raff_gsr Posted November 30, 2007 Report Share Posted November 30, 2007 well as the story goes, ive got a ke30, wanted to put my 4G63 VR4 motor in it but found out it would be more hassle than it was worth so decided to go down the k engined route. ok now basically atm ive got a ke30 sitting at home with a 3k i'll rip out and ive since been collecting parts to build my hot k motor. So far at home ive got a set of 4AGE pistons (81mm diameter, 18mm grudgin pin diameter), two DCOE sidedraught 40 webers and 4k Main bearings (which I'm assuming fit a 5k crank but if they don't i'll cry!) firstly, should i go 5 or 7k? i know they share the same bore and its the stroke that makes them different capacity wise, but the engines, although similar are different. I was thinking about getting a 5k block and running a 7k crank, this along with the 4age pistons and rods, as to negate the need to deck the block later (if i was to use the 5k crank). Also, i know that certain 4AGE rods have a 20mm upper diameter and a 42mm large end diameter (actually I think, I'm probably wrong), and the 5k crank shares a 42mm diameter, but the pistons I have are 18mm upper diameter which would mean i would have to use the 40 mm big end rods. question is, can the crank be machined to fit these rods or am i screwed and have to throw away the pistons? Now i want to run real high compression on this engine, so I will probably go for a 4k head and shave her down a little bit to bump up the compression; should i ceramic coat my pistons? and how hard can I rev the thing without the block splitting (ive heard 8 but i want to rev higher if I can :lol: ) anyway thats all my issues for the time being! thanks for the help in advance! Quote Link to comment Share on other sites More sharing options...
ancullen Posted November 30, 2007 Report Share Posted November 30, 2007 You're right about the diameters of each end of the rods. Basically it seems that you'll have to get pistons and rods from a later version of the 4A-GE. You've got the first generation (three rib block) pistons, and they're the ONLY ones that won't work for your application. Sorry. :lol: Quote Link to comment Share on other sites More sharing options...
raff_gsr Posted November 30, 2007 Author Report Share Posted November 30, 2007 see now these don't work because of the diameter at the big end correct? ive been pondering over getting the early rods with the 40mm big end diameter and machining down the crank to make it 40mm. can this be done and how badly will it effect reliability? Quote Link to comment Share on other sites More sharing options...
Rollaboy2608 Posted November 30, 2007 Report Share Posted November 30, 2007 it can be done, but seems like a lot of effort and money when you should be able to get something tougher without modifying the crank Quote Link to comment Share on other sites More sharing options...
raff_gsr Posted November 30, 2007 Author Report Share Posted November 30, 2007 machining isnt a problem for me cos my uncle owns a mechanics workshop and his mate will do it really cheap for me (obviously id have to ask of course how hard it is first haha). thing is ive spent the cash on the pistons now so I'm sorta stuck with them. a big worry at the moment for me is this notion of the block splitting at high revs. can anyone shed some light on this? Quote Link to comment Share on other sites More sharing options...
camerondownunder88 Posted November 30, 2007 Report Share Posted November 30, 2007 Hi, You will need later model 4age pistons with the 20mm pin as the big end on the rod needs to fit. I have never herd of a crank being machined down to size so as a machine shop. Also will rev past 8 if balanced. My local cam shops does grinds for K motors that go to 10,000RPM and has them on the shelf so Will go pas 8 with a balance. You will need harder valve springs to do this as most re grind cams run 0.400 thou lift or more and stock springs will screw up. As stock they have 0.338" intake valve lift and 0.356" exhaust valve lift. But if you can't find a nice set of dual valve springs holden 202 dual valve springs can be made to fit. But 3K-B r K-B motors factory got harder valve springs in them as they were in the "sporty" corolla so it would rev harder. The sprinter K-B springs ran a tension of 77lbs. Stock springs run 70lbs. But this 7lbs increase made the sprinter rev a lot harder. Now on the crank 4K crank will fit a 5K block it is what a 5K had factory. With the crank the hole in the end that lets the oil in. Turn the crank 90 degrees and drill another hole think it should be 3mm forget exact measurement. This will give you more oil tot he crank and improve life as more oil and more flow will be better. To do this but your oil pump will need about a 3mm shim to maintain pressure and this pressure will also be slightly higher. Also port match the head you build. Also get a 3K head. They are shaved more factory for the 3K that is why they bump up 4K compression more. This will be easier to start with BUT are older so it might be easier to get a 4K head. If you run a 7K they have more studs holding the cylinder head down so parts are not interchangeable for the cylinder head eg 3K/4K/5K/2K/K head WILL NOT bolt to a 7K. Also If you get an early 3K head convert it to the later valve stem seal. Also JDM 5K had nice stainless steel valves. Use them. Also from a knowledgeable source the TRD 3K manual floating around the head porting pattern in it to do a K motor is dated and isnt the best for performance so if you get that don't follow it to closely. Also all K motor heads apart from 5K heads I know of in the exhaust port at the end have a flat angled section where for the USA model they had air injectors there so unburnt fuel could burn was an emissions shit thing. This will hinder flow. 5K heads don't have this there smooth ports so nicer for flow. Also 4age pistons/ rods in your motor will drop compression. Dished piston K motors have a BETTER combustion chamber so if you run a 5K use 4age internals with a shaved 5K cylinder head and porting. Quote Link to comment Share on other sites More sharing options...
raff_gsr Posted November 30, 2007 Author Report Share Posted November 30, 2007 (edited) fantastic info! thank you very much for that. with my pistons, can i drill out an extra 2 mm to fit the rods in? sorry if it sounds like I'm asking stupid questions, its just ive spent $300 on brand new pistons that wont fit now and i doubt anyone will buy them :wink: and just as a quick run down... you're saying, run a 5k, with 4age internals, shaved 5k head with porting and polishing. get her balanced, regrind a cam for 9500-10000 (ssweeeeeeeeeeeettttt!) and a 4k crank? also what about extractors and lightened flywheel? necessary? Edited November 30, 2007 by raff_gsr Quote Link to comment Share on other sites More sharing options...
Trev Posted November 30, 2007 Report Share Posted November 30, 2007 I have never herd of a crank being machined down to size so as a machine shop. So you have never heard of oversized bigend or main bearings? Of course they can be ground down to size just so long as its within the minimal cam specs. Quote Link to comment Share on other sites More sharing options...
raff_gsr Posted November 30, 2007 Author Report Share Posted November 30, 2007 i just spoke to my uncle and he said taking a mm out of each side of the grudgin pin hole shouldnt hurt it at all, so i might go with that and atleast then i can run the later rods which would be stronger right? how would they hold up revving up to 10 grand with say 12:1 cr? I'm happy to spend 500 on h-beam rods if i have to but only if it is absolutely necessary.. Quote Link to comment Share on other sites More sharing options...
Felix Posted November 30, 2007 Report Share Posted November 30, 2007 (edited) Why bother reinventing the wheel? For the amount of money you will likely spend on your 5k, you would be well on your way to finishing a 4age conversion. You could always buy kangaroosa's worked 5k, or madrolla68's fresh 7k with change. By all means if it floats your boat go for it. Just be prepared to sink extra $$ into it for extra work to sort out the bugs. 10,000 rpm from a 5k.... Good luck! I'd say you'll need 45mm webers on jungle juice, an uprighted motor, many many hours on a flow bench with a lot of work invested in the head, plus a lot more. Then you would need a close ratio gear set the keep it on cam between gearchanges (lotsa $), plus a race track to drive it on so you don't get pissed off with traffic. Edited November 30, 2007 by Felix Quote Link to comment Share on other sites More sharing options...
madrolla68 Posted November 30, 2007 Report Share Posted November 30, 2007 Why bother reinventing the wheel? For the amount of money you will likely spend on your 5k, you would be well on your way to finishing a 4age conversion. You could always buy kangaroosa's worked 5k, or madrolla68's fresh 7k with change. By all means if it floats your boat go for it. Just be prepared to sink extra $$ into it for extra work to sort out the bugs. Yeah what he said^^^^^^^^^^^^ and have torque to burn. Quote Link to comment Share on other sites More sharing options...
raff_gsr Posted November 30, 2007 Author Report Share Posted November 30, 2007 10 grand is a pipedream really! and kangrossas engine would be fantastic if he was in adelaide. i don't want to go 4age, too much headf*ck. cash isnt too much of a problem as long as its only for parts, everything will get put together by me and my uncle. and an uprighted engine sounds fantastic to me. ive pmed people on how to do it but no1 gets back to me! i know you got to change the engine mounts, but what bout the gearbox, how do you do it? Quote Link to comment Share on other sites More sharing options...
Rollaboy2608 Posted November 30, 2007 Report Share Posted November 30, 2007 10 grand is a pipedream really! and kangrossas engine would be fantastic if he was in adelaide. i don't want to go 4age, too much headf*ck. cash isnt too much of a problem as long as its only for parts, everything will get put together by me and my uncle. and an uprighted engine sounds fantastic to me. ive pmed people on how to do it but no1 gets back to me! i know you got to change the engine mounts, but what bout the gearbox, how do you do it? If all the machine work your planning isnt a headf**k, then I'll do a noody run down Oxford St Quote Link to comment Share on other sites More sharing options...
love ke70 Posted November 30, 2007 Report Share Posted November 30, 2007 lol, too much headf@$k....this K motor your planning will be worse. and yes you could even offset grind the crank to get an extra 2mm stroke, but are there any bearings that will fit it/ Quote Link to comment Share on other sites More sharing options...
raff_gsr Posted November 30, 2007 Author Report Share Posted November 30, 2007 If all the machine work your planning isnt a headf**k, then I'll do a noody run down Oxford St the only machining i would do is on the pistons to make them 20mm, boring and decking the block, shaving the head and a port and polish and balancing the thing so she'll rev. now, getting an engineers report here in sa for a 4age, going to regency and screwing round with cops let alone the engine conversion is headf*ck fullstop. if I'm wrong there, i'll go sell my ass down hinley street for a weekend lol! anyway i know it will cost money, I'm not a retard, and i know it'll probably end up costing heaps of it too! I'm not too fazed on that. all id like is advice on a setup. is revving over 8 a waste of time? whats the strength of 4age rods? how do i upright my motor? extractors; what should I do there? stuff like that concerns me, rooting around with a motor doesnt, cos at the end of the day, it comes part and parcel with modding your car the way you want it. thanks for the concerns and everything, I know you just want to highlight issues so don't take this as a go at anyone or anything cos all the information has been great and i thank everyone for that, as well as the constructive criticism :wink: Quote Link to comment Share on other sites More sharing options...
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