Aluminum Intakes - What are You Running?

[str12-340]

The best thing to do to a LD 340 for maximum performance is well known with the divider milled and the ports opened up, IF you want to run that route on that intake. I also ran a TQ on mine since it was purchased modified like that. It was a beast of a dual plane. One day I’d like to find another one in good condition already modified. A couple of fellas here have run low 11’s with a RPM. The LD-340 is right behind it.

Yes this is true if the majority use of the car is drag racing. There are even specific directions for the modification in the Direct Connection Engine book. For a street car this would be a bad idea. The high RPM gains come at the expense of low and mid range torque which, IMHO, is where a fun to drive street car gets its seat of the pants feel. This mod basically turns the manifold into a single plane manifold.

 

[rumblefish360]

It looks nicer with them. Imo
They sit proud on motor..so it's like taking a hot chick and sticking a chain nose ring on'er hanging the ground off the front of them.

I think I’m going to look into that battery cable relocation idea of your since it is a minor adjustment that opens up the area, cleans it up a bit, removes the overbearing nose ring.

 

[AlaskaJeff]

Ahhhh, excellent. That spacer will help that system out really well IMO.

The spacer is doing dual duty as an adapter from spread to square bore for my Holley 750, AND a heat insulator.

 

[rumblefish360]

Yes this is true if the majority use of the car is drag racing. There are even specific directions for the modification in the Direct Connection Engine book. For a street car this would be a bad idea. The high RPM gains come at the expense of low and mid range torque which, IMHO, is where a fun to drive street car gets its seat of the pants feel. This mod basically turns the manifold into a single plane manifold.

Having this intake modded as per the DC book suggests, it worked very well even with a small cam. Any loss of torque was not noticed by the young punk (ME - LOL) driving it at the time. It did provide more power top end NO DOUBT! The TQ was also really helpful in this area.

The DC/MP book said it was the best modification for cams over .600. Which back in the day you read between the lines and re entered. Big *** cam.

 

[toolmanmike]

The DC/MP book said it was the best modification for cams over .600. Which back in the day you read between the lines and re entered. Big *** cam.

That would be a "Full Race Cam"

 

[rumblefish360]

That would be a "Full Race Cam"

For the meek……


But your right. I’m is a racing mod after all. Works great!

 

[74Scooter]

Just some worthless info.
Action Plus is same hight tall as the RPM (not air gap).
Has,same size ports in width as the RPM. But RPM has,1/4 " large ports in hight than the Action Plus.
Personally think the Action Plus and it's smaller ports would be better low end tourqe on smaller cam street 340_360. When i say smaller I meen street, not street strip. To bad Ma no longer makes the DP M1

I've read the same about the A+. Seems like a good intake for mild street builds. Don't think I'll lose anything down low with the AG and hopefully will get some cooler air and fuel going into the cylinders. Unlikely, but if the AG craps its pants for my build I can always put the A+ back on.

 

[MOPAROFFICIAL]

I think I’m going to look into that battery cable relocation idea of your since it is a minor adjustment that opens up the area, cleans it up a bit, removes the overbearing nose ring.

Right on. I seen someone drill tap a hole or weld a nut to screw the bolt n strap to.

 

[Detroit Iron]

It dawned on me to finally go ahead and ask what we’re working on here. Weight, gearing, cubic inches, cam, compression, converter/4 speed. There is a point where a Victor 340 or other type of single plane (or maybe even a tunnel Ram) is going to be quicker, but it’s more the exception than the norm.

Just generally speaking, but you're right when it gets right down to it... the rest of the build matters. I mentioned I have an LD340 on a mild 340 engine.... 4-speed wth 3.55s. I may build a 360 in the near future for a daily driver Dart. Again mild, 9.5 compression, automatic and tall gears.... 2.94s. At this point I'm liking the Weiand intakes.... Action Plus and the Stealth.

 

[Garrett Ellison]

It may be hard to believe, but the stealth is a near direct copy of an LD4B. Not mentioned here is a 1971/72 iron 340 intake. Probably as good or better than as most of the smaller aftermarket intakes you’ll bolt onto a 360. I guess it depends on carburetor, too. Spreadbore, the iron 340 or a port matched Edelbrock regular performer (ports deep matched from 318 to 360 size) to are both very good. The port matched performer is a smidge better on top end. At the level you’re talking about building, a Performer RPM will still work the best of all. You’ll actually notice a difference over the other manifolds. Unless you have an LD340 just lying around, then use it.

 

[str12-340]

"Full Race Cam"

Man, you must be REEAALLYY Old

I remember researching the best "3/4 race cam" for my street car in the mid 1970s...

 

[toolmanmike]

Man, you must be REEAALLYY Old

I remember researching the best "3/4 race cam" for my street car in the mid 1970s...

 

[RON REAGLE]

Air Gap for now soon to be a STR-12 Cross Ram

 

[toolmanmike]

Man, you must be REEAALLYY Old

I remember researching the best "3/4 race cam" for my street car in the mid 1970s...

3/4 race topped out at 300° duration and .500 lift. Here's a general quote: "a 3/4 race cam is 1-1.5 sizes larger than an RV cam. and 1-1.5 sizes smaller than a race cam. the RV cams are generally 260*-270* and 455"-470" lift. The 3/4 cams are generally 280*-290* duration and 480"-500" lift. Anything larger is going on full race. Of course this is for hyd SBC cams. "

 

[toolmanmike]

At the speed shop we sold a lot of TRW cams. They had a 300°/.500 lift small block Chevy cam that was pretty nasty.

 

[gzig5]

Car came with a LD4B on the 340 and I changed that to an Air Gap with positive results on the stock cam. Motor is apart and will go back together with the AG and then I have an M1 single plane and a TR5 tunnel ram to play with when I get a bit more aggressive with the cam, heads, and gears. Hopefully will have the chance to play with an STR-12 before I am done.

 

[toolmanmike]

Car came with a LD4B on the 340 and I changed that to an Air Gap with positive results on the stock cam. Motor is apart and will go back together with the AG and then I have an M1 single plane and a TR5 tunnel ram to play with when I get a bit more aggressive with the cam, heads, and gears. Hopefully will have the chance to play with an STR-12 before I am done.

I could see an improvement. The LD4B is a great piece for 66 and up 273's and 318's.

 

[Bakerlite]

Looks like 64-5 heads.

Nope, these are not early heads. 318's, 360's...same issue. people just tighten down the bolt and don't even notice. I've done so many now, that I made a tool to recut the bolt seat angle.

 

[rumblefish360]

Man, you must be REEAALLYY Old

I remember researching the best "3/4 race cam" for my street car in the mid 1970s...

We have/had a resident member from Crower where they actually have a cam called the “3/4 cam” that you can purchase. Yes… it’s monster sized. See if you can find it here with the search.

 

[James Clews]

I asked a guy the other day that put on a forum that he had a 3/4 race cam in his engine , what was a 3/4 race cam. Does that mean that it has only 3/4 of the cam lobes still on it? He did not give me an answer.

 

[B3422w5]

I've looked at these a few times due to the price but have also heard these manifolds fit and perform poorly. Are you happy with how it fits and runs on your engine?
I have ran a weiand action plus and the std edelbrock performer on mild motors and like the weiand better.

Not true. Old wives tale. Those intakes run great. It was used on this trick 318 build for engine masters that made 477 horsepower.
I put the motor in my car, ran mid 11’s with it…. Nothing at all wrong with them.
Iron-Headed Mopar 318 Magnum Engine- Popular Hot Rodding Magazine

 

[rumblefish360]

Not true. Old wives tale. Those intakes run great. It was used on this trick 318 build for engine masters that made 477 horsepower.
I put the motor in my car, ran mid 11’s with it…. Nothing at all wrong with them.
Iron-Headed Mopar 318 Magnum Engine- Popular Hot Rodding Magazine

I’d would love to dyno that engine with multiple different intakes just to see where everyone’s intake performs.
I mentioned I installed one on my son’s truck (in which I still have to get that picture as requested to me… I’m on it, promise.) Everything sat down nice. The ports sizes aren’t to worry about, smaller than the head by a wee bit, no big deal at all. I noticed the runners are thinner/smaller than the RPM’s. This by itself in m head can not support as much power as the RPM.

This does not mean I think the intake can not make or support good power, just not as much as the RPM.
I’ve been proven wrong before on such things of power making, but that’s where I stand on what I see. Hence the wish of dyno testing the various intakes. Let’s face it! That would be fun!

No matter how you slice it, that engine masters entry kicked some butt and for surely makes a fun engine in the car.

 

[rumblefish360]

Can you get a closeup pic of the manifold to head bolt angle? All of these manifolds I've seen have a 90 degree angle which is incorrect.
This is what it looks like, and you need to correct it.
View attachment 1715924425

Passenger side. Not as severe as yours pictured.
In a worst case…. I’ll just back it out and RTV the top third.

 

[rumblefish360]

Drivers side;

 

[B3422w5]

I’d would love to dyno that engine with multiple different intakes just to see where everyone’s intake performs.
I mentioned I installed one on my son’s truck (in which I still have to get that picture as requested to me… I’m on it, promise.) Everything sat down nice. The ports sizes aren’t to worry about, smaller than the head by a wee bit, no big deal at all. I noticed the runners are thinner/smaller than the RPM’s. This by itself in m head can not support as much power as the RPM.

This does not mean I think the intake can not make or support good power, just not as much as the RPM.
I’ve been proven wrong before on such things of power making, but that’s where I stand on what I see. Hence the wish of dyno testing the various intakes. Let’s face it! That would be fun!

No matter how you slice it, that engine masters entry kicked some butt and for surely makes a fun engine in the car.

I kinda wondered regards a different intake on that engine myself. Not sure if it was a dollars and cents thing regards taking it to the competition with that crosswinds or what.
I took that 248/248 cam he dynoed it with out, ran a smaller one. 10 degrees smaller. Never ran the thing much past 6200 shift points..still not a huge believer in beehive’s regards beating on them at the track, so I didn’t push them……
I sure loved that 950 carb…lol.. very crisp.
I bought a pro systems 950 from Patrick, didn’t run as good as that dyno mule 950. When I sold the car, I kept the dyno mule, let the shiny new pro systems piece go with it.
Now a buddy will have it on my old 360 I sold last winter, going in his Scamp( waiting for him to get it out of my bay so I can start getting my car finished with the new BPE heads)…we are getting his out Thursday night, mine gets out of here Friday..finally
I have seemingly gotten rid of the best carbs I have owned over the years. Now I have an 850 race brawler I don’t think is nearly as good as the 950…I may borrow it from him to see…be a while before his is running…….