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| J-H hillclimb and AX project | Rating: 
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| Posted: 03-22-2009 04:48 am |
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1st Post |
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Jensenman Member
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This was Ron Earp's ITS car; I have been making slow progress recently but at least it's progress! I am using a Mazda RX2 rear axle (it's 53" wheel face to wheel face, the stock J-H is 54") with an RX7 clutch type limited slip, 4.86:1 gear, RX7 rear disc brakes and have nearly completed the rear coilover and 3 link setup. Here's the housing and 3 link in place for one of MANY test fits:  I got industrious and completed the upper shock mounting today, here is the left side QA1 coilover in its final resting position:  I still have to brace and triangulate the upper shock mountings and box in the part of the rear inner fender that I had to cut away for shock clearance. Once all this nasty stuff is done the powerplant will be installed! Last edited on 03-22-2009 04:51 am by Jensenman |
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| Posted: 04-29-2009 01:55 am |
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2nd Post |
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Jensenman Member
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Some more progress: This is a reinforcement of the upper shock mounts inside the trunk. The bottom of the 'triangle' is welded to a 'box' which goes all the way across the car underneath. The ends of the 'box' are triangulated to the original frame rails with 18 gauge sheet steel. All the bits are here for the rear axle, so I can assemble and install it for the final time. I can has fat tire? :-D 13x10 wheels with 22 x 10 x 13 Hoosiers. Should stick okay.  The front of the fender opening will have to be trimmed for clearance at full lock. Now I can start plumbing the brakes and building the mounts for the 13B rotary. Last edited on 04-29-2009 01:56 am by Jensenman |
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| Posted: 04-29-2009 02:13 am |
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3rd Post |
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Jensen Healey Super Moderator 
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Wow! I'm jealous! Looks like loads of fun in the shop. Kurt
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| Posted: 05-27-2009 02:55 am |
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4th Post |
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Jensenman Member
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Progress so far: the rear axle and all suspension links are completed and installed, the clutch and throttle cable linkage and installation are complete, the pedal box has been modified to accept an RX7 master cylinder so now comes the fun part: installing the noisemaker! Rear axle in place:  13B rotary viewed from the left. It needs to come back about an inch to get it right where I want it. I discovered that Engine Mount Plan A will not work, so I have to go with Plan B. Problem is, there was no Plan B. Oh, well.  Scads of room in the J-H engine bay. I seem to recall that Donald Healey wanted enough room to allow for a V8 at a later date. I believe it and I thank him. 
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| Posted: 05-27-2009 03:08 am |
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5th Post |
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Jensen Healey Super Moderator
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Front mid engine! Since the JH is already slightly rear heavy, will you have to add balast to the front to re-balance the car? Keep up the good work!!! Kurt... working on my daughter's Volvo today. :-(
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| Posted: 05-27-2009 01:33 pm |
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6th Post |
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Jensenman Member
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This car has been pretty well gutted so I am not real sure about the f/r distribution right now. Nothing scientific, but my wheel spring rates are ~240 front/225 rear and the car settled ~1/2" more in the front than the back once the engine was installed and I rolled it back and forth to settle the suspension out. I'm most interested in keeping the polar moment of inertia to a minimum by placing as much stuff as possible between the axles and then I will corner weight it. My corpulent carcass will help with that a good bit, unfortunately. :-(
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| Posted: 08-10-2009 12:29 am |
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7th Post |
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Jensenman Member
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August 9, 2009: it LIVES! Yee HA! The S5 13B rotary came to life after its long slumber, it took about 20 seconds of cranking, still a little breadboarded and a couple quirks to iron out but it RUNS! :-D Pics and possibly video to follow.
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| Posted: 08-22-2009 12:36 am |
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8th Post |
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Jensenman Member
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Commence boredom as I show the latest. :-D Instrument panel. Still some tidying up to do and I need to add aluminum sheet on both sides. Instruments are VDO Vision series, surprisingly affordable. The big red light is the charge indicator. Rotaries do NOT like overheating, if it throws the alternator belt (which also drives the water pump) I want to know RIGHT NOW.  Engine left. That's a JEG's universal double pass radiator and the oil cooler is from a 1990 RX7. The engine is an S5 13B, rated at ~180 HP stock. With the headers, free flow exhaust and cold air intake I figure probably around 195 or so, with an 8500 RPM redline. So far the engine runs great, the only real problem were a couple of small coolat leaks, then one of the oil cooler hoses sprang a leak and dumped about 1 1/2 quarts of oil in my garage before I could shut it off. Dammit.  Engine right. That's a poor man's Braille lightweight battery; a Wal Mart garden tractor battery, $25.00. :-D  8 gallon RCi fuel cell.  Fuel filter and fuel pump mounting. The exhaust is 3" OD. The small K&N filter is the fuel cell vent filter.  The car as it sits now:  I haven't done anything to the body except remove decals and use a baseball bat to roll the rear fenders for clearance. The bodywork will happen sometime next year, in the meantime I have another 24 Hours of LeMons car to do and also a 2.5 Chrysler turbo to put in a Fiat X 1/9. I still have to fix the hole in the tunnel from the driveshaft explosion, then the rest is minor fabrication. But then comes the real work; tuning and sorting. I'm sure to find more than one thing I did wrong. That's at least half the fun. Right? :-/
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| Posted: 08-30-2009 03:23 am |
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9th Post |
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Jensenman Member
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A bit more progress today. Here's the damage to the tranny tunnel done by the driveshaft 'explosion'.  I put off fixing that until the powerplant was in place and I knew it ran. So now that that's happened a couple of buddies and I got this accomplished today:   Competition debut closer and closer. :-D Last edited on 08-30-2009 03:28 am by Jensenman |
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| Posted: 08-30-2009 10:42 pm |
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10th Post |
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JHRV8 Member
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GREAT RE-BUILD!!! Can't wait to see and hear more!......Bob
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| Posted: 11-20-2010 01:25 pm |
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11th Post |
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Jensenman Member
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A lot has happened in my life since my last post, but even with all that the car has had some shakedown events with a few breakages, updates and repairs along the way. Everything has been autocross so far, if all goes well I will be running the first hillclimb with it in spring 2011. The first event was a small low speed course, I was still learning the car so did not place very well. The motor ran strong and even with the 13x10's I could easily step the back end out on acceleration. I didn't learn much about what the car needed except for one thing: the 13" steering wheel was way too small. There just wasn't enough leverage for the fat tires. I installed a 15" wheel and things were MUCH better. The accelerator pedal broke off at the second event I ran. Not easily fixed in the field, but it's now been welded and reinforced to prevent a reoccurence. I couldn't get full throttle throw at that event so again I wasn't able to truly evaluate the car's performance. But I was still in the top 10 so that was encouraging! I did discover a disconcerting tendency for the engine to go into 'limp mode'. S5's use an electronic oil metering pump, if the ECU thinks it failed it kills the trailing ignition and drops the fuel pressure so you can limp to the side of the road. Obviously that's not a good thing when trying to race, so I got an S4 ECU and converted the engine to a mechanical OMP. So now that problem is solved. But even with that going on the car was still stinkin' fast. At the next event, the car ran strong but understeered like mad. This was due to the extremely aggressive Mazda Motorsports limited slip, it's essentially a spool. I swapped a normal spring loaded clutch type limited slip in, much better. The 4:86-1 gear was also noisy as hell, even though properly set up. So it had to come out as well. The next event was much higher speed, some cars were clocked at 80 MPH. I had a co driver whose input was invaluable. He and I discovered that the brakes were, to put it mildly, inefficient at these higher speeds. I'm glad I didn't discover the brake problem at a hillclimb! This was due to the pedal ratio, the stock J-H is 4:5-1 ratio and I had to redrill the pedal pushrod hole for 6:1. This involved fabricating a new master cylinder mounting plate to raise it 3/4" so the pushrod would enter the cylinder straight. I also was able to finally get some proper heat in the tires to dial in tire pressures. The downside to that event was the motor smoked heavily on deceleration. In 40 runs over two days, the engine used nearly 2 quarts of oil. Not good, obviously a swap and/or an overhaul was in its future. I didn't want the car sitting around undriveable while waiting for parts etc so I bought another used running S5 13B and installed it. It smokes much less than the first one but still more than I would like. It makes good power, though, and is sitting in the car now. I have the original motor apart and as I suspected the O rings for the oil control rings were brittle. The apex seals were pretty well worn out as well. The big parts (rotor housings, rotors, eccentric shaft, stationary gears and the 'irons') are all good. I'm waiting on the overhaul parts from Atkins Rotary. The car has been to one other event with motor #2 and it did well, as in top 5 and winning my class. I discovered that the inside front tire was lifting off the ground in very hard turns, telling me my roll stiffness was way too soft in the rear. I have now gone from 150 pound rear springs to 250 pounders. Haven't had a chance to run it with those yet, but the math tells me the roll couple should be pretty close to right. Something I figured would come up during tuning: first gear in an RX7 transmission is a very low stump puller, then there's a big jump to second. That makes downshifts for very slow corners nearly impossible; second is too tall and first way too low. I can fix that with more 'gear' in the rear so am planning a 4:77-1 ratio swap soon. It's currently 3:89-1. So it's been an uphill battle but the sun's starting to show through the clouds. No new pics at the moment, the car looks pretty much the same. Oh, I took both it and my JH5 to a local British car show, there was much head scratching and furrowed brows. :-D Last edited on 11-20-2010 01:35 pm by Jensenman |
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| Posted: 07-11-2011 01:32 am |
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12th Post |
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Jensenman Member
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My life has settled down a bit so I was able to get a lot more done on the car. The engine rebuild went very well, it makes good power, holds great oil pressure and doesn't smoke. So I can now add 'rotary engine rebuilder' to my resume. I ran it in a couple more AXes and discovered I need MUCH stickier tires. The house has been sold, I have to buy another one and the kid needs braces first, though. Maybe 2012 will be my year...
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| Posted: 03-13-2012 01:22 pm |
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13th Post |
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jcdean Member
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Just wanting to resurect one of the threads I enjoyed. Any new adventures?
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| Posted: 04-07-2012 01:25 am |
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14th Post |
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Jensenman Member
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Not much, unfortunately. Moved to another city and of course the cars went with me, things are settling down now. I can't find sticky enough 13" tires so I am going to 15x8's and Hankook C51 compound tires. If all goes well, I will run a 2 day AX event in July and a hillclimb in August.
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| Posted: 10-14-2012 03:08 pm |
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15th Post |
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Jensenman Member
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I'm looking for a used fiberglass bonnet for this project, a boot lid would be nice too. 1974jh5mws@gmail.com Thanks!
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| Posted: 11-01-2012 09:40 pm |
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16th Post |
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Jensenman Member
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I have finally found some time to put into this project again. I didn't really like the instrument panel I first built, so I decided to fix that recently. V 2.0:  Last edited on 11-01-2012 09:42 pm by Jensenman |
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| Posted: 06-25-2013 03:16 am |
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17th Post |
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Jensenman Member
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Hope this link works! This is from the Chasing the Dragon Hillclimb in Robbinsville, NC on 6/23/13. That's my co driver having a Code Brown moment. He's fine, the car was pranged enough neither of us felt comfortable going up the hill again. I tore into it today, found that the left front lower control arm was bent, the two left tires are ruined, the left front rim is bent and the shock bushings are blown out. Otherwise the car came through with flying colors and will be back on track soon!
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| Posted: 06-26-2013 09:12 pm |
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18th Post |
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Mitch Ware Member 
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It looks like all of the colors were flying, even the brown from when the poo came out. Glad to hear it isn't seriously hurt, and glad to see that it hit the hill climb circuit. Mitch #11002 #19670
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| Posted: 06-27-2013 06:15 pm |
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19th Post |
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James Sohl Member
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When you can see most of the roll cage as a car goes by, then you know why the cage is there.
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| Posted: 07-20-2013 01:52 pm |
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20th Post |
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Jensenman Member
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Video from the first run of the second day, which is the last run I got in before the car got bent. At 1:28 in I go through the corner where the crash happened. http://www.youtube.com/watch?v=r5kiuQIEDyA In the next video, at 1:48 in you can see the launch from the above run. At 17:48 my bud launches for his ill fated run and at 18:06 there is an absolutely stunning McLaren Can Am car. The guy was paddocked across from me and I got a good look, it is a real McLaren not a replica car. 600 HP small block Chevy with mechanical fuel injection! No, he wouldn't let me drive it. http://www.youtube.com/watch?v=jRrXgYOQs5g The car is fixed but unfortunately can't make it back in August. I plan to run some AXes and then the Wolf Ridge Hillclimb next May, I might do a PCA track event in September too. Last edited on 07-20-2013 02:09 pm by Jensenman |
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