Forged rods and crank?

[1sikS13]

As stated on wikipedia

The KA24E was a SOHC 12-valve engine produced from July 1988 through January 1996. It uses SEFI fuel injection, and features forged steel connecting rods, an internally balanced forged steel crankshaft, and a cast aluminum intake manifold.

Does this mean i can use a sohc crank and rods with dohc pistons and have forged internals? or are they not interchangeable. Low cost forged internal project was my thoughts. Can anyone confirm the legitamacy(is that a word) of this claim.

[480sx]

Very doubtful, but my quick search turned up with nothing. If you can find a pic of the rods and crank its pretty easy to tell if its cast or forged.

[-RJ-]

how can you tell? i got a set of kae rods sitting in my spider and wasp infested shed

[480sx]

Cast stuff will have casting marks all over the non machined surfaces. Little bumps basically. Forged stuff will be completely machined and smooth.

[1sikS13]

but it is possible that they will be interchangeable since assentially the blocks are constructed the same and the heads are really the only difference. This is all based on my search findings and from previous forum discussion

[-RJ-]

i know that you can use the pistons between the two. If you use SOHC piston in a DOHC you get higher compression, but I think i read somewhere that you have to use a higher octane too.

[Bigvinnie]

All KA crank shafts are forged steel....All KA rods are shot peened, shot peened is somewhat of a forge but it doesn't have the strength that a true forged rod would have....

[480sx]

shot peened is somewhat of a forge but it doesn't have the strength that a true forged rod would have....

You really say some hilarious things.

[liquid_cool]

i know that you can use the pistons between the two. If you use SOHC piston in a DOHC you get higher compression, but I think i read somewhere that you have to use a higher octane too.

RJ's correct....the higher the compression ratio..the higher the octane..or octain style additive you need to prevent the fuel from ignition before it is ment to....if your at say a 10.0:1..then you cant reall run anything under super unleaded with out knocking..any thing over say 10.5:1 and your looking at close to race gas...depending..(this is an average and depends on state requierments for super unleaded) it may vary some..but you get the idea...you can run pump gas for 10.0:1 and even 10.5:1 with slight risk.

now if your boosting/turbo...if your at say 9.0:1 for your ratio and add say 20 psi..well your increasing your compression ratio allso..and should run super or better depending on boost lvl's..there is a mathimatical calculation to determine your ratio after a turbo install..but i cant remember it to save my life:)..anyways..hope this helpd someone..as for the original arguement/

you have to determine if the rods/pistons are the same in meshurements..ie..rod same length?..pistons same length taper and diamiter?and allso...is the crank the same distance from the head as the ka24de?..is the crank angle and stroke the same?...it may fit..but will it work without pushing the head off of the block ?...its a good question..if i had a spare ka24e..id take a look more in depth at it.

[Bigvinnie]

You really say some hilarious things.

O.K . Well if you would like to educate the forum on the differences between shot peening, and forged be my guest....

[480sx]

'Forging is manufacturing process where metal is pressed, pounded or squeezed under great pressure into high strength parts known as forgings. The process is normally (but not always) performed hot by preheating the metal to a desired temperature before it is worked. It is important to note that the forging process is entirely different from the casting (or foundry) process, as metal used to make forged parts is never melted and poured (as in the casting process).'

Shot peening is simply blasting the piece that is to be treated with a fine, hard median. It reduces the stress on the metal effectively making it stronger.

[Cone Junky]

I have 2 KA24e motors laying around in various states of dis-assemble. Neither set of rods or cranks look like they are forged. Both have distinct rough characteristics of a cast.

[480sx]

Yea i dont think the cranks forged either i just cant find any proof anywhere that they are not.

[Bigvinnie]

I have 2 KA24e motors laying around in various states of dis-assemble. Neither set of rods or cranks look like they are forged. Both have distinct rough characteristics of a cast.

Yea i dont think the cranks forged either i just cant find any proof anywhere that they are not.

Crank shaft is defenitely forged. If it wasn't it wouldn't be able to maintain up to 400hp.....

[480sx]

Crank shaft is defenitely forged. If it wasn't it wouldn't be able to maintain up to 400hp.....

Coming from someone who compared shot peening to forging.. Is that really your only support for your claim that the stock crank is forged? That a cast crank couldnt hold 400 hp?!

Also a stock crank has held a lot more than 400 hp dude.

[1fastbox06]

i'm going to go out on a limb here, but wouldn't this explain why there is no aftermarket cranks?

i mean i understand that the ka's aren't supported aftermarket wise as say a b18, but companies do make forged internals for them. Also, wouldn't knife edging a stock cast crank greatly deppreciate it's strength compared to edging a forged one? JW.

[liquid_cool]

i'm going to go out on a limb here, but wouldn't this explain why there is no aftermarket cranks?

i mean i understand that the ka's aren't supported aftermarket wise as say a b18, but companies do make forged internals for them. Also, wouldn't knife edging a stock cast crank greatly deppreciate it's strength compared to edging a forged one? JW.

sorry bro..brian crower makes a forged balanced crank/piston set..take a look at it..will explain the difference in a forged -vs- cast quickly..one of the big draw backs to the motor is the crank..i mean..its not bad and can withstand punishment..but it you shorten stroke..with crank/rod/piston combo..you can achieve high rpm/hp better for N/A aplications..just my thoughts.

[1fastbox06]

i thought the brian crower kit was to stroke the motor to 2.6l??? also, isn't that kit for the ka24de only?

[blackRB240]

Eagle, Manley, JP, Wiseco, AND Brian Crower make forged internal parts for the KA24de. Neither the SOHC or DOHC came with forged internals, EVER. At least, not in any US-spec 240sx. The stock DOHC motor has been proven to make 400 reliable horsepower. The KA is a very strong motor and with true forged internals, a huge turbo, and a seriously ported head can make well over 600 horsepower. Also, no KA is internally balanced. To be honest, they weren't really balanced at all. That is why they are such a rough running breed of engines. 4340 steel is serious stuff yo.

Bigvinnie: Don't be an *** when you don't know what you are talking about. Please research first next time. Don't make me revoke speaking priveleges please.

[liquid_cool]

yup...2.6l is correct....and ka24de only...but its still a good example of a forged billit crank..and the crower crank does not add to the displacement sire..the rod and piston combo does..allso note you must bore out to 90mm....the crank was made to shorten stroke...but we are talking difference in cast -vs- forged thats all....if ya want differences in the crower crank-vs-normal oem..then a new post would be needed sire.