How is the 351 Lightning EFI intake? It's a stock piece, kinda.
They seem to be pretty rare, I've never even seen one, I assume they are long since obsolete from Ford.

 

The Lightning used the GT40 intake with the tubular upper, the upper is the same part that was available from Ford racing and used on some 5.0 motors but the lower is unique to the 5.8 and pretty rare.

 

I wish my Van had room for these Aftmkt intake manifold upgrades, but no room under van hood for anything..
i am wondering if my 1991 5.8l Van has Coolant running through my Lower-Intake manifold??? as Conanski's great pics look like they are the Dry style-older manifolds???
I wish mine didnt have the coolant routed through manifold as may leak. Reason is I am going to replace my valve-Cover gaskets and thot i wud re-torque my Intake man bolts, and buy new ARP Chromoly bolts first and put threadlocker Loctite glue on threads, and i will Not remove my intake to change-out these intake man bolts.
If i go to auto parts store and look ant Intake Gasket it should also tell me story if my manifold holds-routes the Coolant within the manifold or Not??
I want to re-torque with new bolts using glue so water-coolant wont leak and wont rust threads.
i hope my lower intake manifold has no coolant, and/or Ford used glue on my bolts at factory.
I think my lower manifold holds coolant by pics in my old haynes repair manual. 6 holes per bank, so 4 holes for Air-gas/ 1 at each end for cooling.. so 8 holes total for air-gas and 4 holes for coolant total???
I direly hope-pray that For made bolts that dont loosen or used glue on threads-so my orig gaskets and threads are not compromised-soggy/corroded- As Van is a Bit** to work on and i will be lucky to do the Valve cvr-racker cover gaskets, but i dont want to have to remove the Lower Intake manifold!!!
???Did OEM Ford use Threadlocker on my vans intake manifold Bolts at the factory-assembly line???
Torque spec on my Intakebolts in 23-25 ft lbs, can i safely go a tad higher like 27lbs with Chromoly bolts??
sorry if i hi-jackd this thread, itf so plse re-route it to diff forum location, my apologies.
thx mch, CargoVanMan Ford 1991E-250 5.8L W

 

All the Windsor style engines (221/260/289/302/255/351) had coolant entering the intake manifolds at the front, where they lead to the thermostat housing. You are correct in that each head has 6 holes on the intake side; 4 for the cylinders, and 1 on each end for coolant. Usually the coolant holes at the rear of the engine are blocked off by the intake manifold. But a lot of the newer models have some kind of small passages tapped into the intake for things like cooling the EGR plate.

In all the factory engines I disassembled recently, I do not recall seeing any kind of thread lock on the intake manifold bolts. Their use of bolts with flanged heads seems to work quite well at holding the intake in place. But you can use it if you want to.

Understand that the stock intake gaskets WILL give out after sufficient use and time, and will require replacement. The worst thing has to be using cork gaskets at the eds of the manifold. The cork dries out and shrivels over time, and breaks off like potato chips, and you end up with oil leaks at the front and rear of the engine. The next problem is those end holes where the coolant passes into the intake. Most often, owners don't change the coolant regularly, and the corrosion eats away at the metal around those holes, which causes the gaskets to fail.

I have replaced the lower intake gaskets on a couple of v6 Aerostars, and they are very tight as well. The most tedious part was scraping the old gasket remnants from the heads. It was awkward to reach in from the short hood, and I imagine you would have similar difficulties in a full size van. You may end up doing more of your work inside, with the doghouse opened.

 

Thx xlt4wd90,
yes my coolant was abused also, but i am using this rust eater product-pump lube that seems to be working great, but once the metal is rusted-corroded, even moderately, will a new lower Intake man Gasket solve the leaking problem (mine doesnt leak water yet that i know of) or is Iron Block and alum Intake Manifold too damaged/rusted to ever seal again properly, even with new gasket???
Also, most importantly, i was also told too not replace my intake bolts as they/factory installed bolts usually Dont vibrate-Loosen and/or Stretch very much, And if i Try to re-torque-Tighten them 12 bolts, or Replace the 12 bolts; i was told that at least 1 of the 12 will SNAP-Break!!!
i asked him if a HeatGun may help, and he said No, only flame-Torch, but that torch will also melt the lower Intake gasket in the process.
I worry the 2 bolts you say are near the waterjacket have corroded-rusted threads and are Frozen-stuck and will break-Snap upon removal????? Even if only 1 of the 12 bolts breaks i am screwd!!!..
The ony reason i wanted to change to new Chromoly bolts is to re-torque manifold to avoid future leaks, but his philosophy is "if it aint broke dont fix it"...
What are your thought on all this????
Is there a trick to Remove the 12 lower intake manifold bolts without breaking them in process???
i guess i should leave it alone till it starts leaking oil bad (it does not weep a little at he Ends-front of engine, not sure about rear yet)..??
It may be using-leaking a little coolant now but not visably yet.
I DONT want to Break an Bolts unless im already gonna remove the Manifold to replace gaskets. i just want to replace the 12 bolts with chromo bolts so i can re-torque the bolts to spec, but i guess i "should leave well enough alone" ; my van is almost 30 yrs old with 50,000 miles on motor, never towed-no trailer hitch, but some Coolant abuse-neglect etc. 5.8 motor Runs like new now tho..
Thx, VanMan

 

Slow down Son, if it ain't broke, don't "fix" it.

 

Like others said, if you're not losing fluids, don't mess with it. Keep an eye on those junctions between intake, heads, and block for leakage. The front may be obvious, but you may have to feel around the rear for leaks.

 

Thx All;
I may be losing about a Quart of Coolant per few monthe-3 or so months, not sure. I installed a Degas-Burp Bottle-overflow bottle reservoir, and it loses some always but nothing rapid or drastic.
Ok, but when i do have to dig-in & Replace my lower Intalke Manifold Gasket, you got any Tips like using a Torch or Heat-Gun to remove the Bolts without Snapping/Breaking them off in the heads????
of course i will replace old bolts with ARP Chromoly bolts, but also, once manifold removed, would i need to chase threads with tool-Tap, or if old bolt threads dont seem to be Too Corroded-rusted, I guess I need Not Chase threads???
Or do you suggest i only need to Chase the 4 bolthole threads around-next to Coolant bolts entering coolant jacket-passage bolts (mainly 2 bolts-the other nearby bolt not a bolt but a permanent Stud) per xlt4wd90's advice???

I know the Felpro aftmkt gasket doesnt use cork on their replacement lower intake man gaskets..and my old haynes manual looks like it doesnt use Cork either, except on the valve Covers/rocker covers (but they have also updated the V-cover gaskets (they make both styles- they still make a Cork one and also an updated one non-cork for Valve covers). But hope to heck the Intake man oem old gasket now on Van isnt Cork-has no cork per xlt4wd90's post. ????
Mine may be weeping a litle oil at the ends, but it may also be related to both my 2 very old worn cork valve cover gaskets leaking badly--that are leaking oil down onto lower intake man ends and watr pump.--since the valve cover leak is at the same area/front end of engine as the oil leak.--meaning the VC oil leak is in same area as front-end as lower intake gasket front end.

WHY in the Heck!!! DIDNT FORD factory dearborne Michigan or wherever/whoever assembled the original 5.8 motors, USE (Threadlocker-Loctite-hi temp-medium strength permanent Glue) on these 2 or 4 lower intake manifold Bolts near Coolant jackets so that it would help avoid corrosion-rust and frozen-stuck Bolts!!!!????

Thx mch,
CargoVanMan

 

The cooling passage leaks are usually caused by lack of maintenance; not changing the coolant every 2 years. So you can't blame Ford if an owner does not follow good maintenance practice and his engine deteriorates. Also, I don't believe that thread locker in those corner bolts will prevent them from corroding when the cooling passages decide to leak; the threads would not be the only parts that will be exposed to water. The surest way to prevent those bolts from corroding is to replace them with stainless. You can get them in the appropriate lengths (5/16 coarse) from your local hardware store, and you will need to use lock washers with them. You do not need ARP chrome-moly bolts since this is not a high torque application. Chrome-moly bolts will corrode as well when exposed to water,

It's not the end of the world if you should snap an intake bolt; once you remove all the other bolts, you should be able to pry the manifold off, and have more access to the remnant of the broken bolt to remove it. THEN you can apply heat to help loosen it. Applying heat to just the head may or may not help, since the part that's stuck, the threads, could be more than an inch below the top of the lower intake.

Oddly, Fel-Pro still supplies cork end gaskets with their intake manifold sets. I think Ford has used cork forever from the factory. But the recommendations from anyone who has done this is to throw those away and apply a 1/4" bead of RTV at the end faces. Also put RTV around the water passages. If their faces are badly corroded, you can try using the grey RTV, which sets up stiffer than the other stuff.

You can get the rubber-around steel versions of the Fel-pro valve cover gaskets. They have a spacer around each hole that holds the bolt torque much better than the cork gaskets. Again, they still offer cork VC gaskets, just like factory. That is a terrible decision is curse-worthy.

 

Grt Advice-u r Awesome!!!
i am mor worried about threads inside heads corroding than bolt as bolts can be changed out--
How do I know if Female Threads in Heads are rusted out???
if bolt threads are badly rusted this is a huge sign that threads inside head are also rusted out as well...
Also I can do a trial test and take new SS bolt and with intake man removed from van, place a sleeve same thickness as Intake and place bolt into threads thru steel pipe-sleeve, and then with manifold off heads, do a test-torque of the new ss Bolt to see if the threads are strong enough to hold the torque/(overtourque a little) by 5 lbs or so to see if Female Head threads hold, or if they strip-out it means that they were rotten-corroded-rusted...??
if they-threads do Strip out-pull out the threads of head by the coolant holes, i guess i gotta find a guy who can do a good Tap job or is this a Heli-coil insert job?? as well as hog out the manifold bolt holes to match bigger bolt and bigger threads.???
lmk plse,

thx thx thx,
VanMan

 

The threads in the heads aren't a problem. The bolt shanks are what corrodes to the aluminum intakes. This was never a problem when Ford only used cast iron intakes on the small blocks. I would take a heat gun and apply heat to the bolt head long enough to let the heat soak down into the shanks, then apply slow steady torque to the bolts to loosen them. Same thing happens to the long waterpump/timing cover bolts that extend thru the timing cover. Applying heat and then slow steady torque to them will break them free without snapping the bolt shanks. Felpro does have intake gasket sets with rubber end seals as well as cork The rubber seals work better than RTV and cork as they have tabs on both sides to keep them in place.

 

does anyone know if the wire connectors to the sensors are the same on a 91 and a 92.
I noticed that the harness is different???

 

Yes Ford made a lot of wiring changes from year to year and some years there were major changes, so if you are doing an engine swap don't try to use any wiring that comes with the donor, use only that which was in your truck originally.

 

I got a 91 Ford 460 I was going to swap out with the 92 but harness is different. but wonder if the connection on the sensors are the same connection. if so I can change the motor

 

If the sensor connector is different then swap your sensor over to the “new” engine.