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96 civic HX K24a
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9/26/20 Progress

Today I am working with my extra PRB head. I have been using it for practicing porting and polishing and learning the apex's and concave pockets of the intake and exhaust ports. I am planning to hand PNP the PRB I am using in this build. My intentions are not to wildly bore the ports, I want to mildly accent the existing ports by hand and some machine. My goals are to do better than the RSP head and still keep a strong baseline platform. I want to see the difference the modified RBC IM makes, improve the intake and exhaust ports some, supply a lot of air from a ram air system, and keep the Z1 (PRC) cams. I am not after huge gains from the jump, keeping velocity while making cfm gains is my goal. I am more interested in seeing how well all of the intake and exhaust improvements work together that I have designed.
Taking notes. I have a 06 PRB head on the shelf that i would love to be able to do some work on but as far as porting goes my experience is 2 throttle body openings 🙄😂
 

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Throttle Body boring is a good start to get a feel for removing cast aluminum and learning how different burring bits feel, how certain grit sandpaper feels, etc. When I TB bore, I also taper the bore.

The next step is doing the rest of the intake manifold. Many people underestimate the task, they ruin the important balance between air velocity and cfm improvement. Too much stock is removed in the wrong places that hurts velocity. Too much stock removed in certain areas cans hurt the beginning stages of fuel atomization. And of course at the end of the runners where they meet the head's intake ports - what is port matching ?

Believe me I am not getting on K20a.org and talking like I know this and I know that. There are plenty of pioneers in this business that have figured out how to do this kind of work. However, they had to start some where and had to start on gut feelings, practicing, and finding out if I do this the result is this. I am one of those people that is starting. I have only ported and polished one K series head and I have ported and polished (4) RBC IM's, (1) PRC, and (2) PRB IM's. I prefer to port match RBC IM's to PRB heads b/c once the plenum is removed I can see down the 75% of the runners and use feeler gauges to find out if there is something that needs to be smoothed out. It really helps lining up thermal intake manifold gaskets which disrupt the the meeting angle of IM to cylinder head port.
Areading your post it got me curious, so I went and looked at my thermal intake gasket against the rbc I have, and my rbb-2 head. The first pic is on the rbc , second the tsx head. I thought it was strange to see that it looks like the rbc ports are a bit smaller.
Auto part Metal
 

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View attachment 102561

RBC IM to K20 PRB head. I am not exactly done, there a tiny bit to remove on the last one.
Looks good. I have a couple no name thermal gaskets, one for tsx and one for rsx. I checked the prb gasket against the rbc ports and there wasn’t quite as much leftover but still not a perfect match. I have a friend who’s skilled in these areas, but I’m not sure what the cost would be vs attempting my own matching up. But I would like the incoming air to have a proper path from throttle body to the valves.
 

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No sir. Just 3.5" intake for now. I might play with a 4" section one day. Once I cut the 2" x 4"x Aluminum concentric reducer, I will have a 3.5" x 4" reducer leftover
Gotcha that piece of pipe in the box looked like 4”. I’ve been looking around online for little sections of 3.5 and filter / v stack combos to make my own short ram and cold air when the time comes. But it sounds like what you’re making is going to be way cooler lol.
 

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Unfortunately no the hood has not been cut for the Ram Air. It can still happen though. We picked up the OEM upgrade cast exhaust manifolds that come with the Ram Air 2 package. She is on 5" of gravel pack. It doesn't get wet from the rain with the closed in shelter garage and a car cover. 96,000 miles orginal
View attachment 102656 View attachment 102657 View attachment 102658 View attachment 102656 View attachment 102659 View attachment 102660
That is badass. Is that the original steering wheel to the car ? I don’t know too much about these, but I dig it for sure 👍
 

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Mr. LotusElise check this out brother.


This is the Radical SR8 at VIR in my home state of Virginia. VIR (Virginia International Raceway) is one of the United States best road course racing establishments. At VIR, the Ariel Atom is solely made there and tested there as well. VIR has been coined "the Nurburgring of the United States" in which once the entire track is opened up it offers 4-1/2+ min lap times. I have been taking NASA/SCAA road course classes there since 2005. Doing a 1:44.4 second lap time on what is call the "full course" or the outer ban section is fast. Once the inside tracks are opened up and all tie together, the "Nurburging of the United States" lap sections come together.

One of my great friends, tuner, and professional racer just sold his Yellow "Duck" 2001 Acura Integra Type R that spent many years there tearing up VIR and drawing many other drivers to a walk over to DC2-R to see why it just spanked them out on track. The DC2-R has a JRSC K20a2 swap w/ IPS SC Cams, Eibach Valvesprings, Ti retainers, custom Hytech header, 3" Thermal exhaust, 3" CAI, Pyrometers installed, Brembo BBK w/ Carbotech Pads made for a 3500lb. car, custom Tein coilovers w/ insane spring rates, custom muilt-link front adjustable camber arms, and an endless mod list that cripples most bank accounts. Please note while watching this video of the Radical, one the back straight the 01 DC2-R is hitting the same MPH as the Radical with a 200lb. passenger. I cannot explain the shear pleasure I felt each time I was driving the car or riding shotgun in the car hitting those speeds on the back straight at VIR, in which no one believed us that the car was pushing past 140 mph on the back straight. An on-board cam had to be installed in order to prove going past 140 mph, not to mention hitting 160mph then quickly triple downshifting to enter the downhill roller coaster S turns.

This is some info on the Radical SR8 in case you were not aware. The SR8 is a more extreme version intended for track use but can be registered for the road. The SR8 also features one of the largest engines Radical has ever put in their cars, with the 2700 cc RPE RPX V8 constructed by combining elements of Suzuki inline-4s, and producing 430 horsepower (321 kW). A further variant, known as the SR8LM, increased the engine to 2800 cc and brought power output to 455 hp (339 kW). In August 2009 Michael Vergers, driving an SR8LM, set the new lap record (6 minutes, 48 seconds) for a road legal production car at the Nürburgring Nordschleife circuit.[4][5] This record was beaten by the 991 generation Porsche 911 GT2 in September 2017 with a time of 6:47.25.[6]

The SR8 has the most impressive specifications of any Radical model, bar the RXC Turbo, Turbo 500 and the race cars. It is capable of 0–60 in 2.7 seconds, 178 miles per hour, and a 2.5 g's of lateral acceleration.
Thank you for the good information you supply K20a.org with. I really am thankful for your efforts and dedication to providing good information. I put together a little post for you of a neat build being raced in my home state of Virginia. I hope you like it. I also sent you a video of a Lotus with a turbo K24.
I second that ! I always feel like I learn something I never would have otherwise with the posts from @LotusElise . Much appreciated to anyone who takes the time to spread the wealth of knowledge.
 

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Thanks for getting me clear on the exhaust valve size due to piston valve contact. I didn't even think about that fact.


Thank you brother from another mother. In 2012, I was diagnosed with Sinus Tarsi Alignment Syndrome and once of the worst cases the best foot ortho doctor has seen in 30 years. The cartilage in both ankles was gone and I was on bone on bone over 75% of the ankle joints. The tendons in both ankles were too far gone to repair and were insurance risks to re-attach them to the bones - if they were to only repair them I would have been left with a 80% mobility loss. So the only other option I had was to fuse both ankle joints, leaving me a 50% mobility loss. May 2013 I had my 1st left ankle fusion, then back to work supporting the family, March 2015 1st right ankle fusion, then back to work. 11/2015 additional right ankle fusion work and exoskeleton bone removal. 10/2017 4th right ankle fusion hardware removed and back to work. Raising a family leaves a man no time to recover and repair himself. Needless to say, the ankle fusions didn't warrant me to go back to the output I once did.

I have Hypertension 2 and a pulse disorder - I take 3 blood pressure meds and Lipitor. I skateboarded for 23 years of my life. I played sports. I started doing construction work in 1994. By 1998, I was taking 6G X-Ray pipe welding tests. I am a pipe fitter by trade, pipe welder by trade, metal fabricator by trade, and a structural welder by trade. By no means was I easy on my body. I do not give up easily.

I have one 9 year old daughter. My 3 step-sons (bonus kids) are gone now because of the divorce. I homeschool her. My sister's 3 kids are here b/c of her surgery - so I am getting them through their virtual school days. Which leaves not much room left for working on the car. So I am getting up at 430AM eastern time (east coast time) to work on the car until 730am - then school time until 4pm. Some days I get a 2hr period in there to do stuff. Last weekend it rained all weekend and that made jacking the car up, putting it on stands, and pulling the engine and tranny out.

I just had to order more parts and tools to do my job correctly, so that is good.
Damn dude that’s quite the story. I have some ankle and knee problems from skateboarding all the early 2000s when I was still in school, definitely no fun when doing normal tasks although mine are just bone spurs and strains . The cold weather doesn’t help things either. Sounds like you have made many sacrifices to keep your family going strong , as a good man would. I hope you’re able to get your build done for your daughter without too may painful times.
 

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Thanks for getting me clear on the exhaust valve size due to piston valve contact. I didn't even think about that fact.


Thank you brother from another mother. In 2012, I was diagnosed with Sinus Tarsi Alignment Syndrome and once of the worst cases the best foot ortho doctor has seen in 30 years. The cartilage in both ankles was gone and I was on bone on bone over 75% of the ankle joints. The tendons in both ankles were too far gone to repair and were insurance risks to re-attach them to the bones - if they were to only repair them I would have been left with a 80% mobility loss. So the only other option I had was to fuse both ankle joints, leaving me a 50% mobility loss. May 2013 I had my 1st left ankle fusion, then back to work supporting the family, March 2015 1st right ankle fusion, then back to work. 11/2015 additional right ankle fusion work and exoskeleton bone removal. 10/2017 4th right ankle fusion hardware removed and back to work. Raising a family leaves a man no time to recover and repair himself. Needless to say, the ankle fusions didn't warrant me to go back to the output I once did.

I have Hypertension 2 and a pulse disorder - I take 3 blood pressure meds and Lipitor. I skateboarded for 23 years of my life. I played sports. I started doing construction work in 1994. By 1998, I was taking 6G X-Ray pipe welding tests. I am a pipe fitter by trade, pipe welder by trade, metal fabricator by trade, and a structural welder by trade. By no means was I easy on my body. I do not give up easily.

I have one 9 year old daughter. My 3 step-sons (bonus kids) are gone now because of the divorce. I homeschool her. My sister's 3 kids are here b/c of her surgery - so I am getting them through their virtual school days. Which leaves not much room left for working on the car. So I am getting up at 430AM eastern time (east coast time) to work on the car until 730am - then school time until 4pm. Some days I get a 2hr period in there to do stuff. Last weekend it rained all weekend and that made jacking the car up, putting it on stands, and pulling the engine and tranny out.

I just had to order more parts and tools to do my job correctly, so that is good.
I’m up at 430 daily as well 😆 early to bed and early to rise 👍 gives me some good time in the garage and on modern warfare before work 😂
 

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The valve seals were leaking oil. I am putting the head back together with new seals, retainers, keepers. I cleaned the combustion cambers very good and the exhaust ports are cleaned completely. I used a thin strip of 80 grit sandpaper and cut it very long. The trick for me was to carefully drag the strip of sandpaper against the floor to the valve seats. I did this after using a pick to remove the old stuck on exhaust smutt. I did what I said I would do and lightly ported the intake ports by hand. They look like RSP ports just a tiny bit better. The head is ready to be put back together
Glad to hear you are still at it and making progress, hope the holidays went well for you and the family. I look forward to more posts 👍
 

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Hey KBuilt ... Thanks for the encouraging words brother. I hope your family and the holidays went the same for you. I am still at this build, I am not giving up and going to sell my build off like others.
we had a great time ThAnkyou. I am guilty of giving projects up in the past , but have made a pact to keep this current one for good, sparing nothing. 👍
 

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T
Yes I checked the service limits in the Honda manual. That is always interesting hearing good things about the K24A1 head and that it does flow so well. I am hoping my head flows well with the mild port I did, the port match to the intake manifold. I have been studying valves and valvetrain weight reduction for my next project or my next engine build. I would like to play with compression gains and valvetrain gains with a 4Piston head and better cams with ITB's.
Are you still thinking of using the tsx port ? It’s been on my mind to put the PRB head on my k24 block and then use the rbb head with some work done on the k20z block for a backup. Your ports look nice snd clean 👍
 

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I thought the weight of the valve springs was a cool find. I feel like I have made a good decision going with the 2005-2006 Z1 valve springs, which will match the Z1 (PRC) cams better. The 2002-2004 retainers weight 13.0g and the 2005-2006 Z1 retainers weight 13.5g.

So in order to use the Z1 valve springs, I needed to retrieve the valve seats from my extra K20Z1 head ( which I finally completed this morning ). In that process, I noticed the previous owner of the Z1 head had been using Supertech valve seals. Before I searched to discover they were Supertech's brand seal, I said to myself something is wrong because they look very different from the 2002 K20A2 OEM valve seals I recently purchased for the rebuild. So after cross referencing the part number's for the 2002-2004 K20A2 & 2005-2006 Z1 valve seals -- And they were both the same part numbers for Intake Seal A (12210-PZ1-004) & Exhaust Seal B (12211-PZ1-004).

I can't help buy wonder why the previous owner of the Z1 head ended up using the Supertech valve stem seals. The Z1 cams that came from that valvetrain match up are in great shape. I am still going to verify the VTC gear is functioning correctly before they are installed. By while the cam gears and camshafts are assembled, tape up the holes on the camshafts, poke a hole in one of the taped holes, and use compressed air to inject air inside & watch the VTC slide and make sure it is moving correctly.

I really want to replace the valve guides in the K20A2 PRB-1 head I am using at this point. The process looks & seems very simple. At this point I need to get the build and the car on the road. I really need to tackle this task later on after I have saved up the right amount of money to rebuild & spec the bottom end correctly for higher rpm's with higher compression, ITB's ( or a ported & polished RRC IM ), make the step up to a camshaft like Toda's equivalent of a stage 2-3, a very lightweight valvetrain, and a ported 4Piston head with larger valves. The goal in mind is a 2.15L displacement, usable power band in the mid's and the top end. Basically a badass NA road course engine.
I like the sound of that , the k20 rpm capability mixed with more torque and midrange 👍
 
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