well...

My buddy has a 4th gen lude. He and I swapped the SOHC f22 out for a jdm DOHC F22b, with internals and obviously boosted it. (cause thats what we do, right?) But he seems to have an issue with it consistently overheating.

What we have done
-New water pump when motor was being re-assembled
-New thermostat on rebuild - replaced once in case it was faulty
-Mishimoto rad @ 1.1 bar(stock pressure) with cdm slimline fan
-obviously new coolant - premix
-all rebuild parts where purchased through Honda

What happens
-the damn thing overheats - obvi
-upper rad hose swells
-lower rad hose seems cool in my opinion, esp compared to the top
-I cry.... I hate when things don't work

anywho, my buddy mike posted in the lude forum but I know there are some pretty smart ppl here, plus it is boosted. Here is a link to his post if his reads better than mine.
https://honda-tech.com/zerothread/2416148

I've personally never had an issue like this with any other motor I've assembled, whether it was a honda, toyota or VW motor. Also, I've beat the hell out my turbo LS/V on a stock b16 rad without issues for some time now. So, the build I've kinda ruled out. My tuner (Zeeman) thinks that it could be the headgasket due to exhaust back pressure. In my opinion if that is the problem now, than what caused it?

Misc info about the build...
Has ARP headbolts
Forged internals
stock sleeves
head was sent out for rebuild
TD05-16G large comp wheel - .7 A/R on turbine
Running with Neptune
A/F's are pretty close to 12's in boost
NGK bkre 7's for ignition with MSD coil

Any help if really appreciated...

 

boooo, can anyone shed some light on this?

 

As you sould you already know your stuff, I'm assuming you made sure there is no air pockets within the coolant system. When you say over heating, what kind of temperatures do you get and are you using the OEM heater gauge or have you installed an after market one that gives you degress in Celsius or F?

Does it over heat when idle, driving or both? Fan is pulling air away from radiator? Tried a 2nd push fan from the front of the radiator? Any coolant loss? these are just few of the things that I could think of.

 

Well, I HOPE i know my stuff lol...

Coolant system is properly purged of air.
An autometer gauge is installed - temps run into the 225-230 F range (then we shut down) - does not overheat at idle - rises into ~195 ish then comes back down.
Fan is setup just like stock - in the engine bay sucking air across it back into the engine bay.
No coolant loss has been observed yet. None of plugs look "steam cleaned" either...

I am sooo completely baffled by this.....

 

lower hose feels cool? Thermostat is probably sticking shut.

 

I don't know about optimum operating termperature for F series engines, but in comparison to my B16 your temp seems bit higher. I run an average of 183 Fahrenheit when idle or driving normal give little or take depending on gears and outside temperatrue. When driving real hard I've seen temps go near 201-210 Fahrenheit. I can decrease this by either using a bigger radiator or using another fan on the other end of the radiator to push the air.

Get some other users who have boosted f setups to give you their temperature readings and then you can compare that with yours as like I said I'm running a B16 so don't know if the comparison would be good example!!!

 

my 400 WHP sohc F22/f23 combo runs 180 degrees all day long , 190 on road-course under boost.

 

this is my prelude BIGJ5 is speaking about. when under boost, my temps run around 220-230. and those numbers are from a wide band. if i make 2 hard pulls at 15 psi it starts overheating.

 

Is it filling up the reservoir? Sounds like there is too much pressure building in the coolant system, but the 1.1bar cap *should* squirt air/coolant out if it does. First I'd check that the ARP's are still torqued properly. Sometimes they can back off slightly. Then see if there's hydrocarbons in the coolant, you can get test kits at some auto shops. That would tell you if you are pushing gases past the HG, but not sucking coolant into the cylinders. Injecting any air in to the coolant system, especially 1500F exhaust gas, will severely limit its cooling capacity.

And FWIW, CDM fans are trash. One instance I recall was a "3600" cfm CDM fan not doing it for a big V8, but then had NO issues (temps fell rapidly when on) when changing to a single 2400cfm SPAL. If you have an unwrapped DP and manifold, you will also be adding a lot of radiant heat into the radiator.

 

try removing the thermostat, no cost, cross it of the list.

 

When I torqued my ARP's in, I put motor oil on the threads, tightened them in the proper sequence, and I used the factory Honda torque specs for an H23A1. Should I have used different torque specs?

Also, do you know what the name of the test kit is, to check if I'm getting hydrocarbons in my coolant?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boosted_F22B &raquo;</TD></TR><TR><TD CLASS="quote">When I torqued my ARP's in, I put motor oil on the threads, tightened them in the proper sequence, and I used the factory Honda torque specs for an H23A1. Should I have used different torque specs?

Also, do you know what the name of the test kit is, to check if I'm getting hydrocarbons in my coolant?
</TD></TR></TABLE>

You should have used ARP's recommendations for ARP studs lubed with motor oil. they have two diff specs for motor oil and moly lube.

Also, the tester is called a "block tester".

I would change that fan though. I lost 16-20 degrees off of my cooling by switching my ebay fan to a SPAL 1710.

 

oops double post

 

Remove the T-stat and see what temps you see. If it never heats up or drops below 170˚F then it's probably the T-stat. If that's not the issue then pull the cap off the radiator on the dyno and run the engine up. If you see bubbles or gas displaced then it's either a head gasket, cracked sleave or cracked head.

 

i changed the thermostat a couple weeks ago. i used a genuine honda thermostat. i don't think thats the problem.

and i don't have access to a dyno to check for bubbles in the rad.

 

if lower radiator hose is cold it means that your thermostat isn't opening. You got air in the system and you need to get it out. Use a coolant funnel and push down on upper radiator hose while the car is running. Lift up the front end. Crack open any bleeders if there are any.

ARPs take special torque on the studs not honda ones. And you are supposed to use special lube that comes with them. I hope you used the washers too? Well it's time to pull the head off looks like.

 

Then improvise.

Jack the front end up, choc the wheels and set the front end on jacks and start the car. Put it in 5th gear step on the gas and drag the brakes.

Load the engine and have someone observe the radiator filler neck for bubbles.

Just don't be a dumbass and improperly secure the car and have it fall off the jacks while running. You don't want to damage people or property.

Also you should have used the ARP head torque spec with their moly lube. Their thread pitch is different than an OEM head bolt and a different torque on a different bolt will result in an improper clamping force.