deep narrow V, I offset the centreline junction. This approach is a structural compromise, but allowed me to avoid huge stick-out on the MIG welder, or reversion to flux-core for the acute inner angle. |
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| Author: | modernbeat [ October 6, 2011, 11:42 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Warren, I got a notification that you sent me a PM, but when I try to read them the message box is broken. Send me a message to modernbeat@gmail.com. |
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| Author: | modernbeat [ October 7, 2011, 10:19 am ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Warren, just looked over your build and the only thing I'd change is the rear roll hoop. I'd try to tie it into the body by eliminating the vertical strut in front of the axle and replacing it with the downtube of the roll hoop. But at this point you are so far along in the build I'd just add another tube that connects the bottom of the roll hoop foot to the base of the frame. You should be able to snake it in behind the seat area and inside the perimeter of the body. 
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| Author: | Warren Nethercote [ October 7, 2011, 10:30 am ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Modernbeat, Yes there is certainly a missing piece of structure there! I have been putting off adding anything until I roll the frame over and add the coilover mount to the bottom of the plate on which the roll bar lands. I suspect that the mount will be easier to weld in place without geometry interference from that missing member. But I may find that the reverse is true. Thank you for the observation. |
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| Author: | Warren Nethercote [ April 22, 2012, 10:45 am ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Boy, I just about fell onto page 3. No excuses, just too many 'other things' to do; perhaps I am not single-minded enough. Maybe I should have spent less time on the computer ...  Here is some stuff 'mocked-up.' Not exceptional progress, but at least I'm making swarf and filings again.I didn't quite follow Modernbeat's suggested approach to roll bar support (well, not at all?) and instead developed a mixed arrangement of an 18ga fabricated angle combined with a 1x1 RHS. The photos show pre (RHS) and post (LHS) pictures, albeit with magnets holding it together rather than weld metal. I am using Speedway four-bar ends (instead of Heims) and swaged bars for a three-link system. The four-bar ends work very well with 1 3/4x1 3/4 .100 wall tube for brackets. Only minor shimming will be required. I have mocked up a forward support for the third link based on 1 3/4 RHS supported by 1x1 RHS transverses. I am a little uncomfortable with clearance to the rear u-joint flange at the moment, so I may raise the whole arrangement, which will require more swarf and filing making. I have worked out the clearances - as someone else said, clearance is clearance, but the fear of a u-joint flange whacking solid structure on full bump gives me the willies! The sides of the tunnel are plated in 16ga. steel. Any thoughts on whether I should have more stiffening for the forward bracket? Locomod uses diagonals, but then again he has an 'open' tunnel structure. I'm going away this coming week, but hope to come to a decision on the three-link when I return and do some welding again. Welding the forward third link bracket into the tunnel is going to be 'interesting'. |
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| Author: | GonzoRacer [ April 23, 2012, 8:06 am ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Hi Warren- Good to see you making progress again!  The 3rd link mount looks good, very neat and tidy design. I haven't "studied up" on the welded side plate idea you used, I do know that a "shear plate" like that can strengthen the rectangle it covers, but is it equal to a diagonal, strength wise? You will be seeing some fore-and-aft stress on that upper link. Not knowing about the "shear plate" design, I'd be tempted to put some diagonals on either side of that mount. Just sayin...  Other'n that, how the heck are ya?  JDK |
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| Author: | Warren Nethercote [ April 23, 2012, 8:15 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
JD, Thanks for the observation. The simplest solution to shear stiffnesss in the top plane would be to plate up the square shown in red below, although I'll probably curse when it comes time to bolt up the u-joint flange. At least it should be simple to position the plate with magnets and then downhand weld. I've been fine but busy (on the wrong things). I was chair of the nominating committee at my sailing club but stepped on a banana: somehow I ended up being Vice-Commodore House, which means that I'm responsible for the club's liquor license, running the bar, and personnel. It's not quite what I had in mind for retirement - I'm supposed to be building a car! 
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| Author: | Warren Nethercote [ May 9, 2012, 1:55 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Slowly, slowly .... I decided that worrying about my sums for pinion clearance against the third link mount was foolish. I mocked up a shock (with my one QA1) so I could determine maximum bump and then hoisted the axle and shimmed up the hub carriers to the requisite height for max bump. No interference problems ... (at least where I looked)
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| Author: | john hennessy [ May 9, 2012, 4:49 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
question, the support for the roll bar goes down to the back, there isn't much strength in this area, could you add something to the true frame going forward? |
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| Author: | Warren Nethercote [ May 9, 2012, 8:20 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
John, A few posts ago I showed how I was stiffening the 'vertical' member aft of the axle by a combined 1x1RHS and a fabricated angle. Additionally I an going to partially plate the belly aft of the cockpit, apart from the area under the pumpkin. I believe that this will serve to stiffen up the after chassis, to the benefit of both the roll bar and the coil-over support. |
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| Author: | Warren Nethercote [ October 2, 2012, 6:09 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Back from page 2, after too much time on the wrong things. I decided to tackle something that I could bring to completion of a sort (and generate some feeling of achievement) while I had some time available, so I settled on a spare tire carrier and rear bumper. It's way out of order, and arguably way less important than building suspension, but it is chassis-related and will be required for my Nova Scotia inspection. See viewtopic.php?f=23&t=14095 for more details. And yes, that is paper bodywork, solely for the benefit of the photo. |
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| Author: | GonzoRacer [ October 2, 2012, 8:04 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Quote: And yes, that is paper bodywork And ya just can't get more into the spirit of "adding lightness" than that! Colin would be so proud. Spare tire rack looks good Warren. If that "exhaust pipe" size bit going off to the right is the bumper, I'd want more space between it and the bodywork (even paper bodywork), myself. Perhaps I'm missing something... *** EDIT: I just looked at your thread on the construction of the bumperettes and discovered the attachment to the roll bar, which I see in the pic now. Please disregard my previous statements! *** Good to see you back at it, Sir! JDK |
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| Author: | Warren Nethercote [ March 26, 2013, 4:35 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
This is a bit of a test - I'm strugling to attach photos and will break this post up into parts .... Back from the bottom of page 2, after doing other things. Not always honey-dos, because I built another iceboat hull, a new runner plank and another set of runners. The hull I built last year was OK: I was quite happy with it geometrically, but it was heavier than I wanted – 58 lbs for the hull, as opposed to the 46 lb class minimum. I used Douglas Fir for the hull sides because if was readily available custom-milled, as well as balsa core for the cockpit floor and paid the price of my expediency with excess weight. This year’s effort used spruce for the sides and a Divinycell-cored cockpit floor and is significantly lighter at 48 lbs. I’m not sure the reduced weight is reflected in race results: 10 lbs saving in the hull sounds big, but the overall weight of hull, runner plank, runners, rig and skipper is more like 300 lbs, with 50 lbs difference between the lightest and heaviest skippers, but it sure is easier to put the hull on the roof racks at the end of the day! That’s me in KC 3786 in the picture, in the middle of March, on what was my last day of (ice) sailing this winter. Now I can pay some attention to the Locost 7 build before soft water sailing starts. I guess this story reveals the truth. I build iceboats because I like iceboating, whereas I’m building a car because I’ve always wanted to build one. It is the journey rather than the destination, although it would be nice to drive it one day. I don’t want to encumber my estate with an unfinished project and boxes of mystery parts! |
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| Author: | dhempy [ March 27, 2013, 12:29 pm ] |
| Post subject: | Re: Warren’s Isuzu-based COLD +401 with SR20DE |
Test post. |
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