Cylinder Head Cooling Modifications.

[Doward]

For those that aren't keeping up with my build thread:
http://www.supramania.com/forums/showpost.php?p=954882&postcount=375

Comments on the modification to the cylinder head?

 

[MK3.0dudeman]

COOL you came up with that idea yourself?

 

[Poodles]

Some of the German Supra guys have done it (120+ MPH sustained is the norm on the highways there), and it seemed to work better...

Are you using a standalone though? The stock ECU is tuned for the EGR, so it runs a bit hotter cruising without it (I'll have to search for the thread, but it's around here somewhere)

 

[bloodasp90]

ive thought about this idea my self, but i have no idea as to how to approach this idea

 

[7MGTEsup]

The hole you drilled looks to be very close if not overlapping with the edge of the gasket.

 

[MDCmotorsports]

Doward:
I welded in an aluminum plug plug into my egr port from the exhaust side, then had the head sent to the porting shop.

The car ran much cooler without the EGR system.

~Jon

 

[jdub]

There's a coolant passage on the head side of the EGR cooler...the big heater bypass/feed fitting is directly above it. Without the EGR cooler there and the exhaust port sealed off, I can see coolant temps being a bit lower. Looking at EGT though, having an EGR lowers exhaust gas temps. I had a 50-100 deg C drop in EGT (depending on throttle setting) when I re-installed the EGR to pass emissions.

I've seen guys drill that hole to create a coolant passage at the rear of the head...it's of limited value IMO.

 

[Doward]

Yeah, I was looking over the head's coolant flow in relation to the block, and found the block has the passage crossover to the head, but the head has no receptacle.

Standalone here - The stock USDM ecu is programmed for EGR, but I won't be doing the same in my own tune.

Down, the hole looks very close to the gasket, but it does not overlap when the gasket is lined up correctly. Look at the bottom - it's hard to hold a gasket and head together, with no movement, while snapping a picture

Poodles, any more information on the german guys?

 

[Nick M]

Spent gases are inert. They do not burn, it lowers combustion temps.

 

[tissimo]

there was a thread about this.. either SM or SF

edit: found it

http://www.supraforums.com/forum/sh...ht=head+Modification+Drilling+Coolant+Passage

 

[Doward]

Ah, SF. God, I opened the link in another tab, took a deep breath, and am wondering if I even want to waste my time.



eh, what the hell.


Ok, to hell with that thread. 15 posts, and it becomes a bitch fest.

I think he drilled the holes too big though - look directly above that, you have the main water port coming out of the head, back around the block, to the water pump. Too big of holes right under there will reduce the flow elsewhere in the head. I was mainly looking to even out the flow of coolant around the cylinders, and through the head.

 

[iheartmx83]

in my other cressida, i drilled that hole, cordless hand drill ftw LOL. put arp head studs(90ft lbs), and a 2mm MHG (overkill i know, but the head was machined so boohoo).

the drill bit walked, but eh. good enough. hte hole i drilled is actually slightly bigger then the other coolant passage holes.

lookind down the heater tube thing on the back of the head

meh..been 12,xxx mile... i drive it hard, shit still runs :drink1: