Teg4e

I don't wanna jinx myself with this question, but I was wondering how long everyone else has run on a motor with bad compression. About a year ago, Howard of AR Fabrication was nice enough to do a free leakdown test for me before I dyno'd at his shop. I had been boosting at 6.5 lbs. for almost a year with the standard FMU, inline fuel pump, stock injectors setup. The results came back with no. 1 cylinder leaking a nice 35%, and the others in the 10-15% range. Not exactly perfect.

The car made low power, 192whp @ 6.5 lbs., and I figured the motor was on its way out. After that I was thinking, "I've got AAA plus, which will tow me 100 miles for free, why not just have fun with this LS motor until she blows up?" I got a boost controller and happily went around on 8 lbs., boosting pretty much everday, but nothing crazy. A few months ago, I got a Hondata system with 550cc injectors tuned at 9 psi, where it made a pathetic 210whp.

Pissed about this, I've since turned up the boost to 10 or 10.5psi and she's still running fine! The car is only tuned to 9psi, but it's been running strong. I notice the vaccuum continues to slowly dip over time, but nothing terrible. Idles at 20-22mm, and 24-25mm on in-gear deceleration. I haven't done another leakdown, but I'd imagine the results would be even worse than the 35%, 10-15% I saw before. It's been 2 years of boosting on this motor, and over a year since I first started noticing changes in the vaccuum it pulls.

So, basically my question is how long has everyone's hurtin motors lasted?

G"UNIT

damn thats long time.. sounds like my b17 motor... to low compression..lol

nevin

what is the relationsihp of the vaccum it pulls and it being hurt?

Seraph0

I ran about a year on a hurt motor, but I didn't drive it hard. In fact, I hardly drive it at all.

You risk doing permanent block damage to the cylinder walls. If you intend to sleeve I wouldn't lose sleep over it, but don't go too crazy, you don't wanna blow a chunk out of a cylinder wall either.

Only other thing I can think of is you're hurting the bearing journals a little bit but putting uneven combustion pressure across the 4 cylinders.

Teg4e

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nevin &raquo;</TD></TR><TR><TD CLASS="quote">what is the relationsihp of the vaccum it pulls and it being hurt?</TD></TR></TABLE>

As I understand it, a lower vaccum reading means the rings are getting progressively more worn. The rings seal the pistons and the sleeves, thereby creating a certain amount of vaccuum. The added horsepower wears down the rings over time.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MarkC &raquo;</TD></TR><TR><TD CLASS="quote">
Only other thing I can think of is you're hurting the bearing journals a little bit but putting uneven combustion pressure across the 4 cylinders.

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

I plan to replace this motor entirely with a new (used) LS motor, since they're only $500-750ish. I never want to shell out the money for a build; I just want something in the 250-300whp range.

USDM 4G VTEC

i ran my D15B/Z6 (mini me) for two weeks after i spun a bearing on the dyno

drove like i grandma
but i had to go to work and make cash... so i had to do it...

Teg4e

am i the only one who's running their turbo honda into the ground?

boosted92

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Teg4e &raquo;</TD></TR><TR><TD CLASS="quote">am i the only one who's running their turbo honda into the ground?</TD></TR></TABLE>

Nope Tonight I installed my T-kit on my motor. Stock B18B, 1000CC injectors, inline pro mani, GT3561, AEM EMS. I'm going to try and boost 20 psi on a stock-as-a-rock LS motor with C16 and see how long she'll last I have a sleeved stock bore GSR motor waiting to go in as soon as this one tanks, so don't heckle me

danl

Depends on what you call damaged motor. If its just a burnt piston ring or valve causing a compression drop, well my friends 140K decade old 4g63 ran 12 second passes with 80 psi across the board like that. If you have a spun bearing, it depends on how bad it is. Usually you have a few seconds after spinning it. I have however started a cold but allready spun motor to get it to the salvage yard. Once the oil warmed up, it locked up again. Did that a few times to avoid a tow fee.

boosted-delslow

I ran the ***** out mf my d16z6 after I blew it up on the bottle. Cylinder #3 Had zero compression. We beat the hell out of it every night to see if it would blow up but it never did. It was my second car so i didnt car if it did blow. But I just took it out last night to do an ls swap.

Teg4e

hehe, good times. Is there any risk to other parts of running or blowing a hurt motor? I plan to fully replace my longblock after this one goes, so I couldn't care less about the engine internals. I will be saving the other parts though.

philipwight

if your vacuum at idle is steady(17-21 inches) then dont worry about it, but if it is bouncing around then there is an internal problem. (which you know that, just letting the rest of the board know)

This One

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Teg4e &raquo;</TD></TR><TR><TD CLASS="quote">hehe, good times. Is there any risk to other parts of running or blowing a hurt motor? I plan to fully replace my longblock after this one goes, so I couldn't care less about the engine internals. I will be saving the other parts though.</TD></TR></TABLE>

For the most part you sohuldnt have anything to worry about unless you do some serious damage. You could possibly throw some parts through the turbo.
since the motor is weak you problay smoke the rings or break some pistons b4 anything.

othick

I've been delivering pizza with a busted *** b17 turbo since october. It has low compression in #4 (I bought the engine like that) and actually lopes when it idles. It's gone 12,000 hard miles since then and besides adding oil every week it's still running. I only made 207whp when I dyno'd it with about 7psi but I've had the boost set to 9psi for several months. For all the people who say you can't drive a turbo honda without blowing it up, your wrong! I beat the hell out of my car almost 100miles a day, stop and go and it gets better gas mileage than my accord. I'm going to swap in my ls block soon, but the b17 just keeps running.

Trac226

My car has been blowing white smoke (blow by) for about 6 months now, eating up a quart of oil every couple of weeks. Still feels the same as it was when it was stock, but the turbo definately has trouble spooling up. Looking for a b18c block to swap over spring break!

nevin

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Teg4e &raquo;</TD></TR><TR><TD CLASS="quote">

As I understand it, a lower vaccum reading means the rings are getting progressively more worn. The rings seal the pistons and the sleeves, thereby creating a certain amount of vaccuum. The added horsepower wears down the rings over time.

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

I can remember my motor pulling at min 20 hg and sometimes as much as 24 at idle. must have been pretty healthy.

omahaturbocivic

I drove my turbo d15b7 with bad rings for half a year. 20w50 and a v8 portion of that thick *** stop smoke stuff bought some time and performance. I did not give up on it untill it blew a headgasket and then I still beat the **** out of it while it was overheating. On the way to my buddys garage to swap the motor I unhooked the wastegate and gave it a few pulls at 20+psi while it was overheating on an fmu setup. It sounded crazy but the stock clutch just started slipping at anything past 10psi so it was not putting enough load on the motor to blow it.

philipwight

actually anything over 21 is unhealthy, it means there is an excessive restriction in the exhaust(cat clogged)

kaj

i had a motor that broke the ring lands on a cylinder. i quite driving it right away so i didn't have any sleeve scarring. good thing too!
but i had a compression of 210/200/200/90 and a leakdown of 80% in that cylinder haha.

yeah. it was toast.

fix it A.S.A.P. or it may cost you more later! new sleeves are $$$

Teg4e

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kaj &raquo;</TD></TR><TR><TD CLASS="quote">i had a motor that broke the ring lands on a cylinder. i quite driving it right away so i didn't have any sleeve scarring. good thing too!
but i had a compression of 210/200/200/90 and a leakdown of 80% in that cylinder haha.

yeah. it was toast.

fix it A.S.A.P. or it may cost you more later! new sleeves are $$$</TD></TR></TABLE>

I'm wondering about people driving for LONG periods of time on hurt motors. My rings are just worn, they're not destroyed. Again, I don't care about the sleeves, b/c I'm replacing this motor entirely when it blows.

Teg4e

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by philipwight &raquo;</TD></TR><TR><TD CLASS="quote">actually anything over 21 is unhealthy, it means there is an excessive restriction in the exhaust(cat clogged)</TD></TR></TABLE>

Never heard this before, but it kinda makes sense. What do you think about a motor pulling 20 in. Hg on start-up, but then idling at up to 24 in. Hg after hard driving and a very hot motor?

....cause, uh, that's what mine does. I have a 3" Carsound cat and 3" thermal exhaust, so I don't think there's any excessive restriction. This is how my idling vacuum has behaved since the very beginning.

hadboosttroy

i ran the absolute **** out of my si with low compression in all cylinders, #3 had zero. it would drive fairly well but wouldnt idle, it would just die. it was only good for highway driving. no real damage from it and no BAD wall scoring or anything. .25mm bore cleaned it up perfectly.

still have the blades i sold you?

philipwight

At an idle a turbo is a restriction because it is not spinning fast. A car that i regularly work on had a wastegate bolt break and thread its way into the manifold and stopped the turbine wheel from spinning. This caused the car to be dog slow because of the restriction.

Joseph Davis

I ran the old B18A with a 30 degree section of ring land on the #1 piston broken for 10K miles. Ran well, just blew oil smoke under boost.

I've been driving on a blown headgasket for over a year now. It used to just pressurize the cooling chamber a little and was a "cosmetic" problem. Now I'm getting oil and coolant dumping into the combustion chamber, started getting bad like that three weeks ago and it amazes me the car still runs today. As soon as she blows, the new engine/turbo/manifold/IC/clutch gets installed.

Teg4e

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hadboosttroy &raquo;</TD></TR><TR><TD CLASS="quote">still have the blades i sold you? </TD></TR></TABLE>

Yeah, thanks again for those. They still look great and have amazing grip with the Azenis wrapped around them.