Compression - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

A Dying Devotion · 03-31-2003, 02:04 PM

I just did a compression test on my 89 with 201,000 miles here are the results of my test:

Cylinder 1: 152
Cylinder 2: 155
Cylinder 3: 152
Cylinder 4: 152

Engine runs really strong but im not sure if those #'s are good or not could anyone give me some factory #'s so I can compare. Thanks.

kandyflip445 · 03-31-2003, 02:12 PM

They are fine. The slightly lower compression ratio is due to wear. An interesting thing i heard of one time is that compression being lower across all cylinders COULD also be cause by VERY SMALL timing problems.....I don't really wanna get in to it right now but I'm sure someone could figure out what I'm talking about.

A Dying Devotion · 03-31-2003, 05:07 PM

So im pretty much in the average range of compression? Is their anything I could do to bring those #s up. Also what type of spark plug wires do you guys recommend. I bought some NGK plugs today but still need the wires, thanks a bunch.

Kreator · 03-31-2003, 07:24 PM

umm those are quite low. 140 is a factory rebuild time.

There is nothing u can really do about it, but it's fine, and i'd really not get into rebuilding it. Drive it while it lives, swap it out when it dies.

Tuck&Poke · 03-31-2003, 07:26 PM

what are the factory compression numbers for a ka24de, im looking at one for sale and i wanna check the compression cause its got kinda high miles (103K) for a 96'. im gonna see it this weekend or friday.

Fibercus · 03-31-2003, 07:43 PM

Anyone know the factory compression? on a brand new KA24DE

Tuck&Poke · 03-31-2003, 07:56 PM

Quote:

Originally posted by kandyflip445
They are fine. The slightly lower compression ratio is due to wear. An interesting thing i heard of one time is that compression being lower across all cylinders COULD also be cause by VERY SMALL timing problems.....I don't really wanna get in to it right now but I'm sure someone could figure out what I'm talking about.

could be that timing is advanced or retarded and a valve is slightly open at the top of the stroke....? i dunno im speculating w/ somewhat limited knowledge of engines....

kandyflip445 · 03-31-2003, 09:13 PM

Yes it has to do with the timing being slightly retarded(what a pun....). The intake valve would be opened a little later then it should be and the exhaust would be open later also......but this is still a "theory" to me....I haven't tested it out yet. I'm supposed to in my automotive class. My teacher heard it from another technician and he's the one that told me about it. I'll let you guys know what we find though when we get around to it.

Tuck&Poke · 04-01-2003, 10:28 AM

no ones got the numbers?

Kreator · 04-01-2003, 11:15 AM

180psi

another thing to kill the compression is use low octance gas. In a long run it'll wear the piston rings down

kalieaire · 04-01-2003, 11:22 AM

151 psi is min.

179 is max.

(why the heck does zilvia not let me post??)

put oil in the cylinder the next time you do a compression test, and make sure your efi fuse is disconnected, and floor it when you turn over your engine.

if the capfull of oil brings the compression up, your rings are worn, if not, it's the valves.

03-31-2003, 02:04 PM	#1
A Dying Devotion Leaky Injector Join Date: Jan 2003 Location: Murrieta, CA Age: 38 Posts: 80 Trader Rating: (0) Feedback Score: 0 reviews	Compression I just did a compression test on my 89 with 201,000 miles here are the results of my test: Cylinder 1: 152 Cylinder 2: 155 Cylinder 3: 152 Cylinder 4: 152 Engine runs really strong but im not sure if those #'s are good or not could anyone give me some factory #'s so I can compare. Thanks. __________________ Your my blessing in disquise, you make me realize, just where I want to be years from now.

03-31-2003, 05:07 PM	#3
A Dying Devotion Leaky Injector Join Date: Jan 2003 Location: Murrieta, CA Age: 38 Posts: 80 Trader Rating: (0) Feedback Score: 0 reviews	So im pretty much in the average range of compression? Is their anything I could do to bring those #s up. Also what type of spark plug wires do you guys recommend. I bought some NGK plugs today but still need the wires, thanks a bunch. __________________ Your my blessing in disquise, you make me realize, just where I want to be years from now.

03-31-2003, 07:24 PM	#4
Kreator Nissanaholic! Join Date: Mar 2002 Location: MD Age: 41 Posts: 1,975 Trader Rating: (0) Feedback Score: 0 reviews	umm those are quite low. 140 is a factory rebuild time. There is nothing u can really do about it, but it's fine, and i'd really not get into rebuilding it. Drive it while it lives, swap it out when it dies. __________________ кто болеет за Зенит, у того всегда стоит!

04-01-2003, 11:15 AM	#10
Kreator Nissanaholic! Join Date: Mar 2002 Location: MD Age: 41 Posts: 1,975 Trader Rating: (0) Feedback Score: 0 reviews	180psi another thing to kill the compression is use low octance gas. In a long run it'll wear the piston rings down __________________ кто болеет за Зенит, у того всегда стоит!

04-01-2003, 11:22 AM	#11
kalieaire Zilvia Member Join Date: May 2002 Location: Milpitas, CA - SFBA Posts: 222 Trader Rating: (0) Feedback Score: 0 reviews	151 psi is min. 179 is max. (why the heck does zilvia not let me post??) put oil in the cylinder the next time you do a compression test, and make sure your efi fuse is disconnected, and floor it when you turn over your engine. if the capfull of oil brings the compression up, your rings are worn, if not, it's the valves. __________________ - -- - '93 240sx coupe '93 taurus wagon -kalieaire (maybe grinder too on special occasions)

03-31-2003, 02:12 PM	#2
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	They are fine. The slightly lower compression ratio is due to wear. An interesting thing i heard of one time is that compression being lower across all cylinders COULD also be cause by VERY SMALL timing problems.....I don't really wanna get in to it right now but I'm sure someone could figure out what I'm talking about.

03-31-2003, 07:26 PM	#5
Tuck&Poke Zilvia FREAK! Join Date: Aug 2001 Location: MIA Age: 38 Posts: 1,046 Trader Rating: (0) Feedback Score: 0 reviews	what are the factory compression numbers for a ka24de, im looking at one for sale and i wanna check the compression cause its got kinda high miles (103K) for a 96'. im gonna see it this weekend or friday.

03-31-2003, 07:43 PM	#6
Fibercus BANNED Join Date: Jul 2001 Location: Canyon Country, CA Age: 44 Posts: 714 Trader Rating: (0) Feedback Score: 0 reviews	Anyone know the factory compression? on a brand new KA24DE

03-31-2003, 09:13 PM	#8
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	Yes it has to do with the timing being slightly retarded(what a pun....). The intake valve would be opened a little later then it should be and the exhaust would be open later also......but this is still a "theory" to me....I haven't tested it out yet. I'm supposed to in my automotive class. My teacher heard it from another technician and he's the one that told me about it. I'll let you guys know what we find though when we get around to it.

04-01-2003, 10:28 AM	#9
Tuck&Poke Zilvia FREAK! Join Date: Aug 2001 Location: MIA Age: 38 Posts: 1,046 Trader Rating: (0) Feedback Score: 0 reviews	no ones got the numbers?