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ok, this thread might be kind of dead. Im hoping to have my question answered.

I have a bone stock a3 going into an EK. For my vtec killer setup i would like to just swap the a3 intake rockers for a3 exhaust rockers. I will be using a2 cams and cam gears and doing the timing myself.

WILL MY SETUP WORK? im thinking so... without grinding or modifying the a3 exhaust rockers.

I also have the option to just buy 4 CRV exhaust rockers.... I am pretty sure i will have to grind them though.

Any info would be great thanks!
 

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:facepalm: thanks haha
 

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lol no worries. Some havent had to mod the rockers... others have.

In my case i had to, i was using k20z3 cams and the newer style exhaust rockers. Both sides (IN/EX) had to be modded for clearance. Here are mine for comparison...





All i used was a dremel tool with two reinforced cutting wheels stacked on top of each other. The rest is a steady hand...

My suggestion is for you to do a dry assembly, bolting everything down in place (no cam gears/timing chain) and turning the cams over by wrench, checking each lobe for clearance of the rocker. Mark the rocker with a sharpie and mod if need be. Better to be safe than sorry...
 

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Thanks a lot man that's a good visual! I'm sure it will help others as well. I know I'm going to be using the new rockers so cutting will probably be necessary. I'm using a2 cams and gears. I was hopin I could just use the grinder I have in the garage but a dremmel is more likely.
 

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No prob man. :new_slayer:

If you had a bench grinder and could turn down the speed... if not... one slip and BAM... youre fuct. The Dremel was a little easier to use IMO.

Youll see once you get at it... two lobe VTEC cam lobes and rocker rollers arent as wide as their three lobe cousins. Thats the majority of the clearancing needed.
 

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hey guys, hope i can get some answers here, not getting any luck in other forums. I have an asian 8thgen civic, k20z2 engine similar to k20a3. I just bought k20a2 cams and rockers etc for $200
not the actual pic, but similar to what the seller posted,


I was gonna do the exact same thing on the first page but i found out that my engine head is an rbc head and it has holes for the lost motion springs.



my question is, can i just buy lost motion springs and drop the entire k20a2 cam assembly(with rockers, towers, etc) that i just bought into my engine head and have a regular working vtec head?
what other things do you guys think that i also need to replace? vtec solenoid?

My concern is that, if i do this, im not sure about the oil passage to activate vtec especially on the exhaust side, what if it doesnt switch to high cam in the exhaust?
 

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Im not personally familiar with the k20z2 BUT... if you can take a clean downward shot of the head where the #1 cam support sits on the head, and the bottom of the #1 cam support, i can better answer your questions.

If i remember correctly you CAN buy the lost motion springs separately from Honda... its the rocker assemblies you cannot buy separately. That includes the pins and springs that are supposed to be in each rocker. If youre missing any of those...

:scared:
 

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i can't take pics of my own engine as i am out of the country right now. I only got the pics from this thread. http://www.k20a.org/forum/showthread.php?t=71150&page=2

This guy installed typer cams and rockers on his k20z2 head, tried to pm and email him but no reply. I wanted to make sure that there was no vtec activation issues especially on the exhaust side.

here's an overhead shot of the head


i already bought the rocker assemblies, it came with the k20a2 cams. :)
 

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The head looks to have the same oil passages as a k20a2 or even a k24a1 for that matter... so as long as your cam supports are the same (and they should be), and you have the right rocker shafts... you should be just fine from that stand point.

Spool valves (on the back of the head) should interchange as well. Check the body for this stamping...

 

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The head looks to have the same oil passages as a k20a2 or even a k24a1 for that matter... so as long as your cam supports are the same (and they should be), and you have the right rocker shafts... you should be just fine from that stand point.

Spool valves (on the back of the head) should interchange as well. Check the body for this stamping...

thanks for helping out bro. ill post better pics when the parts arrive. And the spool valve should be the same. if not i can do vtec killer on the exhaust. lol and 3 lobe intake
 

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Re: How to get A2 cams to work in an A3 Head

Can someone reupload pics or post a thread with the same pictures from a different forum?
 

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i read the whole thread, the whole ten pages, and i dont seam to find the answer to my questions :frage::fuuu:

I have a complete K20A2 HEAD (piston hit valves)

i also have a complete k24a1 head.

what exactly do i need to do in order to combine these two heads?
parts i need? from what head?

additional parts i might need?

piston to valve clearance if i use this head (k24a1) (already modified with a2 internals if possible) on a k24a2 block or a k24a4 block.
:door:

please share your experience thank you
 

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i read the whole thread, the whole ten pages, and i dont seam to find the answer to my questions :frage::fuuu:

I have a complete K20A2 HEAD (piston hit valves)

i also have a complete k24a1 head.

what exactly do i need to do in order to combine these two heads?
parts i need? from what head?

additional parts i might need?

piston to valve clearance if i use this head (k24a1) (already modified with a2 internals if possible) on a k24a2 block or a k24a4 block.
:door:

please share your experience thank you

k20a2 internals will not work in a k24 block. Stroke and bore are incompatible.

1) Strip the k24a1 head of everything but the valves (including valve stem seals).

2) Strip the k20a2 head of everything but the valves (including valve stem seals).

3) Install everything from the k20a2 head into the k24a1 head, in this order...

- Install valve spring seats
- Buy and install new valve stem seals
- Install valve springs (EX to EX... IN to IN)
- Buy new retainer cotters or 'keepers'
- Install valve spring retainers using new cotters/keepers

Install the entire rocker and cam assembly out of the k20a2 head. Flip the pins per instructions. If you need another pic let me know.

Valves beteen the k20a2 and k24a1 are the same... so if you have some that are bent in the k20a2 head... the valves in the k24a1 are fine to use... and you can mix and match if need be. Just remember the intake valves stay on the intake side, and the exhaust valves stays on the exhaust side.

Wallah. Youve just assembled a mini-VTEC head. :new_slayer:

There has been discussion over full VTC clearance with a k24a4 block/pistons. Ive never built on a stock k24a4 block... so i can only share what i have read regarding that. The rest is hands on experience. You can use this head with k20a2 cams without worry on a k24a1 block, stock pistons... and a k24a2 block, stock pistons.

If you use larger cams like 06/07 k24 three lobe cams, or other larger aftermarket cams... you may have an issue with PTV contact. This is when you modify the VTC assy for 40/45 degrees max and get into claying the head to GUARANTEE clearance.

That is NOT to say you will NOT clear... that IS to say... to be SURE you WILL clear. There are too many variables to consider from engine build to engine build to give you a definite yes or no when tolerances get that close. Not to mention... you could over rev and ruin that slight chance of proposed clearance anyways...
 

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THANK YOU SO MUCH INFORMATION WAS HELPFUL. At the moment I was able to pick up a a complete k24a2 head that I will try to use for my k24a4, I will consider to use my k24a1 head with k20a2 full internals!

Again thank you for the information I just wanted to make sure exactly what needed to be done since this whole thread left the procedure and parts in the grey area hahaha.

I'll keep you guys updated, and let you know how it goes!
 

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All you need to do is take the long pin in the middle VTEC rocker and move it to the rocker on the left, and take the medium length pin in the left rocker and move it to the middle VTEC rocker. The short pin and spring remain the same in the right rocker. Repeat for every rocker set.

Tune.

Done.
 

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All you need to do is take the long pin in the middle VTEC rocker and move it to the rocker on the left, and take the medium length pin in the left rocker and move it to the middle VTEC rocker. The short pin and spring remain the same in the right rocker. Repeat for every rocker set.

Tune.

Done.
wow big thanks!
 
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