HEMI Tech- Intakes and exhaust manifolds

This has to be one of the most popular topics for Hemis (and any motor for that matter). What should be used and what's available for these old motors.

1) Intake manifolds...
- What's good for what application?
- What manifolds will "over-carb" in relationship to various set-ups?
- Vacuum considerations?
- Cast vs. U-fab intakes?
- Features of various stock manifolds for different makes and models? (I.E. Water flow)
- Who's still making them and where can I get one?

2) Exhaust manifolds...
- Which ones are interchangable and for which makes and models?
- Types available?
- Stock vs. aftermarket?
- Make your own or buy them?
- Who sells the headers, kits, etc.?

 

I see the u-fab units on E-bay alot. Available unassembled, tacked or fully TIG welded in 4x2, 6x2 and 8x2 .
I have a feeling this is going to be a long thread with lots of good tips!

 

Quite a large # of choices on Chr. intakes. Up to '54 are wet with integral thermostat housing. '55 & later are dry intakes. Later intakes can be used on 51-54 by drilling the intake mounting flange where the water ports are, or drilling the front of the heads, & putting fittings in. A remote thermostat is then used. Afermarket intakes for Dodge & DeSoto are scarce!

 

http://www.jalopyjournal.com/forum/showthread.php?t=4086

 

Lake Headers has the U-Fab intakes and are available from raw materials to finished product.

http://www.lakeheaders.com/

There's a picture of one in here and some talk of others. They look nice powdercoated!
http://www.jalopyjournal.com/forum/showthread.php?t=95760

 

Here are some previous discussions on intakes:
http://www.jalopyjournal.com/forum/showthread.php?t=114396&highlight=hemi+intake
http://www.jalopyjournal.com/forum/showthread.php?t=74660&highlight=hemi+intake
http://www.jalopyjournal.com/forum/showthread.php?t=71696&highlight=hemi+intake
http://www.jalopyjournal.com/forum/showthread.php?t=4274&highlight=hemi+intake

 

I like the Weiand inline 4 carb and the stock 4 bolt exhaust manifolds, the exhaust manifolds will take a 2 1/2 pipe right from the flange that you can run down cap off and come off the top of the pipe in 2" or whatever you like.

 

Some time ago in one of those "too little to do & too much time thinking" situations I had the following thought...take a '55 or later Hemi, put the Chevy W/P on it, & a 392 crossover (if '55 331 or 354), & a '54 wet intake. Run both thermostats & run both hoses to the radiator. Make someone walking by think you got a flathead in there & get a real suprise when they look. Sometime after that someone posted on here photo showing an early Hemi w a dry intake. They had tapped either the intake, or front of the heads & run both hoses to the radiator w/o the remote thermostat. Kinda what i was thinking!

 

I think Pinkee's did that with the 29 RPU. Would look pretty neat I think!

Anyone running the U-fab intakes like Crower used to offer and Lake Headers makes now? Anyone runing 6x2 with all six carbs dumping (progressive or whatever)? How do the manifolds hold up? How did you coat them... paint? Powder? Plating?

 

I think Jimmy White's coupe is running all 6 carbs all the time. But it's a Weiand Drag Star cast manifold. Carbs also mounted on spacers.

 

Yes, Drag Star. Love that intake!

This could be asked under the cam thread too, but I'll shoot it here first since it's related to this subject. With respect to cams, when should you jump from a 4x2 to a 6x2 intake manifold (without blocking carbs off)? I know there are lots of details to this answer (jetting, carb size, etc.), but generally speaking, what is a max cam that should be running with a 4x2 before you say... "I need more carbs"?

 

97s are rated @ 150 CFM, so 4 is 600 CFM, 6 is 900 CFM. 94s (depending on witch variant you have) range from 155 to 185. So 4 could be from 620 to 740 CFM. 6 range from 930 to 1110 CFM. You can see where 4 should be fine, but over carbing occurs quickly with 6, not to mention tuning that many!

 

My thoughts exactly! Seems like you would have to have a hell of a cam to run six.

 

I'm running an old U-Fab I'll be picking up soon with 4 GM single barrels on it, might switch out to deuces later, but ultimately I'd like to go injected...might save the injection dream for the drag motor that will replace the current one being built...just as long as I don't pull a Littleman and blow my "street" motor and be forced to finish my drag motor to get it back on the road...

 

anyone have stock 4 barrel intake casting #'s

 

what brand?

 

alright, the old U-Fab I was intending to run didn't work out for me, so I'm now contemplating the Weiand dual quad intake, anyone had luck with those? He doesn't list a powerband for his intakes if memory serves me right, but maybe he'd know offhand if I called?...I'll be running a 331 bored out to a 354 with 9:1 compression, fenderwell headers, stock crank and rods, Mallory Unilite/Pro Master/Hy-fire ignition, and haven't decided between a solid or hydraulic cam...if I do run this dual quad I'd like to run a pair of 600cfm Holleys...I'm trying to keep this build as close to '62-'63 NHRA gasser rules as possible, but would the Hot Hemi Heads tunnel ram be a better choice? he lists the powerband from 2800-7800 because of the design...I'm leaning towards the tunnel ram, not just for the coolness factor, but because of the lower powerband you usually don't see on a tunnel ram, and I'd like to drive this thing on the street quite a bit...what are your guys' thoughts?

 

ok, for retaining the early '51-'54 heads and using the later '55-'57 intake, what exactly do you need to do for water crossovers? George tried to explain it, but it wasn't descriptive enough for me to understand...what needs to be drilled on the intake mounting flange? and if you do that, where do you mount the remote thermostat? same goes for adding fittings to the front of the '51-'54 heads, where does the remote thermostat go?

 

2 pieces of hose(1 each side) Ys into a remote thermostat housing. Then a hose runs to the radiator. Haven't had to use one, probably make a bracket to mount above front of engine.

 

Quick link to some discussion of Weiand Drag Star 6x2 manifolds here:
http://www.jalopyjournal.com/forum/showthread.php?t=136411

Sorry to interrupt... just want to get this link in before I forget.

 

I've seen this too. I'll dig through some pics and see if I can find something. Maybe someone else has some they can post in the mean time.

 

I'm assuming he means to drill and tap the later style '55-'57 intake manifolds in the center of the flange between the number 3 and 5 cylinder ports and the 4 and 6 intake ports where the stock early '51-'54 intake manifolds used to crossover...

 

Yeah, that sounds about right.

 

Anybody seen one of these Desoto manifolds?I know it's not traditional but it looks good to me after searcing for impossible to find and exspensive stock four barrel manifolds.A seller on EBAY makes them for $600 bucks.I didn't post a link for the auction.Is it ok to put EBAY links on this board?

 

I wouldnt post it. If someone wants it thay can search for it on ebay. I do like the looks of those but for 6 bills? I dunno. I think I would make my own for that price. I do like the idea and how the water is routed.

 

Depends on your personal preference. You should be able to get an OEM for that price.

 

I recently scored a factory dual four manifold for a high deck DeSoto. Any body have any ideas on the best carbs for this set up? If this gets buried in this discussion, I might post a new thread. Thanks in advance!

 

I had a 354 out of a dump truck that the exhaust manifolds where gold, 3 inch outlets.

 

Hello..This 3x2 came from Hot Heads..for my 241 Red Ram Dodge Hemi..I believe that the three 81s will perform just right for this mild build engine..Have 97s that I can put on it also..I also have a 4x2 Log intake and I'll see if the 241 can handle it with the 81s..or 97s..My hunchis the 3x2 with the 81s will be the way to go.. Would love to use the 4x2 log because of the looks..
Will let you know which works best.
duane...

 

Edelbrock 500 CFMs. They are wide & short vs Hollys being long. Carter used to make a pair of 400s for dual quads, probably extinct today.