Charlie02 Posted August 17, 2020 Share Posted August 17, 2020 Hi im currently building up the head in my na starlet. I’ve had 0.25 mm skimmed off the head and I’m going to be fitting a 0.5 mm head gasket from ID workz. I’m wondering if there is any difference in cam shafts + valve springs between the 4efe head and the 4efte head. I’ve read up a lot of threads but some people claim that there is no differences and others claim there is. mid like to get some information on this before I put the engine back together! Quote Link to post Share on other sites
Sam44 Posted August 17, 2020 Share Posted August 17, 2020 (edited) Hello. The 4efte has stronger valve springs due to its lighter pistons giving it a higher capable redline rev limmit, but these do improve proformance, gives much better valve seal. Na valve springs start to dance (wobble) around 6krpm. The 4efte also has a higher lift inlet cam giving better higher end torque output. (Increased valve overlap and lift). Hope this helps. Another great mod is to clean up the valve bowl, port cleaning up the tooling marks and lips left from the production line process. These tooling marks are like ridges really bad and just behind the valve head. There's also the lip on the outside edge of the inlet valve in the combustion chamber this stops the valves outer circumference from flowing till around 1mm lift. I'll put up some pictures. Edited August 17, 2020 by Sam44 Quote Link to post Share on other sites
Charlie02 Posted August 17, 2020 Author Share Posted August 17, 2020 Ok perfect that’s really helpful! I was going to put turbo valve springs into it but found mixed information on them! do you know the best place to get the valve springs from ? Only seem to find aftermarket ones for like 200 quid Quote Link to post Share on other sites
Sam44 Posted August 17, 2020 Share Posted August 17, 2020 There are afew different springs used I've heard of Yaris springs, VW polo springs and nissan rb springs. But I've not used any of these so hopefully others can add alittle information here. I'm running a set of cat camshaft springs in the 4efe I have which I got already installed. Quote Link to post Share on other sites
Charlie02 Posted August 18, 2020 Author Share Posted August 18, 2020 Ahh right fair play man !! I’m trying to get a better exhaust manifold as well but they seem to be gold dust !! Quote Link to post Share on other sites
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.