The best thermostat to use in the warmer months is the stock one. There are two other thermostats, the tropical one & the artic one as they were labelled by a friend. the tropical one opens earlier & is best for race cars, while the artic one is good for a cold winter, as it opens later. I think there's a 5 degree celsius difference between the three. I agree with Dodgeman, I think that the problem will be a clogged radiator, as the 'rubbish' from the block will have come out & clogged the core. Happened with the B310 coupe with an L18 I own, there was so much junk in there I've had the radiator cleaned twice & I'm still catching rubbish in the filter. Tefba here in Australia sell a cleanable filter, they have a website if you're interested, but there's no room in the top radiator hose for their one. Natrad here in Australia can supply the filter D'man mentioned, the first time I cleaned mine I found swarth in it from the engine. Hopefully getting the triple core will cure the problem for you.

Then inside it will be. Thanks GreenDog.

u need the cooler air the hit as much of the front of the radiator as possible,putting the fan on the front would reduce the radiator performance.

The temp is hot, you couldn't even open the cap until it was cooled down. It was reading right. But the 3 core is still needed for when I drop my other engine. I just want to have this engine running good before I yank it out of my car. Question DD, I have an electric fan and I was wondering if it works better behind the radiator or front the radiator ?

Why don't you double-check the actual temperature before doing that? The temp sender may just read higher, but it's not actually running any hotter. It is a possibility that happened to another club member last month.

"if it ain't broke, don't fix it"

I didn't touch the timing. A different head ( A13 )now. The compression should be the same or less. My A12 head was worked a little for more compression. But I'm going to change the core of the radiator from a 2 to a 3 core and see from there what happens.

u havent increased compresion??
or have u.
to mutch timing??
diffrent head?

I will do that as soon I get my radiator back. What thermostat do you mates recomend?

Just a word on the thermostat; I 'm in Las vegas and some of our race & trackday weekends will see temps in the 105-112 F range, I run a thermostat and with the 3 core GX radiator have no issue with cooling. Now back when we had the 2 core standard rad (recored) once the car went over 4000 RPM it would run hot, to the point of me running the heater to keep the car in the 7/8ths range. Put the proper thermostat in, the car will be better all around.

Tom

Hi Dodgeman, Ok, my car was running fine without the thermostat when heading to the auto show. This is on the highway doing 80 mph. After driving a little over an hour,when almost there, my alt light came on. I pulled over and verified all fuses,fuse links and regulator. The alt was making a weird noise. I decided to turn around because I didn't want to leave late using my head lights and not be able to make it home. So, while driving back I heard a noise like the belt broke, I didn't pull over because my car is automatic and I was only driving with the charge of the battery. About 20 min. from home I noticed my temp going up really fast and the car started smoking around the hood. I kept going because I just wanted to make it home, my car then started pinging and another big bang...I still kept going. I got about 100 yards to my house when the car shut down. I towed it to my garage with my p/u truck and left it there. Next day I took off my head and noticed that the big bang was the rear seal of the head that flew off. The alt belt was gone and the alt was barely moving. I have a A13 head already prepped from the machine shop. I had all the gaskets. I changed all the gaskets and swapped the head. No lubrication on head. Took off head drilled a 45 angle hole and put it all back together. Started car and great lubrication. I bought a new alt and installed it.All the hoses are brand new even the heater ones are brand new. The car never mixed the oil with water. Car never leaked threw the head gasket.All the water galleries were nice and cleaned. So I started the car and let it running for around 1/2 hour in my garage and noticed the temp rising around 1/2. Took off the radiator cap and the water barely runs when idled but when you hit the gas, it will move but not that much. I took it for a spin and around 10 min my gauge was reading 3/4 temp. I went home and touched the radiator and it was hot. I loosened the cap and it was boiling. So I turned it off till today that I took off the radiator. Looks really dirty. So, I'm thinking of taking it to this radiator place so they can swap the 2 lines for 3 for better flow. That's what happened. Never had this problem before. But the car runs much better with this head than the original one.