Why do I have the worst ******* luck with cars? No it didn't get stolen, but if it did I wouldn't care that much right now. As it sits right now it's an 84.5mm Darton sleeved LS, with Wiseco pistons/rings, and Eagle rods. No more than 100 miles after I get my engine rebuilt. I lose compression again on my #1 cylinder. It was running just fine, till I started to come up my drive way, I goosed it a little bit and it broke traction. When I parked it I noticed it was idling funny.......in a familiar way. I pull the plugs and run a compression test.......sure enough 50,175,175,175.

So I poured a tad bit of oil in the #1 clyinder, hoping that it was just the headgasket or something. Nope I spun it over a few more time and the oil helped the compression, so I guess I've got a bad set of rings on the #1 cylinder. Any other suggestions before I go to tearing apart the engine.........AGAIN.


[Modified by Speed PHreak, 4:36 PM 11/13/2002]

 

i dont have any suggestions... but DAMN, that sux...

im havin some bad luck with my car right now, too. hit a tire on the freeway and now im havin problems gettin it to run right.

 

could the rings not have seated properly? it sounds like something went seriously wrong. who assembled the motor?

 

Thats what it sounds like it'll turn out to be. I'm hoping I can get away with re-honing/re-ringing the sleeve/engine. I assembled the engine, whatever it is it'll be my fualt Unless one of the sleeves dropped, then it'll be the machine shops ***. If it was something as simple as a blown headgasket or a burnt valve, I doubt it will be either of those. It's never that easy.

Last time I completely destroyed the ring land on my #1 clyinder's piston. Those were stock tho, I'm gonna have a serious beef with Wiseco if the ring land went out on only 7~8 lbs of boost. From what I've been able to log with my wideband, the A/F ratios were pretty close to 12:1, so I doubt it was detonation. It's nice and cool here anyways like 60 degrees.


[Modified by Speed PHreak, 4:58 PM 11/13/2002]

 

u were boosting already w/ only 100miles?

 

Didn't you follow the break in instructions that came with the pistons?

 

It's not bad on the engine past the initial time the rings are seated. ***** footing it around doesn't do a damn thing for ya. There was a thread just a while ago that a lot of the engine builders agreed about that.

Yup, I idled it at 2500 RPM for 20 minutes, then drove it to a friends shop and had the oil changed. Drove it like it was gonna be driven for the rest of it's life. Regular driving, plus the occasional boost. But I was being a lot less boost happy than normal.......ugh

 

when you installed the pistons and rings did you gap them and check ring gap etc. also did yo have the blcok honed properly. A good hone with good stone always help seal the rings correctly. looks just like rings are not seated. Can you do a leak down test.

 

Yeah I did it up right, and the rings were seated in. I was pulling about 17~18mm/Hg of vaccume at idle, but over the past 50~75 miles it worked it was down to 20mm/Hg of vaccume. From what I've read thats what one of our Honda engine ought to pull at idle with stock cams.

I've done a shade tree leakdown test. I took my air compressor and pressureized my #1 cylinder with the car at TDC. Some thing odd/good happened air started coming from the #3 cylinder spark plug hole. I was perplexed for a moment. I took out the oil dip stick and the filler cap, no air came from either. So I took off the WG, to see if air was leaking out the exhaust side of #1 and into #3........Nope.

So I sat for a minute, then took valve cover off to check the valve/rocker postitions. Welp at TDC the #3 intake valve is slightly open(*dhur*), but all the valves on the #1 clyinder appear to be down. Again I pressurized the #1 clyinder, air starts shooting out #3, I reach up and twist the throttle body and the air quits shooting out #3.......So I guess one or both of the intake valves are screwed up on my #1 clyinder.

Slight sigh of relief, worst case senario I have to replace 2 valves and a head gasket. Guess that 84.5mm cometic head gasket is gonna go to waste. Anyone know if a stock B20 head gasket will work for an 84.5mm bore?

 

interesting. sounds like your rings are alright. what caused the rebuild? anything related to this current problem?

 

Explanation enough? Bad tuning for about 8 months, and then I added some cams that wanted a lot more fuel than what they were getting....ringlands in #1 clyinder went bye bye.

 

hmm...i still think you jumped the gun a bit with your break-in. I bout my pistons from Endyn and the instructions basically say to drive it like a grandma for at least 1000 miles.

 

i agree to break in the motor w/ boost but.... its one thing to get 4-5psi in the cylinders to seat the rings but its a wholenother to run around at WOT tuning the car. not saying thats what u did wrong, but its a possiblity you shouldn't look over.

 

Where is this thread? I would like to read it.

 

Just for you guys, luckily this thread came along about the time when I was doing my rebuild.

https://honda-tech.com/zerothread?id=214707

I've actually ran the engine fairly easy, seeing as how it's gonna be pretty much a week-end race machine. I've tooled back and forth around town running a few errands, 90% of the time shifting under 4 grand. Granted if I open the throttle I can have 10psi of boost by then. I've gotten 10psi a couple of times, but I found I was making more power @ 10psi than my 450cc injectors can support. I haven't tried to WOT tune or anything.......I dunno, hopefully after a valve job it'll all be ok.

 

Dam. I just put a set of rings in My friends Saab last weekend and today he lost compresion in one of his Cyl's too. I know the feeling just knowing that I have to tear the thing apart again!

 

You broke that motor in just fine, and the rings should have been seated by now. In order for air to come out the number 3 hole from the number one, either you had bad piston seal on both, which you didnt....you had the valves open on 1 and 3 which is possible or the head gasket went bad, but that would usually give you a bad leakdown is both cycl. My guess is you hurt the valves, but the reason it was comming out the #3 spark plug hole was because those valves were open as well. Once you opened the tb, the air took the path of least resistance. You gotta pull the head one way or anouther...but it is a little skepticle because oil comp. being raised with oil.

 

Thanx, thats pretty much what I figured. The only reason that the air was able to get into the #3 cylinder was because I didn't have the car at perfect TDC. I did the best I could manage bumping it over with the starter. I was just slighty past TDC by a few degree's. Which put #3 on it's intake stroke, and with the huge lift on my cams......left the intake valves open on #3. But either way, I took the valve cover off just to 2X check the valves. #1 clyinder's rockers had no pressure on them and moved freely.

Well, I think I can explain that. The car was parked on a slight incline, with the nose facing up. I'm running 8.8:1 Wiseco's which have a fairly good sized dish in them. I don't think any of the oil actually got onto the rings, it just stayed in the dish, and with the incline the car was sitting on most of it pooled in the intake valve recesses. When I bumped it over the offending valves prolly picked up a bit and that helped seal them a tad....fuzzy logic I know, but thats the best I can figure for the *slight* increase in compression.

 

when your ring lands cracked did the car sound different like you had an exhaust leak and were you smoking more than usual(crankcase,exhaust)?

 

Both, it sounded like "putt putt putt" out the exhaust, and smoked out the valve cover.

 

I feel your pain. Before I did the rebuild, the motor would smoke at high RPMs. Now after the rebuild and still in NA form....it still smokes at high RPMs! I'm thinking my problem is the valve seals. I'm wondering how much a shop will charge and if they can do it without removing the head......hmmm.

-Trung

 

i had a cracked ringland on #4 about 2 months ago. when you accelerate, your car runs like one of the plug wires is not connected until 3-4k rpm then it runs smoth like normal after 4k rpm. also when you rev your engine, white smoke will come out of the breather on the valve cover.

 

you can change the valve seals without remove the head, you just need compress air. it's not that hard to do it yourself.

 

Sorry to hear that.

 

when you pulling it apart man???