ford explorer 65 mm throttle body

[87bluebird]

i got an 87 pontiac firebird with the 2.8v6 and auto trans. and i plan to put the ford 2.9 injectors in it to give it more fuel but before i do that i want to get a larger throttle body. i know alot of people make adapter plates and port the stock intake manifold to use larger throttle body's. but i read in a few different places that throttle body spacers negatively affect torque and throttle response on mpfi engines. it is actually better the closer the throttle body is on dry type intakes like my mpfi. and an adapter plate would do the same thing as a throttle body spacer. so what i was thinking is getting a 65mm throttle body and intake manifold from a early 2000's ford explorer with the 5.0. then cut off the neck of both that intake manifold and and my stock intake manifold weld the ford throttle body and intake neck to my stock intake manifold as close as possible. that way i don't have to deal with porting the intake or making an adapter plate. anyone got any tips or suggestions. can cast aluminum be welded. i know how to weld regular aluminum but i don't know if cast aluminum is different or not. thanx

[bszopi]

Welding cast aluminum is a whole different animal than welding standard aluminum. Honestly, I don't see a 1/2" adapter affecting your performance that much, if any. Heck of a lot easier as well. Who's to say that welding the TB neck from the Ford manifold, and trying to make a smooth transition, isn't going to affect performance even more?

[87bluebird]

my plan was to completely remove the stock intake neck and weld the new one to the side of the manifold where the old one was. that way transition wouldn't be a worry. how much different is cast aluminum from regular? i have no clue how i would get an adapter plate made thats why i thought this would be the easier method.

[bszopi]

The transition issue I was talking about it that there is a very slim chance that how the necks mate up to the plenum will be even close to the same between the two setups. So even if you hacked them off right at the plenum, mating the Ford neck up to the GM plenum isn't going to be striaghtforward.

I'll let experience welders chime in on the welding of cast aluminum.

[SappySE107]

Hope you tune for larger injectors. A larger TB alone won't solve any issues the injectors will create. What credible sources have said a TB adapter plate will decrease torque? Cast is porous and dirty and will be difficult to weld to and look good.

[87bluebird]

The transition issue I was talking about it that there is a very slim chance that how the necks mate up to the plenum will be even close to the same between the two setups. So even if you hacked them off right at the plenum, mating the Ford neck up to the GM plenum isn't going to be striaghtforward.

I'll let experience welders chime in on the welding of cast aluminum.

the ford neck i was going to shorten and cut to mate to the stock intake manifold.

[87bluebird]

Hope you tune for larger injectors. A larger TB alone won't solve any issues the injectors will create. What credible sources have said a TB adapter plate will decrease torque? Cast is porous and dirty and will be difficult to weld to and look good.

one of the things that was saying that was on this site and the other i read that on was a mopar site. they said that adapter plates work on wet type intakes like carb and tbi. but dry type intakes like mpfi they decrease torque and throttle response . ill look to see if i can find them again. i was also planing to grind my intake smooth like 58mark did on tgo. would that make welding it easier? cuz it wont have the porous cast.also i realy dont care about the looks this aint no show car and the v6 wont be there for more than a year or 2

[SappySE107]

That won't change anything for welding. It will need to be backed, and then the dirt and oil will come out of it. Adapters work on carbs because it gives the fuel more room to mix with the air, and can also help with distribution of the fuel to each cylinder. On port injection, it doesn't do any of that. It also doesn't decrease torque or throttle response unless its just a really bad design. The ones with fins my screw something up for flow but otherwise, no.

[87bluebird]

wouldn't smoothing it make cleaning it easier? which also make the weld better?

[bszopi]

Smoothing will make the surfaces better, but not the core of the material. And when you weld, you need to get to the core of the material, not just the surfaces.

As far as what we have said about TB spacers, that is strictly "spacers". Pieces that just go into the intake tract in order to make the plenum itself larger. You are wanting an adapter. Sure, it will technically act similar to a spacer, its serving a purpose, which is to mount a TB to a plenum with a different bolt pattern.

[87bluebird]

no matter what method i use to attach the explorer throttle body, what should i do about the egr? explorers don't have egr

[dskopek]

I weld on a lot of cast manifolds and it is very hard to get a clean weld on some of them. It will weld up just fine, just takes a little more work sometimes. If you grind out your weld point and then make a root pass you will see the dirt and oil come up in the top of the weld bead just like Ben from WOT-Tech was talking about, grind this off the top and then make a final pass over the root weld and it will be strong but might have some porous spots on the top of the weld. You can always grind this down and make 1 more pass to clean up the top of the weld if you want it to look real good.

[ForcedFirebird]

I weld on a lot of cast manifolds and it is very hard to get a clean weld on some of them. It will weld up just fine, just takes a little more work sometimes. If you grind out your weld point and then make a root pass you will see the dirt and oil come up in the top of the weld bead just like Ben from WOT-Tech was talking about, grind this off the top and then make a final pass over the root weld and it will be strong but might have some porous spots on the top of the weld. You can always grind this down and make 1 more pass to clean up the top of the weld if you want it to look real good.

Yup. Welding cast isn't easy, but it can be done. I have welded cast aluminum and iron now, both like it when heated first on top of the multiple passes. I start by fusing them together to get the part heated (lots of times they will split apart again), then running a bead over twice.

Here's a cast cat that I cut up and welded back together to make a turbo manifold adapter...





and a cast downpipe I cut and re-welded to come from the turbo...



and finally cast welded to steel





I only have pics of the aluminum I welded on my crappy phone, I will try to take some when I am back at the shop.

[Tbay99Venture]

Wow that looks nice. It sure doesn't look easy.