Intake manifold coolant crossover

[cb84capri]

What is the deal with Edelbrock deleting the rear coolant crossover on their intake manifolds? My thought is that Ford put it there for a reason. My 347 is nearing completion, and the more I think about it, the more inclined I am to put my Professional Products Typhoon back on instead of my Edelbrock Performer RPM Airgap. Thoughts?

Thanks,
Cale

[steven18222]

not to sure but my weiend stealth also has them blocked off

[brianj]

Apparently, it's not needed as much on a vehicle such as ours, where we are willing to accept slower warm up times than a production car. Thousands of these intakes run like this with no problems. Even my blower manifold, Made by Weiand, eliminated the rear crossover.

[cb84capri]

On my car, it seemed the intake temperature ran rampant without the rear cross over. It doesn't seem to care about the RPM manifold being an air gap intake at all, it boils the fuel like that's its job. I think (at least) the rear cross over keeps the manifold temperature from getting out of control because I didn't have problems to this degree with the Typhoon in place. It seems like a half ass'd way of doing things to me.

Cale

[dynodon64]

If you look at, and think about how the water flows through an engine, you will understand it better. Water exits the pump on the front into both sides of the block. It then travels through the block to the rear. Once there it then moves up into the heads, that's why the head gaskets have to go on the right way, the water port in the gasket goes to the back of the block. Then the water flows to the front of the heads into the cross over in the intake, then exit the thermostat housing. Now if there is a water passage in the back of the block, it will only cross over if there is an imbalance of flow through the heads, and may even add to one side over heating or cooling too much. If the flow through the blocks and heads are even, than the rear cross over won't even matter.
And for some who might point out, there are smaller passages in the head gasket that allows water to flow up into the heads as well, those are steam holes. Meant to let air bubbles out, not meant as a passage for main cooling flow.

[cb84capri]

What I think is that the coolant sits in the cross over, and is continually cooled by the water flowing past it. I think if a flow variance did exist, it would balance it out and keep both heads running closer in temperature. I can't help but think that if Ford had any reason to eliminate it they would have. Seems to me it would be one less thing to worry about in the manufacturing process. My carburetor fuel boiling issues got worse after installing the Air gap RPM intake that doesn't have a rear cross over in it.

Cale

[bwguardian]

My Ford Racing intake manifold does not have the rear cross over. I have a heat shield and phenolic spacer under the carb and have had no issues.

[ashley roachclip]

I have never had carb boiling problems with my Edelbrock manifold , even when spraying a 250 shot of nitrous.

That is much more demanding , than any street driving conditions .
I think you are over thinking it.

[mrriggs]

The early small blocks did not have a rear coolant crossover in the intake manifold. Ford added it later when they needed more holes for sensors. If you don't have any sensors plugged into the rear passage then you don't need it.

[cb84capri]

I run an AFB carb, the fuel bowls do not hang off the side like they do on a Holley so they are more susceptible to these problems. If I can keep the toilet bowl flushing the thing will run like crazy all day. I guess I really am my own worst enemy with this problem, if I ditched the dual snorkel and put a spacer under it and a smaller open element to clear the hood I'm sure this would be a lot better. My heat soak issues happen when stopped in traffic, when the car is restarted after running, at the drag strip if I try to hot lap it, etc. If I go out to soon at the track I go to launch, and bahhhhhh falls right on its face when I let off the clutch, get to go wait in the pits for about 40 min until it cools down enough to go back out. I put a cool can on it before I threw the crank out of the block earlier this year the problems were that bad after the manifold switch. The coolant temperature only gets up to about 200 in traffic when the fuel boils. Tried to do the Woodward Dream Cruise last year and it stopped running entirely the gas got so hot, and I got to push it down the street. I wish I had a big old nitrous bottle to spray at the carb so it would cool down enough to run. I have done the Dream Cruise in this car before with the Typhoon on it with no drama.

Cale

[ashley roachclip]

Ever thought of going to a Holley ?

[cb84capri]

I have, but the Edelbrock holds its tune so well and does everything air fuel ratio wise so well everywhere for me I don't want to. I'm not much a fan of the potential for fuel bowl leaks with the Holleys. I know with a Holley I could probably run faster at the track, but I have decided this is more of a street car anyways. I may experiment in the future with one, though.

Cale

[grtskydog]

You could also try the Summit carb. 1-pc body like an Eddy, but with conventional Holley parts. The design is a knockoff of a Holley knockoff of the old Autolites. I ran one for awhile when I had my 302 in and it was a neat carb. That said, I've run Holley, Eddy and the Summit...even messed with a Quick Fuel at the pinnacle of my carb-tuning adventures. Tried heat shields, phenolic spacers, and everything in between. All junk in the attic now. Never was able to solve my percolation issues.

[cb84capri]

You could also try the Summit carb. 1-pc body like an Eddy, but with conventional Holley parts. The design is a knockoff of a Holley knockoff of the old Autolites. I ran one for awhile when I had my 302 in and it was a neat carb. That said, I've run Holley, Eddy and the Summit...even messed with a Quick Fuel at the pinnacle of my carb-tuning adventures. Tried heat shields, phenolic spacers, and everything in between. All junk in the attic now. Never was able to solve my percolation issues.

I remember your write-up about that carb many moons ago, I remember how bad your Professional Products intake manifold was too when you initially went efi. I was half expecting to be called crazy by you when I saw your screen name for the last post, haha! I may have to look you up on some of the parts if you'd like to sell them.

A note on my cars performance while I'm at this... With the 302 the car went 13.6s @ 102 with 3.55s drinking oil on #4 cylinder because of a failed lowly printoseal intake gasket with the ported Typhoon when it decided to launch. Car went 13.3 @ 102 with 4.10s not drinking oil with the ported RPM air gap all day long as the only changes. The Air Gap has smaller ports then the Typhoon and I had to open the ports up a lot more to match my heads. 1/8 trap speed was higher with 4.10 switch but the car wasn't picking up 24mph from the 1/8 to the 1/4 anymore. I think I lost performance with the manifold switch considering the severity of the oil leak, though admittedly not the best comparison. All things considered, I decided to put the Typhoon on my new motor.

Cale

[cb84capri]

Got some driving in tonight. I did all the stuff that the car hated when the RPM Airgap was on it, and the Typhoon didn't give me anywhere near the amount of issues that one did. If I iced the cool can I likely would not have had any hiccups. Aside from the engine being a 347 now, the only other notable differences are bigger needles and seats in the same carb, and 2 carb flange gaskets are being used. We'll see what happens when the hot weather comes.

Cale

[Jackthemind]

I deleted my crossover to eliminate the risk of coolant leaking and being sucked into the manifold.

Sent from my 5017B using Tapatalk

[grtskydog]

I think one of the original purposes of the rear crossover was for OE stuff. Remember the 'ol Thermal Vacuum Switch? They had to have a place to mount stuff like that and sensors in some applications. I had an old Stealth that had the rear passage, and I liked it since I was using the TVS with my vacuum advance. My only guess is the a/m intakes that are mild upgrades allow for use of the OE sensors/switches, while with the hotter intakes they figure you've already ditched all that stuff.

[xctasy]

Same issue over here in Australian 188 hp 4V 302 Fords. No space, even with the cross over on a Cleveland. They mounted them in a second water neck hole, ie two holes on the gooseneck. There was a third whole for another manifold vac at the back


Two red TVS's for-ard if it had optional York A/C pump emissions package.




One at the back of the intake, angled below the rear mounted EGR.





If it was stick shift and manual, 302 or 351, it got this.



Manifold vac, angled down at back via cross over.


Cale, I vote some BSP fittings, a good diameter "oval"-ed with a press or some hammer work 3/4" copper line and make your own adaptor.

Frank Zappa was a plumber!

The I6 1980-1983 3.3 Junction block works as well, its an easy hookup. Junction = Junk Yard, a little word association....

A ported vacuum switch that's in the water outlet will only see actual coolant temperature when
the thermostat is open. A ported vacuum switch that's rated to switch at 125F-130F can't
do it's job as well when it's sitting on the other side of a device that opens at ~190F. A bleed
orifice in the thermostat would help, but it's just better to have it in constant contact with the
coolant inside the engine.

One possible solution is to use a heater hose elbow that has provision for an ECT sensor, and
put the PVS there. Fox HVAC systems do not have a valve that turns off coolant flow in the
heater loop, so a PVS there would work fine.

A PVS that is intended to raise idle speed when the engine cooant is over 225F can do it's job
when it's sitting on the other side of the thermostat, because at 225F, that thermostat had
better be open. It could also do it's job screwed into a manifold coolant passage, but what
to do if you don't have any of those ports available is probably why it's commonly found in
a water outlet. Those PVSs were in use back in '68, when manifolds had fewer places to put
one than they do now.

Ford used the angled goose neck from day 1 for a TVS valve...that's why they went to the Clevelands,M's, 400's and Lima ThundaJet "385" engines...for easier emissions plumbing.

Use the "transferable, relocatable" E0 to E3 Ford I6 part, (like what JA Cokk suggested above) and lock it under the plug wires and run it flat through the water line before the thermostat. It allows you to run the Spark Delay or whatever the 84's ran.

Here's the master list from the 85 manual





verses whatever you might find on the busted a$$ 80'six





http://i1215.photobucket.com/albums/...201981_DCK.jpg


Here's the part again.





And Red78' breakout codes from his files (with my numbers...sometimes Ford likes to add VCV and VLV, TAD/TAB to the list from 1979, and not tell anyone but trained Ford Service Techs, so a little work finding the best of the 74 ding-a lings below is needed. FoMoCo doesn't use the PCV label, and there are IMCO and other terms for the common items which might not be the best descriptions.

1 A/CL: according to Ford, that IS the air cleaner
2 A/CL DV: Air Cleaner Duct & Valve
3 A/CL BI MET: Air Cleaner Bi-Metallic Valve
4 A/CL CWM: Air Cleaner Cold Weather Modulator
5 ACV: Air Control Valve
6 AIR: This is a Secondary air injection Ford calls the Thermactor, short for Thermal Reactor. CA vehicles are installed with it as standard. Air Injection Reaction is what it stands for.
The thermactor system consists mainly of the air pump, the air pump diverter and bypass valves, TAB and TAD solenoids (if equipped) and the catalytic converter.
7 AIR BPV: Air Bypass Valve (aka Thermactor Air Bypass TAB)
8 BV: Bowl Vent (on top of the float tanks)
9 CARB: Carburetor
10 CPRV: Canister Purge Valve ( PURGE CV: )
11 DIST: Distributor of course.
12 EGR: Exhaust Gas Recirculator
13 EFCA: Electronic Fuel Control Assymbly
14 FLTR: Filter
15 FPR: Fuel Pressure Regulator
16 IVV: Thermactor Idle Vacuum Valve
17 MAN VAC: Indicating Manifold vacuum-Vacuum source
18 MAP: Manifold Absolute Pressure
19 SOL V: Solenoid Valve
20 SV-CBV: Carburetor Fuel Bowl Solenoid Vent Valve
21 VAC: short for Vacuum
22 VCKV: Vacuum Check Valve
23 VRESER: Vacuum Reservoir (Actually VRESER just stands for Vacuum Reservoir. It may or may not have a valve or Solenoid Valve inside it.
24 VREST is a vacuum restriction, usually at the thermally controlled valve on top of the thermostat housing.
*On 87 4V 460 F250 truck it is a simple blue plastic orifice inline with the vacuum line.
25 VRV: Vacuum Regulator Valve
26 VRDV: Vacuum Retard Delay Valve, as these can be used on more than just the distributor.
27 TVS: Thermal Vacuum Switch, and is different to a Dashpot. On Fords these are usualy located in the air cleaner.
28 TVV: Thermal Vent Valve. On fords they are mostly controlled by ambient air temps. Simular to a TVS. Located between the carb and the charcoal cannister.
29 PVS: Ported Vacuum Switch: Very simular to TVVs except on Fords they are used in the cooling system and are controlled by water temps.
30 PURGE CV: Vapor Canister Purge Valve
31 EVAP CANISTER ASY
32 Ford refers to theirs as an Idle Speed Control (ISC) solenoid
33 Idle Boost Solenoid (Orange Knob on 81, 82, 83 A/C Equiped 3.3's) or Throttle Kicker Control
34 Carburettor throttle Solenoid Positioner (Anti Dieseling Valve/Idle Stop Solenoid)
35 Spark Port
36 EGR Actuator
37 EGR Port
38 CAT is catalytic converter;
39 ENG is engine;
40 ACT - not sure, but on EFIs it means Air Charge Temperature sensor
41 Inlet Air Temperature Control
42 Green DVCV 2 port PVS vaccum switches
43 Blue TCVV 3 port vaccum switches
44 Dual Diaphram Distibutor
45 Black SDV Cold Start Spark Delay valve
46 Black SDV EGR Vaccuum delay valve
47 Deceleration Valve (PVS Cold Start lockout Dampened, Non Dashpot)
48 Non dampened or 2 port PVS (dampened) control EGR
49 Attitude and Position Fuel Trap
50 PVS Vacuum with Sintered Line Filters
51 Close Limit primary or Main Jets,
52 Lead plug sealed idle screws
53 Carburettor throttle Solenoid Positioner
54 Evaporative Emmission Control System
55 Anti Backfire Valve
56 EGR Valve Actuator
57 Vacuum Regulator/Solenoid
58 Solenoid Valve
59 Venturi Vacuum Amplifier
60 Load Control Valve
61 EGR B/P Transducer
62 Signal Conditioner
63 Ported Pressure Switch
64 Vent Valve Vacuum
65 Vacuum Controlled Switch
66 Vacuum Controlled Switch (Cold Temp)
67 Vacuum Controlled Switch (Decel Idle)
68 Vacuum Delay Valve
69 Vacuum Vent Valve
70 Delay Valve Two Way
71 Ignition Timing Vacuum Switch
72 Ignition Pressure Switch
73 TK (Throttle Kicker)
74 Mushroom caps for charcoal fuel vapor canister vents.

[brianj]

Jeez. Mine is-

1- vacuum brake booster

2- vacuum source for boost referenced PV and boost guage

I like mine better.

[xctasy]

Jeez. Mine is-

1- vacuum brake booster

2- vacuum source for boost referenced PV and boost guage

I like mine better.

BJ, I'd expect that from you. You add 100 pounds of panel steel to create a revolutionary Saleen esque Stripper Stang, then take off the 888 inches of emissions lines, and add a supercharger, and still end up lighter and probably, cleaner than a stock 83.


Note a problem for CB, but any Hot fuel percolation is "hot fuel handling" in Aussie-speak. Ford Australia had the problem on file with the 82 XE Falcons, due to reduced grille area and the thermoplastic Carter carb bodies tendancy to heat sink on the iron intake manifild they used....but as the edict had gone out to kill engine production, Holden used the part on there Police special 333 pack 308 Commodores for the next few years. It was more fuel presure related, and a common problem compounded by the lack of info on Themoquad float level setting. .

Ford US dealt with "hot fuel handling" in 1982 by using the US Trip Minder Ford bleed back valve for the fuel flow sensor in cop cars too.

GM Holden used it, and HDT Brock Commodores used the system as a bleed-back on cars with as little as 195 and as much as 295 hp.

In an Edelbrock world, where excessive gas line pressure or air en-trained fuel isn't dealt with so well, one of the same parts was available off the E6 Areostar 2.8 V6, it can be added to the inlet fuel line with a 27 thou bleed back restriction.

Listed as a fuel regular or vapor kit. I can't find the reference to it just yet, its historically listed elseware and I'll have to check it.

Other Holley or Mr Gasket or Malpassi units do the same thing, but you can also use it as a MPG message center input if you want to run it through your clock facade in the center console.

Apparently, the similar looking Ford Aerostar 1986 vapor separator Assembly is usedas a fuel shut off esleware, and can be used as a bleed back.

Part list is bottom right on this Pinto OHC page (old EAO engine from 70-89)

I would have thought the Merkur XR4Ti or Scorpio would have had it too. They had TripMinder options too.

Euro Part listing is 6097149 and 6161181 for the Fuel Flow Meter Assembly # 4 bottom right.

http://www.fordopedia.org/parts-catalog/pinto-ohc/B5.14




mrriggs was saying, any turbine wheel flow sensor will also be bleed back, so there is a way of making it yourself or by using propriety parts. Or Walkin-Talls method of fuel bleed back used on his 1984 3.8.

And I gotta say it again, looks like Mikes is the simplest.

I ended up having to also cut the tail off of Holley's throttle lever in order to clear the heat riser (blocked off) bolts anyways. Oh well, no sweat, carburetor return springs will hook onto the throttle lever's top.

Today I tackled establishing different fuel and return lines for under the hood to connect to my bypass-return pressure-controlling contraption. The originals are nylon. It's a bit of a wrestling match to get the passenger side plastic inner fender out, but that's what's necessary, because the nylon fuel lines from under the hood connect to steel lines near to the bottom of the wheel well near the uni-body. I bent up two sections of 5/16" steel line, attached them with short pieces of fuel hose and stainless steel clamps. I added sleeves of fuel hose for where they bend and go through the passage to under-hood so they don't rub together or clatter around. Too bad the snazzy red zip-ties get hidden behind the plastic inner fender, lol




The bypass-return contraption's in place alongside the passenger strut tower, ready for connection to more line to the schrader valve pressure-testing contraption, a fuel filter, and the carburetor.