thesiren74
Well-Known Member
360
Magnum 5.2l vs 360 LA?
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The point is for the guy that’s looking for a running engine to do at least 4bbl and dual exhaust to maybe cam and headers, but no porting rebuilding other than some gaskets for say a /6 swap, Say there's no 5.9l around and only finding running 5.2l or LA 360 which I imagine finding running 360 are getting harder at least cheap.
No real plans for future build ups, so does the the magnum heads and cr bump out weight the displacement I think so especially when talking larger cams since we know magnum heads are good for 400hp. I feel the 5.2l will have the advantage or at least on par especially finding good running ones running and obviously if you find a 5.9l that would be the better bet.
Gotcha, depends on how far we take it in the cam department.
TT5.9mag
Two atmospheres are better than one
I think for your rules, they are both pretty evenly matched. So for ease of locating a good core the 5.2 wins. As soon as you are allowed further modifications most guys would be better off starting with a 360.
Main question is what do you want, 340 top end or down low grunt? I like the efficiency of the 5.2. Heads should be equal or better, depending on year. Magnum heads are prone to cracking, larger valves, better chamber, 5/16 or 8mm valve stems, and 1.6 rocker arms. Internal balance, decent compression, roller cam. What's not to like, should be a nice quick engine in an A Body.
I guess I'd have to ask "what year of LA 360??". If it's the roller block 360, I'd take the 360. LA roller 360 with 308 heads would really put the squeeze on a 5.2 magnum.
Either engine is a great foundation for a build. My '89 D150 with a TBI 360 ran a better time than most Dakotas with 318 magnum.
Either engine is a great foundation for a build. My '89 D150 with a TBI 360 ran a better time than most Dakotas with 318 magnum.
Roller 360 would have the advantage thing it'd rated only 10 hp less.
That longer arm is everything!
Those few years that the 360/5.9 blocks oiled to the top end, are the ones to find. after you have gone thru a couple pair of cracked magnum heads, you will know why.
Magnum Blocks (roller cam) that don’t oil to the top, won’t take LA heads. And those years
at least you can have a choice.
Roller cams are expensive. 1.6 rockers aren’t everything, when you consider machining for valve
lift and spring seat clearance.
Those few years that the 360/5.9 blocks oiled to the top end, are the ones to find. after you have gone thru a couple pair of cracked magnum heads, you will know why.
Magnum Blocks (roller cam) that don’t oil to the top, won’t take LA heads. And those years
at least you can have a choice.
Roller cams are expensive. 1.6 rockers aren’t everything, when you consider machining for valve
lift and spring seat clearance.
TT5.9mag
Two atmospheres are better than one
Yes they will. You just can’t oil the rocker gear in the traditional way. You have to get creative. It’s not too difficult.
Picked up a roller LA motor, I think its outta 90s truck? Looking to low buck it. watching these 360 threads.
A roller LA to low buck a build? IF! You stay with the roller cam, be careful on the cam you choose! Watch the riming events!
Without touching the heads? Mild lift cam to .500, duration to suite the rpm band you want to operate in.
(Don’t get greedy here!)
1-5/8 headers I like to avoid in favor of 1-3/4, your call.
Dual plane intake, your choice carb & air cleaner, multi spark ignition, now your down to gear and maybe a stall converter depending on the cam.
This I did to my ‘00 5.9 minus the cam.
750 Edelbrock carb and rpm intake w/Hooker super comps @1-3/4 stuffed in my ‘79 B body Magnum backed by an automatic 727 & 3.55’s in 245/60/15’s.
I got his 80K engine from my daughters wrecked Durango. That truck was real peppy to say the least. So I mimic the rear gear ratio. On the smaller tire and the 2500 stall, car gets up and goes darn well for basically a stock set up.
So, to be clear, in your mind you choose gear and tire size and then match the cam? Kind of like choosing tire size and rims before narrowing a diff? This may seem obvious .....but I like to get a good game plan and stick with it to eliminate extra costs doing things twice.
thanks rumble fish!
replicaracer43
Grumpy Old Man
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You can put any LA style head on the magnum block, use the PRW rockers and a oil through pushrod. Simple, easy, bolt together deal
For a race car wouldn't be necessary unless some gear limit rule. But for the street it's a good idea for most. Cause 90% of the guy's out there are gonna use 3.23-3.55 for a performance street car even if they go to the strip on the regular. Plus depends on cid, larger cid eg. 440 those gears are more likely closer to correct than say for a 273/318. Take My car 68 valiant came this way when i bought it, 380hp crate engine with 2.96 gears, to even get it into the power band need to get it up to 40 mph then crush it to get any sense of it's power and by then going too fast in town. Even though I plan on swapping gears later I'm going with smaller cam air gap cause it almost never see where peak power is , so I'm willing trade top end power for low end power. I care more about 0-60 mph 1st and 2nd gear performance maybe 80 mph on some roads cause it's not a track car and if that's not enough can always move up in displacement
If you don't care about which gear you use and not gonna go to a 1/4 mile track, gear it for the 1/8 more inline with intown light to light.
No. However, when your presented with a package deal like I was, in this case the free 5.9 I just added part to it. No cam swap. The driveshaft fit a 727 & a 9-1/4 rear. They were a package. I married them.
If I was to a cam swap, I’d have to work within the package of a ‘00, 5.9, 727 w/a 2400 converter & a 9-1/4 w/3.55’s. The tires are 245/60/15’s which worked perfectly with the speedometer gear delivering near dead accurate readings.
What cam would you do? I myself , IDK. Thought about a cam swap, haven’t got there yet. Runs and drivers great for me and what I do with it. Drive drive drive!
In your case when you said what you did above. I just adds two cents. If it doesn’t work for you, sorry. My bad.
Also Comp Pro Magnums.
Dear Reverend Rumblefish
......I am still in the learning process of cam selection, but I agree that if I have a runner I usually just go with it. I dont make it to the track much except to watch. IF the cam on this LA is burnt, then Ill go down that path. It is a roller so it will probably spendy. We shall see. I was just curious on the order of events if choosing. I know when I narrow and gear diffs, I choose tires and wheels first, then mold the car around those choices.
valuable $0.02, thank you.[/QUOTE]
dartfreak75
Restore it, Dont part it!
Roller lifters,
Dear Reverend Rumblefish
Thanks! I needed that laugh. I think AJ gets that title.
Happy Hot Rodding!
diymirage
HP@idle > hondaHP@redline
The last years of the LA came with roller lifters
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Well, if you're not gonna open them up, and it's for a two-gear streeter, the 5.2 is a hard combo to step over to get a lo-compression 360LA. Even the roller cam in the 5.2M is about the right size for this. I have it listed as;
251/125/111.5/264/31.5 overlap/113LSA/ in at 110, the Ica is 55* and the lift I have recorded is .432
With a 13* split pattern, you should be able to find a sweetspot.
>The 5.9 cam I have listed looks a lil nicer, but everybody seems to want to throw it away. The specs I have are;
249/131/112/269/41 overlap/109LSA/ in at 104.5, I get an Ica of 49* Yeah you should be able to make a lotta pressure with that. Lift is listed at .410/.417
> The 2bbl cam in the 360LA, IIRC, is
252/124/116/260/32* E-overlap/112LSA. Installed at 110, I get an Ica of 56*. This cam is a lot like the 5.2M cam; but favors power extraction (4.5*) so it may be a lil better on the hiway. the pressure will be down a tad, but maybe not the force so much.
at 160psi and at 3.91bore; the force on the 5.2Mrod is 1921 pounds. For the LA ,132psi on a 4" bore comes to 1659..
By the time that gets to the flywheel, I'm seeing 265 ftlbs for the 5.2M, versus 247 for the LA; so the 5.2M is definitely a lil stouter, 7% by the math.
IIRC the 360 lift is also around .420
Like has been said; the 5.2M is a pretty stout lil item.
251/125/111.5/264/31.5 overlap/113LSA/ in at 110, the Ica is 55* and the lift I have recorded is .432
With a 13* split pattern, you should be able to find a sweetspot.
>The 5.9 cam I have listed looks a lil nicer, but everybody seems to want to throw it away. The specs I have are;
249/131/112/269/41 overlap/109LSA/ in at 104.5, I get an Ica of 49* Yeah you should be able to make a lotta pressure with that. Lift is listed at .410/.417
> The 2bbl cam in the 360LA, IIRC, is
252/124/116/260/32* E-overlap/112LSA. Installed at 110, I get an Ica of 56*. This cam is a lot like the 5.2M cam; but favors power extraction (4.5*) so it may be a lil better on the hiway. the pressure will be down a tad, but maybe not the force so much.
at 160psi and at 3.91bore; the force on the 5.2Mrod is 1921 pounds. For the LA ,132psi on a 4" bore comes to 1659..
By the time that gets to the flywheel, I'm seeing 265 ftlbs for the 5.2M, versus 247 for the LA; so the 5.2M is definitely a lil stouter, 7% by the math.
IIRC the 360 lift is also around .420
Like has been said; the 5.2M is a pretty stout lil item.
Richard Holdener Is doing a 5.9L on the dyno right now, he says he plans on a 5.2l in the future with same Mods, bet it will surprise a few.
Haven't seem you post for a while glad your still around
mygasser
Well-Known Member
mygasser
Well-Known Member
you'll be nailed to the cross for that last remark you blasphemer
mygasser
Well-Known Member
does the roller la 360 come with 308 heads, as this comparison says stock longblock.
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