360 Magnum Build w/ V Belt Configuration Question

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Six Barrel Bill

Six Barrel Bill

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Hi everyone! Been reading threads on here for quite some time, learning as much as I can about Magnum engines. Also on the Magnum Swap site. But I can't really find an answer to this one question.

So, we are building a '71 Demon for my daughter. With the purchase of the car came a 1994 360 Magnum (not installed but was previously in a '68 Charger). The engine has a MOPAR M1 single plane intake and LA style brackets for power steering and alternator (Alternator was still bolted to the engine). As you may know, this intake has the correct style thermostat/bypass inlet for the v belt configuration.

This M1 single plane is not compatible for what we want to do, need a dual plane.

Have any of you been successful with running the LA style water pump/pulleys and accessories (power steering pump/alternator) with the the Edelbrock 7577 Magnum Air Gap intake? I know the bypass inlet sticks straight out on that one as compared to the M1 single plane where it sticks out on an angle.

If the Air Gap is not really compatible with the older v belt configuration, I'm thinking of trying to find a MOPAR M1 dual plane for the Magnum. I know they don't make them any more so I will be hunting. I've been researching 2 other intake options: Assault Magnum intake and the Crosswind Magnum intake. Both of these seem to have mixed reviews with leaking and what not, but some people seem to like them. I just figured the MOPAR M1 may be a better fit? Not sure?

I really don't want to try and hunt down the serpentine configuration just so we can use the Air Gap intake, not when we already have the v belt pulleys and accessories.

Anyway, thanks for any info you can share.

Bill
 
I don't think you'll have a problem. I have a Magnum with said Airgap, but I only have an Alternator/waterpump/crank belt. No A/C or powersteering on the engine. But I don't think you'll have an issue with the ps pump and an Airgap.
 
I guess I'm wondering if the inlet bypass on the Air Gap causes issues with the long snout water pump and pulley. And also, what hose would work? Do you just make something up with the correct size hose or can you order the exact hose?

If you happen to have any pictures of your set up that would be awesome.
 
If you already have an LA style timing cover, water pump, and v-belt pulleys, you can run any intake you want, including the Magnum specific 7577. The straight bypass hose of the intake can still be connected to the LA bypass connection. Some people use different angle fittings at the intake.
LA style power steering should be no problem either.
What is the reason for changing from M1 single plane to a dual plane setup? The M1 single plane is a good intake. Will you be selling or trading the M1 after the swap? Can you post a picture of your current setup from the front showing pulley setup and intake?
 
There should be no real issue running anV belt configuration with the magnum engine. The best way to get everything in line is a total swap over to the LA front. Use the timing cover forward.

The short cam poses a minor problem with ether a cam nose extension from Hughesengines or a swap back to a Hyd. cam. Personally I’d stay with the roller cam, though expensive by itself, you just reuse the OE roller tappets and maybe a new set of pushrods. That depends on the ew cams lift. Just remember LA Hyd. cams are given lift values at a 1.5 rocker ratio and the Magnum has a 1.6 ratio.
 
Six Barrel Bill said:
I guess I'm wondering if the inlet bypass on the Air Gap causes issues with the long snout water pump and pulley. And also, what hose would work? Do you just make something up with the correct size hose or can you order the exact hose?

If you happen to have any pictures of your set up that would be awesome.
Click to expand...
If you use a long brass fitting at the intake the hose connection to an LA water pump gets tricky because the hose wants to kink. Using an angle fitting sometimes helps. Using an actual Mopar intake fitting can help too because the fitting is shorter, reducing the tight hose kink.
 
That M1 single is really a 3500 - 7000 rpm intake. While it can be used on the street just fine & even with smallish cams, the torque loss is hard to overcome. There very effective on strokers.

If I didn’t dump 90% percent of my Magnum parts already, been I’d purchase that intake from you or trade it out for a Edelbrock Magnum RPM intake. The M1 line is still a pretty darn good intake.
 
I do have some pictures. The reason for the 45* inlet is the engine is quite a bit higher than the radiator cap, so that really helped an issue I had with air pockets and overheating.
Screenshot_20201105-105423_Photos.jpg
IMG_20180407_153921038.jpg

Don't pay attention to the rat's nest of wiring. I was in the middle of wiring the truck.
 
Thanks everyone for your replies!

I wish I would have taken more pics before I tore it down. Here's the LA stuff, sounds like I'll be good to go since I have the timing chain cover and other bits.

And yes, my daughter will be using this car for street duty. So the rpm range on the M1 single plane is not what we want. I will be getting rid of it. It is an awesome intake though.

alt.jpg
pic1.jpg
pic2.jpg
 
The worst part was the bypass hose. Just take your time, and cut very little off of it at a time. I was careful and thankfully got it right the first time. you should still have plenty of room for ps, my upper hose is so low due to the engine location.
 
The M1 single plane operating range is the “sweet spot” but it works fine on the street.
Why is it all torn down now; major changes or just little stuff?
RammerJammer75 shows how well the bypass hose will work in his second picture. Nice picture.
Just for reference, I will attach a picture of an M1 dual plane for Magnum heads and with Magnum bypass hose and thermostat.
4B572C5B-B787-43AD-BF77-6B0D2CE2BA59.jpeg
 
Ok, so you just bought the correct fit hose and then modified it to fit with no kinks.

I did find a pic of the engine the day picked up the car.
engine2.jpg
 
Bobzilla said:
The M1 single plane operating range is the “sweet spot” but it works fine on the street.
Why is it all torn down now; major changes or just little stuff?
RammerJammer75 shows how well the bypass hose will work in his second picture. Nice picture.
Just for reference, I will attach a picture of an M1 dual plane for Magnum heads and with Magnum bypass hose and thermostat.
View attachment 1715625159
Click to expand...

We tore it down because we had no idea the condition of the engine. It freaking looks brand new inside. We are going to change heads, cam, intake and possibly bump compression any way.
 
Six Barrel Bill said:
We tore it down because we had no idea the condition of the engine. It freaking looks brand new inside. We are going to change heads, cam, intake and possibly bump compression any way.
Click to expand...
This is what I wondered. Before selecting an intake, figure out which heads you are going to run. The only decent Magnum head right now is the Edelbrock Magnum head. But if you definitely want to change heads and intake, and definitely want to use v-belt LA front accessories, you could convert to LA heads and rocker gear, and an LA air gap manifold at the same time.
Not trying to steer your build, but you may have more parts to choose from if you go that way.
 
I bought a short fitting and a hose from Summit. The fitting worked but the hose did not. So I took the original hose to the parts store and looked through to find a molded one that would work. Power steering but no a/c. 2001 Magnum with an Air Gap. I went with a mechanical temperature gauge. You can see setup in the second picture.

IMG_20201105_115339613.jpg

IMG_20201105_115400265.jpg
 
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RammerJammer75 said:
I do have some pictures. The reason for the 45* inlet is the engine is quite a bit higher than the radiator cap, so that really helped an issue I had with air pockets and overheating.
View attachment 1715625149 View attachment 1715625150
Don't pay attention to the rat's nest of wiring. I was in the middle of wiring the truck.
Click to expand...

As far as the thermostat housing is concerned (in the rats nest pic :)), do you remember what you bought that for? I know the thermostat style is a little different compared to the older LA style.
 
I think the Summit hose fitting part number is PRS-1060.
 
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Just a foot note but the bypass hose is a PITA and wants to kink on a Magnum engine with a factory intake as well.
 
Six Barrel Bill said:
We tore it down because we had no idea the condition of the engine. It freaking looks brand new inside. We are going to change heads, cam, intake and possibly bump compression any way.
Click to expand...
Do you have the pistons out of the bores? Any picture available of a piston? Is there a yellow tag or sticker anywhere on the engine block or cylinder heads with a Mopar part number on it?
 
Bobzilla said:
Do you have the pistons out of the bores? Any picture available of a piston? Is there a yellow tag or sticker anywhere on the engine block or cylinder heads with a Mopar part number on it?
Click to expand...

Yes, it's completely tore down. There is zero lip on the piston bore, pretty happy with it. We are meeting with our machinist this weekend to make sure everything is in spec and will go from there.
bore.jpg
Piston1.jpg
Piston2.jpg
 
For cylinder heads, there are available for you in;

Iron, stock replacement style.
Once such example below, do shop around though.
CHRYSLER 5.2/5.9 MAGNUM New Full - PROMAXX Performance Products

Edelbrock aluminum for the first step up in performance.
Edelbrock Performer RPM Chrysler Magnum Cylinder Heads 61775

Trick Flow heads that will then use a LA intake but yet you will still be able to oil through the pushrods with the correct Harland Sharp rocker arms.
Parts and Accessories - cylinder-heads part-type - trick-flow-powerport-190-cylinder-heads-for-small-block-mopar product-line

You can also use Comp Cams Pro Magnum rocker arms to use oil through pushrods on stock or Edelbrock heads since they allow pushrod oiling. The last two options allow the use of cheaper & a wider verity of LA intake manifolds.
 
Choose head flow over compression! Better air flow is better than compression. This is and has been proven before.
 
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