That set up is really neat, I like it a lot.

Has he done anything to help get the air out from under the bonnet?

The larger radiator is getting closer, I have made the necessary adjustments to the rad support to get it to fit. There is a bit of cutting and fabricating to do to squeeze it in. The bottom of the radiator is flush with the bottom of the chassis rails and the top is flush with the top of the radiator support panel. Just working on the lower mounts now then the upper mounts and fitting the intercooler.
Here's a pic during the initial fitting. Getting the air in doesn't seem to be the problem rather getting it out.

I want to be able to do a full tank of fuel flat out with out having any overheating issues, pit, refuel and send it out again. i don't think the 7 series radiator will handle that.

Have you thought about logging under bonnet pressure to see how efficiently the air is passing through the engine bay?

I'll be interested to see what you have come up with ducting wise.
I am leaning towards venting the bonnet but all the bonnets I have are in great condition so I have been reluctant to cut one up.
I should probably rip a mould off one and make up a CF one to hack up.

Not sure about mods Chris has done to get air out of the engine bay. That sump would create a fair bit of low pressure behind it which would suck a bit of heat out of the back of the bay...

Personally, I think the BMW 735 radiator can definitely be made to work with the right aerodynamics mods.
The bottom of your radiator being flush with the chassis rails isn't going to help cooling? Perhaps overall water capacity due to the larger size, but that's only a matter of time before it all gets up to temperature? Correct me if I am wrong? You will need to increase your water flow (different pulley on the water pump) to try and increase turbulence in the radiator to increase cooling.

Looking at some of the newer performance cars (and even some of the older ones), they have designed some simple things to improve airflow through the engine bay. Like you, I don't want to perform any external panel modifications such as cutting up a bonnet or guards to facilitate better airflow. The problem with venting on the top of the bonnet is finding the low pressure zone and where that is, isn't the most aesthetic place to put vents.
I'm thinking more of venting underneath the car and smoothing out the current non-smooth area under the engine/cross member. A Datsun 1600 with an SR20DET and an extended oil pan hasn't got the most slippery shape underneath. Using an undertray will help minimise drag, allow greater pressure differential and better low pressure areas after the cross member to facilitate air flow through the engine bay and at the same time reduce lift. A win-win. This is the direction I will be heading. Squeezing in an oil cooler for insurance is part of it.

I was curious to know what size cooler race spec SR20DET's used and choosing something around that size would suit. I'm currently leaning towards a 13 or 16 row (depending on space). Going for the 13 row would mean a very elegant duct design and good flow. Going for the 16 would be a small squeeze, but could potentially be the same. I just have to measure up again and see what I can fit.
I would prefer something wide, but with low back pressure.
I will be using an oil thermostat so warm up times won't be compromised from factory. I think the thermostat (Derale/Mocal for example) bypass approximately 5-10% through the cooler even when the system is cold which isn't a big deal.

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1972 Datsun 1600, S14 SR20DET Engineered (204rwkW @ 17psi.)
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Update.
I am moving forward with the oil cooler. I have purchased a Setrab 16 row. I am very impressed with the quality over the Chinese coolers. Even small things like looking down the inlet/outlet and noticing the inlets/outlets to the radiator section. All very nicely made and smart design to minimise back pressure.
I also have a Derale thermostat, so will mount that up in the system to make sure temperatures are getting hot enough to keep the oil where it should be. From memory the thermostat closes at 82degC (180degF) sending most of the oil through the cooler. Below this it still allows 10% through to the cooler to minimise cold shock.
I am going forward with mounting under the car, as mounting in the wheel well just didn't have enough space. The mount will be incorporated into the aluminium undertray. Should work well with the front lip and a small amount of coarse mesh.
The additional ducting around the radiator has made such a difference to temperatures. It still gets hot in traffic (thermatic fan takes care of that though), but as soon as you are moving, the fan never comes on.

_________________
1972 Datsun 1600, S14 SR20DET Engineered (204rwkW @ 17psi.)
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#SR20Datsun @SR20Datsun

I've been running my E36 M3 radiator setup for a while now. On the street it doesn't get hot at all, in fact keeping it up to temperature is more of an issue.

I can drive in peak hour to work and not switch the fan on at all, I normally get a reasonable run but there are some choke points where I will spend 3-5 minutes sitting in near stationary traffic. During these times it creeps up to around 95c but comes straight back down as soon as I start moving. It will also happily idle in the driveway for extended periods without getting overly hot.

No change in water pump pulleys was required and I am just running a single thermo fan with no other ducting or mods.

Unlikely to see the track though while I own it as I bought a race car so this 1600 will be moving to a new home so I can concentrate on my 1600 Coupe

Good to hear the new rad is doing the job on the daily commute. I never had any issues with mine on the daily commute and I used to drive down springvale road...The thermo fan I am running kicks in at 86deg and shuts off at 82. Interesting that you have set your fan to a higher rate? Where is your temperature take off positioned? Mine is right next to the factory ECU measurement location.

I stumbled on a fairly interesting general rule used for radiator core size which is:
The surface area of your core in inches, should be greater than your engine size in cubic inches, plus 50.

So our engine is 122ci. (2 litres). Multiply that by the typical multiplier for equivalent size of an NA to Turbo motor (122x1.7) gives us 207ci (or 3.4litres).
The 7 series radiator core is approx 21"x13" which gives us 273sq inches.
Funnily enough the 7 series rad I am currently using was designed for a 3.4L straight six.
Looking forward to providing some track work feedback on how this whole system goes.

Are you contemplating putting a build thread up of the 1600 coupe?

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1972 Datsun 1600, S14 SR20DET Engineered (204rwkW @ 17psi.)
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#SR20Datsun @SR20Datsun

I am lazy, the thermo fan is still on a manual switch.

Might do a coupe thread build. It will hopefully be home from the panel beaters soon.
Still trying to find someone to make cams for the LZ14 too.

http://www.guy-croft.com/viewtopic.php?t=2549

Note reference to laminova oil cooler & heat exit from engine bay.

http://www.superstreetonline.com/how-to ... exchanger/

I like the concept of the laminova due to mounting & alleviation of air flow problems.

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A little knowledge is a dangerous thing.
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"R.I.P. Baz. 29 April 2022. Thank you for all your contributions to the Datsun community over the years. You will be missed." - OZDAT

Some interesting reading Baz. Unfortunately when it comes to realestate, the ability to fit another radiator for flowing cooling water, or the ability of my radiator to absorb more heat is going to be lacking.
The remote air/oil cooler option seems to be the lightest option with the least amount of realestate.

_________________
1972 Datsun 1600, S14 SR20DET Engineered (204rwkW @ 17psi.)
viewtopic.php?t=6579
#SR20Datsun @SR20Datsun