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Discussion Starter #1
I've searched and seached but I can't find a good listing of various connecting rod weights, more specifically OEM rods.

Down the road I'd like to turn my K20A2 into a K24/K20 frank. I'm sticking with an N/A set-up so I'd like to know how an OEM K24A1/2/3/4 rod compares, strength and weightwise, to what the aftermarket has to offer.

Are all K24 rods the same or are some, I'm guessing TSX rods, stronger than others? While I'm on the subject, is any one K24 block make a better candidate for a K24/K20 frank?
 

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Brand new, the 06 tsx rods/pistons/block will be the strongest oem k24 bottom end.
The TSX blocks have piston squirters, and the rods are stronger than the accord and crv variants.
 

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Discussion Starter #3
Brand new, the 06 tsx rods/pistons/block will be the strongest oem k24 bottom end.
The TSX blocks have piston squirters, and the rods are stronger than the accord and crv variants.

I figured the TSX bottom end would be beefier to deal with the extra power and higher RPM. With that in mind...

Any idea what the "safe" power limit is for TSX rods and pistons? Would the c/r of a K24A2 block with a K20A2 head be something like 13:1?

Are oil squirters still necessary if moving into aftermarket forged pistons and rods when dealing with the K-series? From what I understood with the B-series engines, forged pistons didn't need the oil squirters.
 

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Here are two pics, showing K24A1/A2/A4 rods and BP ultralight "I"beam rods.
K24A4 vrs K24A2


BP "I" beam rod vrs K24A1 rod
 

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Discussion Starter #5
K24A4 vrs K24A2
This pic really show how much stronger the A2 rods looks. Down around the crank end of the rod there's far more material and the middle part is thicker.

For now, my K20A2 is internally stock with a 3" custom intake, RBC IM, DTR headers, 2.5" exhaust and Kpro. If I upgrade to something like IPS-K2's, valvetrain, PnP and maybe over sized intake valves, ported RBC, 70mm TB , 3" exhaust with a K24 block, would forged rods and pistons be necessay?
 

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For now, my K20A2 is internally stock with a 3" custom intake, RBC IM, DTR headers, 2.5" exhaust and Kpro. If I upgrade to something like IPS-K2's, valvetrain, PnP and maybe over sized intake valves, ported RBC, 70mm TB , 3" exhaust with a K24 block, would forged rods and pistons be necessay?
No, they are not necessary, but you could skip the head stuff (pnp/ os valves). Just get the cams.
Spend that money on rods and pistons and you will see a larger gain throughout the powerband and less risk at higher RPM.
 

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Discussion Starter #7
I'm more so just asking if the OEM internals would be able to hold up to that type of motor work. Sounds like the forged internals are the better route. I kind of figured that but didn't want to if I didn't have to. Any porting would be the last thing to be done, planning it all in steps.

So if anyone could confirm my assumption, the K24A2 crank is probably better designed for ~8-8.5k rpm's compared to K24A1/3/4? I could be wrong and all K24 cranks are the same....:up: or :down:
 

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Hi joe.
Here is my set-up , 2006 tsx K24 bottom end STOCK RODS, TYPE S head (stock Valves) JE pistons 13.7:1 compr., ips K2 cams, Super-teck springs, PRC intake & 70mm throttle, R crew header, 3" exaust. 282whp @ 202trq in my 96EK.
I did over 85 passes reving it up to 8500rpm. no problems at all.
I know plenty of guys buying aftermarket parts and their engine parts are all over the track (specially rods & valves) stick to stock if you can.
my best run 11.80 @ 117mph 96 EK 2385lbs with driver (SS/AM classe)
Gary
 

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So if anyone could confirm my assumption, the K24A2 crank is probably better designed for ~8-8.5k rpm's compared to K24A1/3/4? I could be wrong and all K24 cranks are the same....:up: or :down:
I took a K24A1 crank and a K24A2 crank to the balance shop and the K24A2 crank had far less deflection at higher RPM's, so yes the K24A2 crank is stronger.
 

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The A1 crank was new and the TSX crank was a used crank.
 

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Cool, thanks for sharing.
I wonder why one would be stronger than another, are they made in different locations?
Could be, bearings are made by different suppliers, maybe different suppliers for the Cranks, I know that I took 3 cranks to a balancing shop and the CRV ones were not balanced, just the TSX one, They only need it to touch it up when the guy took it to 11,000 RPM.
 

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Could be, bearings are made by different suppliers, maybe different suppliers for the Cranks, I know that I took 3 cranks to a balancing shop and the CRV ones were not balanced, just the TSX one, They only need it to touch it up when the guy took it to 11,000 RPM.
Yeah, I saw that in the other thread. I think talon is on the mark with what he said regarding the difference in oem bob weight.
could be the same molds just different metallurgy....
I was thinking either that or heat cycling. Maybe just a more powerful press.
 

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Discussion Starter #16
I wouldn't put it passed Honda to have made 2 totally different cranks even thought they have the same stroke. From what I researched years ago, the B18C5 crank's counter balances were actually heavier than the B18C1 crank for better balance at high rpm's. Even though thay had the same stroke and were completely interchangable, thay were different cranks.

With this info in hand, I'd much rather go with the TSX crank...even if it does cost a little extra.

Thanks for the info "talonxracer" and "poorg".
 

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Discussion Starter #17
Hi joe.
Here is my set-up , 2006 tsx K24 bottom end STOCK RODS, TYPE S head (stock Valves) JE pistons 13.7:1 compr., ips K2 cams, Super-teck springs, PRC intake & 70mm throttle, R crew header, 3" exaust. 282whp @ 202trq in my 96EK.
I did over 85 passes reving it up to 8500rpm. no problems at all.
I know plenty of guys buying aftermarket parts and their engine parts are all over the track (specially rods & valves) stick to stock if you can.
my best run 11.80 @ 117mph 96 EK 2385lbs with driver (SS/AM classe)
Gary
Thats some insane power! That's got to be at the crank though right?

Are you running pump gas with that 13.7:1 c/r? I was thinking 12.5:1 at most. I can get 94 octane but only at Sunoco stations. I'm not sure if I want to limit myself to one chain in case I'm on a road trip and can't find one.
 

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While I'm on the subject, is any one K24 block make a better candidate for a K24/K20 frank?
There is one thing about the 2008 CRV block that I like, the oil filter location is in the vertical position right next to the oil pan.

This good because it easily allows you to fill a new filter with oil when doing oil changes.

Thats some insane power! That's got to be at the crank though right?
282whp @ 202trq in my 96EK.
 

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Thats some insane power! That's got to be at the crank though right?

Are you running pump gas with that 13.7:1 c/r? I was thinking 12.5:1 at most. I can get 94 octane but only at Sunoco stations. I'm not sure if I want to limit myself to one chain in case I'm on a road trip and can't find one.
No that is at the wheels. I'm using 112 octane , i made this decision before build-up, i drive it only to the track & weekends, its double the price of gas but well worth it if you add all the advantages, keeps engine cooler & specialy cleaner, just got to check youre KM the oil never gets dirty.
 

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Sorry if this sounds naive but doesn't 112 contain lead?

To get around running expensive race fuel one could install a water mist injection system.

I have a customer who installed a full time water mist injection system with a RPM window switch on his NA 07 Civic Si, runs 87 octane and gets better fuel economy and more power than when he ran premium alone. He says he only has to fill the reservoir every 4 or 5 days.
 
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