Stock bottom end 360 magnum

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Archeryguy02

Archeryguy02

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I picked this up yesterday, I was told the mileage was under 100k and it was a runner when pulled. If it looks good enough when I get the heads and pan off I am thinking about slapping it together with a new cam, aftermarket heads, and oil pump without rebuilding the bottom end. I am trying to get a budget street strip motor in my 68 valiant without spending too much.

If I tear into it I fear I will try to justify spending way too much for new pistons or even a stroker kit. I understand the risk of not putting rings and bearings in at this point, but as long as these engines last in the trucks in stock form I would think the risk is low if I don't see any issues.

Has anyone done this? If so what kind of results did you have, IE 1/4 or 1/8 times, as well as a little about the components used and the car it went in?

Thank you in advance.

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Archeryguy02 said:
I picked this up yesterday, I was told the mileage was under 100k and it was a runner when pulled. If it looks good enough when I get the heads and pan off I am thinking about slapping it together with a new cam, aftermarket heads, and oil pump without rebuilding the bottom end. I am trying to get a budget street strip motor in my 68 valiant without spending too much.

If I tear into it I fear I will try to justify spending way too much for new pistons or even a stroker kit. I understand the risk of not putting rings and bearings in at this point, but as long as these engines last in the trucks in stock form I would think the risk is low if I don't see any issues.

Has anyone done this? If so what kind of results did you have, IE 1/4 or 1/8 times, as well as a little about the components used and the car it went in?

Thank you in advance.

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I would give it a quick refresh with one of these kits from Mancini... Fresh rod and main bearings, moly rings, and gasket kit for only $215...

Sealed Power Engine Kit - 360
 
Looks like a clean core you have there. I have gone through lots of steps to do what you are looking to do with my Magnum. Unfortunately, with the stock pistons, you won't be able to put any sort of decent cam in and the compression ratio will hinder performance, especially with the stock heads. Maybe just throw the engine in as-is with MAYBE a cam and call it a day. Then save for heads, pistons, and bigger cam later.
I wound up spending over $4,000 on my "budget" 5.9L Magnum because it just didn't make sense to put any kind of money into a Magnum with stock pistons and heads. Instead, I went with Icon forged 10:1 pistons, cam, and Promaster aluminum 2.02" valve heads with roller rockers. This combo is still cheaper than most crate motors and should make a bit more HP than the 408 crate engines being sold today.
 
Also, if you go the budget route, I would reuse the stock oil pump and instead put in a new timing chain on the original gears. Magnums aren't known to have low oil pressure issues at all. All 3 of the Ram trucks i've owned in the past with 200,000+ miles had awesome hot oil pressure.
 
Archeryguy02 said:
I picked this up yesterday, I was told the mileage was under 100k and it was a runner when pulled. If it looks good enough when I get the heads and pan off I am thinking about slapping it together with a new cam, aftermarket heads, and oil pump without rebuilding the bottom end. I am trying to get a budget street strip motor in my 68 valiant without spending too much.

If I tear into it I fear I will try to justify spending way too much for new pistons or even a stroker kit. I understand the risk of not putting rings and bearings in at this point, but as long as these engines last in the trucks in stock form I would think the risk is low if I don't see any issues.

Has anyone done this? If so what kind of results did you have, IE 1/4 or 1/8 times, as well as a little about the components used and the car it went in?

Thank you in advance.

View attachment 1715578083
Click to expand...
It's been done here a lot.
When you take the heads off, if the cross hair marks are still there....and they should.... proceed to a rod bearing cap or two as well as a main cap or two. Everything should be in really good shape. If the crank isn't ugly, your good to go. By the way, stroker or even new slugs don't go with the word budget....at all when dealing with a Magnum engine. Stick with your planand get ready to rock and roll there buddy!
 
If you have motor apart, a fresh new oil pump may save some more work tomorrow. If you know history of motor like above then maybe reuse it, but not knowing history may be a wise move to change it.
 
I just used headers (Hooker Super Comps @ 1-3/4), JY distributor & Chrome box, B&M flex plate, RPM intyake and 600 carb. Slide in a cam and callit done. Never to the track, but a nice easy going but yet surprisingly powerful ride are the descriptive words given to this when I have first timers in the car. They all love it. Backed by a 727/2800 stall & 3.55's on 26-1/2 tires.
This is a '79 Magnum FWIW weighing in at just shy of 3700lbs. empty.
I'm trying out a little diet for it.

Good mention @tonysrt an oil pump is cheap and a good thing to check.

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I started out as you did and found my low mileage 5.9 had a bent rod due to hydro locking. All bearings were good and no abnormal wear on pistons or bores. I'll let the experts chime in but you have a good plan. Rumble has good advice. Inspect some bearings and lifters, etc. I have spent hours researching in this forum and you can get a reground cam from Oregon and reuse your current lifters. Replacement heads, inexpensive intake, carb and electric fuel pump will have you a nice stout mill. Here is a good reference. Magnumswap.com - Your source for Dodge Magnum and Mopar engine swap tech.
 
black954 said:
Also, if you go the budget route, I would reuse the stock oil pump and instead put in a new timing chain on the original gears. Magnums aren't known to have low oil pressure issues at all. All 3 of the Ram trucks i've owned in the past with 200,000+ miles had awesome hot oil pressure.
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There is ONE problem. The poor design of the "trumpet" pickups can pick up enough...even soft carbon...to plug the pickup at highway speed. I've posted about this. If possible, use a late model LA pickup

Copied from an old post:

I don't know but tuck this away "for later." I'm convinced a large part of oil pressure problems on late Mopars is due to an incredibly stupid pickup design. had problems in my 95 5.2 Ram 1500, now gone

On the left is an 80's pickup I put back in, the one on the right is the problem child. Notice how clean it looks. It was picking up tiny soft flakes of sludge until it covered the pickup (happened twice) and dropped pressure

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pickups out of 5.2/ 5.9 Dakota/ Durango

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Not completely “budget” but I did a 7.80 in the 1/8 with a rebuilt bottom end; hone, polish, new rings, bearings, oil pump and off the shelf 2.02 Eq heads, Oregon cam regrind, RPM Air Gap, 780 Holley. 727 with 3500 stall, 4.30 gears in a 3300 lb 65 Valiant. I later added a turbo to the same combo and went 6.90/105mph.
 
Everyone here is pretty much dead on with their advice. My two cents, while the pan is off, check the rod and main bearings. The odds are good that the mains are perfect. The odds are good that the LOWER rod shells are good. Be sure to slide a rod up into the cylinder and check the UPPER shells as well. If that has had a bad plenum gasket, I'll bet you a nickel that there has been enough detonation to show just a little bit of copper in the center of the upper shell.
 
Did you check the thread on magazine build articleS?
 
Archeryguy02 said:
I picked this up yesterday, I was told the mileage was under 100k and it was a runner when pulled. If it looks good enough when I get the heads and pan off I am thinking about slapping it together with a new cam, aftermarket heads, and oil pump without rebuilding the bottom end. I am trying to get a budget street strip motor in my 68 valiant without spending too much.

If I tear into it I fear I will try to justify spending way too much for new pistons or even a stroker kit. I understand the risk of not putting rings and bearings in at this point, but as long as these engines last in the trucks in stock form I would think the risk is low if I don't see any issues.

Has anyone done this? If so what kind of results did you have, IE 1/4 or 1/8 times, as well as a little about the components used and the car it went in?

Thank you in advance.

View attachment 1715578083
Click to expand...

I did almost exactly this with a 1996 5.9 with 96k on it.
Cylinders were perfect as were the bearings.
Barely even any marking showing on the bearings.
I wanted a reliable driver and used an Oregon cam 214/224 split duration on a 110 center.
Used the stock roller lifter, Hughes 1110 springs and the 2.2 retainers for more valve to seal clearance. (5.12 lift with the stock 1.6 rockers an stands.
New double roller timing set, car pan and LA style pickup.
New standard oil pump.
Engine Quest 318B heads with 1.96 valves, viton seals, 64 cc closed chambers.
Edelbrock dual plane, Holley Avenger 770 cfm, 1 5/8 long tube Hedman. 3 inch collectors into dual 2.5 pipes exit in front of the rear tires.
All LA front accessory with V belt and electric cooled 26 inch radiator.
Also run the 42RH overdive behind that.
My friends tell me it’s pretty quick, but I don’t have many friends.:lol:
 
I found the articles of Mopar action feb, apr, aug, oct 2014 and I tried to post pics from magazines on here before with lackluster results. Summary is they made 468hp for $2050.

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Update. I finally got around to taking this thing apart. I was exited to see the cylinders as all of them had very defined crosshatching. I pulled one rod cap as seen attached and it showed much more wear than I hoped for. The main cap showed much less wear but still not great. Looks like my budget is going to have to grow.

I have a LA 360 with low miles from a rebuild 25 years ago that may be a much cheaper to rebuild as I think I may be able to get away with rings and quick hone.

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How do the crank journals look? I would mic it to check. If ok, polish, replace bearings and keep moving forward. Maybe engine had more than 100k???
 
Good mention. I’d drop the crank off to be inspected. (Not all of us can or have the tools to mix it properly and KNOW for sure.) worst case Scenario, you spend a few bucks for a drop in crank and bearings.
 
I am a tool and die maker by trade, I have the tools in my shop to measure most of these critical surfaces. I will need to take a close look at the crank and have anything that looks marginal addressed. Although the areas I took both these caps from look pretty good at a glance, things might change when its out of the block and all the oil is cleaned off.
 
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