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Tom1200

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About Tom1200

  • Rank
    Advanced Member

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  • Location
    Las Vegas
  • Cars
    Datsun 1200 coupe
  • Interests
    Vintage racing, rally , vintage motocross, riding my Beta 520RS
  1. Tom1200

    Nissan a14 motor reaching 100kw

    So here are some options to get the compression up. Custom pistons; this is what I did. $600 for forged JE pistons with rings. The standard A15 pistons come in a 6cc and 10cc dish and the head gaskets standard have a 1.2mm crush thickness. You can get a GX head gasket with a .8 crush thickness and a Nismo one with .6 crush thickness. Both available on EBay. Bprojects is on EBay (there a Japanese company that specializes in A-series stuff for Sunny models) You could get 6cc dish pistons and the thinnest gasket, I believe that will take you to 10-1 compression or close to it. Honda pistons come in 76mm with flat tops / near flat tops; I can't remember if it's the D15 or B16 but you can look it up on the Internet. They Honda piston uses the same 19mm pin as the Datsun. You can use Mazda MX-5 / Miata 78mm pistons, the small end of the rods will need to bore to 20mm and the piston tops milled flat. The issue with this solution is the compression ratio may be rather high for a street car. I don't know what head you're using, they vary from 29cc to 32cc combustion chambers and you would need to use one of those online compression ratio calculators. DO NOT, DO NOT mill the head to get the compression up; this causes all sorts of issues with push rod lengths and rocker arm geometry. One of my cylinder heads has had 2mm milled off it and due to that I've had to fly cut deep notches into the forged pistons as well as make shims for the rocker shaft pedestals, as well as mill some of the pedestals. I have to mix and match the modified parts to get everything correct when every I fit different cams. It was a pain to sort, luckily I have a machinist friend who's able to make these little custom bits. It's one thing to do it for a race car but quite another for a street car.
  2. Tom1200

    Nissan a14 motor reaching 100kw

    Pierre you will not be able to use the A14 pistons with the A15 crank because the pistons will be sticking up 2.5mm above the deck. Not the previously mentioned piston pin heights, due to the 5mm longer stroke of the A15 Nissan decreased the piston pin height 2.5mm. You can mill the A14 piston down of course but that would likely lead to piston failure.
  3. Tom1200

    Nissan a14 motor reaching 100kw

    The A15 and A14 use the same block with a deck height of 204.1mm, the A14 uses a 77mm stroke with a piston pin height of 32.5mm and the A15 uses a 82mm stroke with a 30mm pin height. They both use a 76mm bore. As to the original question first I will share this; my so called race motor makes 99hp at the wheels. It uses a ported GX head with 39mm flatslide carbs, 278 cam, headers with 2 inch exhaust and 11.90-1 compression. It's streetable but uses 100 octane fuel. While the motor will run at any RPM it's happiest above 4500rpm and doesn't really make power until 5500 rpm. Realistically 110hp at wheels is probably the turning point. A b140 makes all of 80hp at the crank stock (55-60 at the wheels?) so getting one up to 85-90 at the wheels is a huge improvement.
  4. Tom1200

    280zx front coil over caliper facing front or back?

    Krafor, the spacers can be used regardless of ride height. You can measure the ride height and then reset it after installing the spacers. While you indeed swap the struts side to side, the brake lines on your car now may not be the correct length and or have routing issues. Dependent on what size wheels you have you could also run into clearance problems Swapping the struts from one side to the other seems like a lot of work just to avoid using spacers. I do one of two things to fix it. A. Use the spacers even if I didn't like the look of them. B. Just change the pads more often. If you're only having to change them once a year or ever other year it's not a big deal. I'm cheap and lazy so I'd go with option A. Note there is no wrong answer if at the end of the day you're happy with it.
  5. Tom1200

    Suzuki GSX-R carbs on A-series???

    On my car the velocity stacks are close to the hood. When the A15 goes back in I will likely have the dry sump system done so the motor will be sitting close to 2" lower which may allow me to get a proper air box on it.
  6. Tom1200

    Suzuki GSX-R carbs on A-series???

    My car actually uses fuel filler hose to mount the carbs to the manifold. On the surface it seems a bit cheesy but the set up came off a RunOffs winning sports racer so it's good enough for me. The filler house actually allows for a little bit of adjustment. Now as for that video; why are they lugging motor??? A-series motors make a very distinct sound above 8000 rpm, sort of a high pitched screech..........this is how I know to shift. At 9,000 it sounds like the rods are going to fly out the block. The motor in the video sounds like it's in the low to mid 7s. I suck at posting pictures but here's a link to my set up. http://datsun1200.com/modules/myalbum/photo.php?lid=26124
  7. Tom1200

    Best battery for a B210???

    In my 1200 I'm using a group 51 Honda Civic battery, a Miata battery would work as well. My motor has 11.89 compression and the battery has no problem firing up the motor. Also note the flat slide carbs on my car have no choke so a I have to crank the motor more than you would on a street car. As for brand I have an Autozone battery because here in the desert batteries don't last more than 3-4 years. I always preferred Interstate and had good luck with them, I was managing to get 5 years out of them. I was also getting them at a discount.
  8. Tom1200

    Suzuki GSX-R carbs on A-series???

    This will break your heart, I got mine with the manifold for $250! If you shop around carefully you can find them for the same price you'd pay for Mikunis. You have to look around on various bike sites. The smaller sizes, 39mm, can be found for a lot less, I've seen them as low as $500 but you're more likely to pay $750 to $1,200. Like anything you need to shop around. Nothing should make you shy away from a used set, they are simply but absolute works of art. The FCR carbs flow more than DCOE style carbs mainly due to the lack of a throttle shaft (8-10mm restriction). Even if you spend $600 more they make enough power to justify buying them. My otherwise standard A12GX motor with the only change being the Keihin carbs made 73whp. That is 18hp more than the SSS (DCOE carbs) motor done in New Zealand and the twin carb standard GX motor. The D-Sports Racer guy I got the carbs from said the made an instant 12hp increase on there race A13. Also a big plus for left hand drive cars is you don't have to move the brake master like you do if you wish to install a pair of DCOE style carbs. They only knock I will give them is you need to run pod filters on the street or fab up a custom air box. The motor will make more power with a proper air box.
  9. Tom1200

    Suzuki GSX-R carbs on A-series???

    I've run 39mm Keihin flat slides exactly like the ones pictured above. They are awesome, the only thing with bike carbs is you need very low fuel pressure (no more than 2psi). I had been running an A15 in my car but the A12 in my car now. It's just a matter of jetting. Camshafts can have a unexpected jetting change. If the cam has a lot of overlap you'll end up going leaner on the pilot jet regardless of engine displacement. If you do get bike carbs get the airbox as well. You will need to come up with a custom manifold, go to Datsun1200.com for that as there are several different set ups that people have done. I wa lucky in that the custom manifold came with the carbs. A final word on the Keihin FCR flat slide carbs; if someone tells you that your going to have flat spots or they won't work well at low RPMs, they don't know what they are taking about. My Beta dual sport bike uses the same carb and both it and the 1200 work flawlessly.
  10. Tom1200

    1.4L race motor needs more ...

    My car would be right on 1525lbs without the cage. Over the years we've added to the cage and it's between 125-130lbs. My car is a bit of a porker, it's 1787 with me in it (I'm 140lbs). It's a lot of little things that add up. The A15 is 12lbs more than the A12, the 60 series or 63 series transmission will add 16lbs, the upgraded rear end is an extra 15lbs, the ZX struts and brakes are boat anchors that add at least 20lbs. My car is also still all steel panels and that's an extra 16lbs. I'll be taking another 50-60lbs out of the car by going to a LiPo battery redoing the exhaust as well as milling out some non critical items. Using an ITC spec cage kit would likely add 100lbs to a 210 so I'd plan on around 1750 to 1800lbs but if your not being held to SCCA rules you could likely get it closer to the low 1700s. While I whine about the 510s and BMW 2002s blowing past me down the straights, I really enjoy the nimbleness of an A-series powered car. Even if I built an all out motor I'd still be 5-8% down on power. I'm willing to give that up beciase you can absolutely drive the wheels off the A-series powered cars, if you ever seen me drive mine or the videos I sometimes post you know what I mean. The cars remind me of my my days club racing a 125GP bike, you had to be on it every inch of every lap and that's what makes them fun. I also have a Formula 500 I use as an autocross car that I could take to vintage races, while its fast it lacks the hooligan factor that I enjoy in small bore coupes.
  11. Tom1200

    1.4L race motor needs more ...

    The largest bore you can get with an A-series motor is 79mm and consequently the largest valves you can fit are 40mm intake and 34mm exhaust. The larger bore of the L series allows you to stuff bigger valves in it. There was a fellow who managed 200hp at the flywheel with an A-series engine but you'd be rebuilding the engine after every race to keep it from coming apart. For vintage B Sedan there are some possible advantages a 1300cc A series car is allowed to weigh 1300lbs. The 500-600lbs won't make up for the 50 horsepower deficit but on low to medium speed tracks. I can tell you from experience (following Lotus 7s) that a 1300lb car is good for 3-5mph in every corner versus my 1640lb car, so it would be quite possible to build a big gap to 1900-2100lb 510s in the twisty bits that they wouldn't be able to claw back on the straights. 210s like Tim has are a bit porky but they have more in them than a 1200 so there is quite a bit of weight that can be pulled out of a 210. It's been a long time but I think you can get them down to 1700lbs.
  12. Tom1200

    1.4L race motor needs more ...

    I can't speak for Tim but in my case vintage racing rules are such that I could go to an L-series motor as the PB110 came with an L14. Like tune for like tune L-18 and A15 are roughly 20hp apart. The L18 motor and gearbox will add about 130lbs to an A-series car, granted the weight only equals about 5-6hp. It also changes the handling a bit. You can close the gap with the A-series which can be bored to 1600cc and if you install an E16 crank that will take it out to 1700cc. A 1600cc motor is easily and cheaply attained using Mazda pistons. The 1700 motor requires machine the E16 crank, custom pistons or rods, so not cheap. The A15/16 can be brought up to 10-12hp of the L18, that coupled with the weight difference would get a car close.
  13. Tom1200

    1.4L race motor needs more ...

    To get the most out of A -series engines you have to rev the snot out of them and winding them to 9K doesn't do much for piston ring life. You can get decent power out of them and engine life if you keep them to 7800-8000 rpm. As I've mentioned in various posts my A15 did a whopping 99whp but I'm still running the standard 37/30mm valves and a pretty moderate cam. There is likely another 10-15 horsepower to be had without reducing the engine life. I run motors for ridculous amounts of time, if one were willing to go through their motor more frequently them my every 5 seasons standard, going to a 10-15 race rebuild schedule would probably make 125-130whp possible. The other limiting factor is the gearbox. The 60 series 5 speed is strong enough but the ratios suck, unlike L series powered cars where you can find a 280ZX box with decent ratios, the only cheap alternative is to use ultra low gearing (4.88 -5.12) so that you only use 3rd, 4th and 5th gear. I can't remember who off the top of my head but Kameri, Tomei or someone else in Japan was talking about making a closer 2nd 3rd gear set but it's been at least a year since I've heard anything new on this front. My cheap gearbox solution is to use a 63 series 5 speed and search for the alternate second gear from a Z-series 200sx. I have the gearbox and believe I've found the second gear. The problem this option is the parts are not readily available. This combo will give you a mid-close box. The not so cheap but not $4000.00 alternative is adapting a Ford type 9 5 speed as close ratio gear sets for those are $750-$900. The type 9 box can be had for $500-$600, you need an A-series auto bellhousing (I think I paid $50 for mine). This option may be possible for as little as $1500 but more likely will be $2000. FYI the $4000 was derived by taking the $1000 to get a Toyota T-50 5 speed and adapter and $3000 for a gearset from Housman. The powerband on the 99whp wonder is such that it only drops 3-4hp from 8k to 7k and only loses another 4-5 to 6200 rpm but by the time it gets down to 5600 it's dropped down to 78. The gear ratios are such in the stock boxes that the motor drops 2900 rpm between 2nd and 3rd. Much like Tim's Grandson is experiencing, I too feel the pain of being out accelerated but much like Tim I'm not willing to spend crazy money. As noted above a race box is $4,000 and a professionally built motor can easily be $10,000. An extra 14k to go from 5-9th overall to 3rd-5th overall is just crazy. Even my Ego has tough time justifying that.
  14. Tom1200

    1.4L race motor needs more ...

    Tim I've always used bronze guides, they are $4-$5 or so. Other guys may use something different but I'm revving the motor to 8200 and they've never given me an issue. My one cylinder head had 50 events on it, the head gasket popped but the guides still appear to be fine. The springs I have are used, I have the retainers as well so I'm thinking $75.
  15. Tom1200

    1.4L race motor needs more ...

    Tim I have a spare set of Isky double valve springs with retainers that I'd sell cheap. With that said you can get them brand new from Isky I think they run around $100-150. As for valve guides you can still get them from Rockauto.
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