im just wondering... what does it take to raise the compression of our usdm motors... all the jdm motors compression ratios are high... what do they do to raise them... raising them would increas power wouldnt it..
i unno...

boost?


Modified by Dj14aZnS at 8:44 PM 9/11/2005

 

If you wanted to boost you would want a low compression ratio. You can raise compression depending on motor by changing out Pistons, Decking your block etc etc. There are a lot of ways to raise compression ratio just depends on what engine your planning to do it with.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NAiL05 &raquo;</TD></TR><TR><TD CLASS="quote">If you wanted to boost you would want a low compression ratio. </TD></TR></TABLE>

there are advantages to boosting a mild compression motor. but yes all the things stated above will raise compression. i think jdm motors use a thinner headgasket so that is why some might be around .2 higher cr....

 

i know that boost works good with low conp. but im just saying ... with a n/a f22b1 what will higher compression do for it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dj14aZnS &raquo;</TD></TR><TR><TD CLASS="quote">i know that boost works good with low conp. but im just saying ... with a n/a f22b1 what will higher compression do for it?</TD></TR></TABLE>

Not much without a more agressive cam.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Escobar &raquo;</TD></TR><TR><TD CLASS="quote">Not much without a more agressive cam.</TD></TR></TABLE>

higher compression will inheritly make more power....your making the air fuel more dense....

 

so lets take the h22 for example.. if it was sohc would its compresion still be the same.. or is it the cams that make up most of the compression?

 

Whoa whoa whoa. Slow down. I suggest you go to http://www.howstuffworks.com and take some time to read through their article on how the internal combustion engine works. You're mixing up a lot of different things. The number of cams don't determine compression and neither do the type of cams.

Compression is a ratio between the volume in the cylinder at Top Dead Center and Bottom Dead Center. Or the ratio between the piston all the way up and all the way down.

Decking your block will lower the top of the combustion chamber making the volume smaller at TDC but also bringing your valves closer to the piston. Therefore decking the block too much can cause valve clearance issues. Valves dancing on pistons is NOT good.

Anyway, I don't want to get too far so I suggest you go to http://www.howstuffworks.com first and then if you have some more questions repost them here.

 

LOL.

Agressive cams have longer duration. Longer duration makes you lose compression.

Reading "how stuff works" will not explain this to you. Experience will.

If you're going to go through the trouble of putting high dome slugs in your F22, do yourself a favor and get a bigger cam to take advantage of your new found compression....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Escobar &raquo;</TD></TR><TR><TD CLASS="quote">LOL.

Agressive cams have longer duration. Longer duration makes you lose compression.

Reading "how stuff works" will not explain this to you. Experience will.

If you're going to go through the trouble of putting high dome slugs in your F22, do yourself a favor and get a bigger cam to take advantage of your new found compression.... </TD></TR></TABLE>

? huh? lol

all i wanted to know was what factors into raising compression... i was thinking it had to do with the cylinders and pistons...

if you got bigger (in diameter or length?) pistons... would that raise compression?

 

Pistons can't really get longer but they can have a raised dome which will increase compression.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dj14aZnS &raquo;</TD></TR><TR><TD CLASS="quote">

? huh? lol

all i wanted to know was what factors into raising compression... i was thinking it had to do with the cylinders and pistons...

if you got bigger (in diameter or length?) pistons... would that raise compression? </TD></TR></TABLE>

No. You asked

&gt;&gt;i know that boost works good with low conp. but im just saying ... with a n/a &gt;&gt;f22b1 what will higher compression do for it?

There is your answer.

 

getting raised dome pistons will do it. Putting a turbo will do it. be careful you dont detonate your engine. If you raise your comp... start running higher octane fuel.

 

running a turbo does NOT raise compression.

pistons, block decking/head milling, thinner head gasket, sometimes cams, all these can cahnge ur compression, most make it higher, but cams can make it lower.

 

if you run a turbo your stock pistons you will raise your compression.

 

wtf? give me an article that states that. where did u hear that? word of mouth?

i have NEVER heard of this, maybe thats cuz its not true.But find an article that states that a turbo will raise the compression, then i will believe you.

 

i would never use a thinner headgasket. a thicker one sure but never a thinner one. and if you are really serious about raising compression to get more power why not look into different gear ratios for your transmission. im sure that will make it go much quicker than it is now. [dont know if anything like that is available for cheap though]

 

There is so much crap flying around in here it is ridiculous. Every single person here needs to buy a decent book about engine theory and READ it. Please.

 

yes, thank you for posting something stupid. ^^^. pls dont post **** thats absolutley NOT neccessary.