A2 head ?

[2k2hawksi]

does swapping heads change the redline on the engine and how reliable is the swap how much for the compltete head and ecu and common installation

[Siman]

well, for starters, changing the head would not "change" the redline so to speak, you would have to get the type-s ecu for that! the head is a DIRECT swap, if you know what you are doing it wont take anytime at all.....

but after you get the ECU in the car, it will run in "limp" mode, for short, the emobilizer code from the Si's key hole computer doesnt match the code for the type-s's ecu, therefore you must go to a honda dealer, show them the papers that you have bought the pieces legitamently, and pay about $80 fot them to switch the code into the ECU....

the bottem end, though not heavily tested, is thought to handle the higher rev limit of 8,000 rpm's....it is basically the SAME bottem end as the K20a2 motor,

the only downside to the performance side is that the pistons in our Si are only 9.8-1 vs. the type-s's 11.0-1 compression....so top end power wont be AS POTENT.....maybe you will run close to 190 hp at the Motor...there is about a 10 hp loss because of compression....but you can battle that with Spoons's or TODA's thin head gaskets, for one, you will need to replace the headgasket anyways every time you take off the head!

i am sure there is a little more to talk about but i will let a few others fill in what i have missed...

peace;)

[KeNnYtAkEr]

Originally posted by myeverlovinsir
I should start by saying I paid very little for my A2 head. (350US)
It included everything that was required (complete head), however I did have to get the valves reground to seat properly, after which the bleed through in cylinders 1 and 3 were fixed. I recommend you have a bench leak down and valve seat pressure test done BEFORE you put it on. Have it inspected for cracks/warpage/wear etc. by a qualified tech. (should not cost more than 150 bucks and well worth it)

The head I got also had dual (RSX-S 02) springs on the intake side and were fitted with new 03 single springs for the exhaust side. I have revved it past 8k rpm a few times and is not a problem for the head. The bottom end is where the constraints in rev limit would be IMO. Just don't expect it to be a safe 10k revving engine. You don't need a new valve cover, but I did swap out to a new head gasket kit. (40 bucks from the dealer)

I also swapped the timing chain to a new one, however it was not really required for the mileage I had. Use a new head gasket. You will have to upgrade your injectors to at least 310cc over the 270cc stockies. I got mine from RC engineering (400 bucks with wire connectors and fuel rail spacers). Get the RSX-S manual to know what special tools and the torque specs your need. I got the Helms which included the base model specs. The vtec solenoid is a straight swap and does not change. ECU and immobilizer will need to be matched at the dealer (40 bucks). You can run it on the A3 ECU until you have an A2 or Kpro, and would have that done sooner than later. You will be riding the large lobes on the A2 head @ 2200rpm as I did for a couple of days with the A3 hondata ECU, and it gave me an opportunity to see where the power occurs in the rev range on the large lobes. I currently have my vtec engage @ 4300rpm and think it's really close to where it should be until I dyno tune it. I have also advanced the timing by 2 deg on all low-speed and high-speed maps for all cam angles. I Will go to 3 deg and monitor the knock sensor to see where things are. Fuel will be tuned as well and is hovering around 13.5:1 average under load. It's worth about another 10-20whp to have it tuned correctly over the stock A2 ECU and it really depends on other mods you have as well. When I get it dyno tuned I will put up charts before and after. I am enjoying it too much right now as it is, and will likely not make many more adjustments before I get to the dyno. I also plan to have the JRSC fitted in the next month.

Good luck with the head swap, it's a great learning experience and may seem a little more involved than you origionally thought. It has been nothing but a great addition to my ride (along with the other mods I have)
I have over 4k miles on the head now and about 800 miles on the tranny/clutch/fly/brake kit:D

[myeverlovinsir]

Thanks, I read the title and thought oh shit, gonna have to set things straight again, arrrg.;)