5.9L Magnum questions

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1. Don't tear it down to re ring it. Waste of time and money and you're not gonna improve on the seal. You mentioned how nice the bores look. What makes you think they're out of spec needing a re ring?

2. Bump up the cam. It's a hotrod right? Get something with a lope and some power.

3. In accordance with the cam, go higher stall than you think you need. Let's say you think you need 2500. Get a 3500.

4. Put the 273 manifolds where they belong. In the garbage can. Get those dougs or TTI or whatever fits. Are the Doug's long tube headers? If so all the better.

5. Agreed on the intake. Upgrade that for sure.

6. Don't bother with bumping compression. Shaving heads etc will create other headaches like intake port mismatch issues.

7. Good call on Oregon cams they have a lot of good reviews from this site.
 
Mean416 said:
1. Don't tear it down to re ring it. Waste of time and money and you're not gonna improve on the seal. You mentioned how nice the bores look. What makes you think they're out of spec needing a re ring?

2. Bump up the cam. It's a hotrod right? Get something with a lope and some power.

3. In accordance with the cam, go higher stall than you think you need. Let's say you think you need 2500. Get a 3500.

4. Put the 273 manifolds where they belong. In the garbage can. Get those dougs or TTI or whatever fits. Are the Doug's long tube headers? If so all the better.

5. Agreed on the intake. Upgrade that for sure.

6. Don't bother with bumping compression. Shaving heads etc will create other headaches like intake port mismatch issues.

7. Good call on Oregon cams they have a lot of good reviews from this site.
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I'd disagree with #2 (I wouldn't trade bottom end for anything on a street car (choose wisely))

#3 good converter>headers

#4. Depending on what he's doing with the car I've heard headers on an early A are an absolute pain in the butt!
I'd take whatever power loss manifolds brought for the possibility of power steering and money being saved from the swear jar installing them.
 
skep419 said:
I'd disagree with #2 (I wouldn't trade bottom end for anything on a street car (choose wisely))

#3 good converter>headers

#4. Depending on what he's doing with the car I've heard headers on an early A are an absolute pain in the butt!
I'd take whatever power loss manifolds brought for the possibility of power steering and money being saved from the swear jar installing them.
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Well you know what they say about opinions. Opinions are asses. Everyone has them. Some folks have better asses than others. I think that's how the saying goes ☠️

Anyway...

Nothing in this build screams high mpg daily driver. 350+ gears, 3000stall, 750 carb, etc.

At 360 cut in, you're not losing low end power with a slightly larger cam. But you are gaining a lot of general area under the power curve as the RPMs climb to 3000 and higher. I'd absolutely not go lower than a 218 duration on the intake side cam. Especially not with a 3000 stall.

Also, honestly, you're not gonna replicate what Charles Servidio does on his YouTube channel. Ootb Magnum heads are just fine for this combo. If you're smart you'll have no problems whatsoever getting to 350 HP.

Put those 273 manifolds on though and indeed... you'll choke that engine down and it's not gonna be nearly peppy as you'd like.
 
You already have tons of good advice here. I'll add my $0.02 based on my experience.

I put a 150K+ mile 5.9 in my Dart. The cylinder walls and heads looked pretty much like yours does.

- I did not touch the bearings or the rings, and I did not hone the cylinders.
- All I did to the bottom end was put in a Hughes cam that is suitable to run on the stock Magnum tune, because I used the stock Magnum EFI (cam: SER0814ALN-14). Otherwise I would have gone with something bigger.
- I bought a stock replacement oil pump. Maybe should have gotten a high volume unit, but I did it during COVID and the HV units were out of stock. My oil pressure runs at about 42 psi (hot) when running at cruising RPM (~2000 rpm). Hot idle at 600 rpm is about 15 psi. Obviously these numbers are totally fine (for me).
- I used all the factory lifters except for 1, because it had a little scar on the roller. It might have been fine, but a replacement was $10 and I didn't want to take a chance with my new cam.
- On the stock heads I spent a few hours cleaning up only the most ridiculous casting flaws in the intake and exhaust ports.
- I lapped the stock valves until they ended up with a good sealing surface. Incidentally, 5 out of my 8 cylinders have cracks between the intake and exhaust valves. Don't sweat it, the cracks don't get into water and almost never cause issues.
- I already had a set of Doug's headers on my LA 318, so obviously I reused those.
- Initially I had a 904 with a stock converter, with a 3.23 Sure Grip. The converter would flash at about 1900 rpm with the 318, but with the 5.9 it flashed at around 2100.

My engine runs incredibly well, no smoke and no blow-by, with solid compression across the board. Bottom line, considering your "20 year old's wallet", I think it's likely doing the rings and hone and block decking is not needed. You might find most machine shops won't touch the stock heads because of the cracks that are almost certainly there, so just save your money and do the best you can with them. But I think you really need to try and find a set of headers. Keep in mind headers don't only make 20+ horsepower at peak RPM, they make more power everywhere in the RPM range. And the bigger the cam the more important headers will be.

Good luck!
 
I question what people mean by bottom end, cause I don't think it's necessary torque their talking about.
 
Magnum rings and bearings are good for 150K plus.

Mine is at 178,000 and has as much torque and power as the day I bought it with 31,000.

Inspect the bearings, then save the money.

If anything, a rod bearing or a cam bearing will go first.
 
273 said:
I know :) was talking about post #27



People say/imply bottom end torque, but don't really see the dyno evidence backing it up.
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This cam was a pooch below 3500.......no dyno needed
 
skep419 said:

This cam was a pooch below 3500.......no dyno needed
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Doesn't mean it is/just from a lack of torque.

Is there a minimum acceptable amount of torque at crank/wheel ? does that mean large engines can't have soft bottom engines and or that all small engine will always be soft ? Part throttle vs Full throttle etc..

What about stall, gearing, tire size etc.. ?

It definitely a bigger discussion then we can have here.


Sounds good though :)
 
I'm thinking this grind from Oregon- 213/220 @ .050”, 265/275 adv, .480”/.498” lift, 110 sep, becàuse it looks a lot like this original 340 grind - 0.430in/0.444ex, Dur 268in/276ex.
Any reason this wouldn't work well as a 360 roller?
 
skep419 said:

This cam was a pooch below 3500.......no dyno needed
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Xe 284 is a 240/246 @ 50 cam. We're all talking sub 220 numbers. Not a fair comparison here.

What converter and gears do you have? I'd probably not go below 3500 stall with that cam.
 
MechNerd said:
I'm thinking this grind from Oregon- 213/220 @ .050”, 265/275 adv, .480”/.498” lift, 110 sep, becàuse it looks a lot like this original 340 grind - 0.430in/0.444ex, Dur 268in/276ex.
Any reason this wouldn't work well as a 360 roller?
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that would be my choice for the set up/parts that you have to compliment it.

with a 3.55 if you put wings on it that early a would fly.

put whatever exhaust you have on it while you save for headers. no sense in making a half step with whatever combo of manifolds for minimal gains.
 
With all the talk of whether or not to inspect/re-ring bottom end, I'm surprised no one has stated the fact/obvious. Any Magnum engine with over a hundred thou on the clock needs the rid shells checked. Plenum gasket is most likely out and it has been sucking oil. Thus, detonation. The upper shells are almost always wore. Only way to know is to look. No piston/rod removal necessary. It's been 50/50 for me on the cam bearings. Mains are usually perfect.
 
408 swinger said:
With all the talk of whether or not to inspect/re-ring bottom end, I'm surprised no one has stated the fact/obvious. Any Magnum engine with over a hundred thou on the clock needs the rid shells checked. Plenum gasket is most likely out and it has been sucking oil. Thus, detonation. The upper shells are almost always wore. Only way to know is to look. No piston/rod removal necessary. It's been 50/50 for me on the cam bearings. Mains are usually perfect.
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I second this. And if you just pull a rod cap, the lower shell usually looks great. You have to look at the upper shell. And most of the ones I’ve done needed cam bearings.
 
408 swinger said:
With all the talk of whether or not to inspect/re-ring bottom end, I'm surprised no one has stated the fact/obvious. Any Magnum engine with over a hundred thou on the clock needs the rid shells checked. Plenum gasket is most likely out and it has been sucking oil. Thus, detonation. The upper shells are almost always wore. Only way to know is to look. No piston/rod removal necessary. It's been 50/50 for me on the cam bearings. Mains are usually perfect.
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Yes, 100% the OP should check the rod bearings. I was lucky in that mine looked fine.

My cam bearings, maybe not so much. Actually they all looked great except for one. Check this out:

Screenshot_20240912_120937_Gallery.jpg



At first I thought I did that when pulling out the cam, but the cam had a shadow on that journal right where it was riding on the gouge, so I figure that bearing was damaged when the engine was initially assembled in the Chrysler factory. I couldn't feel any imperfections at all on the journal, so I guess they wore in together. I talked to a few experienced guys and they all said I should change the bearings, but if I didn't it would probably be fine. So I did the right thing and did not change the bearings. So far it's been about 10,000 miles it seems to be fine. To be clear, I don't recommend to the OP that he do this! Do what I say, not what I do :D
 
autopar3000 said:
Yes, 100% the OP should check the rod bearings. I was lucky in that mine looked fine.

My cam bearings, maybe not so much. Actually they all looked great except for one. Check this out:

View attachment 1716302322


At first I thought I did that when pulling out the cam, but the cam had a shadow on that journal right where it was riding on the gouge, so I figure that bearing was damaged when the engine was initially assembled in the Chrysler factory. I couldn't feel any imperfections at all on the journal, so I guess they wore in together. I talked to a few experienced guys and they all said I should change the bearings, but if I didn't it would probably be fine. So I did the right thing and did not change the bearings. So far it's been about 10,000 miles it seems to be fine. To be clear, I don't recommend to the OP that he do this! Do what I say, not what I do :D
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Have seen that as well. If the op wants to keep it cheap, down, and dirty, slam it home. But, I agree completely with you, "Do as I say, not as I do." :lol:
 
MechNerd said:
Well, I was lucky enough to get my hands on a decent 1998 5.9 Magnum core locally. Supposedly out of a Dakota R/T. Stripped it down that day and was pleasantly surprised at it's condition, considering it supposedly had 100K plus miles on it. Virtually no ridge in the cylinders, and they still had crosshatch in them! Inside was very clean, no chunks or gunk inside. Heads were clean also. Had a couple broken studs, but I was able to extract them without any damage. Haven't got to the bottom end yet, but it spins free and and if it looks like the top, I'll be happy.
My goal for the motor is to do a "best bang for the buck" build I can while creating a reasonable amount of HP/TQ. I realize that everyone's definition of "reasonable" is different. Just hear me out...you can take turns kicking me in the nuts later.
Motor is going in a 66 Barracuda that has the original 273/904 in it. Want to transfer all the 273 parts (timing cover, pulleys, EX. MANIFOLDS, etc.) to the 5.9 if possible and keep the 904 behind the 5.9. Will try to be more specific below- not necessarily concerned with any hard numbers right now, just tell me if the info below makes any sense. I know you guys have been at this WAAAYY longer than I have, that's why I came here. All comments welcome.
Here we go- pretend I have a 20 yr. old's wallet, because I pissed away too much money on my Belvedere ll previously. (I'm 66 and still working. American dumbass).

1. Hone/re-ring motor with stock pistons. Would like to improve CR if possible. Deck/square up block, cleanup cut on heads, and .027 Cometic gasket? Maybe worth .040?
Pistons "in the hole" as follows- only checked the corners- #1 .045, #7 .044, #2 .044, #8 .051
2. Check/mic main and rod journals. If clean, new bearings and re-install.
3. New high volume oil pump. Double roller timing chain and gears.
4. Intake- Edelbrock Performer...or maybe even the Chinese version. Have one on the 5.2 in the garage, haven't run it yet. Looks well made and machined though.
5. Carb- something in the 650-750cfm range I would guess. Not partial to any particular brand.
6. Heads- stock, fresh valve job, stock 1.6 rockers, cleanup cut, home ported ala Charles Servidio videos. Fingers crossed.
7. Cam- see attached pic. I intend to go to Oregon Cams and get a regrind based on the Hughes cam numbers shown. If anyone can give me a yea/nay on this choice, or provide a better grind for this combo, I'm all ears. Required springs, too. 5500 rpm max should keep me out of flying parts territory, and most of my driving will be midrange anyway.
8. 3000 stall converter, manufacturer unknown at this point.
9. 3.55 SG in rear. I have a 3.91 in the Belvedere...and a 5 gal. gas can in the trunk. You know, just in case...
10. Exhaust- this is where I'm a little stumped. By that I mean efficiency versus $$. The headers I WANT are $1000+. The manifolds I HAVE and I know will fit, are FREE. Question is, what is the loss in efficiency/fitment between the Doug's (or any) headers and the iron manifolds? Can I modify the iron to improve flow? Dunno. Yes, planning on using a header flange on the drivers side if I use manifolds.

I'm sure I forgot about 100 things, but please feel free to remind me. Best I can do on a Sunday morning. Any and all responses will be considered to get me to the most efficient, economical build. Thank you.

View attachment 1716300585

View attachment 1716300586

View attachment 1716300587

View attachment 1716300588
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I have the hughes cam you pictured in my 5.9 2002 Ram van and really like it. (Edit- mine is 114 lsa version for stock magnum fuel injection) Did a stock bottom end rebuild with the hughes cam and eq nz heads. Big difference in power and engine doesn't stop pulling.

Might as well go ahead and buy a set of cam bearings. They are usually on their way out on the magnums I have torn down.

Before I spent a grand on headers, I would get a set of pistons and get them set up to zero deck or slightly above. Magnum exhaust manifolds are decent for stock pieces, and with the cam we have headers won't make much difference. Split duration on the cam helps the exhaust side, and magnum heads have really good exhaust flow even in stock form. You can always add the headers later if you want.

Just my two cents since you asked.
 
junkyardhero said:
that would be my choice for the set up/parts that you have to compliment it.

with a 3.55 if you put wings on it that early a would fly.

put whatever exhaust you have on it while you save for headers. no sense in making a half step with whatever combo of manifolds for minimal gains.
Click to expand...
Been looking around at exhaust options. As far as headers go, I think the Sanderson DD9's are going to be my choice. Kinda cheap, and I hope they flow air better than iron manifolds.
 
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MechNerd said:
Been looking around at exhaust options. As far as headers go, I think the Sanderson DD9's are going to be my choice. Kinda cheap, and I hope they flow air better than iron manifolds.
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if i was building an automatic and trying to keep the $$ on the low end, those would be my choice.
 
The ongoing saga has brought about 2 new questions- never pulled a roller cam before. Was going to send this cam to Oregon Cam to see if they can regrind. Does this type of wear make it useless? The associated lifter looks fine.
Question 2- best method for replacing cam bearings? Any help would be appreciated.

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