So I just rebuilt my engine Ill give you the run down.

B20 block bored to 84.5mm
Arias pistons eagle rods
skunk2 valve train and pro 1 cams
Edlebrock intake mani
custom ram horn mani with precision SC 67/65

The car went on the dyno and did great we only ran it to about 14 psi on pump gas no smoking nothing ran cherry. However I took it out for a spin the day after the dyno and it ran fine while on the freeway. But as soon as I get into town where there is allot of stop and go driving due to traffic lights and such the engine starts to over heat. I thought maybe a heas gasket but there is no loss of coolant and there is no bubbles in the radiator the car runs too strong I beleive for that to be the issue. I was told to get a Mugen fan switch and mugen thermostat. If anyone has had this issue before an suggestions is great.
wanted to also add if and when it starts to overheat i put a fan in front of the car to help push air and it starts to cool currently I have a 12 inch Hayden puller fan on there maybe i need something stronger?

 

Any pics of how it's setup?

I recently finished my b20/vtec 62-1 setup and was having problems with the car overheating. It was a combination of buying a cheap pep boys fan, improper channeling of air into the radiator and an old rad cap with cracked/rotted seals. I put my factory fan back in, cut some holes in my bumper and bought a new 16 psi cap, car runs fine now even though i still need to add some guides to stop the air from going around the radiator.

 

check your thermostat

sounds like its sticking

 

Some puller fans may claim higher cfm ratings than stock, but without the correct shroud they won't move half that.
Check to see that the fan is mounted securely against the radiator.
What coolant mixture are you running?

 

Im rinning standard coolant just a 50/50 mix

 

i had similar problems but at highway speeds, after a custom shroud and 13" spal high performance fan i no longer have any cooling problems

https://honda-tech.com/forums/forced-induction-16/spal-13%22-fan-2371027/

 

What kind of car is this? I had my GSR turbo with a half size alum rad, and it was overheating, I put the full size back in and it solved my problem. But it also gets hot a hell in Louisiana.

 

Im having an issue like this but Im running no thermostat, just the housing with the thermostat opened. Im thinking it may be due to the amount of underhood heat. Im bout ready to start cutting holes in the hood for some extra airflow.

 

Do you have an aftermarket aluminum radiator or are you using the stock radiator?

 

I am currently runnin a Fulidyne radiatior aluminum it is a 99 civic SI there is allot of engine heat im wondreing if the puller fan is just drawing in the heat off the engine at idle

 

is your lower hose cold or hot

 

Do what is stated above, your thermostat probably isn't opening up... Once the car is running and heated up grab the lower hose, if it is cold then your thermostat isn't working. It's a very easy and cheap fix...

 

No bro its for sure hot both hoses are very hot im not sure I just went ahead and ordered a new thermostat and fan switch I AM USING A 12 INCH HAYDEN THIN FAN its a puller fan so i modified a stock fan shroud for it as well yesterday just got home from work it made it thhrough town ok but when i got home and the car was running off the turbo timer it overheated again until i PUT A FAN IN FRONT OF THE CAR AND THE TEMPS DROPPED QUICKLY. I am thinking of adding A FAN INBETWEEN THE INTERCOOLER AND THE RADIATOR TO HELP DRAW AIR IN THAT DIRECTION IS THIS A GOOD IDEA.

 

i think you just need a better fan, or maybe you have your fan wired up backwards

 

The fan should be fine, it's the lack of a well designed, properly sealing shroud. The shroud needs to be tight against the radiator with absolutely no gap.

 

Change the th therm stat i was having the same problems with my it would stick sometimes and the car would never warm up to normal running temp. and sometimes it would overheat at idle with the fan running. silly things like this bite you in the a$$ cuz your so focused on the big pic and not the lil things.