Coolant Crossover on front of heads: 2V vs 4V?

1379 Views 25 Replies 3 Participants Last post by mercenvy_3114, 27 d ago

KEVINS

Discussion Starter · 1 mo ago

I'm studying the 4V water crossover design between the front of the heads but noticed that my 2V doesn't have any type of crossover..

Do the 4V heads have such poor cooling that this crossover is required or is it possible to block it off on the passenger side but leave the driver side open similar to a 2V setup?

I remember reading how poor some of the earlier 4V head castings had cooling issues on the back cylinder(s) but not sure if this was one way it was being resolved.

ks

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eschaider

· #2 · 1 mo ago

If you maintain the OEM heater feed plumbing on the back of the passenger head that feeds into the water pump cavity from between the two cylinder banks, you might be OK, but I would not bet a set of heads on it, especially expensive, modified heads. When the passenger side head has no way to return coolant to the radiator, it will overheat. Normally it is the driver-side head that experiences this problem because of the lack of a coolant path out the back of the head like the passenger-side head. I would highly recommend the use of the coolant return ports on the front of each head.

When the heads overheat, the first sign of trouble is frequently the OEM exhaust seats loosening up and falling out. You are having aftermarket seats installed so this type of failure would be less likely but not inconceivable. For the cost and effort involved, I would use both return ports on the front of the heads.

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mercenvy_3114

· #3 · 1 mo ago

The 4v intake manifolds do not flow any coolant through them, only air/fuel. The coolant ports are in the heads, not the intake, and a remote thermostat housing is used.
2v intake manifold flows coolant through it with the thermostat mounted in the intake like a traditional v8. There is a crossover there that is part of the intake manifold itself.
I am running a 4v with a "coolant crossover delete" with a remote thermostat housing mounted before the radiator, along with the "cooling mod" from the top/rear of the drivers head that is plumbed to the thermostat housing as a bypass.
Something like this

www.lethalperformance.com

On3 Performance Coolant Crossover Delete v.2 – 1 Port - CCD1

On3 Performance Coolant Crossover Delete v.2 – 1 Port - CCD1 Also many people have issues after time with the factory coolant crossover leaking and needing replaced. This is a great option to not only replace the leaking factory unit but give the engi

www.lethalperformance.com

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KEVINS

Discussion Starter · #4 · 1 mo ago (Edited)

2

Once I get the 4V heads in my hands I will see how I may be able to design/make a crossover among other things. I have a lot of custom parts on the engine that fit around the 2V platform but the more I review photos of 4V's the more it looks like new parts will need to be made: Thermostat housing, fuel lines, coolant crossover, heat shield, etc..

I designed a heat shield that covers the turbos but the 4V front crossover may interfere so something will have to be fabb'ed differently and in order to get a better idea what I have to work around I may also need an intake.

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If I have the room with the new intake I may try to make the crossover similar to the Vic Jr where it runs behind the altenator and keep the same type of t-stat housing that I originally made:

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ks

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eschaider

· #5 · 1 mo ago

Kevin,

This is the coolant crossover you need for the 4V heads:

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This crossover was used on all the non-supercharged 4V engines, I think, from the very beginning in the Mk VIIIs, and at the very least all 4Vs beginning from 1997 and later. It is widely available in salvage yards. The two tangs on top attach to the alternator. There is a downpipe on the right that is located on the bottom of the manifold to go to the OEM T-Stat. The OEM T-Stat and coolant plumbing was emissions inspired for a fast warmup — you don't need it. You want to place the T-Stat in the top hose to the radiator and either plug or remove and cap the coolant downpipe on the right side that you can not see in the pic above.

About a dozen or so years ago, James Hell at Cobra Engineering came up with a very nice and very simple T-Stat solution using a Mezier T-Stat housing; click here for the housing =>Meziere T-Stat Hsg and click here => Simplified Cooling System for James write-up on the modifications to use it. If you decide to go this way, be sure to remember to drill four 0.1875" bypass holes in the t-stat, or you will have warm-up problems. you can or can not use the additional fill-up reservoir James used. If you do, it must be the highest point in the cooling system, or the coolant will backflow out. Your upper radiator hose should go directly from the t-stat to the upper inlet nipple on your radiator. The lower radiator hose should run from the lower radiator outlet nipple directly to the coolant inlet nipple on the side of the block. There are a number of higher-dollar solutions available today, but this is simple, inexpensive, and works very well.

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mercenvy_3114

· #6 · 1 mo ago

KEVINS said:
Once I get the 4V heads in my hands I will see how I may be able to design/make a crossover among other things. I have a lot of custom parts on the engine that fit around the 2V platform but the more I review photos of 4V's the more it looks like new parts will need to be made: Thermostat housing, fuel lines, coolant crossover, heat shield, etc..

I designed a heat shield that covers the turbos but the 4V front crossover may interfere so something will have to be fabb'ed differently and in order to get a better idea what I have to work around I may also need an intake.

View attachment 176548

If I have the room with the new intake I may try to make the crossover similar to the Vic Jr where it runs behind the altenator and keep the same type of t-stat housing that I originally made:

View attachment 176549

There's no room behind the alternator on the 4v for a crossover. Which is why Ford ran that crossover pipe. I don't think $180 is "high dollar" but that's just me. Also, finding a stock coolant crossover pipe that is not rusted/corroded is difficult, and good-condition examples are easily the same money or much more expensive than the kit that i linked to.
If you have a lathe, you could machine the O-ring fittings necessary to fit the coolant ports on the heads i suppose. I don't have a lathe so the kit solved a lot of problems for me.
ks

KEVINS

Discussion Starter · #7 · 1 mo ago

I purchased a complete Mach1 intake so I will be running this instead of a Sullivan. The heads and intake should be here this week then I can start mocking it up to see what I can come up with.

ks

Reactions: 1

mercenvy_3114

· #8 · 1 mo ago

KEVINS said:
I purchased a complete Mach1 intake so I will be running this instead of a Sullivan. The heads and intake should be here this week then I can start mocking it up to see what I can come up with.

ks

I am also running a Mach1 intake. Just an FYI, you cannot run stock Teksid knock sensors with a stock Mach1 intake. They are too tall.

KEVINS

Discussion Starter · #9 · 1 mo ago

mercenvy_3114 said:
I am also running a Mach1 intake. Just an FYI, you cannot run stock Teksid knock sensors with a stock Mach1 intake. They are too tall.

I'm lucky, my block is a Cobra block and the Safeguard knock sensor is on the side of the block... =).

What throttle body are you using with that intake?
I've been studying photos and reading threads and plan to remove the center divider to use a single blade throttle body but this will require fabbing new ports for the IAC to function - not a big deal for me. But I'm comparing the Accufab Oval throttle body to the Elliptical one and trying to decide which one makes more sense to open the intake too. I will know more once I see it in my hands, tho.

I spoke with Ed for a few hours on the phone the other night and he convinced me that my current Livernoise rotating assembly will handle more than I could ever throw at it so as of now I have abandoned the idea to build a backup short block. I will still collect the parts this week (crank and block) but I will hold onto them until this motor gets re-dyno'd.

ks

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mercenvy_3114

· #10 · 1 mo ago

OK cool
My Teksid is just an N/A street car so my TB setup is prob all wrong for your TT build.
Single blade would prob be great for your boosted combo tho i bet.
Oval or Elliptical i have no idea.
Someone with more experience will be able to help

Reactions: 1

eschaider

· #11 · 1 mo ago

Kevin,

Because a TB in a turbo setup is a post-compressor rather than a pre-compressor item like in a PD blower setup, throttle body dimensions have less impact on the engine performance. Of course, when we begin to talk about flow differences like 30%, then the story changes. Either of the two Accufab TBs should work similarly. If you could find one of the old Dragon TBs it would be a better choice, not so much because of power, although there is some anecdotal evidence to that effect, but rather because of stickiness where the throttle shaft binds in the aluminum housing. Additionally, there were a number of users who claimed Accufab TBs used an aggressive cam profile on the opening arm to open the throttle wider per inch of motion of the gas pedal to give the effect of more power being produced. The aggressive opening ramp on the Accufab TB made it more touchy to drive around town in normal traffic. There could be some Dragon units laying around that could be had at a good price.

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KEVINS

Discussion Starter · #12 · 1 mo ago

Looking at pics of the tunnel of the manifold behind the TB the roof looks more flat which should be a better transition path when matched to the elliptical TB - not to mention re-fabbing the IAC ports would be easier with the flat roof..

The Oval TB would raise the roof creating a weirder transition not to mention doing a lot more fab work to get the IAC functional.

I can tell you for a fact that with a 90mm TB it is real touchy with the cruise control. The extra volume of air that goes past the blade is so much more that the car bucks bad with the cruise control on when it tries to maintain speed. I had to add about 1.5" to the lever arm on the throttle body AND make a smaller pulley on the cruise control motor all in an attempt to decrease the distance the blade is opened when the cruise motor pulls on the cable. It works really well when in OD but in Drive the car still has enough power to cause bucking when the cruise tries to adjust the speed.

ks

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eschaider

· #13 · 1 mo ago

The oval throttle body has a smoother transition from idle flow figures up to WOT flow than the straight-sided SBTB that is commonly associated with Accufab. Ford either offers round or oval throttle bodies, most likely for that reason. They do not show TBs with straight-sided throttle blades. This is their current 03/04 SVT Cobra performance throttle body:

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If possible, I would try to find something like this that is out there in good, used condition.

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KEVINS

Discussion Starter · #14 · 1 mo ago

eschaider said:
View attachment 176557

Those oval TB's don't have the IAC port on the back that matches up to the IAC port on the Mach 1 manifold which is where the "extra-additional" fab-work comes in. I would either have to get creative by adding the port to that TB off to one side so it can access incoming air or relocate that IAC port externally to the up-pipe or just use an external IAC like I made for mine...no bid deal on any of these.

Since I like the idea that the Oval has a smoother idle transition the extra fab work will be worth it.

I will also do some digging around, maybe someone makes an Oval with IAC ports.

Ks

Reactions: 1

KEVINS

Discussion Starter · #15 · 1 mo ago

eschaider said:
The oval throttle body has a smoother transition from idle flow figures up to WOT flow than the straight-sided SBTB that is commonly associated with Accufab. Ford either offers round or oval throttle bodies, most likely for that reason. They do not show TBs with straight-sided throttle blades. This is their current 03/04 SVT Cobra performance throttle body:
View attachment 176557

If possible, I would try to find something like this that is out there in good, used condition.

Warning- Dumb question ahead:
Do you have a link or p/n for the 03/04 SVT Cobra performance throttle body? Nothing is coming up for me.

I can find oval units BUT the throttle linkage is on the wrong side. That TB is the only one that I see with the linkage on that side..

ks

KEVINS

Discussion Starter · #16 · 1 mo ago

2

Hmmmm...Studying the design of Accufabs TB's it looks like the oval could work if I simply flip it upside down.

ks

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I need the below version:

Font Circle Machine Auto part Metal

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eschaider

· #17 · 1 mo ago

KEVINS said:
Warning- Dumb question ahead:
Do you have a link or p/n for the 03/04 SVT Cobra performance throttle body? Nothing is coming up for me.

I can find oval units BUT the throttle linkage is on the wrong side. That TB is the only one that I see with the linkage on that side..

ks

Here you go, Kevin click here => Oval Throttle body

It turns out to be a Whipple not an FRPP TB — my bad.

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eschaider

· #18 · 1 mo ago

KEVINS said:
Hmmmm...Studying the design of Accufabs TB's it looks like the oval could work if I simply flip it upside down.

ks
View attachment 176559
I need the below version:
View attachment 176560

If you look at the linkage arm on the Accufab units, it looks like they flipped the throttle body over for the Oval body and reinstalled the throttle blade so the logo read properly.

Reactions: 1

eschaider

· #19 · 1 mo ago

3

KEVINS said:
Those oval TB's don't have the IAC port on the back that matches up to the IAC port on the Mach 1 manifold which is where the "extra-additional" fab-work comes in. I would either have to get creative by adding the port to that TB off to one side so it can access incoming air or relocate that IAC port externally to the up-pipe or just use an external IAC like I made for mine...no bid deal on any of these.

Since I like the idea that the Oval has a smoother idle transition the extra fab work will be worth it.

I will also do some digging around, maybe someone makes an Oval with IAC ports.

Ks

Check out. Cobra Engineering, James has several IAC adapters he makes. This is a custom one that I used to put the IAC on the back of the blower where the EGR valve originally was.

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I suspect James will have something that you can use.

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KEVINS

Discussion Starter · #20 · 1 mo ago

I woke up this morning with a goal to see if I can find IAC plumbing info and viola, I see it all right here! What a dream...

KS

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