So I just wrecked my built k24a4/k20a2 swap. Looking at a used k24a2 long block and wondering if its worth spending the money machining my current head or just saving the money and sticking with the k24a2 head. My old build was a 9:1 compression with stock cams and flat valves so im wondering if I would notice much of a power decrease by just leaving the k24 head on. If anyone knows anything about this I could use the advice. Thanks crsx!
woolleyfooley
I *think* just from what I've read on here, but you won't be too disappointed with the K24A2 as is, but if you're going to get aftermarket cams, the K20A2 head is better. Why would you have to machine it though? (<-- could reveal my frank noob status :noes
The motor was built for boost with blueprint pro I beam rods, je pistons, toda tensioner, bc valves, valve springs and retainers and stock cams. Like I said it was built for boost but it never happened. So basically im just wondering if I'm going to notice a hp/torque decrease just dropping in a full k24a2. I honestly don't think I will seeing as I was 9:1 and the k24a2 is 10.5:1. Oh and basically the toda tensioner failed after only a couple months and the head gasket went which is why the motor is cooked.
If you have a k24a2 longblock just swap in the whole motor and be done with it. Fix what you can of the blown motor and part it out to make some money back.
Also, if you plan on swapping in the k24a2 and leaving it the way it is for a DD I would suggest just staying with the RBB manifold as opposed to the RBC. You'll have more tq low and midrange.
Yeah I have the rbc off my old motor but apparently it won't fit on the k24a2 head? So in that case I probably will just leave the stock rbb manifold on there. And I'm not sure if the tct and head gasket were related just my bad luck.
And I just realized the motor is from an 05 tsx. Should I pass and get one from an 06+ tsx since im leaving it completely stock?
exhaust cam is the same for 04-08. only intake cam is different. also 06+ has different valve springs and intake valves. exhaust valves are the same for all years. pistons and rods are different. piston rings are same for all years.
In short, the PRB head will out flow the RBB head all day. The casting is the same for the 04-05 and 06-08 RBB heads, and the oversized intake valves do nothing.
Via K20A.org...given the dyno is comparing the FD2 RSP head vs. the RBB 36mm head, it still gives a good comparison between the K20 and K24 style heads.
"Back from the dead with another test on a different motor
2008 stock TSX (longblock) with:
RRC IM, Injen Intake, P2R TB spacer, Header & exhaust
before stock RBB head with stock valves (+1mm oem intake)
after RSP with Ferrea 6000 (std size) valves. Gained 19whp up top! fyi we were able to eliminate the tq dip from 5000-5700 with a stepped intake w/velocity stack. Getting that to fit is another story LOL"
![Image]()
Also, flow charts for most of the K series heads.
![Image]()
http://www.k20a.org/forum/showthread.php?t=107797&page=2
Via K20A.org...given the dyno is comparing the FD2 RSP head vs. the RBB 36mm head, it still gives a good comparison between the K20 and K24 style heads.
"Back from the dead with another test on a different motor
2008 stock TSX (longblock) with:
RRC IM, Injen Intake, P2R TB spacer, Header & exhaust
before stock RBB head with stock valves (+1mm oem intake)
after RSP with Ferrea 6000 (std size) valves. Gained 19whp up top! fyi we were able to eliminate the tq dip from 5000-5700 with a stepped intake w/velocity stack. Getting that to fit is another story LOL"
Also, flow charts for most of the K series heads.
http://www.k20a.org/forum/showthread.php?t=107797&page=2
So... there must be other things at play with the RBC then? Cuz I've clearly seen gains demonstrated in the higher rpms once tuned. Maybe resonances with the flow into the cylinder chambers, etc.
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