nissanprerunnerdavid Posted February 18, 2012 Report Share Posted February 18, 2012 So I am going to rebuild my z24 and was wondering if it would help me at all to o er bore the head and put some ka pistons in there? What ka pistons would work if I bored it over to 89? Where could I also find the pistons and rods? And any information on boring it out and what to do with that would be awesome!! next I want to get an after market camshaft. What camshaft should i get for the rebuilt z24? And where would I find one of those? Last, I want to get a new carb. What is the best upgrade from the Hitachi that the 720 comes stock with? And also where would I vet that? I don't want the most expensive e one just a really good one to upgrade:) Thanks for all the help!! Quote Link to comment
elfirebeasto Posted February 18, 2012 Report Share Posted February 18, 2012 I don't know a whole lot about this yet, but a couple of the parts you are asking about are available on 4x4parts.com (cam and carb) The carb I seem to read about most often is the Weber 32/36, and the cam is just a slightly more aggressive cam profile than stock. but ultimately if you're looking for power, I read that the z24 head is far too restrictive. Anyway, here ya go. Cams: https://www.4x4parts.com/nissan/performance-cams-c-367_130.html and Carb: https://www.4x4parts.com/nissan/performance-carburetors-c-367_132.html Good luck and keep the posts coming! Quote Link to comment
nissanprerunnerdavid Posted February 18, 2012 Author Report Share Posted February 18, 2012 Than you so much!!! So what would you suggest about the head?? Swap it with the ka head possibly? How could i get the most amount of power? Quote Link to comment
nissanprerunnerdavid Posted February 18, 2012 Author Report Share Posted February 18, 2012 Where would I get some semi cheap but good quality rods and pistons? Quote Link to comment
elfirebeasto Posted February 18, 2012 Report Share Posted February 18, 2012 I have heard of ka head/ z block hybrids and L20 head / z24 block combos. I think the L20 head is more common. I believe all of that information is available with some lengthy searching. I stumbled upon it by accident (I wasnt looking for that particular knowledge at the time). Quote Link to comment
datzenmike Posted February 18, 2012 Report Share Posted February 18, 2012 So I am going to rebuild my z24 and was wondering if it would help me at all to o er bore the head and put some ka pistons in there? What ka pistons would work if I bored it over to 89? Where could I also find the pistons and rods? And any information on boring it out and what to do with that would be awesome!! next I want to get an after market camshaft. What camshaft should i get for the rebuilt z24? And where would I find one of those? Last, I want to get a new carb. What is the best upgrade from the Hitachi that the 720 comes stock with? And also where would I vet that? I don't want the most expensive e one just a really good one to upgrade:) Thanks for all the help!! I'm sure you meant to over bore the block? There's no need to over bore the Z24 block they use the same diameter pistons as the KA24E. Well you could go to a slightly oversize if the block is too worn but the KA pistons will fit right in. The KA pistons will increase your compression dramatically though to 9.52 There are two different KA24E pistons. The ones in the 240sx are fully floating pins while the D21 truck are of the press in type. If you use the truck KA pistons you can use the Z24 rods. Don't misunderstand this but I think from your questions you need to research, research, research. You seen to know the KA has 89mm pistons yet not that your Z24 does too? Have you given any thought to the fact that your Z24 pistons have a 15cc dish in the top while the KA pistons 'dish' is barely 2.8cc?? This will mean your Z24 valves are going to have a lot less clearance and an after market cam will likely have more lift, moving them even closer together? Research this and also why are you raising the compression? Going from 8.5 to 9.6 is about one point of compression, worth about 4% increase in power. That's about 4-6 hp on a Z24... not worth the bother and expense plus having to run higher octane gas.... forever. Biggest bang for the buck is a direct replacement Weber carb from Redline. For $300 you get everything you need to install it. Linkages, manifold adapter and everything bolts up to it. Z24 guys rave about this modification because the stock carb is quite small for the Z24. Yes you can buy them cheaper but you get a 25 year old worn out and rebuilt three times pile of junk with missing parts. Plus it's jetted wrong and doesn't come with an adapter plat for the Z24 manifold. Research! A mild cam would work with this but beware many makers sell basically a stock cam and call it something it's not. Find the stock cam specs and compare. Research! Forget a header, they are a waste of money for the small amount of power gained and the money could be spent on something much more important. 1 Quote Link to comment
nissanprerunnerdavid Posted February 19, 2012 Author Report Share Posted February 19, 2012 Thank you so much. That is example fly what I needed to know and I will try to do more research. I didn't really search the forums too hard before posting which I should have. Thank still for all your time and energy to help me!! Quote Link to comment
datzenmike Posted February 19, 2012 Report Share Posted February 19, 2012 Hey, we all have to start somewhere right? I can point and you do the heavy lifting, ok? Quote Link to comment
nissanprerunnerdavid Posted February 19, 2012 Author Report Share Posted February 19, 2012 Sounds good!! Thanks again! Quote Link to comment
nissanprerunnerdavid Posted February 20, 2012 Author Report Share Posted February 20, 2012 hello all so i ahve just finished taking my z24 apart down to the block. when my truck stopped working it had a very loud knock on start up and at high rpms, but not under load and low rpm. i want to rebuild the engine anyway thats why i took it apart. but what do you think the problem is? is it a rod, valve slap or what? i dont know exactly how to check for any of these things so any help on how and what to check would be greatly appreciated. Quote Link to comment
ggzilla Posted February 20, 2012 Report Share Posted February 20, 2012 main bearing. Check with plastiguage which cost $5 at you local auto parts store. the first thing you should buy is a 720 repair manual Quote Link to comment
datzenmike Posted February 20, 2012 Report Share Posted February 20, 2012 This should be on your other post called Z24 rebuild. This will keep all the information you get in one place. Once you read this I'll move it over for you. A tapping sound (from sharp clicking to loud tap) that stays the same but speeds up with the engine speed is likely a lifter that needs adjusting. A knocking sound, from a heavy hammer hitting wood to a muffled sledge hammer on metal that is louder with heavy throttle and lighter with no load and increases with engine speed sounds like a bad rod bearing. By the time you hear it the crank is udually damaged. Random rattling at idle can be worn timing chain guides. Changing the oil or using thicker oil can sometimes cure this for a while. Get a borrow a digital camera and take lots of good pictures. Post them along with your questions. Saves a thousand words. Quote Link to comment
nissanprerunnerdavid Posted February 21, 2012 Author Report Share Posted February 21, 2012 thank you once again for helping the newbie:) Quote Link to comment
nissanprerunnerdavid Posted February 22, 2012 Author Report Share Posted February 22, 2012 so where would be the best site to buy stock nissan 720 engine parts?? i need a whole lot of engine parts and i havent found a good trustworthy site to buy them from? any sugestions? Quote Link to comment
elfirebeasto Posted February 23, 2012 Report Share Posted February 23, 2012 for stock replacement, I'd suggest http://www.rockauto.com. I've dealt with them on a few occasions for various vehicles. They are inexpensive, fast and reliable. And should they have a screw up and send the wrong part, they are more than happy to fix it, and get the right part on its way that same day. Quote Link to comment
nissanprerunnerdavid Posted February 23, 2012 Author Report Share Posted February 23, 2012 Sweet!!!!! Thanks man!! Another question about the rebuild what would i do if i wanted to delete most of my vac lines? Which ones do i take out and which one do i leave on? Does this hurt your gas mileage or what? If you have pictures or know of any i would the help!! Thanks again!! Quote Link to comment
Hardbody Posted February 26, 2012 Report Share Posted February 26, 2012 I need to ask this question in this thread. I bought a hot street cam(Part# 15-062) from web cams for my z24 and wanted to know if I need offset cam keys or offset cam bushings? I have been searching every where for them or is this cam change and easy replacement? Running a weber 38 as well. Quote Link to comment
datzenmike Posted February 26, 2012 Report Share Posted February 26, 2012 Sweet!!!!! Thanks man!! Another question about the rebuild what would i do if i wanted to delete most of my vac lines? Which ones do i take out and which one do i leave on? Does this hurt your gas mileage or what? If you have pictures or know of any i would the help!! Thanks again!! If you don't know what they do, don't touch them. For example the Z engines have a fuel shut off system. When decelerating at speed and foot is off the gas the engine is still sucking the idle mixture which is wasted out the exhaust. This system shuts off the idle cut solenoid and actually saves you fuel.Has no effect on running or performance.... why mess with it? EGR.... reduces cylinder temps and risk of detonation but is disconnected at full throttle... why mess with it? Quote Link to comment
nissanprerunnerdavid Posted February 28, 2012 Author Report Share Posted February 28, 2012 Ok so got the motor pulled apart to find i spun my #4 rod bearing. There was no bearing keft at all. Im sending the block and head in to get machined monday. Here is my list for the next couple of weeks. Order my rebuild kit from rockauto Order my weber order my header Then after the engine is done i am. Going to Paint my dash and steering colum Re upholster my door panels with black material finish my prerunner bumper Re index my torsion bars Find some new seats get my new tires Thats it for the next couple of weeks:):) will post pics tomorrow!! Quote Link to comment
nissanprerunnerdavid Posted February 28, 2012 Author Report Share Posted February 28, 2012 O and make custom hard vacuumn lines!! Quote Link to comment
poor-mans-720 Posted February 28, 2012 Report Share Posted February 28, 2012 I am pretty sure I heard more then a couple places that the stock header is the best for the 720. I think it is the pacesetter that everyone usually gets. It takes away from the low end torque which is important for us wheelers... unless I am mistaken and this is not for your wheeling rig. Someone chime in and correct me if I misspoke... I will begin the research on it now. See what I come up with. Quote Link to comment
nissanprerunnerdavid Posted February 28, 2012 Author Report Share Posted February 28, 2012 I will check and see. I wonder if running muffler delete with the header will just counter act tbe loss of power. I will do some research. Quote Link to comment
poor-mans-720 Posted February 28, 2012 Report Share Posted February 28, 2012 thats why im doing right now on a z22. Could definetly feel the power gain once the pipe was cut off... Quote Link to comment
nissanprerunnerdavid Posted February 28, 2012 Author Report Share Posted February 28, 2012 http://imageshack.us/photo/my-images/51/546nl.jpg/ Quote Link to comment
poor-mans-720 Posted February 28, 2012 Report Share Posted February 28, 2012 http://forums.nicoclub.com/frankenstein-builds-look-here-for-project-info-t469980.html check this out... Might be helpful. Quote Link to comment
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