SEM600 Posted June 7, 2013 Report Share Posted June 7, 2013 I'm from the melbourne region of victoria and want to know if anyone has bored out a4k to take 5k standard replacement piston heads and toped it off with a ported 3k head? Also a good place i could find barnd new pistons and head for a good price. Quote Link to comment Share on other sites More sharing options...
luk3333 Posted June 7, 2013 Report Share Posted June 7, 2013 (edited) Pistons can be bought new from precisionintl.com . I believe it has been done successfully several times but there is concern about cylinder wall thickness as the 4k casts apparently don't have the bores centered as well as the 5k casts. It is suggested you have the block tested by the machinist to ensure you have enough wall thickness. Edited June 7, 2013 by luk3333 Quote Link to comment Share on other sites More sharing options...
altezzaclub Posted June 7, 2013 Report Share Posted June 7, 2013 I've heard quite a few people argue that the walls will be too thin, but I haven't heard from anyone who has done it and had the walls collapse. I HAVE heard of and from people who have done it successfully, and its on the list for whenever I need to rebore the 4K. Then again, I want the 1500cc torque rather than the ultimate high compression race engine, so mine won't get thrashed as much as some. The sonic testing costs about $100 and they measure the wall thicknesses up and down the bore, so you can offset the rebore a mm here or there to get an even wall thickness. ""my flat mate had a 4k bored out 2 1486cc using 1600 mazda turbo pistons, 5k head gasket, valve grind, and f13 cam. went prity good in a road car. not 2 sure what was dun 2 the head in regards 2 compretion ratio but i no its about 9.8;1 "" http://www.club-k.co...d.php?tid=14162 ""previous owner took the 64k 4K engine out of his Starlet, bored it out to 5K, put in new pistons, and used it for about 10K, then he ditched it for a 4AGE. "" http://www.club-k.co...d.php?tid=15972 ------------------------------------------------- ""my bro bored a 4k out to 5k (80.5) so it can be done. BUT you need the right block its a commercial block with siameze bores""""i had a 4k that was bored out to a 5k, completlely balanced, shot peened rods, 11.5:1 compression, lightened flywheel, ported head, 304 deg cam and a 32/36 webber as well as 2 1/2inc exhaust and extractors. it made 56 rwkw's and it revved to 8 (as far i felt safe to rev it)"" joeschmo_57 http://www.rollaclub...4k/page__st__30 Engine specs: Twin solex carbs double valve springs ported head extractors Bored out to fit 5k pistons Deburred block knife edged crank electronic ignition http://www.ae86drivi...rens-KE70-wagon ----------------------------------------------------------------------- ""na didnt have any block problems at all just had to use a 5k headgasket with it. thats all a 5k is, a bored out 4k really.... no problems and u really notice the extra torque. compared to a stock 4k it putts along quite nicely and my mate refered to mine as " it goes like a 4age "" --------------------------------- The 9000rpm 4AGE head 4K- ""Block Sonic tested Bores repositioned and overbored by 6mm"" ----------------------------------- Couple of Club-K have worked http://www.club-k.co...d.php?tid=22491 Quote Link to comment Share on other sites More sharing options...
SEM600 Posted June 8, 2013 Author Report Share Posted June 8, 2013 Sweet thanks Quote Link to comment Share on other sites More sharing options...
philbey Posted June 8, 2013 Report Share Posted June 8, 2013 But it would be cheaper and easier just to drop a 5k in and get the engineering done. 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.