bajango Posted September 16, 2016 Author Report Share Posted September 16, 2016 make this simple Pull 720 motor and trans/slave/release collar/bearing together install in 521 That's what I plan on doing, that's why I'm confused on what mike is trying to tell me.. 2 Quote Link to comment
banzai510(hainz) Posted September 16, 2016 Report Share Posted September 16, 2016 just ck the slave style you have 1 Quote Link to comment
KoHeartsGPA Posted September 16, 2016 Report Share Posted September 16, 2016 Mike has me confused too, maybe he thinks you're marrying the 5spd to the L16... 1 Quote Link to comment
datzenmike Posted September 16, 2016 Report Share Posted September 16, 2016 Yes, I did think that. Just swap everything together but replace the bearing. Use the 521 engine mounts. Think about using your 521 exhaust manifold on the L20B engine and you won't have to join the 720 down pipe to your exhaust system. This will save you some welding fabrication headaches. You may not be able to use the 720 alternator that comes with the L20B. 1 Quote Link to comment
scooter Posted September 17, 2016 Report Share Posted September 17, 2016 Hey Mike, is the 71c 2-3 and 3-4 the same as a zx box? Like I've said in another thread that the ratios in the newer tranny were a lot better than a l series dogleg. Even with the widest ratio Trans if you shift it past peak power (7000-7500) your gonna Land on the high side of peak torque. Even cammed up its not bad putting around town at low rpm, I wouldn't say it's any worse down low than a stock motor. If you built a hot motor and put it in a street car, your not just gonna putt, your gonna brappp your ass off all over town and put those Subaru vape smokers to shame Quote Link to comment
scooter Posted September 17, 2016 Report Share Posted September 17, 2016 When I had my 620 with the l16 I wailed the fuck out of that thing non stop, because if I didn't, it was too God damn slow! Haha. 3 Quote Link to comment
Tom1200 Posted September 17, 2016 Report Share Posted September 17, 2016 Mike, yes I am aware it's a percentage, I should have spelled out directly rather than mentioning needing 4500 to get the car rolling. Yes shifting at 6K would "only" drop the motor down to 3700 rpms but there are two big problems with that; first the motor has now fallen of the cam & the motors bucking like a rabid mule, second is the motor has also dropped off about 30 horsepower. Revvy motors typically have the meat of powerband 2000 rpms wide at best, hence the ultra close ratio boxes. When some says revvy motor I, wrong or right, assume they mean something that revs to at least 8000 rpms. Now granted with the A series I calculate shifts based on 8600 rpms for an A12 and 8100 for the A15. My fellow vintage racers with L series suffer the same fate. The dyno even sheets I've seen show a 50hp drop between 8500 and 5500 rpms, we're talking 15 hp for every 1000 rpms, again the flat part of the power curve is only 1500-2000 rpms wide. A real world example was my A12 with 290 duration cam with 104 degree lobe centers; my tilt trailer is fairly steep (think pulling out of a downtown parking garage) and it's a bear to ease up onto the trailer. As part of choosing what motor to build I'd be taking a good look at dyno sheets to see what will make the most usable power on the street. Many many years ago I had a heavily ported Yamaha RD350 as a street bike with a powerband similar to my race A12. It was wicked cool but a real PIA especially if you needed to pull away quickly. Having a cop in the lane next to you made it even more rocky. I'm not meaning to drone on about this but it should absolutely be a factor when doing a street car or bargain race car that will be running a standard box. Quote Link to comment
datzenmike Posted September 17, 2016 Report Share Posted September 17, 2016 Hey Mike, is the 71c 2-3 and 3-4 the same as a zx box? Just like the 71B there are probably 2 (at least) set of gears for them. Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 Except I don't think my little 100 some HP truck is gonna make any Subaru guys think twice about thier stupid underwater headers and AWD 1 Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 You may not be able to use the 720 alternator that comes with the L20B. I'm already using a 720 alternator. I robbed a bracket off my old 1983 Nissan 720. It's a tight fit,. But I got it to work. I wanted to be sure that I had no issues with my electric fan and small subwoofer. Quote Link to comment
scooter Posted September 17, 2016 Report Share Posted September 17, 2016 Except I don't think my little 100 some HP truck is gonna make any Subaru guys think twice about thier stupid underwater headers and AWD I thought the purpose of this thread was to make a lot more than 100 hp Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 I thought the purpose of this thread was to make a lot more than 100 hp Ooook oook ok. 117.7hp lol. My point is that its not easy making horsepower on an all motor 2L. I'd like to make 150hp. That would make me happy. At least from what I've read, that's about the street limit on a L20B Quote Link to comment
datzenmike Posted September 17, 2016 Report Share Posted September 17, 2016 I'm already using a 720 alternator. I robbed a bracket off my old 1983 Nissan 720. It's a tight fit,. But I got it to work. I wanted to be sure that I had no issues with my electric fan and small subwoofer. Yes a tight fit. You know that the 521 alternator uses an external alternator, correct? and that the 720 alternator has a built it regulator inside it? The 521 wiring needs to be changed slightly if you are running an internally regulated 720 alternator. Quote Link to comment
scooter Posted September 17, 2016 Report Share Posted September 17, 2016 Ooook oook ok. 117.7hp lol. My point is that its not easy making horsepower on an all motor 2L. I'd like to make 150hp. That would make me happy. At least from what I've read, that's about the street limit on a L20B I think you can make 150 fairly easy. If you do a 2.3, you can make more. 1 Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 Yes a tight fit. You know that the 521 alternator uses an external alternator, correct? and that the 720 alternator has a built it regulator inside it? The 521 wiring needs to be changed slightly if you are running an internally regulated 720 alternator. Yeah they are internally regulated and I've done all the wiring bits to make it work correctly 1 Quote Link to comment
datzenmike Posted September 17, 2016 Report Share Posted September 17, 2016 Setting a 50% increase in stock HP goal is.... I don''t know... kind of... counter productive. A 150 hp L20B will not be as 'driveable' as a stock one. Sure, it will go like 150 hp when revved up but it wont start in the cold as well, won't idle as well, wont stop and go in traffic as well and, won't hot re-start as well. Now if you have a car that you only drive after work or weekends for fun then this isn't as big a deal but if you might drive daily and to work you want something more reliable and 'drive able'. If 150 hp is a goal, get an engine that does this all day long in stock configuration, like a KA24DE. Tons of low speed torque and lots of fun. Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 The 521 isn't my daily anymore. It was for a while and that's why I couldn't do anything with it until now. I was gonna save a FI engine swap for my 1972 Toyota Carina... when I finally drag that thing home lol. I wanted to keep my 521 oldskool cool. Ya know? Quote Link to comment
datzenmike Posted September 17, 2016 Report Share Posted September 17, 2016 Yes. !50 hp is extremely ambitious. Header, multiple carbs, really hairy cam, high compression, porting, large valves on and on.... Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 Well like I said, I'd be happy if I hit that. Im a little leery of cams over 1/2in of lift and more than 280* of duration. I'll do the headers, bike carbs and head work for sure, but we'll see what happens on the dyno. Quote Link to comment
banzai510(hainz) Posted September 17, 2016 Report Share Posted September 17, 2016 115 hp to the ground would be MAYBE realistic with a L20 Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 Well that's something like 130 flywheel about twice the L16... haha! Quote Link to comment
banzai510(hainz) Posted September 17, 2016 Report Share Posted September 17, 2016 stock 510 is like 65 hp. Seen a dual SU SSS L18 an that was 77hp to wheels.. L20 with dual Mikunis 100hp. So you figure the magic in another 30 hp on a L20 I seen a rebello LZ hybrid coil pack crank fire and guy paid 5k and got like 145 hp. Quote Link to comment
racerx Posted September 17, 2016 Report Share Posted September 17, 2016 Bajango, what is your budget? Quote Link to comment
bajango Posted September 17, 2016 Author Report Share Posted September 17, 2016 About $3k. I won't spend nearly that much since I work at a parts store and you wouldn't believe the upmark on parts. But if I wanted to get really stupid, I have the ability to spend $3k Quote Link to comment
datzenmike Posted September 17, 2016 Report Share Posted September 17, 2016 Byron's sheet. Thrown together LZ22, home made ITB EFI, mystery cam and springs. The year previous was with side drafts and was only 6hp lower. This is RWHP!!!!! You're looking at $1,000 to rebuild your engine, might as well get a larger block Quote Link to comment
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