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4/30/2020 10:29 PM  #1


Adapting a 5.0 car upper to a 5.8 truck lower

I have been messing with EFI and a 351W.  I wanted to use an OEM intake and got to looking at the differences between the truck lower that came on my engine and a 5.0 car upper and realized an aluminum adapter could be made to combine the two.  I ordered the aluminum and began drawing it up but then I found a Bronco company that makes the exact adapter I was going to make. I ordered one and while it will do the job it is a cast piece and very "one size fits all" so I decided to make my own anyway so I could have a precise fit.

I started with a 3/4" thick piece of 4"x16"aluminum


I then took the 5.0 gasket and the 5.8 gasket and traced them on to the aluminum


From there drilled the mounting holes and then filled in the area that both sets of ports share 


To open up that area I began drilling holes


With the truck gasket traced on the bottom I was able to see that all my holes were in the correct place

I need to cut out the chunks outlined by the holes and grind the ports to shap.

I did make one mistake and started drilling in the wrong spot but I didn't go very deep and all that material will be removed when I blend the port.  I had to mark it in red to make sure I didn't keep drilling it.


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4/30/2020 11:02 PM  #2


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Could you add pictures of both manifolds you’re using?
What 351w lower are you using?
Thanks

Great idea BTW

 

5/01/2020 5:12 AM  #3


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Its a conundrum.  The 5.0 lower doesn't fit the 5.8, and the 5.8 upper is for a truck and has the throttle body in a bad location for anything other than a truck.  The problem is that the only vehicle that used a 5.8 with a car style intake was the '93-'95 Lightning.  You can use a Lightning lower and Explorer upper or any GT40 upper, but you're going to pay about $750 for the lower alone. 

An adapter is certainly a work around.  I suppose it depends on what you want out of the engine.  For a stock type application its probably going to be okay.  For anything else I worry that some of the passages are half occluded and the flow cylinder to cylinder is going to be different.  I think I'd look to build a new upper if I wanted the engine to make a lot of power.  It would be fairly easy to copy the way a tubular GT40 is done if you can weld aluminum.

 

5/01/2020 5:48 AM  #4


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Daze, you could mill 1/2 way through adapter with one pattern.
Flip it over and mill 1/2 way through with other pattern.
Then blend them together where they join.
Just have to make sure of orientation of adapter.

 

5/01/2020 8:00 AM  #5


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Nos681 wrote:

Daze, you could mill 1/2 way through adapter with one pattern.
Flip it over and mill 1/2 way through with other pattern.
Then blend them together where they join.
Just have to make sure of orientation of adapter.

I am using a truck lower, and yes once i get back to the project I will open up the holes to be the correct pattern and smooth flow on both sides.
 


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5/01/2020 8:14 AM  #6


Re: Adapting a 5.0 car upper to a 5.8 truck lower

TKOPerformance wrote:

An adapter is certainly a work around.  I suppose it depends on what you want out of the engine.  For a stock type application its probably going to be okay.  For anything else I worry that some of the passages are half occluded and the flow cylinder to cylinder is going to be different.  I think I'd look to build a new upper if I wanted the engine to make a lot of power.  It would be fairly easy to copy the way a tubular GT40 is done if you can weld aluminum.

I don’t agree. Once the adapter is done it will be a smooth flow and equal opening size across all 8 cylinders. I think little to no power would be lost even on a performance engine. In fact the power limitations are probably the OEM pieces. I will concede that having to make a slight turn could reduce airflow slightly however it is so minimal that you’d have to be running hugely high RPMs and a much higher displacement to even see noticeable number changes. In my case it should not matter anyway because it’s a stock rotating assembly and the only the only power adders are aluminum heads and headers.

I thought about making a custom upper and there is no EASY way way to do it and still have roughly equal runner length. Tubular upper intake’s are offset cylinder to cylinder so a person can get around to weld the tubes to the flange. There is not enough space between where the tubes would go on the truck pattern and if you don’t go tubular the only other option is an open plenum just dumping in to all 8 ports and there’s definitely no equal flow at that point. I really do think the adapter is the most elegant solution to this problem.
 


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5/01/2020 8:31 AM  #7


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Is this engine for the Galaxy?

 

5/01/2020 8:37 AM  #8


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Nos681 wrote:

Is this engine for the Galaxy?

sure is
 


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5/01/2020 9:18 AM  #9


Re: Adapting a 5.0 car upper to a 5.8 truck lower

It looks good  Daze, I cant see why it would not work for you. 
Aint it fun working with aluminum, one of my favourite metals!


Good work ain't cheap, Cheap work ain't good!   Simple Man
 

5/01/2020 11:07 AM  #10


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Rudi wrote:

It looks good  Daze, 

Thanks!!!

Rudi wrote:

Aint it fun working with aluminum, one of my favorite metals!

I love aluminum especially when using the lathe.  The only down side to it is tat your tools clog up with aluminum as you work it.

 


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5/01/2020 12:09 PM  #11


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Are you using indexable carbide inserts or high speed steel tooling?
Carbides are available specifically for soft alloys and with the proper cutting fluids galling is virtually eliminated. Travers tool company has some good cutting fluids foe aluminum.
If you are grinding your own tools, put a lot of back and top rake on the tool bit, that along with grinding a chip breaker on it works very well.
Proper surface speeds and feeds for the grade of alloy you are cutting will affect the kind of chip the tool makes, charts are on the internet for speeds and feeds for all kinds of materials.
Hope this helps.


Good work ain't cheap, Cheap work ain't good!   Simple Man
 

5/01/2020 1:34 PM  #12


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Great idea Day.


Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
 

5/01/2020 3:45 PM  #13


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Daze wrote:

TKOPerformance wrote:

An adapter is certainly a work around.  I suppose it depends on what you want out of the engine.  For a stock type application its probably going to be okay.  For anything else I worry that some of the passages are half occluded and the flow cylinder to cylinder is going to be different.  I think I'd look to build a new upper if I wanted the engine to make a lot of power.  It would be fairly easy to copy the way a tubular GT40 is done if you can weld aluminum.

I don’t agree. Once the adapter is done it will be a smooth flow and equal opening size across all 8 cylinders. I think little to no power would be lost even on a performance engine. In fact the power limitations are probably the OEM pieces. I will concede that having to make a slight turn could reduce airflow slightly however it is so minimal that you’d have to be running hugely high RPMs and a much higher displacement to even see noticeable number changes. In my case it should not matter anyway because it’s a stock rotating assembly and the only the only power adders are aluminum heads and headers.

I thought about making a custom upper and there is no EASY way way to do it and still have roughly equal runner length. Tubular upper intake’s are offset cylinder to cylinder so a person can get around to weld the tubes to the flange. There is not enough space between where the tubes would go on the truck pattern and if you don’t go tubular the only other option is an open plenum just dumping in to all 8 ports and there’s definitely no equal flow at that point. I really do think the adapter is the most elegant solution to this problem.
 

Equalizing cross section area isn't the same thing as equalizing flow.  Some of those ports are pretty severely offset.  Sure, you can cut partway in one pattern on one side, partway on the other on the other side, and blend the transition in the middle, but air doesn't care about cross section it cares about changing direction.  You're still asking it to make a dogleg of varying degrees in varying cylinders.  If the intake were pressurized it wouldn't much matter, but when relying only on the vacuum produced by the cylinders its going to lose boundary layer adhesion and spall, creating turbulence and hindering flow.  Were it doing this uniformly it wouldn't matter, my concern is that the best cylinder almost perfectly lines up, but the worst is less than half aligned. 

How much difference will it make, its hard to say without very sophisticated computer modeling, a flow bench, or running the engine with EGT probes in each header pipe.  In the end, it may seem to run fine, but there's no way to tell it really is.  EFI covers a lot of sins. 

As far as making a new upper, you would weld the tubes on the underside of the flange that bolts to the lower intake, not the top.  The tubes could be right next to each other and it wouldn't matter.  Then the tubes go into a plenum tapered to the TB flange.  You're worrying too much about equal length.  The plenum is the equalizer.  Its not a wet intake where you have to worry about the fuel falling out of suspension as it reaches the ends of the plenum. 

On the cheap try dipping your burrs in ATF.  It keeps aluminum from sticking to the burs.  Also using single cut burs keeps them from loading up as much.  Double cut work good for steel and iron, but not for aluminum; they are too prone to loading up. 

 

5/02/2020 10:03 PM  #14


Re: Adapting a 5.0 car upper to a 5.8 truck lower

TKOPerformance wrote:

On the cheap try dipping your burrs in ATF.  It keeps aluminum from sticking to the burs.  Also using single cut burs keeps them from loading up as much.  Double cut work good for steel and iron, but not for aluminum; they are too prone to loading up. 

The burrs I have are double cut.  I tried dipping them in ATF as you suggested and it made all the difference in the world, no gulling at all.  Thanks for the tip.

I cut out the openings and roughed them in with a carbide burr.  This is the first time I had used a die grinder on aluminum so there was a little bit of a learning curve for me.  I made sure to keep it well inside the lines.


Once I had the openings roughed in I traced each gaskets ports on its appropriate side and began doing the port matching and smoothing.  The more work I did the more comfortable I became with the way the burr removed the aluminum.  With this test fit it's starting to really take shape.


I then traced both gasket outside shapes on to it so that I could cut it. I cut it with a bandsaw then used the carbide burr to clean up the outside.


This is what the finished adapter looks like bolted to the upper intake.


and here it is on the lower intake.


As I mentioned when I started this thread, I designed my adaptor and then discovered an aftermarket made one.  Mine is on the top theirs is on the bottom.


They are almost identical.  The only major difference is mine is 3/8" thinner.  The advantage is it will git me a little more hood clearance but the dis advantage is the transition from the 5.0 upper to the 5.8 lower is slightly sharper.  Other slight differences, the shape of their ports are a little rounder where mine are obviously hand cut. Also there threaded holes are poorly cut and mine are much cleaner.



This is what it looks like all bolted up.



Here is a comparison between the stock 5.0 upper and lower (on the left) and my 5.0/5.8 setup on the right.  If I had used the aftermarket piece they would be the same height, but with my thinner adapter is slightly lower.


Had a lot of fun on this project and learned a TON.  The piece of aluminum I started with cost me $65.00 even with my commercial discount.  I had about 16 hours fabrication time into this project.  The aftermarket piece cost me $143.44 shipped so When I compare my time and expenses compared to the ready made uint I was a little less than $5.00 an hour   Not sure what I am going to do with the aftermarket unit.  Might keep it or eBay it... we will see.


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5/03/2020 10:22 AM  #15


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Hang on to both for now.

Have you mocked it up on engine yet?

May want to check clearances for valve cover and throttle body linkage interference.
Especially with the lower height.

Just to save ya some choice words later.
Great work!
Did you make that in your sleep? 😁

 

5/03/2020 10:26 AM  #16


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Excellent fab work as usual Day. Ya got a bit of education along with that $5/hr.

ATF on on a carbide bit eh, who'd a thunk? Wish I'd have learnt that about 20 years ago.

Last edited by Bearing Bob (5/03/2020 10:27 AM)


Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
 

5/03/2020 11:13 AM  #17


Re: Adapting a 5.0 car upper to a 5.8 truck lower

I love it when a plan comes together. Back in the day guys would cut down SBC heads and put them on there in line sixs, now there doing it with LS heads. I love thinking outside the box.


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
 

5/03/2020 11:50 AM  #18


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Nos681 wrote:

Have you mocked it up on engine yet?

May want to check clearances for valve cover and throttle body linkage interference.
Especially with the lower height.

Just to save ya some choice words later.

Yep everything clears with room to spare.  The PCV valve is close but still clears. I am using ev6 24# injectors, they are is about 3/8" taller than the OEM bosh ones, but I still have 1/16" of clearance between the fuel rail and the underside of the 5.0 upper


Bearing Bob wrote:

Ya got a bit of education along with that $5/hr..

That I did.  The education part was well worth the time.  It was also a ton of FUN so from that aspect it was basically free.

Bearing Bob wrote:

 ATF on on a carbide bit eh, who'd a thunk? Wish I'd have learnt that about 20 years ago.

It worked amazingly well.  I would dip the burr then shake it over a rag to get the excess off and then start cutting. After a couple minutes I would notice a little aluminum building up in the burr so I would dip it again.  There was no need to pop the aluminum chinks out just dipping it and resuming work caused the aluminum to come loose from the burr.  I also used ATF when I tapped the holes.  Worked IMHO WAY BETTER than traditional cutting oil.
 


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5/03/2020 3:25 PM  #19


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Finished product looks great.  Keep this updated when the engine runs.  I'll be curious to see.  What are you using to run the EFI?  EECIV or aftermarket?

I can't remember where I got that tip about ATF, but its kind of the miracle oil of the shop.  Its also great for dissolving really caked on grease.  Mixed 50/50 with something like acetone it also makes a great penetrating oil.  Only downside is they will dissociate if left to sit, so you have to shake up the bottle before each use. 

 

5/03/2020 3:42 PM  #20


Re: Adapting a 5.0 car upper to a 5.8 truck lower

I like to put  "some"...in with the oil in my lawnmower engine. Seems to help with all that crummy stuff that settles in the crankcase.
6sally6
PS............I enjoy a couple tablespoons on my green leafy salad too!  "REAL" car guys use this with a glob of garlic and jalapenos.......also great for mild constipation...(withOUT the jalapenos)
J/K.....(don't sue me for fun'in!)

Last edited by 6sally6 (5/03/2020 3:43 PM)


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

5/03/2020 8:13 PM  #21


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Bearing Bob wrote:

Excellent fab work as usual Day. Ya got a bit of education along with that $5/hr.

ATF on on a carbide bit eh, who'd a thunk? Wish I'd have learnt that about 20 years ago.

I've always squirted 'em with water displacer #40.  No sticky 'lunium.

BB1


"you get what you pay for, good work isn't cheap, and there are NO free lunches...PERIOD!"
 

5/03/2020 9:35 PM  #22


Re: Adapting a 5.0 car upper to a 5.8 truck lower

I used it to clean my cylinders when building my engine and put it on the pistons and rings when installing them.


70, ragtop 351W/416 stroker Edel Performer heads w pro flow 4, Comp roller 35-421-8. T5
 

5/03/2020 10:08 PM  #23


Re: Adapting a 5.0 car upper to a 5.8 truck lower

TKOPerformance wrote:

Finished product looks great.  Keep this updated when the engine runs.  I'll be curious to see.  What are you using to run the EFI?  EECIV or aftermarket?

Thanks, it will be running soon but with a carb on my carb to EFI adapter. As to the EFI, I have a 96 IV computer and TFI ignition parts, a mega squirt computer with duraspark ignition, and Holley’s multi-port self tuning system that will work with either ignition system. Will probably mess with all three. I love having an engine run stand.


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5/04/2020 9:26 AM  #24


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Bullet Bob wrote:

Bearing Bob wrote:

Excellent fab work as usual Day. Ya got a bit of education along with that $5/hr.

ATF on on a carbide bit eh, who'd a thunk? Wish I'd have learnt that about 20 years ago.

I've always squirted 'em with water displacer #40.  No sticky 'lunium.

BB1

I have always used diesel as a lubricant for machining aluminum. Works great and tastes better than ATF


Gary Zilik - Pine Junction, Colorado - 67 Coupe, 289-4V, T5
 

4/22/2022 6:51 PM  #25


Re: Adapting a 5.0 car upper to a 5.8 truck lower

Daze wrote:



This is what it looks like all bolted up.



Here is a comparison between the stock 5.0 upper and lower (on the left) and my 5.0/5.8 setup on the right.  If I had used the aftermarket piece they would be the same height, but with my thinner adapter is slightly lower.

 
What fuel rail is this Daze?
Is it at an angle?

You mentioned in a different topic that you used the Foxbody fuel rail.
How did you clamp the new fuel line to make it wider?

 

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