5thgencivic

We fired up my motor yesterday morning for the first time since assembly and let it idle for about 10 minutes or so varrying the throttle a tad. The temp needle reached almost half way, but there is the "slapping" sound or dieseling as some would say and it didn't go away. The block was bored by the machine shop to exactly what cp said which was 2.973" on my z6 which would make the clearance .0035"(I had the machine shop talk to the tech guy at CP) We haven't put any load on the motor yet(driven it) but I was just curious if this was normal? The temp was most likely about 30-40 degrees outside when we started it up.. We will probably take it for a spin tonight but I was just curious. Thanks.

earl

The clearance sounds perfect, it should not be making noise with that clearance.

leadfoot78

I'm getting those pistons too, same compression 84.5mm for my ls-vtec. Earl do u think that the pistons are not getting hot enough cuz he is not boosting and not puting load on the motor? So the pistons are not expanding as much as they should.

earl

No, getting hot enough is not the problem. There could another problem but it is hard to say without hearing it. Maybe piston hitting head, pin not installed properly (lock popped out because it was not in the groove completely) or maybe timing is way off or head gasket on wrong. These are just off the wall guesses. Did you check the piston to wall yourself or just what the machine shop said. Just not sure, could be anything including a rod noise or excessive rod side clearance.

5thgencivic

Hmm, not what I wanted to hear... We went by what the machine shop said Also the headgasket is stock bore and the pistons are .020 over. Would that be a problem at all?

FredoSP

maybe your next step is to pull the head and investigate

InfamousRS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FredoSP &raquo;</TD></TR><TR><TD CLASS="quote">maybe your next step is to pull the head and investigate </TD></TR></TABLE>

Thats what Im going to do. I am the one who assembled the motor...I wish I would have messured the pistons/wall clearance...but it skipped my head utill I was torquing the head down. Im 99% sure its not the head gasket or wrist pin locks.

MiraiZ

I use to get that at startup when the engine is cold....once its up, everything sounded stock....nowadays, it doesn't make any noise at all...I think it goes away after its broken in. Here is a boring little vid of a cold startup:

http://www.we-todd-did-racing....D.jpg

5thgencivic

By the sound of that video clip I think it sounds almost exactly like that! I am praying that's what it is...
Is it the same with me as it is with everybody else? A stress buildup when a motor is started for the first time after assembly?

BlueSi2k

Mine sounded like that video too. It pretty much goes away when they warm up. Been like 8k miles and its fine.

5thgencivic

Awesome. thanks guys. We are going to pull the head tonight anyway just to be safe.

5thgencivic

Turns out it was combination of the distributor and the timing belt most likely being off one tooth. The ex distributor I bought was no good so we held the cx one up there just to see if it worked for start up. So once we swapped the disi internals over, pulled the head, pulled a piston out, measured some things and put it all back together it started right up and purred. No slap whatsoever.... Man were we relieved

Arturbo

to you and InfamousRS.

art

earl

I know you guys have the pistons out of the hole a couple of thousandths so be sure you use a head gasket with the proper diameter bore and one that is slightly thicker. Clay in the valves to check the clearance also. I'm glad everything worked out for the good.

InfamousRS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Arturbo &raquo;</TD></TR><TR><TD CLASS="quote"> to you and InfamousRS.

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

Thanks Art! We just got back from driving it for the first time! We did a few 4000RPM pulls in 2nd and 3rd gear, then let off the gas and let the motor slow the car down. The car drives and sounds PERFECT! Almost time to instal the turbo stuff and have it tuned by Jason