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mattswan2512
16-10-2009, 07:54 AM
Hi all I know you have probably discused this in length but! Engine cooling (liquid) has anyone done it and how did they go about it. Ie radiator placement and radiator cooling. Plus feed me your info. Matt. :please:

nbb350
16-10-2009, 03:52 PM
There's a handful of use with water-cooled engines. Simply put, you can either put a big radiator up front where the spare tire would sit or two smaller radiators in front of the rear tires - sucking air from the vent there. With the former setup, you have to run two coolant lines the length of the car - either in the side pods or (preferrably since they'll be more protected and unobtusive) down the center of the car between your dropped floor pans. With the latter setup, you can use simple rubber flex hoses to make your connections, but you'll need a big ol' shoehorn to fit everything in there! :wink:

some pix of my radiator: http://s59.photobucket.com/albums/g294/ ... /Radiator/ (http://s59.photobucket.com/albums/g294/nbb_garage/Radiator/)

LotusNova
16-10-2009, 04:33 PM
Wherever you end up putting the rad(s), do not overlook the importance of ducting.

Air is as lazy as me on a Sunday :blushing: . It'll do anything it can to take the easy route around, instead of diving between those fins and doing its job. You need to force it through like a cat through a wringer. :D . For any particular application, closed ducting in/ free flow out vs 'stick the rad in the hole & hope for the best' can halve the size of the rad you need, to attain the same cooling efficiency.

Preferably the surface area of the vent input should be smaller than the effective SA of the rad (as in nbb's above). This means that once the air is inside the vent, the path of least resistance is through the rad, rather than creeping back out the input. Much though I love the look of the upper rear intakes on the Nova (due to their uniqueness), they're the epitome of inneffective design when it comes to airflow. Most hits the front & bounces straight back out. If you're going to mount rear rads, then I'd suggest considering the elephant ears (with a narrower input apperture than normal...).

***Cue Bushboy's pics of what he spent his latest garage time vouchers on. Lauren also has an efficient setup for a front mount. :wink:

mattswan2512
16-10-2009, 05:56 PM
right well lauren if your out there i need info on your efficient front mounts :wink:

bushboy
17-10-2009, 12:51 AM
Back in Oz, when I had the Subaru EA82 donk in it I had two radiators custom made to fit in front of the rear wheels

http://i6.photobucket.com/albums/y231/bushboy554/rearrad2.jpg

http://i6.photobucket.com/albums/y231/bushboy554/rearrad1.jpg

To feed them I cut & them moulded two large "scoops" in the side of the body work.

http://i6.photobucket.com/albums/y231/bushboy554/rearrad3.jpg

I never had the Subaru engine running so I do not know if they would have been sucessfull or not.

Then when the V6 came along, I thought that the twin rads would have been too small, so I ditched them in favour of the rad taken from the donor.

http://i6.photobucket.com/albums/y231/bushboy554/radiator002.jpg

This is located just behind the rear tub bulk head. It is feed air via the two larger additional scoops in the main bodywork & the two lower modified scoops in the side valance panels.

http://i6.photobucket.com/albums/y231/bushboy554/radiator004.jpg

The radiator air flow is assisteb by two large, twin speed fans. Due to poor air flow, both fans work hard in the summer to keep the engine temp below 100 degrees C. There was a lot of leakage and I have hopefully solved a lot of this with a recently added shroud.
Lotusnova has said that the intake should be a smaller area then the radiator to prevent air "leakage" back out of the openning. This is something I had not thought of and I can see where he is comming from with this.

Why the "midship" location? Well I had the scoops already fashioned, It helps slightly with weight distribution, shorter pipe run. amd the fuel tank had to go up front as the air box is taking the space that it use to.

Front mounting helps much better with weight distribution. I have, however seen a couple with the radiator mounted right at the back of the car.

That's my two bobs worth.

bushboy

LotusNova
17-10-2009, 07:44 AM
The general rule of thumb is that the air inlet area should be approximately 25% of the core area. Anything bigger is unnecessary.

bushboy
17-10-2009, 07:58 AM
Is it unnecessary or counter productive as well? As I think that I would have about the same. My side ducts look impressive but could they be too big?

bushboy

LotusNova
17-10-2009, 08:10 AM
Certainly anything over 100% is counterproductive. I'm not sure if it starts at a lower value.

Lauren? :wink:

bushboy
17-10-2009, 10:09 AM
Dam :cry:


bushboy

CyCo
17-10-2009, 01:56 PM
There are a few photos of my radiator setup amongst my photos (http://s4.photobucket.com/albums/y105/cycoholic/My%20Eureka%20F4/).

Basically, I think it's a radiator from a Commodore, with copper pipes running down each side of the car in the side pods. One going to the engine, the other leading back to the radiator up front. There's enough copper piping so that it acts as a radiator itself. It takes 2 containers (8 -10 litres) of coolant to fill the system.

But in installing it like that, the previous owners butchered the poor car. :(

Spacenut
17-10-2009, 06:58 PM
What engine are you trying to keep cool Matt?

Modern engines are designed to run a lot hotter due to the poor quality of today's fuel. My engine is not highly stressed, but the cooling system is efficient and there seems to be good margin if I wanted to go for a more powerful engine. The trick I used was to cut out and turn around the bonnet nostrils to act as air extractors, and open up the front undertray intake. There's a bit of footage on "2Novas2". The fuel tank has a front slope that forces the airflow up to the extractors. I am using the standard Alfasud radiator, with twin electric fans instead of the single factory item.

http://www.youtube.com/watch?v=f8UU4K9LhSg

The biggest problem every watercooled conversion seems to have is airlocks causing the engine to overheat. I have domestic radiator bleed screws in the tops of the copper elbows in the front compartment - that's where my airlocks congregate. I've used 32mm copper pipe going from front to rear, and this also helps to dissipate some of the heat in the sills.

Lauren

ydeardorff
17-10-2009, 07:18 PM
Back in Oz, when I had the Subaru EA82 donk in it I had two radiators custom made to fit in front of the rear wheels

http://i6.photobucket.com/albums/y231/bushboy554/rearrad2.jpg

http://i6.photobucket.com/albums/y231/bushboy554/rearrad1.jpg

To feed them I cut & them moulded two large "scoops" in the side of the body work.

http://i6.photobucket.com/albums/y231/bushboy554/rearrad3.jpg

I never had the Subaru engine running so I do not know if they would have been sucessfull or not.

Then when the V6 came along, I thought that the twin rads would have been too small, so I ditched them in favour of the rad taken from the donor.

http://i6.photobucket.com/albums/y231/bushboy554/radiator002.jpg





This is located just behind the rear tub bulk head. It is feed air via the two larger additional scoops in the main bodywork & the two lower modified scoops in the side valance panels.

http://i6.photobucket.com/albums/y231/bushboy554/radiator004.jpg

The radiator air flow is assisteb by two large, twin speed fans. Due to poor air flow, both fans work hard in the summer to keep the engine temp below 100 degrees C. There was a lot of leakage and I have hopefully solved a lot of this with a recently added shroud.
Lotusnova has said that the intake should be a smaller area then the radiator to prevent air "leakage" back out of the openning. This is something I had not thought of and I can see where he is comming from with this.

Why the "midship" location? Well I had the scoops already fashioned, It helps slightly with weight distribution, shorter pipe run. amd the fuel tank had to go up front as the air box is taking the space that it use to.

Front mounting helps much better with weight distribution. I have, however seen a couple with the radiator mounted right at the back of the car.

That's my two bobs worth.

bushboy

I have seen quite a few production cars use this mid mounted rad setup and rather than add ducting from the sides of the car, they grab it from underneath via a louvered panel, or belly scoop. This air is then "ducted" through the engine bay and out the rear of the car. I wonder how well this would work on a nova/sterling's design? There seems to be a bit of room although not much behind most ppl's seats, but it would require moving the aft bulkhead forward, and might be rather involved.

mattswan2512
14-11-2009, 06:46 PM
hi all back on the old engine chat again. ive decided im going to go for a rotary from a mazy rx8 with a 5 speed box. Right with the rx8 engine there not all that big so will have a fair bit of room for 2 rads behind the drink holder air ducts, (will probably fabricate some air scoops unless anyone knows anyone who sells them) Would i be able to wack a couple of radiator fans that will constantly run to maximise the cooling. would this be enough? also what size rads would i need. Has anyone ever put a rotary in a nova :confused1: if so pleaseeeeeeeeee send me your do's and dont's :please:

Big Birds Car
14-11-2009, 09:14 PM
I believe there has been a few bugs with rotary engines but not sure if fitted to a Nova, however, (doom and gloom bit coming) what 5 speed box do you envisage using? Isn't the Rx8 a front engine rear wheel drive configuration therefore you would have to be looking at a mid mount system if using the Mazda box as well. (encroaching on small cabin space).

mattswan2512
14-11-2009, 09:56 PM
yes bbc it is as you say front mounted rear wheel drive and i was indeed looking at a mid mount as is the only option with the mazda box. if im honest the main reason i chose this engine is that it is of a size that i could manage to to efficiently cool the car from the rear withought getting out a tool ajuster (HAMMER) to fit everything in but as you say i will encroach on the cabin space but im at a loose end when it comes to engines and transmissions ive looked at boxer engines also but i just prefer the rotary although 1 thing i have read and haven't been able to get a strait answer on is that the carbon tips wear and need to be changed at around 50000 miles and its not cheap?

letterman7
14-11-2009, 10:27 PM
Rotary? Absolutely - in fact, one of our guys here in the States has a turbo 13B, and it fits quite easily in the engine bay of a standard Sterling/Nova. Plenty of photos of his build here http://www.sterlingkitcars.com/members_ ... fegnubbin/ (http://www.sterlingkitcars.com/members_n_forums/blogs/farfegnubbin/)
His radiator is, I think, straight out of the donor car and installed almost flat in the boot. The last time I saw the car I abjectly failed to get photos of the radiator install - I'll see if I can get him to post some detail shots.
As for the rotor tips... can't say for lifespan, but 50K sounds about right. It's like replacing a timing belt on a new motor - it's just one of those things you have to do. Ask around at some of the car club chapters there. Surely there's a Mazda group somewhere.

Spacenut
15-11-2009, 07:08 PM
Hmm - there's plenty of rotary-to-VW adapter plates around for the RX7 engine, but I'm not so sure about the RX8. Its a completely new engine, for a completely new car. Even with the small size of a rotary, I doubt you could get the engine and gearbox into a mid-mount and still have room for a suitable diff without drastically extending the wheelbase. There again, the rotary is low profile enough to squeeze under the front of a Nova, if you were so inclined!

Rotaries have good and bad points. The rotor tip seals are an obvious negative, but they are also thirsty engines (which is why they did not find their way into many cars in the 70's), and their torque profile is not good at the bottom end, although their excellent dynamic balance means they can rev like crazy! This means that porridge stirring is the order of the day, so a 5 or even 6-speed gearbox is needed to ensure that you don't drop out of the power band in any gear.

Lauren

mattswan2512
15-11-2009, 07:21 PM
hi there thanx letterman and lauren for your input ive spoken to a friend of mine who is a mechanic and he has basicly said to me what you just said lauren that they are thirsty wich i new (doesnt bother me to much as a summer car really) the tips can be a pain and also the nightmare i may have with the box due to the engine set up he is a man to listen to but i really fancy a rotary. Lauren i see that you said there are adaptor plates for the rx7 already, does this mean that it will run of my box? (beetle) hmmm surely as you say keeping her in the power band with my box could be a slog CONFUSED

letterman7
16-11-2009, 12:39 AM
Matt,
The 12A and 13B rotaries will run a Beetle box just fine, though you'll be screaming revs come 4th gear. Your best bet is to have a box built with different gearing to take advantage of the power band, or at least as much as you can. It's not horridly expensive to do that, and at least here in the States one can find a rotoary motor for cheap to play with.

Also, in reference to your posts... punctuation is always appreciated! Run-on entries give old eyes fits sometimes...

CyCo
16-11-2009, 01:28 AM
Matt, there are quite a few 'reeks here in Oz that are running 12a or 13b rotors, turbo or n/a. But like Lauren said, they're mostly from RX7s.

Shouldn't be hard to get an adapter plate to go between the VW gearbox and the rotory. I think all the rotory powered 'reeks here are hanging off the VW gearbox. There's only a couple of 'reeks that I can think of that have anything other then the VW gearbox in fact.

Or you can go the Scooby. Mine gives the rotors a run for their money. :wink:

Spacenut
16-11-2009, 07:25 PM
Matt,
The 12A and 13B rotaries will run a Beetle box just fine, though you'll be screaming revs come 4th gear. Your best bet is to have a box built with different gearing to take advantage of the power band, or at least as much as you can. It's not horridly expensive to do that, and at least here in the States one can find a rotoary motor for cheap to play with.

What he said :crylol:

Lauren