Magnum Intake on LA engine?

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BillGrissom

BillGrissom

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With all the "clunkered" vehicles, I wonder if there is a wealth of good engine parts. Specifically, can a 1990+ intake manifold fit an LA engine?

Dumb questions:
1. Are engine parts available or did they shred the whole car? I don't see much on ebay. Haven't inquired at yards.
2. I know little about later engines. Poking around, it looks like 5.2/5.9L Magnum intakes may match LA heads. It looks like later 5.7/6.1L Hemis bolt to a horizontal surface and wouldn't mate, unless a part I don't see.
3. I know intake bolts are a different angle (vertical?). My 273 holes are ~16 deg off vertical, so maybe filing the holes would work if in the same place.
4. I must close the hood. The Magnum photos I see have a throttle body on top (too tall). Was this just trucks? Did any magnums use multi-port injection?
5. Can't interfere with other components. I have a York-type AC, but am switching to a smaller Sanden on the York bracket.

Answers to "why bother" comments:
1. I don't race. Top priority is smooth idle & good mileage.
2. It would be cool to open the hood the next time a clueless person fusses about my out-dated engine.
3. Not considering a 360 engine swap. 4.7L is fine. It works in $80K luxury cars.
4. I prefer EFI. The only time I know what is happening in a carb is when I see fuel overflowing. I want to try MegaSquirt for fuel and spark.

Please comment, throw darts, relate your experience. I will only proceed if I find a complete solution cheap, no searching for stray parts. No $1K solutions. I am deep in parts already. A '65 Dart should be cheap fun.
 
clunker engines and trans were not to be resold ....

magnum are mulit port injection...

magnums intakes are vertical where as LA engine are at angle...

the professional products air gap has bolt pattern for bolt magnum and LA engine....
 
The Magnum engine is very different than an LA small block. There is a crank position sensor that bolts to the block behind the right head needed for the fuel injection not there on an LA block. The top end is oiled through the pushrods, hydraulic roller cam, different intake bolt angle and accessory drives. You would do much better to find a running '92/'95 ram van to get all the stuff needed for the swap. The throttle body injection may be adaptable to an early LA motor but you wont find many of those in the cash for clunkers program as they were too old.
 
Bad they clunkered everything, Magnum parts will be rarer. I found photos of Magnum intakes showing multi-port injectors, which is preferred. I haven't seen how they make the 90 deg turn to the throttle body. I'll have to go to a yard and measure if it can clear the hood.

Re bolting, great info 70aarcuda. I attach a photo of the Professional Products Crosswinds intake for everyone. It looks like Magnum head holes are in the same place, just different angle. My 273 holes are closer to a magnum than to 66+. Wouldn't it work to bend studs 16 deg so they sit vertical and use nuts like an exhaust manifold or carb? We aren't talking head bolts here.

I know Magnum internals are different, but I am keeping my 273, just feeding fuel-air different. Magnum intakes have long runners for a ram effect (better mid-range torque). For fuel, I don't need a crank sensor. Megasquirt can use the coil for rpm. But I want distributorless. For that, I need a crank sensor and Ford EDIS is simplest. I measured that their 36-1 wheel should clamp perfect behind my crank pulley. It is also best to time MPI to valve, but not required (little effect at higher rpm). Megasquirt can use a cam sensor. Did Magnums have one that bolts in place of the distributor like I have seen for Fords? If not, easy to modify my XR700 optical wheel to work.

Re cost, I am following a truck intake on Ebay now w/ throttle body, injectors, and sensors for $50 w/ shipping. Perhaps cheaper locally. I bid on a newer MegaSquirt w/ whole EDIS-8, but lost (sold $205, in Poland probably scared buyers). Even if I install the Holley Projection, I want to control w/ Megasquirt, plus ignition. I don't trust distributor weights, vacuum plates, and spark phasing. Coil-On-Plug is best. If I get a Magnum intake, the Projection will serve backup for my Newport's since no option for big blocks.

Ideal would be a Magnum intake with front inlet like the car Hemis. Was there such a thing?

Professional Products 55026.jpg
 
Magnum Distributors have a cam position sensor not a pusle ring like a standard electronic distibutor. It is an on/off set up. There is a sensor that sits over a stamped steel ring that has a 180 degree window in it. I believe it is a magnetic trigger not optical.
 
mischiefdart,

Thanks for the cam sensor info on Magnums. I didn't find any photos on the web. Using the factory distributor as a cam sensor offers the advantage that I could easily switch back to regular ignition if a highway failure, but a Magnum sensor would look neat.

On my 65 Dart, I have 12.5" from the 273 valley to hood. Scaling photos of magnum intakes, they might barely fit, depending on air inlet above the throttle body. Several types, with the Ram vans looking thinnest. Magnum throttle bodies use 4 bolts and look like a 2 barrel carb might fit. That would allow an easy backup for breakdowns. Probably couldn't close the hood, but could get home.

For now, I'll probably install the Edelbrock Performer manifold and my 2-barrel carb (w/ adapter). I still haven't returned to DMV for an inspection and worry they would void a modern solution. Also, Megasquirt doesn't have sequential fuel injection yet, so better to wait for that. I'll collect parts for a while.
 
Update.

Clunkered vehicles don't have to be shredded. PickN'Pull has a large sign "the clunkers are here". They spray purple paint on the engine blocks. I bought some 5.9L engine parts from a RAM and a Grand Cherokee. I wonder if the engines could be resurrected.

Before that visit, I bought a 5.9 Magnum intake on ebay. $90 w/ shipping and not as corroded as most. I figure PickNPull would probably charge that much. I also got a bag of Magnum intake sensors and IAC valves for $20 on ebay. List price ~$70 ea.

Photos below show the intake test fit on my '65 273. Clearance isn't a problem. The Jeep air inlet stands only ~1" above the throttle body (top of stud). I have another 2" to the hood, so could use a taller chrome after-market inlet w/ conical filter, which look better than the ugly black plastic duct and filter box. I have the thinner engine mounts (later engines). The original mounts are ~1" thicker (and 3x price). A close eye will see the fuel inlet is broken off. I didn't notice until today. Obvious in the ebay photo if you know what to look for (seller might have mentioned). Back to PickN'Pull. I also show the innards of the intake. A metal plate and gasket seal this. Nice place to hide contraband.

Bolting the intake requires more thought. My head holes are 25 deg off vertical (67+ are ~45 deg). I hoped they would line up so I could just bend a 7/16" stud. However, the intake holes are slightly further out so you see only ~1/2 of my holes when looking down, which I tried to photograph (shone light thru gap, need a macro lense). My holes have a slight counterbore, so cutting into the top edge would allow the studs to bend up earlier. The intake holes have an undercut counterbore in the casting (most), so studs could be bent to snake back to the intake centerlines. Another thought is to put inserts in each hole and use smaller studs (~1/4") for easier bending and clearance. I prefer buggering with the intake, though I just bought a seized 273 so not afraid to molest some heads. I also had to grind a little metal off the intake near the distibutor hole, where an oil passage bumps out slightly.

It will be a while before I move forward on this. Besides other projects, I need to work out a controller for fuel and ignition. Megasquirt isn't quite ready for sequential fuel and spark without clunky add-ons, plus I haven't seen any good prices lately. I am trying to get LS1 coils for spark. For now, I will bolt on an Edelbrock PF and use a Holley Economaster 450 cfm carb. I want to start driving the car and that will give a good baseline to see if MPI improves fuel economy. I have an RV cam (0.422/0.444), Edelbrock SureSeat springs (90 lb) and Rhoads leak-down lifters. The later improves low end torque and mileage, and less valve train wear, which concerned me with the stiffer springs.

PICT2527.jpg


PICT2528.jpg


PICT2529.jpg


PICT2533.jpg
 
BillGrissom said:
Update.

Clunkered vehicles don't have to be shredded. PickN'Pull has a large sign "the clunkers are here". They spray purple paint on the engine blocks. I bought some 5.9L engine parts from a RAM and a Grand Cherokee. I wonder if the engines could be resurrected.
Click to expand...


I was at the local bone yard a couple of Saturdays ago and all the clunker vehicles had their engines sprayed with flourescent green paint and had an official looking tag wired on stating they were part of the clunker program and had been run with whatever the goop they put in them and had serious internal engine damage but they weren't restricting you from purchasing parts off them. I pulled some trim pieces for my Dakota off one.

I am quite sure the engines could be resurrected, maybe require new cranks though.
 
Bill if you use a 318 you could just use the magnum heads. They sell coversion pushrods and you will also need AMC style tappets for pushrod top end oiling. The 318 has hydraulic valvetrain and the larger bore will give less shrouding on the larger intake valve. 318's are cheap and not hard to find plus more cubic inches will make more power. Nothing wrong with a 273 but they are very limited as far as how much more you can get out of them.
 
Mishiefdart,

A 318 is always an option, though a complete Magnum engine would be easier. I would need the special collar to fit the crank to my cable-shift torque converter. Changing the tranny gets harder - driveshaft, shift linkage, speedometer? One can bolt Magnum heads to a 273, but the compression ratio would be too low (maybe not w/ HiPo pistons). Anyway, if I can bolt the intake to my heads, that seems simplest. If anyone else want to blaze the trail, I would love to hear. I have other tasks for now.
 
I think you can probably bolt in a Lean Burn distributor in to a Magnum block (or your 273) and that would supply the "normal" signal that MS could work with. I'm running one of those on my 340 and it's keeping the GM EFI controller happy (90-92 Z-28, batch-fire MPI).

If I was in your shoes and was interested in keeping the 273, I'd look close at what the Maggie heads really were going to do to the CR. I suspect that it's not that big of a hit to the CR if any, and the ports are SOOOOOO much better you'd more than make up for any HP lost due to the lower CR. Maggie heads are on my list of things to do to my 340 - if I don't ditch it all together for a 4.7L HO or a 3G Hemi. Neither of those will be any time soon, I need to get the 340 tuned first.

Clair
 
A few more issues for anyone stumbling on this thread.

Pressure Regulator:

In replacing the broken fuel rail, I noticed it didn't have one and not on the missing inlet stub. Turns out they dropped them after ~2000. I found a federal mandate stopped the practice of circulating fuel to the engine and back since it warms the fuel in the tank increasing evaporative emissions. All cars now (I think) have the regulator built into the pump assembly in the tank, so a single fuel line makes a one-way trip to the engine. I confirmed on ~2001 RAM Magnum truck at PickN'Pull. Cheaper for the manufacturers, though they no longer regulate pressure exactly at the injectors. Of course, the filter must now be inside the tank so no uncompensated drop. I got a 1988 fuel rail off ebay w/ regulator ~$15 total. Ditto for anyone installing an entire Magnum engine. Either change to earlier injector rails or install a separate regulator w/ return somewhere between your last fuel filter and rail.

Magnum heads:

Difficult fit to a 273. The biggest problem is you must notch the block at the top of the cylinders for valve clearance. Not only difficult and tricky, it is a permanent change you can't unbolt.

I also read that Magnum heads often develop a crack between valves. They induction hardened the casting at each seat, instead of using hardened inserts as done to upgrade older heads for unleaded gas. The hardened cast iron is brittle and the distance between valves is short, so it sounds like most will eventually crack. Racers don't care, but us daily drivers need reliability.

Ports:

The 273 heads inlet ports are slightly narrower than Magnum intakes. Since this makes a forward facing step, it will produce turbulence. Great for improved mixing, so one would expect better mileage and torque, but it decreases max air flow (peak horsepower). One could grind a smooth transition (~0.050" each side I recall), but no backing up if it actually degrades performance, and I don't prefer permanent changes to my collector car.

Another approach is to add transition cones inside the intake ports. Perhaps using the epoxy rolls you knead with fingers. One could get clever and sculpt little vanes in the epoxy to spin the flow as Magnum heads do. Another approach is to make sheet metal cone inserts. Perhaps aluminum so less chance of engine damage if they get sucked in. Maybe get real fancy with rotation vanes that almost close at low rpm for max mixing and expand open at high flow. Why didn't auto makers think of this? Likely there are already patents (most anything automotive). If not, I already disclosed it. It should work better than the over-priced plastic "Tornado" cones you put before the throttle body to improve "3-5 mpg" ("your results may vary"). Anyway, diverging since just dealing with a 50 mil step.

My status? Still thinking. Implementation is still at least a year off (many projects). Edelbrock inlet and carb for now. I may install an extra Holley Projection I have between the carb setup and going MFI.
 
Bill, ran into this thread as an archive, doing a search on same setup. 273 getting a beer barrel intake, may drill new holes in 273 heads and tap for magnum bolts. There is a jig someone made floating around out there, you borrow it and send it back! Part of a mopar club I believe. I was actually going to use everything off a barrel intake onto a bunged 2bbl intake. Hog out the 2bbl mount and chuck the TB onto it, then MS it and follow up with a T68 turbo. And I got a 450 economaster Carb too along with a 360 intake so seems we are in the same boat parts wise. Is there a way to mount the TB in the front by the water inlet? The angle does not matter, dry air can make all the turns it needs. Make a plate over the old inlet and cut a new port up front, tig weld a new mounting pad, or will I run into a runner?
 
Drilling new holes in the head might be the best choice for 66+ small block heads (45 deg bolt holes). If so, stuff many rags and use a shop vac, so no chips get in the engine. If you remove the heads for this operation, it might be smarter to just install Magnum heads.

I don't think there is an easy way to mount the throttle body in front. Hood clearance is a concern. Seems my hood will just close w/ the Magnum "hat" on there, or an aluminum after-market one. One might use later thinner motor mounts to gain 1", but the later p.s. pump might then touch the K-frame.
 
cracked Magnum heads? And change the pushrods to oilers, different lifters, no more 273 adjustable 1.5 rockers? Nah, Ill drill 12 holes..;-)
 
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