S13/R32 Posted October 13, 2006 Report Share Posted October 13, 2006 (edited) umm, it will read less 4 sparks per rpm if set to an 8 cyl motor its expecting 8 sparks per rpm so your poopy k motor is doing 6000 rpm. this equals 400 sparks per second a v8 at 6000 rpm would produce 800 sparks per second therefore the tacho if hooked to poopy K motor but set to 8cyl will read 3000 rpm when real engine speed is 6000. sorry but no, lets set some reasons/rules to this rpm = one complete revolution where the crankshaft spins 360 degrees from the center of its axis stroke = where the pistion travels from etheir TDC (top dead center) to BDC (bottom dead center) this equates to half a revolution from the crankshaft now when we're talking about 4 stroke combustion engines there are 4 stroke, induction, compression, power and exhaust and since there is only one spark within those four stokes (ie power stroke), and there are 4 clylinders that means for every 'one' revolution of the crankshaft there is going to be 2 power (for a v8 there is 4 power stroke per revolution) now you could be a smart arse and say my mum 98 camry has 4 sparks per one revolution, yes cos it waste a spark, it has two coil packs, and when one of the packs fire for a power stoke, since its connected to 2 spark plug the other power is then fired on the clylinder thats on its exhaust stroke, therefore wasting a spark, but you couldn't care less cos park plugs to today aren't that expensive* and are far superia from plugs made say 10, 20 years ago (they last longer)(*unless your an idot that buys HKS plugs for $50 each which are really NGK plugs you could buy from autobarn or supacheap for less) Edited October 14, 2006 by S13/R32 Quote Link to comment Share on other sites More sharing options...
love ke70 Posted October 13, 2006 Report Share Posted October 13, 2006 you fail to make a point a tacho's needle moves depending on the number of pulses per second (or part there of) its getting. if you tell it to expect 8 sparks per revolution of the crankshaft (in the case of setting it to a V8) but only provide it 4 sparks per revolution (coz its connected to your poopy K motor(which has 4 cylinders incase you didnt know mr new guy who hasnt introduced himself)) so if the tacho is thinking to itself 8 sparks = one revolution the poopy K motor has to do 2 revolutions to create these 8 sparks, which means the tacho will read half the RPM the motor is actually doing.... Quote Link to comment Share on other sites More sharing options...
Trev Posted October 14, 2006 Author Report Share Posted October 14, 2006 umm, it will read less 4 sparks per rpm if set to an 8 cyl motor its expecting 8 sparks per rpm so your poopy k motor is doing 6000 rpm. this equals 400 sparks per second a v8 at 6000 rpm would produce 800 sparks per second therefore the tacho if hooked to poopy K motor but set to 8cyl will read 3000 rpm when real engine speed is 6000. I did it to my 3k and it worked. Quote Link to comment Share on other sites More sharing options...
S13/R32 Posted October 14, 2006 Report Share Posted October 14, 2006 no i agree if you set the tacho to v8 config it'll read less rpm my point is you won't get four sparks per revolution also i can see i've stuffed up in a 4cly you get 2 sparks per revolution (not 1 like i sed b4) v8 you'll 4 per revolution Quote Link to comment Share on other sites More sharing options...
love ke70 Posted October 14, 2006 Report Share Posted October 14, 2006 this is true. my mistake here i was trying to ignite the exhaust stroke :) hehe anyways, trev i don't see how it works Quote Link to comment Share on other sites More sharing options...
Trev Posted October 14, 2006 Author Report Share Posted October 14, 2006 this is true. my mistake here i was trying to ignite the exhaust stroke :)hehe anyways, trev i don't see how it works I'm confused now aswell as i did this 10year ago when i had my ke55 p/van (yes i was 11) i put a tacho in it and it idled at 3000rpm and been 11 i didnt take any notice and i was told it was wrong and to adjust the switch and when i did it went to 800rpm but tonight i got my monster tacho out of the cupboard and on idle on 4,6 & 8 it all stayed the same and i even switched it off between switch changes, maybe the tacho i had was for a boat or something. Quote Link to comment Share on other sites More sharing options...
irokin Posted October 14, 2006 Report Share Posted October 14, 2006 I think your tachos probably broken. It will be signifigantly different for 4, 6 & 8 Quote Link to comment Share on other sites More sharing options...
Trev Posted October 14, 2006 Author Report Share Posted October 14, 2006 I think your tachos probably broken. It will be signifigantly different for 4, 6 & 8 All i can do is shrug my shoulders and laugh, i will have a look another day :) Quote Link to comment Share on other sites More sharing options...
love ke70 Posted October 14, 2006 Report Share Posted October 14, 2006 :) :y: irokin and trev in the same thread and no one has thrown a cream bun yet!!!! WTFBBQ!!!! Quote Link to comment Share on other sites More sharing options...
Raven Posted October 14, 2006 Report Share Posted October 14, 2006 I bent a pushrod AND a valve in my 3k haha. Quote Link to comment Share on other sites More sharing options...
Super Jamie Posted October 15, 2006 Report Share Posted October 15, 2006 word is, the harmonics are such that regular runs over 8000rpm will crack the block. balancing will obviously help eliminate this honestly tho, i'd rather an engine with torque and a 7000rpm redline, than nothing down low and something you need to rev the tits off of to make power Quote Link to comment Share on other sites More sharing options...
love ke70 Posted October 15, 2006 Report Share Posted October 15, 2006 agreed most motors have a certain amount of torque they will produce, and you can just move this torque curve up or down depending on your cam. more revs just means more wear. rather than making an engine rev higher to go faster why not reduce the rolling diameter of your tires :) Quote Link to comment Share on other sites More sharing options...
Trev Posted October 15, 2006 Author Report Share Posted October 15, 2006 :):y: irokin and trev in the same thread and no one has thrown a cream bun yet!!!! WTFBBQ!!!! Were all mates here :y: Quote Link to comment Share on other sites More sharing options...
Brendo Posted October 15, 2006 Report Share Posted October 15, 2006 my 3k tops at 10000, i set limiter to 9000 but rarely rev it past 7800 or so as it does more bad than good. i be lucky to drive it once a month on the street tho its not very streetable, too hardcore lol cheers Quote Link to comment Share on other sites More sharing options...
toybox Posted October 20, 2006 Report Share Posted October 20, 2006 my old ke70 snaped a rod and put o hole in the block the size of a bundy can at about 8400 rpm at easterm creek race way but that was a bog stock motor my ke38 revs to 6500 no worries Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.