Mike,
A stock radiator with a 4 row high efficiency core does a great job for
cooling even with the mickey-mouse stock 4 blade 67.5 SPL fan and shroud.
It cools a 2L pushrod engine with 200-205 psi pressure in every cylinder at
cranking speed. It didn't get too hot when I blew the head gasket during
an abusing drive. It is best to use a radiator with a filler in the top
tank like the 2L one or a filler neck added to the SPL one.
Stan
========
At 12:48 PM 4/25/01 -0400, datsunmike wrote:
>Ron,
>
>One of the problems with the stock shroud is that it is way off center no
>doubt due to the fact that the fan is off centered and so when I center my
>electric fan the shroud gets in the way. Oh well.
>
>The Scirocco rad seems to be the rad to use in a variety of cars but the
>problem w/the roadster is the limited width. I was given a 240 rad and
>someone else gave me a used Scirocco rad but I had no luck trying to mount
>them as there is too much in the way and they are way too wide.
>
>How do flex fans work out? Anybody try using them?
>
>Mike
>
>----- Original Message -----
>From: "Ronnie Day" <ronday@home.com>
>To: "datsunmike" <datsunmike@nyc.rr.com>; "Datsun Roadster List"
><datsun-roadsters@autox.team.net>
>Sent: Wednesday, April 25, 2001 12:39 PM
>Subject: Re: Cooling
>
>
>> >However now that I stroked/bored the engine do you think the cooling
>system
>> >will be taxed even more? I had it recored with a core that has many more
>> >fins per inch than my old radiator but both are the same number of rows.
>> >
>> >I also have a stock 7 plastic bladed fan that I can use or I can buy a
>> >Flex-a-lite fan.
>>
>> An increase in engine size is going to increase the load on the cooling
>> system in any case. The key to making a fan work is a good shroud so that
>> the fan pulls air through the entire surface of the radiator, not just
>> the area directly in front of the fan itself. The fan need to be centered
>> on the shroud opening and allow just enough clearance so the fan doesn't
>> hit the shroud when the engine torques over. With electric fans you don't
>> have to deal with engine movement, but you still need a good shroud for
>> maximum cooling efficiency. I don't remember if the roadsters have a
>> shroud, but they probably should. It would take some work, but I'd think
>> fabricating a workable home built version shouldn't be too difficult, and
>> would yield measurable benefits.
>>
>> If the OEM radiator still falls short, a popular radiator swap for the
>> 510, as well as being used in a lot of other modified cars, is the
>> Scirocco (VW) unit. It's so popular that there are a number of versions
>> available up to a very heavy duty all aluminum unit from Griffin. To
>> compliment the design, you can get a dual electric fan/shroud combo that
>> completely covers the back (engine) side of the radiator. This is the
>> setup I plan to run in the 510s from now on, provided there's enough room
>> between the Scirocco radiator and the water pump pulley for the fan
>> assembly. Some that have used this radiator use one or two smaller fans
>> offset to avoid the pulley. Most of the time this radiator has enough
>> cooling capacity to work well without a shroud. In case anyone wants more
>> info, Jegs and Summitt both sell an aluminum/ABS version for $110, the
>> fan setup is around $180. The Griffin unit is $200 plus, but should
>> handle just about any motor at any power level.
>>
>> In any case the fan is really only needed when a car's not moving at all
>> or in slow or stop and go traffic.
>>
>> FWIW, Ron
>>
>> Ronnie Day
>> ronday@home.com
>> Dallas/Ft. Worth
>> '71 510 2-dr (Prepared Class Autocrosser)
>> '73 510 2-dr (Street Toy)
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