<FONT COLOR="blue">-normal for a 80K GSR is???</FONT>
I did it the other day..and (I'm kinda hoping we did it wrong.. but I think we did it correctly)..
<FONT COLOR="blue">-I got 175/180 all the way across.. </FONT>
I know this isn't that great so what can I do .. (I'm poor btw) .. that will bring it back up to where it was..



Modified by Heisdan at 1:19 PM 7/19/2003

 

well to do the test you have to pull you fuel fuse..its the 15amp on the rear of your fuse box...hold the tb at wide open throttle and crank it until you get the highest compression #...it will eventaully stop going up any higher ans thats your number....i got 210's across the board on my gsr w/ 110k but seems to be your a little low....not a very good motor but still decent...prob in need of a rebuild in a year or so if you plan on boost or anythign else...

 

hmm.. yup correctly done.. which of course I'll do it again to make sure i"m not crazy ..

Rebuild as in .. pistons/rings etc head gasket (already replaced because we took it apart to fix an oil leak.. (gasket on left side of head))

or what else?

 

I didn't pull the fuse when i did the compression test on a 95 ls. Is that going to effect the #? It showed 175 to 180 on all. How long do you think the motor will last since its running a 55 shot zex kit used maybe twice a week?

 

you pull the fuse to turn off the injectors so you dont flood the motor. Does it make a difference in the numbers? probably not. I pull all the plugs and then start testing, it'll blow the fuel out the plug holes anyways.

 

it actually does matter...the fuel washes away any oil that is sealing the rings so you will get faulty numbers...if you still get lousy numbers try adding a cap full of oil thru the spark plug hole...if you still get bad #'s its your rings...

 

The important part on not blowing your motor up is having the numbers close to eachother, yours are great since they are only 5 apart. Keep in mind your is an LS, which has lower compression than that guys GSR.

My LS's compression was 175 to 181 and i'm spraying a 65 shot on it, so you should be fine. These numbers are effected by air temp and humidity anyway, so don't worry how high they are, just how close. Hope this helps, happy spraying.

 

that seems pretty low.
my compression was 230-240 across, 95 as well.

 

actaully he clearly states its a gsr w/ 80k...read! his compression should at least be 200 or else his motor hasnt been properly taken care of and isnt worth much!

 

and can i get some gnaze for my slo ***....

 

so the point of the question is.. what should I do?

 

a stab in the dark: leak down test?

 

if he's geting shitty compression number we already know its his rings...use a leak down test to see if you valve seals are leaking and other various things....but as long as you dont plan on running nitrious or turboing you car..it will be fine...but if you plan on adding any major performance a rebuild is in store...and those will set you back a few dollars round 3000 depending on where you go and what you get done...unless you can build a motor youself then its a lot cheaper...but then again i never touched my motor until i knew i was good at it and wouldnt mess it up...but i still send out all the machine work to a buddy of mine...and on a budget i can do a complete rebuild for a little over a grand...so id stick w/ what ya got and do another test in like a few months...in the mean time keep checkin your oil...and stay on time w/ the oil changes.

 

yup.. oil changes suck on this car taht's why I checked.. I run the **** outta it .. (can't do that anymore.. haha) and I just figured it was going down cause I ran it so hard.. I just got the car about.. 10K ago.. and I've put a tranny in it already.. (dude before me messed this car up bad!!)

Anyway.. I have a friend that does motor work for me.. I am learning everything but... I can't learn fast enough .. I've been reading/working with cars for only 2 years so I have a lot to learn..

So .. lets say piston rings were letting compression through.. could it be mainly the piston rings... that couldn't be too bad to replace .. if a friend and I do it.. and I get rings at cost

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by whitelightning &raquo;</TD></TR><TR><TD CLASS="quote">that seems pretty low.
my compression was 230-240 across, 95 as well.</TD></TR></TABLE>

What car? This seems pretty high for stock (according to Helms).

 

high compression head gasket? haha that would raise my compression (just kidding)

I'll do a leak down and if it turns out to be the rings I'll replace those.. and then I'll post again I'm sure you guys would like to see how it turns out..

 

99% chance it is your rings...to do the job right...you would have to:

1) overbore the stock bore of 81mm to 81.5mm or 81.25mm depends on you cylinder wall condition and rehone the block

2) get bigger pistons to accomadate the new bore size and new rings for the pistons

3) if your doing the rings might as well rebuild the enitre bottom end...w/ new gaskets (aka oil pan, oil pump, etc.) and if you water pump and t-belt hasnt been done now is a good time....also in the rebuild replace all you bearings w/ new acl ones or hondas (if you got the wallet to support them)...besides that a basic hot tanking will lean everything thing up and you have a block that pretty much brand new.

once again, you motor is fine for now...but start saving for the rebuild of your bottom end...the machine work will cost you a bit of change but its well worth it if you plan on running FI or nitrous...or any other form of big power gains (cams etc.)

btw the way a higher compression gasket will only temporarily aid the problem...not cure it.

the compression wont be exactly the bump up in the claimed size of the gasket...it will be lower because you head is losing pressure...and making a higher pressure cylinder will just cause the problem to get bigger

laters

 

I was kidding about the head gasket btw.. thanks for all the info!!.. and the effort put into the post.. water pump timing belt done..

are you talking about new gaskets for the oil pan and oil pump.. or new oil pan and pump.. if its gaskets I understand but.. if I'm replacing the oil pan & pump what's the point..

THANKS FOR ALL THE HELP.. now is time for me to start learning about all this so I know exactly what I'm in for

 

no no no, just the gaskets....imho oil pumps are good for a long long time...but if your building a high end motor for fi...its better to be safe then sorry...for a $150 pump that could starve you 3000+ motor and 700-800 turbo...150 is a drop in the bucket...new gaskets to prevent leaks and a h20 pump will suit you just fine. no need for a new oil pan...but when you take it apart you have to clean the oil pickup and all the grime and stuff but you'd do that anyways...hope i helped ya out some any more questions just shotem my way

 

Thanks .. pistons.. piston rings.. clean it out.. rods cause I'm in there.. bore it out.. for the new pistons (oil gauge.. cheaper )

What else?

Rehone the block (not familiar w/ that) anyone have a link so I can learn?

new gaskets for the bottom end..

Hot tank it cause .. its coming outta the car anways (ahha)

 

Sorry about the confusing it with an LS. You'll need to have a machine shop re-hone the block. I'm not sure how much it will cost, if i had to guess i'd say ~$200. The process just shaves a little bit off the cylinder walls so you have nice smooth walls again.

 

BORING is removbing material!!!

Honing is making the cylinder wall smooth!

A good align bore and hone will cost you about $200

 

200.. or 2000.. cause 200 might happen soon haha.. 2000.. that's new motor instead.. haha

if its 200 its time for me to start saving for rebuild/build.. cause if I rebuild it.. I'll build is as a high compression motor.. I mean.. what's the point of building it stock

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drumking15 &raquo;</TD></TR><TR><TD CLASS="quote">BORING is removbing material!!!

Honing is making the cylinder wall smooth!

A good align bore and hone will cost you about $200 </TD></TR></TABLE>

Actually, honing does remove material as well. Honing does not make the walls smooth, it gives the cylinder walls a crosshatch that allows for the rings to seat properly. It uses a 320-400 grit (on average) sanding stone that forces the rings to "seat" against them.

Boring should not cost any more than $100 for a 4 cylinder, they usually include honing as well since you HAVE to hone after boring.

 

very minute....nothing compared to boring is what i was tryin to point out....and honing is to make the walls smooth for good ring seals... wow wish i had a cheap machine shop....although my wokr gets done right everytime so i cant complain about the prices...good work costs $