Honda / Acura K20a K24a Engine Forum banner

How To: Modify The RBC Manifold (k24a1)

31K views 23 replies 8 participants last post by  le6ion66  
#1 ·
Sooooo,any body feel free to correct me if I'm wrong. I got an RBC manifold, and wanted to install it on my stock k24a1. So i bolted it up and noticed the coolant passages were very different. Did a little research, found out i had to cut the coolant passage off the RBC and use the stock one off the K24a1. So here's how i went about it.

First off: How it looks without cutting the passage off:

Image



So first i used the Stock K24a1 intake manifold gasket, used bolts to make sure it was steady (as well as some one holding it steady) and marked the end of the gasket with a sharpie. The Inner line is where it ends the outter is where i started cutting, you can always take off, you can't put back.

Image



This is as i'm cutting it.

Image


And after test fitting it a couple time's and seeing where i needed to take more off, finally got it all lined up.

Image


and here's the piece i cut off of the RBC
as well as my help.

Image





Hope this helps. Please let me know if there is a better way!


T
 
#2 ·
Forgot to add, I used a grinder to do the first cut and trim off the big stuff, i then used a dremel to clean it up. (not shown). used a shirt to cover and help prevent sctraching and dust. Then after all said and done ( AND BEFORE YOU MOCK FIT ON THE ENGINE) blow out ALL cavities with a blow gun.

Shoots, hope this helps. Aloha
 
#3 ·
Did you grind off the rest of the RBC water passage that is still showing in the pic where it's mounted to the engine(after you modified it) or no?
 
#4 ·
Yeah i used a dremel cutting wheel(about 2, aluminium is soft) and a dremel grinding stone. I was wondering though i still kinda want to polish it or do something to make where i cute look a little cleaner? i did all my strokes one way on the last few passes so it looks directional and symetrical but still not all that pleased. any ideas ontouch up?
 
#5 ·
well,that area will still lok different unless you gring the whole manifold that way(just to texture it,not really remove metal).You could polish the manifold or powdercoat it(smoothing out the whole manifold will make the powdercoating look even).Alternatively you could wrap it in DEI reflect-a-gold or a similar material,nice shiny gold tape and functional heat rejection(in the area of 80% reflection of radiating heat,combined with a thermal gasket like those made by Hondata and you seriously lower intake temps).
 
#6 ·
hmm, could be nice i will def look in to it. Do the Hondata gaskets REALLY make that big of a difference? I guess i could def seeing it make a difference. but kind of curios if any body has any temp. numbers that you have seen? i.e external temp of the manifold?
 
#7 ·
well,IF you believe hondata(which in this case I do) they claim an IAT drop or roughly 10 degrees,I've seen as much as 15 by a magazine that tested them.That was on an unwrapped manifold in the cramped engine bay of an 8th gen honda civic Si,I'm sure in a more open engine bay and with some sort of heat reflecting film you'll much lower temps,moreso if you were to the manifold and intake in reflect-a-gold.
 
#10 ·
That looks good. I'm pretty sure that hole is not threaded on my head. You tapped it? It looks good painted too!
Also, you say the radiator will effect IAT i can see that, but i was wondering do you have a Full radiator or a half? I would think a full would cause the manifold temp. to rise more.
 
#21 ·
Yeah I always trim the RBC's down even when used on the Z3 and TSX heads. I had that mani powder coated black along with the VC and fuel rail. I smoothed and coated the coolant outlet and the timing chain cover with black Polane.
 
#15 ·
lol those border collies are so smart, we have 5acres for the girl to run around on, she only got shocked once and know the boundries already. lol i always feel bad though the first time they get shocked.

11SEC_CRX:
I'm not sure if i understand what you mean? do you mean they are interchangable? Or that they are the same stock?
If you look at the pics Look at where his water outlet is on the side by the cam sensors, and then on my head its right next to the Intake manifold?