head build up

[jetblacknismo]

im trying to get some info on the head im gonna rebuild. first i need to know what the numbers on the side mean"40f 4r"it supposedly came out of a hardbody truck. and its a sohc 12 vavle off of a ka24e.any help is appreciated.

[deviousKA]

Right above or around that casting number, do you see an odd looking M casting of some sort? Do you see any japan casting labels under the valvetrain area? If its truly off a truck, It will be a mexico casting and have the large M casting on side. The 240sx/stanza heads were cast in japan and only in small port. The mexico casting came in two versions, small port (same as the japan version) and the later 95?+ hardbody large port head. The truck heads also had the truck cams.

I dont have a list as to what casting number (40f 4r), means what. You can identify it in other ways like i listed above.

All of the rebuild components for ka24e heads are the same.

[jetblacknismo]

right on! finally someone that has some answers for me. thanx. ive been waiting for some one to respond to my other thread i had . but anyhow, what is the size of the large port vs. the small port. im trying to determine what year it came off of. not that it maters much since im gonna port it, but i want to know if the guy that sold it to me is being straight with me. and yes, it has that weird "m" on the side of it.

[deviousKA]

Unfortunatley i dont have any reference for the large port ka heads, as in size difference etc.. I have only worked with the small ports myself. The large port is known to be not as good of a performer as the older style. I do not think the intake ports are just larger, other changes in the port design to suit for the truck application are there im sure.

Large port is on 96/97 hardbodies, and some 95's ive been told. 93 is definately small port, 94?. Sidefeed injectors came in the trucks from 94 and on i believe, not sure if port change occured at same time. Anyone with access to the full nissan service bulletins could find out.

[jetblacknismo]

thanx dude, it doesnt mater that much i guess. im gonna port and polish the thing anyways. im wondering if i could enlarge the valves on that head. if not, oh well. with the port and polish, and a nice cam what do you think i might get out of that, hp wise. maybe 10 to 15hp? i hope.

[deviousKA]

I dont know of any full set of larger valves for the ka24e. On most of the race ka setups, they are allowed to use larger valves. They use manley exhaust valves, not sure of the intake but i know manley doesnt have one to fit. I think you can get +1mm or so, from a sohc L series (l20, l24,l26/28 z car) for the exhaust. Now i havent done this, its all in theory. Check out the manley catalog for the datsun valves and compare some specs, crane cams may also have some.

BTW. L series valve springs (available in different spring rates) will work on ka24e exhaust side. They are very cheap. The exhaust side of ka24e does not have as good of spring rate/valve weight ratio, the exhaust valve is also the one to come closer to piston in a float condition. So upgrading only the exhaust springs/valves, i dont see as to bad of an idea.

10-15 hp from some decent headwork isnt an unreasonable expectation. Make sure your intake manifold will work with your head, if 97 you have large port manifold. Or better yet, swap to the 240sx intake, and go with nice small port setup.

[jetblacknismo]

yes i want to find a 240 intake and port match it . i got the head all torn down. i didnt know it had double springs on each vavle. doing the exhaust side only sounds good, since it has 2 intake vavles on each cylinder anyway. so if i do get a 240 intake, i hear it bolts right up to my head, but what about the other stuff? you know, throttle body, and vacuum lines and what not. what will i have to do to make it work?

[deviousKA]

You could make it work with the existing ecu and harness, in theory, because it uses basically identical setup. Obviously you would have to relocate maf using 240sx parts, but using the actual 240sx maf sensor im not sure. The 240sx and truck use two completely different ecus, made by different manufactures and different board layouts/components. The ecu plug itself, is the same between the two, i would assume full pinout is the same. If so, you could use the 240sx ecu plugged into truck harness, using 240sx maf sensor and tps. Or you could also try using your stock truck ecu and harness, with truck maf rigged in 240sx external housing.

vacuum is pretty straight forward, brake booster, fuel pressure regulator, etc... just the basics. If you need to keep you aiv/egr system on your truck, you may need to use some extra 240 parts to get it all together.

[jetblacknismo]

sounds like a lot of trouble to do the 240 intake. maybe i'll just stick with the head alone.

[jetblacknismo]

hey devious! i notice on your sig that your coming up with a website for engine components. are you gonna have anything for me and other ka truck owners?

[deviousKA]

Sure will, most dont know i used to have a fully bagged nissan hardbody. Most of the 240sx ka24e parts work directly, I am also working on a few different stages of ecu tuning for both 240sx and ka24e truck. Im going to do an ebay store for a few months, keep your eyes open.

btw. Still have the bagged D21, its jet black, just like yours. Actually its my brothers now as i sold it to him, but im still attached.

[jetblacknismo]

so you say to keep my eyes open on ebay? i dont go there much, but i will if your gonna start selling stuff there. i will DEFINATELY be interested in the ECU tuning. especialy after my head build up. btw, i found some specs on the ka truck engines.cam lift: .388" (9.86mm)intake vavle dia. : 1.34" (34mm)exhaust valve dia: 1.58" (40mm) but i think thats a 95 ka. sorry , just thought you might want to know.

[lovemysan2]

jet BTW the max duration on the cam is 232 I could send someone the cam card if they would interpret it for me.

I talked to "jeff" at colt cams and $205 will get you a performance regrind shipped. There is a refundable core charge or you can just send it in.

Hey devious, did you get the email I sent you?

[deviousKA]

I dont have any items up yet, ill let everyone know when and what i have soon. I do smaller orders as of now for various products when i have time off work.

Hey lovemysan i havent gotten any emails from you recently? Worthless spam filters maybe?

[jetblacknismo]

do you guys believe that a STOCK TRUCK KA can handle 260 hp?if it had 7lbs of turbo boost.could it even make that much power with that much boost?

[lovemysan2]

7lbs is right at the limit. 260 bhp is reasonable. How long it last will depend on how you drive and largely how its tuned. Tune it properly and you should be all right. remember that the truck bottom end is not quite as sturdy as the 240sx. The ka24det section would be more helpful than me.