i have a 99 prelude that has a h22a4 that is in the car (lost a rod @ 107000 mi) i bought a short block it was suposted to be a h22a4 but it ended up being a h22a(jdm 30,000mi) . so i guess this question is this is a closed deck and my motor that is in the car is an open correct ? i have read throug a lot of the forum but i did not see it covered. are their any benifits to running one or the other ? Is all the wiring the same sesors .
thanks (by the way it will be turbo'd @ no more then 10lbsof boost at all times. all ready have new eagle rods new jg springs and ti retainers new valves oversized 1mm to regind seat am thinking arias forged pistons over bore .50 and balance .
i know that i will be heckled so i am prepaired thanks .


Modified by 2slo2bst at 5:47 PM 2/14/2006

 

closed deck will be better for hgih power motors, since the cylinder walls have morer support. an open deck is better for a daily driver, since it allows for the coolant to cool the cylinder better. i don't know if the sensors will work the same though. try swapping the sensors and see if all the oil/coolant passages line up just to see if it is do-able.

 

i have never seen a daily driver prelude hv cooling issues cause it has a closed deck. i am willing to bet that the only diff between closed and open deck was a cheaper production cost for the open deck....

 

main difference between h22a and h22a4 is two things. The open and closed deck is the most obvious. The second and more important to some motor builds is the main journals. The h22a4 is a 55mm main and the h22a is a 50mm main. that might make a difference in the build.

 

you are planning on sleeveing this block?

does it matter if its open or closed if you are sleeveing it anyway?

 

The higher compression pistons in the JDM H22a isn't going to help your turbo tunning..

H22a4 - 10:1
H22a - 10.6:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tarheelsoldier &raquo;</TD></TR><TR><TD CLASS="quote"> The h22a4 is a 55mm main and the h22a is a 50mm main. that might make a difference in the build. </TD></TR></TABLE>

make sure that you say 98+ is 55mm mains, because the h22a4 from the 97 has 50mm mains..

personally i like closed deck best.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kulrevon &raquo;</TD></TR><TR><TD CLASS="quote">you are planning on sleeveing this block?

does it matter if its open or closed if you are sleeveing it anyway?

</TD></TR></TABLE>

just depends on the type of sleeve. if you go with the all out wet sleeve then it wont matter what you start with, however if you just go repair sleeves then it will probably limit your bore potential due to lack of support at the top of the cylinder.

 

i wasnt planning on sleaving the block i was defently gonna bore to clean up the cylnder walls wasnt planning on sleaving unless needed but being as i olny lost a rod i wasnt planinng on it .

 

you do know that you can't run forged pistons in the frm prelude block? and I don't think you can bore the stock prelude motor .5.

 

So with a closed deck you trap more heat and the open deck has limited support? However closed decks don't seem to cause any particular over heating problems and open decks don't just fail and blow?

I guess if you were building it up or riding it stock it really makes no difference.

I'm also getting the impression that all H22As are closed deck like the A1s and 97 A4s.

 

so does a sleeved open deck block have less wall support than a closed one? or sleeving is strong no matter its open or closed?

 

The block will work. You may want to run the old pistons, and you may want to move the old oil pump to the new block to get the crank position sensor to match the existing wiring. Use the closed deck head gasket. Oh, and if you have atts you will want to make sure it will bolt to the new block.

 

what i ment to say was .5 mm to an 87.5 mm i thought i read in the fourm building a motor that u could use a wiseco or the mahule piston if it was coted with somthing . i have been thinking more and more about sleaving with just regular darton iron sleeves not M.I.D sleeve because that costs like a thousand buck or more right? where just a regular sleve is olny a couple of hundred bucks . with the new steel sleeves i wont be running into any prolbems with the type of piston i will run correct?