Got my junkyard magnum motor in the 11s!

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Myron, did you read the "title" of this thread, it says "junkyard" magnum, don't know where your going with this, I'm sure he is running a bolt-on junkyard magnum, Lets see a 70s stock longblock 360 do that & over 110 MPH in a somewhat fully dressed A body, i've never seen it, I've messed with several LA 360s with stock longblocks, they don't run as strong, obviously the guy asking about his build is impressed, I guess his LA ain't cutting the mustard IDK, Sure he doesn't need to get a magnum, just drop some good heads on the LA, but if he wants a roller cam, thats another story.
 
Thanks for all the compliments guys.

The shortblock is stock as I pulled it out of the junkyard. If memory serves its a 2000 motor. As I was going to run it as-is, I wanted low mileage, and this one had under 80K. I've spent so much money in machine shops over the years, and I really wanted a motor I didn't have to worry about blowing up. When I saw how much LA stuff transferred over, and that it came with a hydraulic roller cam, I thought the Magnum had a lot of potential. I'm used to Ford 302s, so a 360 is a gigantic motor to me. LOL

I intended to use the stock heads too, but they were cracked.

The car has Pro Stars on it. I wanted to go with Billet Specialties, but the budget won out on that one.

Compression is a little over 9:1. I'm using the skinny head gaskets, and the pistons are .050 in the hole from the factory. I forget how big the magnum's stock piston dish is. Heads are 58cc.

The big problem with the Magnum is the valvetrain. I've had serious issues with it (though that was a problem in the head rather than the design as it turns out). Hopefuly its fixed but I'm always sure it could go at any moment. I'm running the stock Magnum rockers for right now. There are some other issues with the Magnum too. You can't get a good balancer that I can find, and its a hassle to get the heads drilled for the older intakes (the Eddy Magnum and Crosswind intake SUCK compared to the Eddy Air Gap for the LA bolt pattern).

If you've already got an LA, I too would recommend checking out the LA-X heads. Keeping the proven valvetrain (or at least the one you're familiar with) is probably a good idea.

Stuff I would do differently:
To be honest, this has been a significantly greater challenge than I thought it would, due to bad luck, a lack of car money, and some general ignorance on my part.

If I had it to do over again, I'd go with less lift on the cam. Its got (EDIT:) .544, and that's just too much. It causes valvetrain issues, puts a hurting on the springs, and I cant get the cool Hughes shaft rockers because they're 1.65 ratio. I bet if I had .525 lift the power would be exactly the same.

I would also have the heads machined for better springs than the ones Hughes provides (though to be fair I didn't realize they had to be machined for that when I bought them).

Stay tuned: I'm putting some slicks on the car, and I've got the front suspension working better now too. If the valvetrain will hold together I think there's a significant amount of ET left in it, especially in fall air.
 
Here's a couple of other pics:

Interior: This is the unrestored interior. Running down the track on a bench seat is weird. I've got a couple of gauges under the dash, but you can't see them in this pic. The map light still works, as does the little lamp that shines on the ignition where you put the keys.

SAM_0466.jpg


Motor: I've tried to make it look like an LA as much as possible.

SAM_0469.jpg
 
JoeDust451 said:
Myron, did you read the "title" of this thread, it says "junkyard" magnum, don't know where your going with this, I'm sure he is running a bolt-on junkyard magnum, Lets see a 70s stock longblock 360 do that & over 110 MPH in a somewhat fully dressed A body, i've never seen it, I've messed with several LA 360s with stock longblocks, they don't run as strong, obviously the guy asking about his build is impressed, I guess his LA ain't cutting the mustard IDK, Sure he doesn't need to get a magnum, just drop some good heads on the LA, but if he wants a roller cam, thats another story.
Click to expand...

I quoted "wedgie" in that one post who said he had a LA race engine he is considering replacing with a Magnum. He didn't say if it was worn out or not. But if not, the LA-X heads could go a long way in in boosting his performance which are pretty much just like the other aftermarket cast iron Magnum heads. It would also boost his compression. He would need to make sure that the rest of the upgrades and set-ups were correct for the overall combo, but then he could expect similar performance to LXguy.

LXguy apparently found a Magnum that was well maintained, added a variety of parts to the engine (mainly the Iron Ram heads) and has a good combination of parts throughout the rest of his car that works well together.

A Magnum short block or a roller cam aren't magic parts that will automatically improve performance. A long block, as you brought up, will not do 110 mph in the 1/4 - LA or Magnum. But his Iron Ram heads helped the most on the Magnum just like the LA-X heads can on wedgies LA. Wedgie would just need to find the correct parts and tune-up to go with the LA-X heads. If his short block is in good shape and the pistons are at "0" deck or below, swapping heads would be a lot cheaper than a junkyard short block and aftermarket heads. LXguy changed the cam also, so that's another thing that can be done to a LA short block, even if it's a flat tappet hydraulic. So I'm just offering some ideas to save money if the existing LA short block and valvetrain is in decent shape. Money could be saved on the intake too!


Personally, I think an OEM '74 360 4 barrel would run pretty close to an OEM 360 Magnum with a 4 barrel added if both were in the same condition and tune.
 
I agree, I wouldn't pitch a good LA in favor of a magnum. I'll bet an LA 360 in good shape would run awesome with a set of those RHS heads and a good camshaft also.

For me it was the right choice, but I was starting from scratch with the original 2bbl 318. Well, I had a timing cover....

I've got about $2800 in my engine carb-to-pan (including gaskets, bolts and oil-LOL), and I think that's pretty good for an 11 second Mopar combo considering I started from zero.

With all these new cylinder heads on the market, its a really good time to be a small block Mopar guy.

Steve
 
After reading the replies, I think that I should just finish the season as-is and redo the LA this winter with more compression, a bigger cam, and some good heads.
 
I think there is a perception that Magnum = huge improvement over LA. The Magnum gets the nod in stock or closed to stock situations because of the roller valve train, better flow heads, and the reality that most Magnums are in better shape in junkyard and stock configuration because they are newer, and fuel injected.
I think the Magnum maintains a slight edge on a higher HP build because of the probable better condition of the core engine, roller valvetrain. The LA equivalent, if built the same, does have some parts availability ease (dampner, better intake), but has added cost if you want the roller valve train.

I would love to see a competitive fresh build... Magnum 360 with the better aftermarket heads, performance cam (using stock rollers), and best MAGNUM based intake, versus a LA 360 with the same family of heads, performance flat tappet cam, and best AL intake, to see which comes out on top.
 
LXguy, congrats! awesome, again.

To all you who guys jockin the magnum...

tell me, what is different about the crank and rods?
tell me 'those who have sonic tested' are those magnum cylinders thicker? or thinner..
Now, The magnum block has 3 spider bosses as where it used a .390'ish lift HYD roller cam huh? Do you think he's running that stock cam? NO!!!!!!!!!!!!
I bet he had to buy a 'new roller cam' and where 'IF' he wanted, he could use the stock HYD lifters, 'don't know about havin any cam warranty with'em' but he still could...
I do know that if he does...he has commited to a hyd roller cam, no solid unless he buys NEW LIFTERS AND CAM , so that is somewhat of a compromise....

the heads... ha ha not factory 'magnum stuff' , more like after market heads based on magnum valve train and the massive pinch from the enlarged push rod hole, thats an improvement???

all you guys thinking your gonna go out and get yourself a magnum and be ahead of the '360' la, you're kiddin yourself, maybe in stock form and from purely a stock 2 barrel stand point, and thats do to the tiny roller cam and fuel injection.

No factory magnum head flows more on the intake side than the 2.02 340 x/J head, and don't tell me **** about the port volume and air speed cause I have the heads and the port volume #'s in front of me and the magnum has no advantage in the performance world , unless you consider the air speed from that MASSIVE pinch a advantage...

Other than the exhaust port flowing a whole 2 cfm more 'as stock' and doing it through less volume, which btw would suck on a stroker that needs spent gas to get the fk outta the way with back pressure taking the 'back seat' with extra volume necessary while pushing the R's, The magnum head was a way to save money and put out lesser emissions by means of the closed chamber, funky turbulent toilet swirl ports and fuel injection it is only but a minor improvement but with the expense of cracking/faillig head cores.
BTW when you go racing and the compression go's up, you need not give 2 shts about swirl ports and their turbulence cause the damned piston is sending the signal right fk'n NOW and not just lazily taking it's time like a 8.5.1 pos...

I'm shocked but not surprised to see everyone backwards on this, it's been this way for yrs sadly enough.
And only nowadays AFTER the indy rhs manufacturers have already not learned from the past and are having to recast with LA port windows that don't restrict air...

sorry to hyjack the already hyjacked.

LXguy, again..Right on man!
 
wow are people getting mad about theys engins both are good engins, to have in stock form i give the it up to the magnum and if you are bulding both theys engin they are the same dipending on how much of this you $$$$$$ you have to spend but in stock form i think a magnum is a better balenced engin thats were it ends . hence were they get a little more out of it becuse they can rev a littel hire.
 
robert 68 cuda said:
wow are people getting mad about theys engins both are good engins, to have in stock form i give the it up to the magnum and if you are bulding both theys engin they are the same dipending on how much of this you $$$$$$ you have to spend but in stock form i think a magnum is a better balenced engin thats were it ends . hence were they get a little more out of it becuse they can rev a littel hire.
Click to expand...

Fuel injection is nice isn't it.
 
HEY LX \\\ GREAT COMBO.
I think the best part of it is how fast your going with dish pistons and such a small cam @ 50.
You still have great cylinder pressure i would think???
If you know what the cylinder pressure is, please post it.
Also if you know your piston to valve clearance post that too.
I run a 360 with dish pistons and about 9.4 to 1 compression.
One more thing :?:.
How high is the sea level for your track???????
Great job.
If you get the car to go even faster,you will have a great blue print for a cheap engine and car combination for everyone to follow.
 
you think the .555 lift is alot? i know of someone using a .588 in a magnum.
 
Thanks all.

My track is about 770' above sea level. But in the summer the DA is rarely under 2500' on a race day due to the humidity. If you want less than 1800' DA you have to race in October at night.

I don't know what the cylinder pressure is, but its a pain to turn the motor over by hand, even when its cold.

I checked the P/V when I installed the heads. I didn't get a good reading because the valve didn't dent the clay, but I figured that was plenty. Between the piston being .050 in the hole and the dish, its a mile of clearance.

I was back at the track Saturday with the car. Didn't set a new best as I was running a 12.00 index class. Quickest all day was an 11.97. Did manage to qualify number 1 with a 12.005 though. Got to the semis before I screwed myself up.

Was running a wideband. Not sure now how much more to be gained by jetting up. Was in the 13.5-13.8 range going through the traps. Carb is probably a restriction being only a 670, but won't be spending money on anything bigger until after the points race wraps up at the earliest.

Ran some Quick Time Pros this time around. Didn't end up getting my 60' time back to where it was before (track is pretty slick), and the tire was turning on the rim, so that didn't help either. Might have pulled the wheels off the ground though. reports vary.

Might go test and try to run a number next weekend.

Steve
 
Call MoPar Muscle/Car Craft and tell'em what ya did..... on the cheap!
 
Hey:

That's a good idea. I sometimes think they wouldn't be interested in a car like mine because it specifically doesn't sell a lot of parts. LOL

I still haven't weighed the car. Maybe this weekend since my plans for the Nats are in jeopardy.

Steve
 
LXguy said:
Hey:

That's a good idea. I sometimes think they wouldn't be interested in a car like mine because it specifically doesn't sell a lot of parts. LOL

I still haven't weighed the car. Maybe this weekend since my plans for the Nats are in jeopardy.

Steve
Click to expand...

Steve, let us know what it weighs, i'm curious myself 8)
 
Lx \\\ What is the cams lsa (center line)108?110?112?

What jets where you running and how is your carb set up????

Thanks for all the info.
This is what happens when you have a engine in the 11's from a junk yard.
Everyone needs to know how a stock short block with a lack compression and quench run's so well.
This is what most people have already in there car for a short block.(stock)
Thanks again.8)
 
Hey:

Cam is 110*.

Carb is a 670 Street avenger. Its out-of-the box with slight idle screw enrichment changes and jetted up two sizes from stock. This fall will need jetted up again. This week I put the jet extensions on it, but it went 1.59 60' without them. Probably could use a bigger squirter, but on the street it transitions fine. I would probably benefit from a double pumper, but not spending the money right now.

Compression isn't awful, 58cc heads, skinny head gaskets (.028?), etc. Cam was spec'd with a short IC to help keep the dynamic compression up.

The stock LA stuff is a lot more irregular than the magnums I've fooled with, and the pistons have always been further in the hole.

Fishy: Thanks! I run at No Limit Raceway in Morocco Indiana. Used to be called US 41 Dragway. Also run at Terre Haute. Probably will run at Coles county at some point, but I haven't made it down there yet.
 
Weighed the car this weekend.

Turns out its 3270 with me in it, which is 10 pounds heavier than when it was completely stock.

I weighed it with the Quicktimes, with the radials the car would be 3300 pounds even. I was running the radials when it went the fast pass.

I have pulled the AC, power steering, now have aluminum intake, monoleafs, welds instead of steelies.

Added back the Magnum (Iron Ram heads are heavier than stock heads, magnum must be heavier too), 8-3/4 instead of 7.25, subframes, ds loop and ignition box. Still have the full stock interior, bench seat, etc.

Man, I'd LOVE to see what this motor would do in a gutted full-on race car.
 
My build and car are very close to yours except I have a little less cam 512@278 degrees112 centerline and I have a 3.91 instead of 4.11, 3500 loose converter. and a 750 holley vac sec with a proform carb body. I will be tickled if it runs 12.70 unassisted as I will be putting a 150 horse nitrous kit on it. Im shooting for mid 11.50 in street trim thru the mufflers. I want to be able to keep up with the Stangs and Vettes that are running 11.70-11.80 from the factory.
 
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