Posted By: a12rag
Original 360 vs 5.9 magnum to build - 07/28/14 07:23 PM
I am thinking that after 70k + miles, and having oil consumption going up, and perhaps a weak cylinder, it is time to look at the E58 360 in my 74 Duster360. It is the original engine, rebuilt 70k+ miles ago, can't recall what went into it, pretty much all stock.
I love to drive this car, long distance, etc . . . so, do you guys think another stock rebuild would be the way to go ?? Or get a 5.9 magnum and rebuild it (maybe even stroked ??) . . . I do like the "go", but also like having a smooth idle and some sort of mpg ! Would also like to keep the exhaust I have on the car - factory manifolds, right side the the Y style off a 340 and left is the 360 factory manifold. Stock 727 and 8.25 rear (still has the 2.45:1 gears - even the tired 360 cranks the tires over !!! And pulls 22mpg at 70mph) . . . . .
Just interested to see what is happening out there these days, and what your thoughts would be. . .
Thanks,
Mark
Posted By: dogdays
Re: Original 360 vs 5.9 magnum to build - 07/28/14 07:51 PM
Miles per Imperial gallon?
The Mag engine has a much better combustion chamber, might be worth 3mpg over the typical 360 head.
I'm going out on a limb here, but I'd suggest a 5.2 Mag motor, built correctly. Board members say the built 5.2 Mag and the LA 360 in near-stock form are quite equivalent in terms of acceleration, but the 5.2 increases mpg by something like 5 or 6.
Seeing how you like to drive the car, and it isn't primarily a drag racer, this sounds like the way to go.
R.
Posted By: MarkZ
Re: Original 360 vs 5.9 magnum to build - 07/28/14 07:54 PM
I would use a late model LA block or Magnum for the next build to be able to use a roller cam. The LA blocks from 89 to 92 I believe had provisions for roller cams and all Magnum motors had them. A roller would give you a nicer idle with a bit more aggressive profile than a comparable flat tappet. Magnums have the added benefit of coming with a superior head.
If you don't plan on going much over 300HP I would keep the factory manifolds for the ease of working on it, ground clearance and quietness. Much over 300HP though and you start to leave a lot on the table without them.
Posted By: a12rag
Re: Original 360 vs 5.9 magnum to build - 07/28/14 08:09 PM
Thanks for the input - yes those are mpg for imperial gallon, not US. If I was to stroke out the 5.9 magnum, I would probably look at headers and different exhaust . . . keeping the 5.9 magnum, relatively stock would certainly be better than the LA, I was thinking . . . and of course keep the original engine tucked away . . .
The MPG concern isn't so much for what it gets, rather, how many miles I can go between fill ups, as the Duster has a small tank !!!
Posted By: RUNCHARGER
Re: Original 360 vs 5.9 magnum to build - 07/29/14 02:28 AM
I'd be tempted to put Engine Quest Magnum heads on the original 360 block. Matching block would be in the car and you could build a real nice, efficient engine.
Sheldon
Posted By: FuryBoy
Re: Original 360 vs 5.9 magnum to build - 07/29/14 03:42 AM
I thought magnum blocks don't have provisions for a mech fuel pump. Is that going to be a concern? I don't like electric fuel pumps...
Posted By: can.al
Re: Original 360 vs 5.9 magnum to build - 07/29/14 04:25 AM
what is required to put magnum heads on an LA block?
Posted By: Supercuda
Re: Original 360 vs 5.9 magnum to build - 07/29/14 05:01 AM
Heads, intake, pushrods, rockers, cover the requirements. You can redrill the heads to accept an LA intake, someone on Moparts had a jig that got passed around years ago just for this. You may, or may not, need to replace the lifters for oil thru the pushrods, you will have to look and see to know.
LA valve covers can work on a Magnum head, just pay attention to fitment as they are not identical. Exhaust manifolds/headers should bolt up for the most part. If you have air injection manifolds you might have an issue there.
Posted By: Montclaire
Re: Original 360 vs 5.9 magnum to build - 02/05/18 07:40 PM
Neither the magnum block, nor the LA block have provisions for a fuel pump.
Incorrect, the LA TBI motors did have a long snout cam with the pump eccentric with a block off plate. This changed on some 318s so you have to check before you buy - later cams used a spacer instead of the eccentric (can just swap out) or went to a cam without the provision. AFAIK the 360s all came with the long snout cam and eccentric up until phase out for the magnums.
Posted By: Supercuda
Re: Original 360 vs 5.9 magnum to build - 02/05/18 08:39 PM
Neither the magnum block, nor the LA block have provisions for a fuel pump.
Incorrect, the LA TBI motors did have a long snout cam with the pump eccentric with a block off plate. This changed on some 318s so you have to check before you buy - later cams used a spacer instead of the eccentric (can just swap out) or went to a cam without the provision. AFAIK the 360s all came with the long snout cam and eccentric up until phase out for the magnums.
Ah, the old Moparts illiteracy program. Let me clarify for you.
Neither the magnum
block, nor the LA
block have provisions for a fuel pump.
As Foghorn Leghorn would say, pay attention son, I say pay attention.
Someone in the thread claimed the magnum block had no provisions for a fuel pump. No [censored] sherlock, none of them do, that's not where the fuel pump mounts.
Posted By: dogdays
Re: Original 360 vs 5.9 magnum to build - 02/05/18 08:50 PM
Count on Montclaire to resurrect a 3 1/2 year old post to give a wrong answer!
R.
Posted By: Montclaire
Re: Original 360 vs 5.9 magnum to build - 02/05/18 09:25 PM
LA TBI does indeed have provisions for a fuel pump. Eccentric on the cam and a bolt-on block off plate. Not that the provision is in the block anyway, it's in the timing cover; casting #3769996, the same one used from 1979 to 1990 and the end of the 360 TBI motors. It really is as simple as pulling the block-off plate and installing a mechanical pump.
Your phrasing is misleading - you are trying to score points on a technicality because FuryBoy used the word block instead of engine. Please use words instead of obscure abbreviations like otoh. There is already enough misinformation/confusion out there on the last of the LAs.
Posted By: 70AARcuda
Re: Original 360 vs 5.9 magnum to build - 02/06/18 04:38 AM
my 88 318 tbi has been converted to carb and mechanical fuel pump..I removed the blocking plate and installed a pump...