Matt2458

Didn't really know what section to put this in so here it goes, and thanks for any replies / advice / help guys!!!



I currently have a 1990 Honda CRX with a built d16y8.

I've been having serious issues with the car running really hot (temp gauge goes to Hot pretty quickly).

Notes:

• Car idles fine at normal operating temperature (50% of time)
• Car goes hot under boost / under idle same
• Coolant system has been drained and refilled
• Coolant system has had bubbles and air pockets removed
• No leaks or spewing coming from motor or radiator
• All coolant and radiator hoses are new
• All clamps are tightened
• Block deck and head have been checked with straight edge for deforms (both fine)
• No cracks visible in block (extensive searching)
• Cylinder head has been replaced (switched y8 cylinder heads just to double check for cracks - still same overheating issue)
• Cylinder head gasket HAS been replaced (Stock - MLS)

More info for diagnosis:

• Do not have coolant temp gauge or external electric thermometer
• Do not have EGT Gauge hooked up
• Radiator mounting has been modified / fabb'ed to sit to side of engine bay because of the Holset mounting
• Downpipe is open (not connected to exhaust yet)
• Bumper has been taken off to further access to intercooler
• Overheating issue is same with and without hood on
• Turbocharger does not have turbo blanket
• Boost is currently set at 10lbs
• Downpipe is wrapped with Lava heat wrap
• Sparkplug wires are stock
• Sparkplugs are gapped at .18 for e85 (sparkplugs are standard NGK BKR6's)

Have changed:

• Thermostat (now running stock Honda thermo.)
• Coolant Temp Sensor
• Radiator (half-size from civic)
• Added two electric radiator fans (1 is pushing 1 is pulling)
• y8 Cylinder head
• Headgasket

Okay, here is my full setup:

(Listed everything just to make it easier and to clear up any questions)

• Full D16Y8 Motor
• YCP 75mm Vitara pistons (8.5:1 comp)
• Eagle H beam rods - crankshaft has been balanced
• ARP Headstuds
• ARP rod bolts
• Golden Eagle blockguard
• LS throttle body
• FIC 1050cc injectors
• Walbro 255 fuel pump
• Custom-made exhaust manifold
• Tial external wastegate
• Turbo XS, dual stage boost controller
• Mishimoto front mount intercooler and piping
• 7 blade Holset Hx35
• 3" downpipe obx, full exhaust
• Streetfire ignition box, and msd external coil
• 6 puck sprung clutch disc
• act extreme hd pressure plate
• ECU is chipped and tuned on CromePro for e85

phat00civic

Just thinking out loud but is your tune actually from a dyno or one you bought based off your specifics?

Any error codes?

What is your A/F ratio? Idle and running?

Thermostat - Is this for a D16 or another D series motor? Is it functioning?

Matt2458

We used a tune from the previous chassis (EK hatch) and tweaked it. Street tune.

A/F - no idea because Wideband has not come in yet. Very rough estimate but no smell of gas as for rich.

No codes being thrown.

The thermostat is now - currently is the stock, OEM one straight from the honda dealership for the d16y8. It is functioning and brand new. Replaced after first time overheating (had a duralast from autozone i'm guessing).

Freshdot

you are dealing with dreaded D series headlift it is because D series cylinder compressions go ape **** under boost..

The only known 100% fix for this is to have the block deck about 0.030 shorter than cylinder wall heights to allow movement for the lift and not affect compression. So says the good people I spoke to at speed factory regarding this.

I fell victim to this as well the only thing that has made the problem better for me was to create a boost table in hondata and have my ign timing retard by 1.50 degrees per PSI. while this has caused a sacrifice in perfomrance I haven't been overheating anywhere near the way i was before after ripping on the car.

phat00civic

That might explain overheat on high throttle but what about when at idle? I am throw off by that.

Also check out this thread it might help:
http://www.d-series.org/forums/force...heating-2.html

ZMX

Head lift will blow a head gasket.

Good link, BTW

wolve

guestimated tune with no wideband. so you have no clue how the setup is running

stupid if you ask me, it can be running 14+ afr for all you know at max boost?!

Freshdot

oh wow dude, i musta missed the part where you didn't have a wideband..you should prob get on that.

Headlift will cause the temps to soar at idle after you've been beating the **** out of the car..why? because your radiator is empty and all of your coolant is in the god forsaken reservoir.