Finest

Just finished a turbo install on a friend's D16Z6. Tuned for about 8psi on Hondata, but after going to tune for 10psi, coolant started steaming out the overflow and the engine temp started to climb. (noticed it when logging in Hondalogger) We get it back to the shop and pulled the head to sure enough, the headgasket was blown. (Also, the ARPs were pretty easy to untorque, aren't they suppose to be torqued down to 70-80lbs?)

But anyways, cleaned everything out and also saw that the valve reliefs in the JE pistons had a chip broken off in the upper right corner. They all chipped off in the same area! But there's no scarring in the walls, so is it okay to run it like it is? Or should I grind them down and sand them smooth? I'm pretty sure they'll be a "hot spot" when we turn up the wick (shooting for 15psi and 300whp out of this Ninja!) TIA!

boostincoupe

The ARP's should be torqued in this process (at least, this is what I did on my D16Y8 a couple months ago):

hand-tight, 14 lbs., 20 lbs., 40 lbs., 65 lbs., 65 lbs. again to check.

Make sure to use the right tightening sequence and get the head to a machine shop to get resurfaced and checked out!

I did it right the first time and I have had no more issues.

rioninja

With wisecos, i know they state that you can safely modify the valve releif "edges". I would assume with the JEs its also safe to do.
Check your tune. Sounds like you may have timing issues.

Finest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rioninja &raquo;</TD></TR><TR><TD CLASS="quote">With wisecos, i know they state that you can safely modify the valve releif "edges". I would assume with the JEs its also safe to do.
Check your tune. Sounds like you may have timing issues. </TD></TR></TABLE>

I'll give it a try then. The material on that edge was pretty thin, so I was thinking to just grind and sand it down.

The timing was pretty much conservative. Max advance @ 8psi was only 20 degrees, so I'll have to double check the low/high ign maps again, maybe I missed something? Probably cut back another degree or so up top. EGT's were pretty even too, and the wideband A/F reading was slightly rich @ 11:5-12.5's across the board. The logs didn't show anything out of the ordinary. I'm thinking the person he bought the "built" motor from already caused the damage. It was originally a nitrous built motor, so you know what that means!

If all goes well this weekend, look for another 300whp SOHC NINJA!

USDM 4G VTEC

make sure the engine is timed correctly

what i mean is that the head and block are aligned
remember if the head was milled, or something, the timing changes.. and a cam gear is need to compensate

if there was piston to valve contact, i would take the valves out and have a machine shop check them for not being bent
i have 8 valves i dont need.. brand new, that i can let go veryyyy cheap...D16Z6 btw

Finest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDM 4G VTEC &raquo;</TD></TR><TR><TD CLASS="quote">make sure the engine is timed correctly

what i mean is that the head and block are aligned
remember if the head was milled, or something, the timing changes.. and a cam gear is need to compensate
</TD></TR></TABLE>

The problem is that I didn't build the motor myself, so I don't know what's all in it. From what I've seen after getting into the motor, it has JE pistons/Eagle rods, Crower valvetrain, P&P head, blockguard (we had a helluva time removing that POS!), and I remember him saying the head was milled a few mm's. I just set the base timing to 16 degrees (per Hondata), so you think it's a little off? There's an AEM camgear on there, but it's set to 0.

So if it's milled, that would advance the timing a few degrees, correct? And in correcting it, I'd have to retard the camgear to compensate? Or is it the other way around? Hmmmm, you could be on to something here. Thanx!

please.laugh

More compression = more violent explosions in the chamber.

The bigger ***denser explosions happen ***faster.

So you RETARD timing so the new fast explosion *finishes at the same time*

Finest

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by please.laugh &raquo;</TD></TR><TR><TD CLASS="quote">More compression = more violent explosions in the chamber.

The bigger ***denser explosions happen ***faster.

So you RETARD timing so the new fast explosion *finishes at the same time*</TD></TR></TABLE>

Umm, I was referring to the valve timing actually. If a head is milled, would that advance or retard the valve timing?

tgreaves

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

Umm, I was referring to the valve timing actually. If a head is milled, would that advance or retard the valve timing? </TD></TR></TABLE>

From thinking in my head I would say that it would retard it

Finest

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

From thinking in my head I would say that it would retard it</TD></TR></TABLE>

Thanx.

Muckman

iTrader: (2)

Yea it does retard it when the head or deck is milled. Does anybody have a rule for how much taken off equals how many degrees of change?

tgreaves

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Yea it does retard it when the head or deck is milled. Does anybody have a rule for how much taken off equals how many degrees of change?</TD></TR></TABLE>

Hmm... You got me there.. Usally what is done is after you assemble the motor you get it on a dyno and adjust the cam timing to suit your power needs.. In that case it doesnt matter how far advanced/retard is it, it will be set correctly..