staynspray Posted October 8, 2008 Report Share Posted October 8, 2008 Hello does any one know the weight for 4 k pistions?? and i was wondering how much skirt you could take off it before the become unrelable (standed pistions only) and all so has any one tryed grinding there own cam ? i have a spare and the way i figer why pay some one else to do it when i can learn by stuffing it up and trying a difent appproch and learn a bit more plus if i stuff it up it will only reck my valve train i got spares but no money (2 kids and wife) and all most got a launch control hooked up i just need to find some thing that turns 12v 32a pulse (form points) in to a growing frequent voltage the put a varable ristor to a relay to cut the point going to the coil so if any one has any ideas plz help out Quote Link to comment Share on other sites More sharing options...
towe001 Posted October 8, 2008 Report Share Posted October 8, 2008 and all so has any one tryed grinding there own cam ? i have a spare and the way i figer why pay some one else to do it when i can learn by stuffing it up and trying a difent appproch and learn a bit more plus if i stuff it up it will only reck my valve train i got spares but no money (2 kids and wife) and all most got a launch control hooked up i just need to find some thing that turns 12v 32a pulse (form points) in to a growing frequent voltage the put a varable ristor to a relay to cut the point going to the coil so if any one has any ideas plz help out Its called a metal lathe A pretty specialized one at that If your still want to have go at cutting your own cam i'd suggest selling the wife and/or kids But on that note it could be done, but at the same time..... Quote Link to comment Share on other sites More sharing options...
SLO-030 Posted October 9, 2008 Report Share Posted October 9, 2008 It sounds like your looking for performace here. may i suggest you use 3k pistons.AFAIK they are apparently better than the 4k pistons as they are made by Toyota not by repco (4k pistons) and less likely to crack. I have a set of 3k pistons of your keen. Quote Link to comment Share on other sites More sharing options...
staynspray Posted October 9, 2008 Author Report Share Posted October 9, 2008 It sounds like your looking for performace here. may i suggest you use 3k pistons.AFAIK they are apparently better than the 4k pistons as they are made by Toyota not by repco (4k pistons) and less likely to crack. I have a set of 3k pistons of your keen. its all right thank you any ways i was just thinking of ways to free up a bit of easy power i don't mid if they crack gives me some thig to fix any one have any ideas on some thing that will convert a pulse in to a rising voltage as it pulses more (ps tryed to sell the kids and wife nz extange rate not that good at the mo lol pls she would beat me ) Quote Link to comment Share on other sites More sharing options...
DearmanKE Posted October 10, 2008 Report Share Posted October 10, 2008 pls she would beat me ) ahahah Quote Link to comment Share on other sites More sharing options...
philbey Posted October 10, 2008 Report Share Posted October 10, 2008 Man, I'm pretty interested how you're going to grind your cam at home, you can't do it with a lathe you need a cam grinder. OR.. I've got a mate with a 4 axis CNC Mill that he can fit a grinding head too, but that took him 18 months to convert it to CNC and he had a 2 tonne Cincinnatti Mill to convert to begin with. That only gets halfway too, you still need to calculate your cam acceleration profile and model and program the mill. As for your skirts, what are you trying to get by shortening them? Less moving mass? taking them off will reduce the rotating mass bugger all if you consider the crank, rod and piston crown are all significantly more massive than the skirt. Quote Link to comment Share on other sites More sharing options...
snot35 Posted October 10, 2008 Report Share Posted October 10, 2008 (edited) You also need a pretty good surface finish on a cam. If you don't get these surfaces and treatments right the motor will be junk pretty quickly. You'd want a lot of spares, and would want to love changing over heads! Usually cams are ground using a grinding wheel that follows an eccentric blank that moves the wheel as it's rotated. Ramp rates and lift are also quite important. If you're interested, hunt down a copy of a book like Four stroke performance tuning, by A. Graham Bell. You could go OK lightening the pistons a little, but I don't think I'd get too carried away. 3K pistons would be a better start. You could also lighten rockers and definitely look into porting if you haven't already. Balancing is always good as well. I don't know where to start with the launch control. It would be a pretty harsh way to do it, cutting ignition at a particular revs. One thing you could explore is some of the kits available from jaycar.com.au. They have high energy kits and one that I can recall had a box so that you could program advance. You could possibly play with the advance as a form of launch control? That's definitely a big project though. If you're on a budget and have heaps of spares, I'd be playing with porting and lightening both fixed and rotating components. Have fun! Edited October 10, 2008 by snot35 Quote Link to comment Share on other sites More sharing options...
orangeLJ Posted October 10, 2008 Report Share Posted October 10, 2008 As said, grinding your own cams would be a pretty worthless project without the right gear. Even if by chance you managed to work something out, keeping the ramp and duration the same between lobs would be a killer. For the cost of a cam grind, I think you will find it is well worth it. Even new billet cams are only a couple hundred dollars. (was $440 for a pair of cams for a 4AGE) Quote Link to comment Share on other sites More sharing options...
staynspray Posted October 10, 2008 Author Report Share Posted October 10, 2008 well i don't think i try grinding my own cam lol yeah i think the launch control going to hash on my coil and points but it will be fun and all so allow you to quick shift through the gears as well by running it to a switch on the clutch pedle Quote Link to comment Share on other sites More sharing options...
staynspray Posted October 10, 2008 Author Report Share Posted October 10, 2008 oh and all so does any one have plans for a msd system or a cdi ?? Quote Link to comment Share on other sites More sharing options...
towe001 Posted October 11, 2008 Report Share Posted October 11, 2008 cam grinder. Thats the word i was trying to think of, all that was going though my head was metal lathe. As with the lunch control. If i remember right the programmable ignition by Silicon Chip magazine has something similar with its rev limiter where it cuts, something like, every second or third spark. I think Autospeed.com had an article on it on a DIY launch control thing. But the down side to having a lunch control a carby car is that you'll be dumping raw fuel down the exhaust. Most launch/traction control units operate on EFI - instead of the spark cutting out its the injectors that cut out much safer and engine friendly MegaSquirt Forum might have something worth while Quote Link to comment Share on other sites More sharing options...
staynspray Posted October 11, 2008 Author Report Share Posted October 11, 2008 yeah i know about dumping fuel in to the exaust use to have an fxgt 4age with a gizmo launch control it use to cut the spark only you would get the mad back fires (had no cat and one muffler) thats part of the fun lol so does any one know know what would change pules in to a rising voltage?? Quote Link to comment Share on other sites More sharing options...
staynspray Posted October 13, 2008 Author Report Share Posted October 13, 2008 hey found info on cdi here it is CDI.pdf 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.