Blue Thunder Install this weekend

[rcadd1ct]

I did not block the exhaust cross over, I removed that part of the gasket, But I am running the block off plate on top of the intake as my current carb has no choke. Will there be an issue having the exhaust ports functional?

It heats the intake, which is undesirable as it can percolate the carb and other reasons.

For a mild performance build it is ok.  If you are searching for the max, block it off.

 

[Stanglover]

To the question of blocking off the heat risers to the carb base. I touched on that in a post recently, 351 4V carburetor.

I absolutely believe it is necessary if using an aftermarket carb. I thought I created a thread on what I did, but alas, I can seem to find it, but I know I posted in someone else's thread on the subject.

So, I'll try to recap it here,

The first attempt was to simply tap the two holes in the carb surface area and insert 5/16" set screws ( grub screws to the Limey's). Picture #1. This worked to stop the hot vapours reaching the gasket, but did little to lower the temp under the carb. The issue I found was that this unwanted heat caused the fuel to vaporize thus causing hard starting. Even though I used a 1/4" fiber spacer, it still was a problem.

Next I removed the manifold, had to anyway for another reason, but while it was off, I blocked off the passages. My solution was to hand "mill" a step all around the opening approx. 1/8" wide X .08" deep. I had some 1/16" stainless steel, so I cut two pieces to fit (plugs) and used a pointed punch to stitch them in place with some exhaust cement. See picture #2.

When installing, I also took the extra step of using a piece of .020" SS to fill the holes in the paper gasket, just larger then the size of the plugs. Trim the paper hole size to suit. This also meant I needed to rework the valley pan seal to allow for the slight extra thickness. It probably would have been ok as it was, but that's the way I think. These thin plates were held by some Permatex 2 while placing the paper gasket.

I've described in this thread, what else I did including using a 1" thick fiber spacer. Picture #3.  Fel-Pro make a gasket with a metal insert which should go under any carb imo in case of hot vapor leaks, which will burn the bottom of your carb.

Hope that helps, it's just one of many "fixes", but unless you drive in winter, that extra heat is not needed, so stop it!

Geoff.

 

[tony-muscle]

What about using J-B Extreme Heat metallic paste, https://www.jbweld.com/products/j-b-extremeheat

Reportedly it withstands up to 2400F so it should be okay. Maybe adding an undercut to support the paste so it doesn't move due to expansion/contraction of the materials.

 

[Stanglover]

What about using J-B Extreme Heat metallic paste, https://www.jbweld.com/products/j-b-extremeheat

Reportedly it withstands up to 2400F so it should be okay. Maybe adding an undercut to support the paste so it doesn't move due to expansion/contraction of the materials.

I guess any high heat product like that will work as a filler/sealer. One thing I didn't mention is that the heat ports do not have a lot of material to cut the step I described. One corner is especially light, so be careful not to over cut it or you'll have a bigger hole to fill. I wish now, I'd taken more pictures than I did, but that was before I joined the Forum. Who knew!!

Again, I tend to overkill and that's why I added the thin SS plates in the gasket. The reasoning being that it would add pressure to the block off plates and hold them tightly in place.

Recently, several have gone the Blue Thunder manifold route, and to be honest if I'd known about that manifold, I'd have saved myself the trouble and killed two birds with one stone, no unwanted heat and extra power. Apart from the Ford numbers and with a coat of paint, it looks the same as the original.

 

[asajay]

Recently, several have gone the Blue Thunder manifold route, and to be honest if I'd known about that manifold, I'd have saved myself the trouble and killed two birds with one stone, no unwanted heat and extra power. Apart from the Ford numbers and with a coat of paint, it looks the same as the original.

I found this thread while searching for information on what intakes will fit under a stock Ram-Air system.  My last engine for the Mach I had a stock cast iron intake.  I'm working to build my next engine and want to move to a suitable intake for the horsepower.  I've used the Blue Thunder previously for an engine build in a Pantera I used to own.  I really liked that manifold and am considering it for the build in my Mach.

The thread originator mentioned it would not fit under his Ram-Air, but someone immediately commented that it fit fine under theirs.  The comment above indicates many others are using the Blue Thunder intake as well.

I'm already sold on the performance of the intake, question is, will it properly fit the Ram-Air setup?  Photos?

Thank you,

Asa  Jay

 

[tony-muscle]

According to my measurements it should fit, but with some mods of the air cleaner. I have a 71 with ram air and after modifying the air cleaner i was able to fit a 1" spacer under the carb with the standard Edelbrock intake. Now i have installed a BT without spacer that will go in the engine bay soon. The BT is about an inch taller.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[tony-muscle]

Here I found a picture that shows a Blue Thunder side-by-side to an Edelbrock. As you can see the BT is about an inch taller.

 

[Carolina_Mountain_Mustangs]

I did not read every part of the thread but thought I would toss out something.

The engine mounts vary in height from year to year and also between vert, coupe and fastback. Might be possible to mix and match to lower engine to get the ram air to work. Do not know all the specifics but know there are differences.

 

[73pony]

You could technically use 73 frame perches with 71-73 mounts. This would lower the engine about 3/4” - 1” based on my measurements. Use caution if you go this route as it will cause a host of other issues like the fan not lining up in the shroud, difficulty fitting headers, exhaust, and potential driveline angle issues.

 

[asajay]

You could technically use 73 frame perches with 71-73 mounts. This would lower the engine about 3/4” - 1” based on my measurements. Use caution if you go this route as it will cause a host of other issues like the fan not lining up in the shroud, difficulty fitting headers, exhaust, and potential driveline angle issues.

Not to mention it would put the oil pan lower to the ground and potentially in the path of oncoming debris.  Although it sounds like a neat idea, I think the idea of modding the air cleaner is better.  I can get a spare from Dynacorn to mod.



Thank you for the feedback.

Asa  Jay

 

[Fabrice]

I got that RAM AIR fitting problem a few times over the years, only I got tired and did not want to change engine angle, so I took the prob way around.

I'm not doing original restorations and for the time that I spend detailing my engines, I don't want to end up with a huge flying saucer hiding everything.

I've made a mould of the ram air unit and where the flat surface is with the opening. I've spend time enough to prep and wax the original donor unit to the point that I even got the original serials of the original reproduced into the copy. I have then added an induction shape that inserts exactly on top of the carb/EFI. That was the bitchy part, to make it to match the right arc when closing. The air filter is now a high flow flat one and is into the ram air. So when I open the hood, I see my engine.

Last in date was to fit the Holley Sniper that is 1/2 inch taller than the previous combo with a 650 Holley carb.

Because it was taller, I only needed to shorten it by the diff.

Here a very poor pict.



You could also mod the flat shape on the ram air, or remove a slice off the air filter casing or make your own filter casing.

On my 429 its even worse, the huge original air filter casing weights a ton and its base goes very low. So I'll be soon reusing my mould to make a new copy for it, instead of trying to change the engine angle.

 

[asajay]

Nice execution of a difficult problem.  And yes, it helps show off the engine nicely.  Truth be told and money being no object, I'd go with this intake:



with two air boxes (one on each bank of throttle bodies) and a modified underhood plenum that matched them.  It would be a lot more work on the plenum but man would it show off the engine and the bling of that manifold really well.



Okay, sorry for hijacking the thread, I got my answer.  Thank you.

Asa  Jay