Sharpie Posted December 13, 2002 Share Posted December 13, 2002 Did you know that the FAQ's on mkiv.com is now working ? http://www.mkiv.com/faq/index.html NEW - http://www.mkiv.com/faq/acronyms.htm - NEW Just found this posted from Gavin which, is very nice http://mkiv.com/tmp/ Supraforums: http://www.supraforums.com/forum/forumdisplay.php?s=&forumid=61 I-supra http://www.i-supra.com/6/ubb.x?a=frm&s=154607117&f=9126041111 Supra Nz site http://www.mkiv.co.nz/techo.htm Oz Supra site http://www.ozsupra.qld.org/web/faq/faq.htm And do not forget http://www.mkivsupra.net/resources/technical.html Quote Link to comment Share on other sites More sharing options...
Druid Posted December 13, 2002 Share Posted December 13, 2002 They have been working for some time now Quote Link to comment Share on other sites More sharing options...
Sharpie Posted December 13, 2002 Author Share Posted December 13, 2002 I had stopped trying this link since April as it had stopped. It's helpful to the new guy's & me! Quote Link to comment Share on other sites More sharing options...
Druid Posted December 13, 2002 Share Posted December 13, 2002 It def. is. Never seases to amaze me how much info on the MKIV is readily available. Quote Link to comment Share on other sites More sharing options...
Adam_SG Posted December 13, 2002 Share Posted December 13, 2002 That is a shed load of info. Cheers m8 never knew it was there. Ad. Quote Link to comment Share on other sites More sharing options...
SMW Posted December 14, 2002 Share Posted December 14, 2002 Thanks Peter This will keep me occupied for a few hours:) Quote Link to comment Share on other sites More sharing options...
Steve W Posted December 14, 2002 Share Posted December 14, 2002 Just out of interest WHERE/WHO did all this info come from ? ? The bit that interests me is where it says the mkIV has a NON- Interference engine ! ! There are VERY few modern engines that are non-interference. THAT MEANING: if the timing belt breaks NONE of the valves will touch ANY of the pistons regardless of position or how many times the engine turns over after it's broken. ie. YES, you should get the belt(*) changed when recommended to avoid breaking-down in the middle-of-nowhere.... but, NO, it won't cause any major engine damage, and, providing an EXPERT replaces the belt (ie. times it up right - cams/pulley etc) it will just start/run/and carry on as normal ? ! ? (* AND tensioner ! !) The problem is, that to make an engine NON-interference, by default the valves cannot open so far that they could touch the piston crowns. This means LOW-LIFT cams = LOW power ! ! (OR, very low compression pistons that can't 'reach' the valves) LOVELY if we have a really powerful engine which won't self-destruct when the belt goes:thumbs: [ we've discussed this before in other threads, but NO-ONE was willing to say YES or NO ? ? ] ANYONE know wether it IS or NOT and WHERE's the facts ? ? MORE to the point - anyone had a belt actually BREAK ? We'd know once and for all then.... (it either DID, or it DIDN'T....THAT person would know ! as long as the repair garage didn't lie:sly: ) FatS. Quote Link to comment Share on other sites More sharing options...
Druid Posted December 14, 2002 Share Posted December 14, 2002 As far as I know, ALL recent toyota blocks are non-interference, which is part of what makes those blocks so damn good (especially the 3S-G(T)E and the 1/2 JZG(T)E). A somewhat shady list can be found here, a better list is this pdf. Non-interference engines simply have more clearance between valves and pistons than interference engines. This still allows high lift. Quote Link to comment Share on other sites More sharing options...
Steve W Posted December 14, 2002 Share Posted December 14, 2002 Non-interference engines simply have more clearance between valves and pistons than interference engines. This still allows high lift. You either need Low-Lift valves, OR, Low compression (ie. large combustion chamber). You can't have a small combustion chamber + High-Lift Valves and still have a NON-interference engine ? EVERY modern car we deal with that's had a belt 'gone' has got bent valves ! !:- ALL diesels (Pug/Ford/Vauxhall/Renault....) [the last diesel that sometimes didn't do valves was the Ford 2.5Di - that bent pushrods and sometimes the rockers] The last petrol that didn't was the Ford Pinto 2.0 (even the 1.6 tended to clip the valves) All new engines: Rover K-series, Ford ZETEC/DURATECH, Vauxhall Ecotech (ESPECIALLY the 2.5/3.0 v6's ! ! = ALL 24valves !) THEY ALL BEND VALVES in a BIG WAY..... I'm not saying it's NOT a N/I engine.....just want to know FOR SURE ! FatS. Quote Link to comment Share on other sites More sharing options...
Druid Posted December 15, 2002 Share Posted December 15, 2002 Diesel engines have very high compression ratios and it's therefor pretty much impossible to have a non-interference diesel... too little space between the head and the pistons. However, I think you should never rely on NI to save your ass... just replace your belts (instead of letting 'em snap) and you'll be safe. The stock supra block is NI, but obviously you can turn it into an interference engine by adding very high lift cams. Quote Link to comment Share on other sites More sharing options...
Steve W Posted December 15, 2002 Share Posted December 15, 2002 .......to save your ass...just replace your belts ..... Of course..... and, mine's rather a large ASS to save ! ! Quote Link to comment Share on other sites More sharing options...
Digsy Posted January 8, 2003 Share Posted January 8, 2003 There was a lengthy thread about this a while back. I was as gobsmacked as you, Steve. I don't know about other Toyota engines, but apparently some guy in the states took one apart and deduced that it was non-interference. Quote Link to comment Share on other sites More sharing options...
Gaz Walker Posted January 9, 2003 Share Posted January 9, 2003 Well, thats the second thing I've learned today. Knock me down with a feather. Gaz. Quote Link to comment Share on other sites More sharing options...
Supra Pilot Posted January 9, 2003 Share Posted January 9, 2003 I agree for the TT it is Ni, but for N/A's with higher compression ratio it may not be the case..... (IMHO) Dom Quote Link to comment Share on other sites More sharing options...
Terminator Posted January 9, 2003 Share Posted January 9, 2003 Having had the head of several MKIV's, in breakers yards, one engine with no belt, but can't be sure if the bottom end was still turning when the belt came off. I have not seen any signs of contact in the piston indentations. With pistons at DTC there was no contact when the cams were turned on stock valves on a Jap spec 94 engine. Still not worth not changing the belt, to put this theory to the test on the road. Quote Link to comment Share on other sites More sharing options...
400BHP Posted June 7, 2003 Share Posted June 7, 2003 I dont know if its the same on a supra because I have not had a close inspection but there is a really easy way to change your timing belt without the need for re-timing. All you do is remove all the plugs and cam cover, get a sharp stanley knife and push it into the belt in the middle, NOT acrossways, along its length, then either turn the engine over by hand on the crank pulley bolt (best to get a mate to do this) or if you have a steady hand, crank the engine in short bursts (mate here would be useful) Until you have cut the belt completely into two seperate "belts" that are still on the pulleys, pull the front half off, and put the new belt on, cut off the other half and push the new belt all the way on, job done! It definately works cos i've done it on several cars, and it saves a shedload of time and hassle. chris Quote Link to comment Share on other sites More sharing options...
Steve W Posted June 7, 2003 Share Posted June 7, 2003 Unfortunately, you have to get the Crank' pulley off to get the old belt off (and new belt on!) the Ancillary belt pulley completely masks the crank 'cog' so.... ....OFF IT COMES, I'm afraid ! ! Quote Link to comment Share on other sites More sharing options...
Sharpie Posted June 23, 2004 Author Share Posted June 23, 2004 Links updated and a new one added. 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.
Note: Your post will require moderator approval before it will be visible.