ThePass

iTrader: (3)

Just finished fabbing the mounting solutions for my v-mount. You could say the hard part's over, but I still need to make it actually work

From the googling I've done it seems this topic isn't amazingly well covered in terms of write-ups/how-to's/discussions/etc., a lot of the reason seems to be many people think it's too much work for a small cooling benefit - well, I think it's quite worth it - first of all, I'll take every bit of cooling I can get, but the advantages to the cooling system are only part of the benefit. Equally or even more important is what it makes possible in terms of how you can play with the airflow.

So, I'm hoping to put our collective heads together and anticipate whatever issues need addressing for a v-mount in terms of functionality so that I can put things together properly the first time. Don't worry about packaging or airflow, I already have that covered. I know there's a handful of miatas out there already that have done this, if anyone can chime in with first-hand experience that's even better!

Cooling system - As far as I can tell, the main issues here revolve around the radiator no longer being the high-point in the system. It appears that a "surge tank" or "expansion tank" (interchangeable terms depending on where you are in the world) is the solution to this - it has a radiator cap on the top which becomes you new coolant fill point, and this must be mounted as the highest point of the system. You run a hose from the top of the radiator to the input on the side of this tank, and run a drain hose from the bottom of the expansion tank to a point post-radiator/pre-water pump (lower radiator hose in other words). By pouring coolant into this tank, you're filling the cooling system from the bottom up. As far as I can tell, this solves the issues for the cooling system. You can add a "swirl pot" as well but AFAIK it's not a requirement for this, that's just an additional element to further aid in removing air bubbles, but an expansion tank is designed to constantly bleed the system of air, so things should be covered?

Radiator - next biggest issue is altering a radiator to work while mounted at an angle. This is assuming you aren't just buying a super fancy custom radiator.. From what I can tell a radiator will function just fine at any angle relative to the ground, but the issue lies with the input and output which are intended for vertical orientation - these need to be modified or replaced with inlets that come off the radiator horizontal to the ground. Cutting them off and welding on new inlets seems the only real solution.. Then there's the matter of the radiator cap on top, which isn't necessary any more. Probably best to cut it off and seal the hole with a welded on patch or something similar, but I've also seen mention of dummy radiator caps that just seal the top. The other modification to the radiator is adding the port on the top to supply the expansion tank as mentioned above.

This seems to be the extent of the issues that I've come up with so far, please throw any other issues you can think of out there on the table. I'm ordering the bits I'll need by the end of tomorrow, want to make sure I get the right stuff.

-Ryan

ThePass

iTrader: (3)

Here's the expansion tank I'm considering. The shape/dimensions would work well in a location I have in mind.. it has two inlets, I'm thinking just cap one and the other gets the line from the top of the radiator and then the port on the bottom goes down to an in-line junction with the lower radiator hose. Small barb fitting on the neck to the cap goes to an overflow tank like usual:

Keyser Manufacturing Surge Tanks



But I like the price on this one, which is even better because it comes with fittings. Not sure of the advantage/disadvantage between the difference in shapes.. it's rather tall (12") but I'm sure I could find a home for it:

Speedway Coolant Expansion Tank

Leafy

iTrader: (1)

I'd prefer to run a swirl pot basically in line in the upper radiator hose. AND since the radiator cap is no longer the highest point in the system you're going to want to put a really high pressure cap on that and put your normal pressure cap on the swirl pot. Thats easier than trying to make a weld seal on the radiator.

And on the radiator, IMO it makes sense here to switch to one that flows side to side at this point rather than one that flows top to bottom like ours. It'll make it a whole bunch easier to seal the radiator to the intercooler where they come together when the new radiator has a flat surface up there. There should be some sort of high end takeoff radiators from roundy round cars that already lack a rad cap and have the end tanks on the sides that would be cheap enough to not hate yourself as you cut it up to fit what you need, might even be able to pickup the swirlpot/surge tank as a takeoff from the same person.

Braineack

iTrader: (62)

I just want to put this here:

nitrodann

I run dem der 11 mounts.

Braineack

iTrader: (62)

ThePass

iTrader: (3)

Mine will be a "7-mount" in that case although I can't tell if that post is in jest or actually intended for educational purposes.. but then a "v-mount" should really be a ">-mount"

Leafy - a swirl pot inline with the upper radiator hose that doubles as the coolant fill point was what I was thinking would be ideal, but I can't find anything for sale that fits this design - there aren't a ton of off-the-shelf swirl pots out there for starters, and all the ones I could find have a small hose nipple on top as opposed to a fill cap, so a custom one would be the only option in that case. I don't think my aluminum welding is up to that task yet.

Any particular reason you think the swirl pot would be ideal over a surge/expansion tank? From what I've seen it seems the general consensus is that the surge tank is a requirement whereas the swirl pot is on the "would be nice to have" list..

-Ryan

Leafy

iTrader: (1)

The swirlpot helps de-aerate the coolant, it'll bleed faster and more completely, and it'll get most of the bubbles out if the coolant ever cavitates in the pump or you get some slight boiling. Finding one that isnt designed for like a formula car might be difficult.

ThePass

iTrader: (3)

Nearly all the swirl pots I have found are in the UK or Japan. It's like over here nobody knows about them.. it looks like the only option would be to source one from out of the country and then cut off the nipple on the top and have a fill cap TIG'd on...

I suppose what I'm wondering is whether a swirl pot - if it had the fill cap on top - would make a surge tank unnecessary.

I found something that resembles a swirl pot from a Ford Probe! Here
but it doesn't look to be the best design...

Leafy

iTrader: (1)

I swear taylor race or pegasus sell a swirl pot with a rad cap. If you put the swirlpot with rad cap at the highest point in the system you wouldnt need a surge tank. You'd still need an overflow.

cjsafski

iTrader: (2)

The setup on mine worked pretty well. For the few laps the car would get in before breaking something coolant temps where around 200 and inlet temps 20 above ambient at most. I also tested it by tailgating someone around the track and temps stayed down.

As far as coolant cap goes I just left it alone. When burping the car I just parked it on a slope then lifted the front as high as I could. Seemed to get all the air out.

ThePass

iTrader: (3)

Chris, did you have an expansion tank in that setup at all? I'm assuming that's the coolant line running over the valve cover, much higher than the radiator.. are you saying you just filled from the normal radiator cap location??

-Ryan

concealer404

iTrader: (3)

Maybe i'm missing the point.... but why not just an in-line fill at the highest point with a bleeder nipple at that point running to an overflow tank?

Leafy

iTrader: (1)

Yes, you could just use an inline fill point with a normal rad cap and nipple. But where would the fun in that be?

concealer404

iTrader: (3)

I mean.... i hate working on and fabbing stuff for cars, so the 10 minute easy button solution sounds pretty fun to me.

nitrodann

Thats some sort of blow of valve recirc. Look carefully it comes from the intercooler.

Dann

ThePass

iTrader: (3)

A; as-is, the highest point is actually at the water neck on the back of the head. Hose from there to the top of the radiator runs downhill, so no way for an in-line fill to be at the highest point of the system.
B; both the surge/expansion tanks and swirl pots have specific benefits for a race car running at high temps over just providing a high fill point, so being able to address the need for a new fill point while improving expansion and air evacuation would kill multiple birds with one stone.

We would not get along

ctdrftna

iTrader: (1)

Go look at my car search "tube front drifter"

I did V-mount, i made a custom thermostat housing that had the new filler in it, I used a scirocco radiator made by afco. and i used -16AN radiator hoses.

I never ever had cooling problems, not that i was road racing, but i was doing back to back drift runs down at E-town on a 90* day and had no issues. Oil cooling wasn't keeping up though.

ThePass

iTrader: (3)

Thanks, I've taken a look at your build, definitely like some of the stuff in there. I'm pretty close to done with my v-mount. I made it work with a 55mm aluminum miata radiator with oem fans too.
All the mounting is done, ducting both in and out of the heat exchangers is finished.
Most of the plumbing is finished just waiting on a TIG welding class that I am taking soon so that I can fab cold side piping.
Made a mount for the surge tank yesterday, getting lines for that today, and probably doing the hood vent today as well.

-Ryan

comradefks

iTrader: (3)

I believe Chris' car has the radiator pretty much vertical so it would function just like OEM. Probably different mounting but no an angled V-mount as such. Mainly he got the intercooler horizontal and therefore out of the way for air flowing into the intercooler.

Don't know if that would accomplish your goals Ryan.