distributorguy Posted April 21, 2017 Report Share Posted April 21, 2017 Does anyone stock an adjustable cam gear that fits an L20b in the US??? I need one that actually adjusts. I just tried installing one with 8 holes last evening. I can't get to the setting I need. The funny thing is that I get the same 106 degrees at settings 1,2,3, and 4 gives me 114. A,B, C, D are all obviously way off, and I can't skip a chain tooth to get there either. This is checked reading .050" down each side of peak, always checked while rotating CW to account for chain slack. Thanks for any leads, a sale is guaranteed! 1 Quote Link to comment
Doctor510 Posted April 21, 2017 Report Share Posted April 21, 2017 Does anyone stock an adjustable cam gear that fits an L20b in the US??? I need one that actually adjusts. I just tried installing one with 8 holes last evening. I can't get to the setting I need. The funny thing is that I get the same 106 degrees at settings 1,2,3, and 4 gives me 114. A,B, C, D are all obviously way off, and I can't skip a chain tooth to get there either. This is checked reading .050" down each side of peak, always checked while rotating CW to account for chain slack. Thanks for any leads, a sale is guaranteed! 106 degrees of what? BTW, ALL L series motors use the same gear Sounds like the 8 hole unit you have is NOT a NISMO unit but rather a modified stock gear. Quote Link to comment
Stoffregen Motorsports Posted April 21, 2017 Report Share Posted April 21, 2017 For what you're doing, I would not run and adjustable gear. NOTORIOUS for coming loose at sustained RPM's Just drill out the hole in the gear ind use a cam degree bushing. They are rock solid and stay where you set them. 1 Quote Link to comment
distributorguy Posted April 21, 2017 Author Report Share Posted April 21, 2017 106 Intake centerline. I'm trying for 107, 110, I ordered an adjustable gear out of Japan this morning. If I can pinpoint a couple settings that work on the dyno, I can drill stock gears to match what the adjustable gear is set to very easily, so I don't even have to use a bushing. I also plan on modifying a "fixed" timing chain tensioner, given how short our races are. That would allow us to try cam timing changes on the course in a matter of minutes. Isn't the Nismo gear a modified stock gear? Assumptions are a dangerous thing. The big problem is that we don't know who is modifying them, and how many people/shops are doing it. All of this is required due to the radical cam I'm playing with. The guys at Schneider Cams said it was the most extreme 4 cylinder cam design they've ever ground, which means it had to be ground off-center from a normal grind to provide enough meat for the lobes without running out of hardened material. I'll have to break it in with light valve springs, then install something a little stiffer to be able to sustain the high rpms I need without valve float. I'm pretty sure 225 over the nose isn't going to cut it. 1 Quote Link to comment
Stoffregen Motorsports Posted April 21, 2017 Report Share Posted April 21, 2017 Why replace the bushing? Consider that the stock cam bolt torques to about 170#/ft, which will clamp everything in place. I'm getting really excited to see your finished product. And I'd love to see you run it at Bonneville. Quote Link to comment
distributorguy Posted April 21, 2017 Author Report Share Posted April 21, 2017 Given the issue I had in our test motor with the cam dowel walking out into the gear, I'm not taking chances on anything. I want a solid gear on the race motor so that nothing can move or be moved. The adjustable gear is a tool to make that happen. I'm excited too, but we're still a few weeks from hearing this thing run. More if cam timing isn't the only issue that arises. And I have other irons in the fire so to speak, so a few of those projects need to be addressed in between all the assembly fun. At least last night I test fit the 3.89 ring and pinion into the Detroit locker and clearances look great! It was just a simple carrier swap in the N2 housing along with some new bearings. Add some magic "special sauce" and it should be very, very low rolling resistance. Quote Link to comment
G-Duax Posted April 21, 2017 Report Share Posted April 21, 2017 To drop some parasitic drag, run a single #35 timing chain ? Modern kart chain (NOT industrial) doesn't use a master link, and can take 50 hp being driven from a 9 tooth engine sprocket. Quote Link to comment
Doctor510 Posted April 21, 2017 Report Share Posted April 21, 2017 106 Intake centerline. I'm trying for 107, 110, I ordered an adjustable gear out of Japan this morning. If I can pinpoint a couple settings that work on the dyno, I can drill stock gears to match what the adjustable gear is set to very easily, so I don't even have to use a bushing. I also plan on modifying a "fixed" timing chain tensioner, given how short our races are. That would allow us to try cam timing changes on the course in a matter of minutes. Isn't the Nismo gear a modified stock gear? Assumptions are a dangerous thing. The big problem is that we don't know who is modifying them, and how many people/shops are doing it. All of this is required due to the radical cam I'm playing with. The guys at Schneider Cams said it was the most extreme 4 cylinder cam design they've ever ground, which means it had to be ground off-center from a normal grind to provide enough meat for the lobes without running out of hardened material. I'll have to break it in with light valve springs, then install something a little stiffer to be able to sustain the high rpms I need without valve float. I'm pretty sure 225 over the nose isn't going to cut it. I don't know where you are getting the info on the gear changing the Cab lobe separation angle, the gear will change the torque/HP band. The Nismo Gear is NOT a re-drilled stock unit, Google for the Nismo specs/ even the stock settings in holes, 1,2 & 3 Quote Link to comment
distributorguy Posted April 23, 2017 Author Report Share Posted April 23, 2017 510guy, where did I ever mention changing the LSA? I'm trying to dial in the intake centerline. Intake lobe. #1 intake. And yes I'm trying to optimize my power band/rpm range for the cam I designed. Maybe you should read the build thread I have going in the 620 section. http://community.ratsun.net/topic/66750-620-land-speed-record/ As far as Nismo's gear, I don't really care what it is or where its from. I have to assume they don't make it, as they don't make most of the gear in their catalog. Maybe none of it? As far as I know they could be buying parts from you. No idea. Don't care. I just know the gear I purchased with 8 holes in it is seriously made wrong, and it came in the same generic type package you see from Nissan. The vendor who sold it to me promptly offered to replace it, so I'm guessing its a known issue. 1 Quote Link to comment
Xnke Posted April 27, 2017 Report Share Posted April 27, 2017 The Nismo gear works fine-but it's fiddly and just isn't as nice as the Kameari gear. I've *never* had a properly torqued (use a damn torque wrench!) cam gear come loose or the adjustable cam gear loose it's grip and slip. Quote Link to comment
datzenmike Posted April 27, 2017 Report Share Posted April 27, 2017 The stock cam sprocket has 4 degree increments per hole 1, 2, 3. So 8 degrees advance starting on the #1 hole. Assuming #1 is the TDC center of the cam. Each cam tooth is 9 degrees. So if on the #2 hole (advance 4 degrees) and remove a tooth you have -9 +4 = -5. There are a lot of different combinations you can get but only on the stock Nissan sprocket. Quote Link to comment
bananahamuck Posted April 27, 2017 Report Share Posted April 27, 2017 http://www.thezstore.com/page/TZS/PROD/classic12f02/10-2042 Says they stock it but i don't know for sure ,, they have 800 number though . Quote Link to comment
distributorguy Posted April 27, 2017 Author Report Share Posted April 27, 2017 I have a new stock gear to play with from Cloyes. Tomorrow the one arrives from Japan, if I'm here to sign for it. One way or another, I should be able to have it sorted before the weekend is out. I'll post what I find. Mike, keep in mind that 9 degrees (per tooth) at the cam reads as 18 degrees at the crank where all measurements are taken. Cam moves at half speed so all measurements are doubled. You always degree the cam from the crank to get more precise measurements. This means a 3 degree jump at the cam is a mile at the crank. Frustrating. 1 Quote Link to comment
banzai510(hainz) Posted April 27, 2017 Report Share Posted April 27, 2017 the Cloyes I never liked as one cant see the timming marks as the view hole is in the wrong spot. for the stock initial set up Quote Link to comment
G-Duax Posted April 27, 2017 Report Share Posted April 27, 2017 The Tomei is a good one also, pretty much the same basic design as the Kameari. There was one out of Japan that only had 4 bolts, on a very small bolt circle. I don't think I would run one of those. $150 for a Kameari is a great price !! Quote Link to comment
distributorguy Posted April 28, 2017 Author Report Share Posted April 28, 2017 The Kameari gear should arrive today. BTW $167 with 2 day shipping from RHD Japan. It took them 3 days for them to ship however, so 6 days total, ordered over the weekend. Quote Link to comment
Mattndew76 Posted May 8, 2017 Report Share Posted May 8, 2017 I had a Kameari timing gear in house a while back and made some solid models of it from solidworks. After talking with Peter Mcdonell (https://www.instagram.com/petermcdonnell65/) about using them, and I decided to not make them. He recommended that the Kameari adjustable cam gears be inspected after every use if a person was going to use one. Quote Link to comment
Mattndew76 Posted May 9, 2017 Report Share Posted May 9, 2017 Want to share why ? The customers he had come to him with problems was from catastrophic failures from the Kamaeri cam gears. Its why he stated that inspections should be done before a run and after. They are not items you can install, set, and ignore. Quote Link to comment
G-Duax Posted May 9, 2017 Report Share Posted May 9, 2017 I have never had one slip, and never had any external cam pulleys slip. But then again, I know how to put things together...... In any form of racing, or in all of things dealing with life, the intelligence of the people involved can be charted on a graph. And it will always be a bell curve, with a most of people in the bottom half, then decreasing numbers of people as the brain power increases. And some people think they can build a race engine, and never look at it, while others do a complete tear down after every event, 1 Quote Link to comment
distributorguy Posted May 10, 2017 Author Report Share Posted May 10, 2017 Winners believe in overkill. Losers take things for granted. I'll experiment with the Kamaeri, but if the other aftermarket gears can't replicate the settings I need, then I need to make the Kamaeri more "durable" by locking it permanently into the setting that works. Its craftsmanship is exceptional, so the only issue I can image would be bolts that come loose. Mine is already pinned into a position I need it to hold. The bolts are red Loctited. They will be marked with paint to see if they shift. What more do you need??? 1 Quote Link to comment
loungin112 Posted May 10, 2017 Report Share Posted May 10, 2017 I have never had one slip, and never had any external cam pulleys slip. But then again, I know how to put things together...... In any form of racing, or in all of things dealing with life, the intelligence of the people involved can be charted on a graph. And it will always be a bell curve, with a most of people in the bottom half, then decreasing numbers of people as the brain power increases. And some people think they can build a race engine, and never look at it, while others do a complete tear down after every event, That's actually not a "Bell Curve"...better to remain silent and be thought a..... Quote Link to comment
Mattndew76 Posted May 10, 2017 Report Share Posted May 10, 2017 That's actually not a "Bell Curve"...better to remain silent and be thought a.... We got what he was trying to illustrate. Winners believe in overkill. Losers take things for granted. I'll experiment with the Kamaeri, but if the other aftermarket gears can't replicate the settings I need, then I need to make the Kamaeri more "durable" by locking it permanently into the setting that works. Its craftsmanship is exceptional, so the only issue I can image would be bolts that come loose. Mine is already pinned into a position I need it to hold. The bolts are red Loctited. They will be marked with paint to see if they shift. What more do you need??? I like your reasoning. Be safe. Quote Link to comment
G-Duax Posted May 10, 2017 Report Share Posted May 10, 2017 Ok, ok, so I used the wrong terminology. An exponential curve..... There, are you happy ? No matter how I put it, there would have been someone trying to pick it apart, after all this is a forum, and we are dealing with the same bell, err, exponential curve of intelligence. 1 Quote Link to comment
distributorguy Posted May 10, 2017 Author Report Share Posted May 10, 2017 I knew what you meant, despite what you typed. :thumbup: 1 Quote Link to comment
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