Cheap Rods

[S13Ka24e]

Now i know that the cheapest forged rods made for the ka24 are crower rods. The cheapest price I have found is $640 for them. Now i feel that this is too much for rods. So i began looking for other rods that were close to these rods. Rods are made for GM 454 can be bought with a 6.535" and the stock rods are 6.495". With a set of custom Pistons that .040" could be adjusted to get the desired compression ratio and I would think it wouldn't interfer with the block for being just barely longer. Also the Pin size on the small end is also larger but with custom pistons this would also be no problem. The ONLY problem i see with using these rods are the size on the large end is 2.1" and the crower rods have a size of 2.086". I don't know if having a .014" difference is a huge deal, i assume that it is, is there anyway i could counter that? The only reason i'm considering this is i know I can get 8 rods of these for $500. It is alot cheaper. What do you think?

[WDRacing]

I'm copying this to the tech section as well...

WD

[sil80drifter]

Copy is good, but will it work is better.

The first number I guess is the length of the rod.When you talk about the large end, do you mean inside diameter? Outside diameter? Inside/Outside width? sil80

[S13Ka24e]

The stock rod for the ka24 engine would have a

C-C length : 6.495"Big End Bore : 2.086 or 2.087" (i have heard both)Big End Width : .975" Pin Dia. : .827"Small End Width : .975"

The rods i was looking at were

C-C length : 6.535"Big End Bore : 2.100"Big End Width : .975" Pin Dia. : .990"Small End Width : .975"

[sil80drifter]

I wonder which is the REAL stock KA24 Big End Bore. I tried researching that a while ago, and came up with same results; people say different things.

sil80

[TrunkMonkey]

I wonder which is the REAL stock KA24 Big End Bore.

i suggest that some of you buy an FSM.

the KA rods have a big end bore diameter of 2.0866"-2.0871".

give your rods and crank to a very competent machinist and they should be able to make (or know someone who can make) custom bearings to make the setup work.

-demetrius

[sil80drifter]

I have the FSM. The difference between the two numbers you mentioned, is that the play of the piston in the cylinder?

sil80

[S13Ka24e]

i suggest that some of you buy an FSM.

the KA rods have a big end bore diameter of 2.0866"-2.0871".

give your rods and crank to a very competent machinist and they should be able to make (or know someone who can make) custom bearings to make the setup work.

-demetrius

Do you know could they make custom bearing more that just .014 bigger, i ask because i I found Billet Rods but they have a 2.200 big end bore, and that is .114 bigger but 8 billet Rods for $500 that are good for 500+ hp if a machinist can do that, that is definatly something i will consider.

[S13Ka24e]

Never mind about the last post, I don't think i'm going to bother with bearing and that stuff. I have just found out the rods out of a 5.4L ford engine have the same Big end bore as the ka24. This is how they compare

Ka24

C-C length : 6.495"Big End Bore : 2.086 or 2.087" (i have heard both)Big End Width : .975" Pin Dia. : .827"Small End Width : .975"

5.4L Ford

C-C length : 6.657"Big End Bore : 2.086" Big End Width : .939" Pin Dia. : .865"Small End Width : .939"

Now as you can see the Center to Center lenght is quite a bit longer but I think i can still get the correct CR with these rods, i mean Nissan Motorsports uses 6.748" lenght rods and as long as it fits in the block i think that i can adjuest the pistons to get the CR. The bad news about these rods are they are more expensive, they are $660 for 8 rods, but are good to 850hp in a V8 so i would think they are good for atleast 450hp in a ka. Well, i got to think this over, but if i do this and find another person who would want rods too, that is only 330 for good rods. They are eagle rods.

[U12 2NR]

You're trying to find cheaper rods by comparing rods from other cars. Good idea, but by the time you finish all the machining and what not to get these different rods to work, the prices will surpass the $640 for Crower rods that already fit fine. No one wants to gamble money into an engine.

[Jays90240SX]

I agree, if there were stock rods that were stronger from another motor, and it only needs slight machining to fit, then that would be feasable.

[GatorS14]

http://www.240sx.org/links/gro....html

these look to be a good price.not sure if this helps.

[U12 2NR]

they dont' carry KA rods.

[GatorS14]

s*** my bad.that sux! I cant read,dont tell please

pretty good price though huh?

[sil80drifter]

Maybe they can make such cheap rods for the KA too? Someone should ask them

sil80

[S13Ka24e]

If i use the 5.4L rods there will be no need for any machining. I just have to move the compression length from 1.336" to 1.174" That will make a 9.1 to 1 CR in a ka24e engine and make the pistons with small end pin of .865" That is is and it should fit in a ka24e engine with 9.1:1 (i'm thinking though that i would rather go with 8.5 or 8.0 CR.) These calculations are with a 9.722" finished block height, but i don't know the deck clearance, does anyone know the deck clearance?

Also what is the Heads cc's (i used 78.58cc for both the head gasket and the head cc's).

What is the stock head gasket thinkness?

I'm would order pistons from ross, and they ask for Head type anyone know what is for the ka24e?

The valve diameters for the ka24e are 33mm on the intake and 39mm on the exhaust?

Also what is the Intake valve location when on the seat as compared to the surface of the head (flush, amount recessed, or amount proud)?

Finally what is the Camshaft lift at split overlap when piston is at T.D.C.

Thanks.

[sil80drifter]

Those are excellent questions...and if you DO get 9.1 compression, u can always get a 1.5mm-2mm head gasket, and solve that problem. I hope someone can answer these...it would be extremely beneficial to all of us KA-E owners.

sil80

[89S13SILVIA]

I have an 89 240sx and i am considering boosting it and was looking at this thread in the n/a section and it had a link to http://WWW.REALNISSAN.COM and they have alot of stuff for our engines for cheap. just my 2 cents

[U12 2NR]

Real nissan isn't a company and if something goes wrong with products you buy from them i don't know how they will handle it.

In their FAQ section if specifially states that they aren't a company and their shop is their garages.

You should know who you buy from. It's great that the have alot of things available and they have experience, but they aren't a company and it seems like alot of people think so.

[Kinesthesia]

So what are all the forged rod choices (I mean rods that don't require modification) ?

Crower ? Pauter ? Manley ?

Where did you find Crower rods for $640 ?

[groundhogday1976]

Someone in another threadsaid the stock ka24de rods are forged. Is the same true for the ka24e? I have the de, and I'm thinking of just having the stock rods cryo treated and shot peened. Does anybody know how much that costs and how much strength is gained?

[TrunkMonkey]

Someone in another threadsaid the stock ka24de rods are forged. Is the same true for the ka24e?

the E and DE use the same rods, and yes, they're forged.

-demetrius

[S13Ka24e]

So what are all the forged rod choices (I mean rods that don't require modification) ?

Crower ? Pauter ? Manley ?

Where did you find Crower rods for $640 ?

I have only heard of Crower and Pauter rods. At http://www.importperformancepa....html there are the $639 for crower rods. Here http://www.importperformancepa....html there a $695 Pauter rods.

Yes the stock rods at forged but just because they are forged and shotpeeded from the factory doesn't mean that they are super strong. I'm considering using the stock rods, but i'm still unsure. I have hear many people talking about how the stock rods hold up to 350rwhp but i don't believe that it can handle that reliably because i have hear of plently of people throwing rods that don't even use turbos or nitrous. I'm considering lowering my power goals down and then using the stock rod because i would think it could handle 275rwhp. I would use new stock rods, i can get them (all 4) for $256.95 and then use stock bolts to hold them down. But, i rarely race, i want a car that flys, but will last under boost for 50k miles. I still have to weight the cost vs. benifts.

[TrunkMonkey]

I have hear many people talking about how the stock rods hold up to 350rwhp but i don't believe that it can handle that reliably because i have hear of plently of people throwing rods that don't even use turbos or nitrous.

just because an engine throws a rod doesn't mean that the rod itself was weak. usually when an engine throws a rod it's because of a seized bearing. the cause of a seized being is usually oil starvation.

if a bearing seizes, even the best of the best aftermarket rods will give.

-demetrius

[95_240sx]

Nissan also makes lots of different bearing sizes so if you were to find a rod that has a big end bore almost the same as a KA you could either plus up or down on the bearing thickness, i think theres 9 or so different sizes they make for the KA's.

Rick

[king_johnthegreat]

The Ford 5.4's rods simply won't work. They are too narrow. The thrust play would be too great, and the crank walk would basically obliterate the thrust bearing. Once that happens, forget about it. Each rod would act like a peening hammer on the crank faces, and that all translates through the rod journals to the main bearings. That is, if you don't spin rod bearings from the constant pounding they will suffer. There are very important machined tolerances involved that simply cannot be compensated for in this instance. You cannot add to the crank to narrow down the journals, and you cannot add to the rods to fatten them up. Just not gonna work.John

[95_240sx]

I didnt mean to take up a lot of space, I simply meant this as fine tuning.

Rick

[TrunkMonkey]

You cannot add to the crank to narrow down the journals, and you cannot add to the rods to fatten them up.

yes, you can.

the journals can be welded and ground to achieve the desired width. but you do have a point. i didn't notice that the ford rods were narrower. if you're going to go through all that trouble to make them fit, you might as well spend the money on custom rods.

-demetrius

[S13Ka24e]

yes, you can.

the journals can be welded and ground to achieve the desired width. but you do have a point. i didn't notice that the ford rods were narrower. if you're going to go through all that trouble to make them fit, you might as well spend the money on custom rods.

-demetrius

Ya that is what i'm thinking now, i might as well just spend the money on custom rods or go with the stockers.

[king_johnthegreat]

You would need a whole lot of trust and money to add weld to four big end bearing journals just to fit four rods that cost a few bucks less. And, call me crazy, but unless you've got supreme confidence in your welder, you'd have a much greater likelyhood of weakening the crank with all that welding. You would need a cryogenic treatment on the crank just to get some of its integrity back if you pulled that welding stunt. May as well just design your own new crank in CAD, then pay to have a forged 4340 chromoly one completely fabricated for you. So, in short, no you can't add material to the crank or rods to make them fit; it just isn't feasable for a motor, much less a boosted one.John