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

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

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

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.

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"

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 ?

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.

Then inside it will be. Thanks GreenDog.

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.

Nissan has a t-stat kit that has gaskets in it
Part # 21200-P7990...fits most datto engines from the '70s and '80s including the A
probably around 20 to 25 USD if it is still available though the dealer, been about a year since I got one
Good luck with it