swiftless Posted February 23, 2015 Report Share Posted February 23, 2015 Hi Everyone, I've got a 4k head that's having issues and it's coming on time to replace it (believed to be cracked). I'll be going to a wreckers where you do all the parts pulling yourself simply because it's so cheap ($40-50) and my question is, how can I tell if the head is a 4k head? The 3k/4k/5k are apparently interchangeable with varying degrees of performance but I just want another 4k head as I don't want to change anything else other than the head. If you had to walk up to a k engine and pick which head it had, what would you be looking for? Or would you just be going on the make/model of the car and trusting it hasn't had the engine or head swapped? Thanks Quote Link to comment Share on other sites More sharing options...
Banjo Posted February 23, 2015 Report Share Posted February 23, 2015 (edited) Hi Donald, The easy way to identify a K Series head is by the casting number. All the info is there in the WiKi on this forum. http://www.rollaclub.com/wiki/index.php?title=Tech:Engine/K_Series/Heads Cheers Banjo Edited February 23, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
swiftless Posted February 23, 2015 Author Report Share Posted February 23, 2015 Great, thanks Banjo! I had a feeling this information would be around already, just didn't have any luck searching for it. Have now bookmarked the K Motor part of the Wiki. I see on the page they list a Standard, Mildport and 4K-E. Would anyone know the difference between the standard and mildport? A quick Google search mentions higher fuel consumption but better performance for mild port vs standard port, but I can't find mention of a mildport 4K engine anywhere but here on rollaclub. Quote Link to comment Share on other sites More sharing options...
Banjo Posted February 24, 2015 Report Share Posted February 24, 2015 (edited) Hi Donald, First question you should be looking at, is what is the type of 4K engine you are are going to put this replacement head on. There is a 4K-U engine that has dished, or "D" type pistons, which can create real issues of low or high compression, if you don't fit the appropriate head. What is your engine serial number ? Assuming the engine you have, and the cracked head that came off it, are the original "paired" components, what is the "cast" number on your cracked head ? I might be able to help you out with a 4K head, depending on what cast number yours is. Have you pulled the cracked head off yet ? A photo of the block without head, with 2 pistons at TDC could assist. Cheers Banjo Edited February 24, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
swiftless Posted February 24, 2015 Author Report Share Posted February 24, 2015 (edited) Hi Banjo, I just thought it would be a regular 4K-C since it's a 1.3L from a KE70 Corolla, but I don't know the history of the car so it might not be the original engine/parts. The engine number is 4K 5952891. The head has a big 12 between the 3rd and 4th spark plugs. Funnily enough, I can't find 12 in the head numbers Wiki page. Here's a photo showing the top of the pistons from when I last took the head off to swap out a gasket (which didn't fix my issue, hence wanting to identify and replace head). Sorry it's so large. Thanks, Donald Edited February 24, 2015 by swiftless Quote Link to comment Share on other sites More sharing options...
Banjo Posted February 24, 2015 Report Share Posted February 24, 2015 (edited) Hi Donald, Definitely a 4K-U engine with the dished pistons, in the "D" shape. Now you may well have a problem, as unless you replace your head with one matched/suited to the 4K-U, you could finish up with very high or low compression, as eluded to in my earlier post. Happened to me in my early days with a 4K-U. I actually have a 4K-U in my Corolla at present, so I'll go and have a look now, as to what casting number is on the head. If you can't get a 4K-U replacement head, you may have to get the replacement head skimmed to bring the compression ratio back up, if it's a 4K-C or the like. Maybe a 5K head that has dished pistons would be closer to the compression ratio required ? Cheers Banjo Edited February 24, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
swiftless Posted February 24, 2015 Author Report Share Posted February 24, 2015 Hi Banjo, Had no idea, this post was well worth it for me. On the plus side I believe the 4K-U had a few extra horses if I recall. That's got to be the easiest performance mod available, finding out you have it already. That brings me back to the original post: The best way for me to identify the correct head would be to 1) Check the casting number and 2) Check the shape of the pistons (in my case). It looks like the wrecker I was going to go to only has KE70's from 83-85 but the 4K-U was only in 82, that's unfortunate. I'll have to shop around. Does the 4K-U fit with any other heads or would they all require modifications? Thanks, Donald Quote Link to comment Share on other sites More sharing options...
Banjo Posted February 24, 2015 Report Share Posted February 24, 2015 (edited) Hi Donald, Just checked my 4K-U running engine. It also has a head with casting number 12, the same as yours, so you can be pretty sure the head no: 12 goes with a 4K-U, which like you, I can't find any reference to, but will keep looking. You are lucky, as the 4K-U certainly has a few extra horses, and puts out almost as much power as a 5K, off memory. Do a bit of searching on this forum, as there's a bit about it. Think off memory the 4K-U came from Japanese imported models, as most AMI KE Corollas had the common 4K-C engine fitted. I've always found that it was a far more lively engine than the 4K-C. Trouble is, they are apparently fairly rare, and you might have trouble finding a replacement head in good condition. Your options are to get your existing head welded & skimmed, if it hasn't got too much corrosion. Other alternative is to probably get hold of a "good" 4K-C head and skim 2-3 mm off it. I'd probably be looking for a CR of about 9:1 Suspect solution ! Others on here might like to chip in if they have solved your issue previously, using another K series head. Cheers Banjo Edited February 24, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
swiftless Posted February 24, 2015 Author Report Share Posted February 24, 2015 (edited) Thanks so much for your help. I might actually invest in sending this head off to get checked out and if possible, fixed. It sounds like it will quite a bit of work to find another head for this particular engine. Definitely interested to hear if anyone has any other solutions as it may make life easier in the future. I was hoping it would be a simple 'buy a head and swap it'. Oh, I just tried to edit the Wiki page to add the 12 cast for the 4K-U but it looks like it takes different login credentials to the forum. Thanks again, Donald Edited February 24, 2015 by swiftless Quote Link to comment Share on other sites More sharing options...
Banjo Posted February 24, 2015 Report Share Posted February 24, 2015 (edited) Search this site for anything related to 4K-U Head. There's few stories worth reading, and collectively, it might help you as to which way to go. http://www.rollaclub...-4k-comression/ Cheers Banjo Edited February 24, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
Banjo Posted February 24, 2015 Report Share Posted February 24, 2015 (edited) Hi Donald, Don't forget that simply putting another head model head on the 4K-U block may introduce other issues like push rod & rocker height dimensions etc. Does your 4K-U have adjustable tappets. Read on here somewhere once, about someone coming across a 4K-U with hydro lifters, although they might have been a mod. You could always fit an unmodified 4K-C head, then boost the engine. That would certainly give you a sizeable number of extra horses ! Ha Ha ! P.S. Just of interest your 4K-U has engine no: 4K 5952891. My 4K-U has engine no: 4K 5880640 Someone else on here has one with a 4K-U engine number 4K 5982696. Cheers Banjo Edited February 24, 2015 by Banjo Quote Link to comment Share on other sites More sharing options...
swiftless Posted February 24, 2015 Author Report Share Posted February 24, 2015 Hi Banjo, Adjustable tappets for me. I've heard stories of hydro lifters as well but yet to see them. I'm not particularly after the extra horses but out of curiosity, is that something that could be done? Or am I going to blow something up by even thinking about it? Because a regular 4K-C head is much more common. Already getting quotes for having the current head checked, if anyone knows of any decent places in Adelaide, let me know. Thanks, Donald Quote Link to comment Share on other sites More sharing options...
tojo2 Posted February 24, 2015 Report Share Posted February 24, 2015 (edited) you can use a 5K head With lumps under 1 and 4 spark plug Edited February 24, 2015 by tojo2 Quote Link to comment Share on other sites More sharing options...
kickn5k Posted February 24, 2015 Report Share Posted February 24, 2015 Hi Donald, Definitely a 4K-U engine with the dished pistons, in the "D" shape. Now you may well have a problem, as unless you replace your head with one matched/suited to the 4K-U, you could finish up with very high or low compression, as eluded to in my earlier post. Happened to me in my early days with a 4K-U. I actually have a 4K-U in my Corolla at present, so I'll go and have a look now, as to what casting number is on the head. If you can't get a 4K-U replacement head, you may have to get the replacement head combustion chamber increased, a bit to bring the compression ratio down. Cheers Banjo Flat top head on a 4k-u or 5k will drop the comp to around 8.5:1 or lower depending on bore size. The majority of 4k heads are the large chamber head to suit the flat top piston. Quote Link to comment Share on other sites More sharing options...
tojo2 Posted February 24, 2015 Report Share Posted February 24, 2015 Have seen on forums 4k-U has become the popular term for a dished pistoned 4k . Some 4kj , regular 4k and 4ke also came with dished pistons Some 4k-U also came with flat top pistons. If you do a bit of partnumber crossreferencing on toyodiy, youll find some 4k and 5k shared heads. both flat top vertions and dished vertions. Quote Link to comment Share on other sites More sharing options...
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