Mitch-12 Posted October 14, 2011 Report Share Posted October 14, 2011 hey ive been looking around to try and find oversize valves for 4k all i can find so far is that gemini apparently can be put in and some type of laser anyone here know any bigger valves to fit 4k head and what springs are you guys using with bigger cams? Quote Link to comment Share on other sites More sharing options...
Evan G Posted October 14, 2011 Report Share Posted October 14, 2011 (edited) take it to a machinist! you will need new seats to suit the bigger valves and possibly bigger/smaller valve guides to suit. how about valve retainers/springs? will the head be ported? crow cam double valve springs p/n 4220 $90 a set. .500" max lift before they bind Edited October 14, 2011 by Evan G Quote Link to comment Share on other sites More sharing options...
Mitch-12 Posted October 14, 2011 Author Report Share Posted October 14, 2011 its 7k mani s/c and ported like all F talking to my machinest today said maybe we can go a little bit bigger and use stock seats and thanks for letting me know about the crow stuff. Quote Link to comment Share on other sites More sharing options...
Mitch-12 Posted October 14, 2011 Author Report Share Posted October 14, 2011 does anyone do titanium retainers? Quote Link to comment Share on other sites More sharing options...
kickn5k Posted October 14, 2011 Report Share Posted October 14, 2011 crow cam double valve springs p/n 4220 $90 a set. .500" max lift before they bind I don't believe they have enough seat or nose pressure for a big boost/big cam application. My old setup required 90-100lb at installed height and 240ish lb at nose of cam. Stu. Quote Link to comment Share on other sites More sharing options...
Mitch-12 Posted October 14, 2011 Author Report Share Posted October 14, 2011 what springs did you use kickn5k? Quote Link to comment Share on other sites More sharing options...
Evan G Posted October 14, 2011 Report Share Posted October 14, 2011 theres another valve spring they make i think its the 3880. single with a helper strip with max lift of .480 Quote Link to comment Share on other sites More sharing options...
Mitch-12 Posted October 14, 2011 Author Report Share Posted October 14, 2011 ill choose a cam then get springs to suit with around 50thou before bind on max lift Quote Link to comment Share on other sites More sharing options...
kickn5k Posted October 14, 2011 Report Share Posted October 14, 2011 what springs did you use kickn5k? I used the crow 60lb at installed height springs. Even though they are not what the cam guy wanted me to use they were closer than the 40lb STD spring. I also had them. Stu. Quote Link to comment Share on other sites More sharing options...
Figjam14 Posted October 14, 2011 Report Share Posted October 14, 2011 i use some sort of commadore spring? think its maybe vn.. not sure Quote Link to comment Share on other sites More sharing options...
Evan G Posted October 14, 2011 Report Share Posted October 14, 2011 holden 202 springs will fit vn or any 3.8L commo will NOT fit. i have pics to prove this Quote Link to comment Share on other sites More sharing options...
kickn5k Posted October 15, 2011 Report Share Posted October 15, 2011 holden 202 springs will fit vn or any 3.8L commo will NOT fit. i have pics to prove this Don't forget Evan Holden did make a 5ltr V8. I'll have to check over some measurements. They were the closest I could find to fit from memory. They are a bit bigger in diameter and 3/4mm taller in installed height. But that's an easy fix if you've got the head at machine shop getting bigger valves fitted. Mitch what boost is your thing running again? You'll need to factor that into your spring pressure choice. Stu. Quote Link to comment Share on other sites More sharing options...
Mitch-12 Posted October 16, 2011 Author Report Share Posted October 16, 2011 12psi :) now tuned on E85 with 130hp not bad for stock cam Quote Link to comment Share on other sites More sharing options...
tunsafun321 Posted October 16, 2011 Report Share Posted October 16, 2011 nason engine parts had a special a while ago on some OS valves... i bought a set for like 20 bucks. i can't remember part numbers but i think they were gemini ones??? if you can find a parts store that deals with nason (repco, autopro etc) they should be able to call them and get the info. upon a quick search part no's could have been GEMEX2144 and GEMIN2143, probs best not to quote me on that though Quote Link to comment Share on other sites More sharing options...
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