DOHC Vtec Turbo

So i got my car dyno tuned and while getting it tuned, something bad happened. on like the 7th WOT run about 6-8k rpms the motor just shot out alot of white greyish smoke through the exhaust. after that the motor started ticking. did compression check and #1-130, #2-180, #3-180, #4=130. took the motor apart did a leak down on the head, everything was good no leaks. checked the head and all LMAs were shot, so i replaced that. now what do you think could of caused all this rukus? i'm guessing #1 and 4 cylinders read low due to the head lifting....also this motor is a fresh build, fully built bottom end, arias pistons, ge sleeves, eagle rods, acl bearings. top rings were gapped to .19 and second ring was gapped to .21.


Modified by DOHC Vtec Turbo at 11:28 AM 10/28/2006

DRAGLS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DOHC Vtec Turbo &raquo;</TD></TR><TR><TD CLASS="quote"> top rings were gapped to .21 and second ring was gapped to .19.</TD></TR></TABLE>

who put this motor together

Is it still ticking after the lma replacement?



Modified by DRAGLS at 10:32 AM 10/28/2006

CroteTurbo

Sorry for your engine man, I'm not that good in english, what is LMA?

BoostedEG6

LMA = Lost motion assembly

Have you retoqued the headstuds?

What motor is this?

How much boost where you running?

turbotime

how did you know the lmas were bad?? they just didint spring back up or what?

B18C Turbo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbotime &raquo;</TD></TR><TR><TD CLASS="quote">how did you know the lmas were bad?? they just didint spring back up or what?</TD></TR></TABLE>

thats what i wanna know.

DOHC Vtec Turbo

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

who put this motor together

Is it still ticking after the lma replacement?

Modified by DRAGLS at 10:32 AM 10/28/2006</TD></TR></TABLE> whoops it was a long night, i meant to put 19 on the top 21 on the bottom, that was with using the "Upper ring gap.... .006" x bore, Second ring gap.... .0065" x bore method. I put the motor together myself. i didn't get put the motor together after changing the LMAs just yet, i want to make sure everything is good before i put everythign back together. LMAs had no tension on them, you can literally pinch them and they will squeeze down to their max and at the end you can hear and feel it stick. Also the vtec lobe on the cams showed signs of wear. <TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostedEG6 &raquo;</TD></TR><TR><TD CLASS="quote">LMA = Lost motion assembly

Have you retoqued the headstuds?

What motor is this?

How much boost where you running?</TD></TR></TABLE> no i didn't retorque the headstuds, i just took the head out. it's a 83mm gsr motor. 16lbs on a gt30r turbo.

DOHC Vtec Turbo

i thought i mentioned this the first post but the walls also have scratches. i was told that the hone was maybe bad and possibly it made the rings blow

thomas@LPS

how long did you break the motor in before the dyno?

DOHC Vtec Turbo

the motor only had 15miles before i hit the dyno.

thomas@LPS

if you only had that many miles the rings more than likely werent seated yet. i would drive it 500 miles without reving past 4500rpm to break the motor in.

BoostedEG6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by civic_ex_95 &raquo;</TD></TR><TR><TD CLASS="quote">if you only had that many miles the rings more than likely werent seated yet. i would drive it 500 miles without reving past 4500rpm to break the motor in. </TD></TR></TABLE>


http://www.importbuilders.com/breakinarticle.htm

"What about the guy who told me I need to put 1000 miles on my motor before I tune it and that I need to "break it in"? I will be blunt. That person is not educated on motors. With 1 exception...if that person told you to DYNO your motor at narrow throttle, that your going to be driving it for a few hundred miles, that's fine"

https://honda-tech.com/zerothread?id=878397

"One of the most asked questions is how do I break in my new motor? The short answer is that no break-in is necessary. The only thing that is necessary is to seat the rings. All clearances and fitments should be perfect after blueprinting and precision assembly. So how many miles do you have to drive it to seat the rings? The cylinders are round, the rings are round, the bore is freshly honed and therefore your engine should be ready for tuning immediately."

"Do I need to drive it 500 miles before I tune it? Absolutely not. How about 50 miles? No. Perhaps the best thing to do is to drive it all the way to your trailer and tow it to a competent tuner. In second position on the “things NOT to do list” is trying to break in an un-tuned engine by driving it. "

NJIN BUILDR

Most of the domestic race engines I have built got broken in on the engine dyno.The engine got warmed up with a light load for ten minutes or so.Then we did a part throttle pull to about 70% of the redline.If everything looked good the testing would begin.Three pulls,make a change,three pulls,make a change...Many engines would leave with 50 or 60 pulls.On engines with hard rings (chrome face or ss) we break the rings in a little lean before we did full power pulls.Engines broken in on the dyno are going to be the best in the long run or short.You just have more control of the environment and data.

DOHC Vtec Turbo

bump