Motor Build

Mopar_Fire · May 1, 2017

Hey ladies and gents

I have a 1998 5.9 4wd I'm looking to build the motor . It needs everything since a buddy left it outside .

What pistons should I run ? I'm thinking speed pro ? Any other suggestions .
I'm NOT looking for some ***** ape machine I'm looking for a motor that I can get 200k plus out of .

Basically a stock motor but I can't go stock pistons due to rusty cylinders so I'm going to .030 over . And a small cam . Keeping the kegger style intake . Stock fuel rails etc...

Looking forward to all the replies !!

Yeret · May 6, 2017

Sealed Power makes the factory-style dish pistons in a variety of overbores and they're pretty cheap too. Never heard anything bad about Sealed Power as a brand.

Wouldn't bother with a cam unless you're gonna swap heads/intake as well. I've finally conceded that the factory cam is really the best choice for the induction setup. The kegger really doesn't like operating north of 3,000 RPM and most aftermarket cams won't offer much improvement under that.

Put the money in a tune instead to get rid of the damn "death flash." That will offer much better improvement with the factory intake/heads.

bulrid8 · May 7, 2017

Yes, a tune will wake these motors up. Best money spent for the 5.9

Sent from my VS985 4G using Tapatalk

goodtodoo · May 7, 2017

Can someone explain to me what the Tune is, and what is the death flash?

Yeret · May 7, 2017

A "tune" is basically a re-write of the ECU's programming typically done for purposes of improving engine performance. Such a re-write is done via a handheld "tuner." For our trucks, the SCT X3 is popular and more flexible than Superchips.

The "death flash" is Chrysler's half-assed answer to the spark knock issue that the Magnum engines are notorious for. The problem was primarily caused by a leaky intake plenum gasket which caused oil to contaminate the air/fuel mixture and make it "knock." Of course, replacing the plenum gasket on every single truck would be expensive and time-consuming, so Chrysler released an "update" to be loaded into the ECU. This is commonly known as the "death flash" and basically it flattens the ignition curve across the RPM range which reduces power and makes the engines feel weak (which is amplified by the already oiled-up fuel/air mixture). Funny thing is this rarely actually did anything except "Old Yeller" your power and sometimes fuel economy. I speak from experience on this.

The only way to rid yourself of the "death flash" is via custom SCT tune. Hemifever is popular but Flyin' Ryan gets a much better rep. I'm running a canned tune from Ryan and would recommend it to anyone.

Mopar_Fire · May 8, 2017

Thanks for the replay , I've been hearing and reading the speed pros or " sealed powers will basically come apart with detonation , kinda scares me but let's be honest any piston probably would . I think I'll just go with the sealed powers . I have also decided that a stock cam is what is gonna be best for me as I'm not looking to go fast . I also have to get new heads .. mine are both cracked like most magnum heads and I'll be replacing with with Bare " EQ " heads and put stock valves and replace the springs . Since the block has been left out in the weather I'm going to purchase a new crank also but I'd like to run a better main and rod bearing then what is provided with the crank . Thinking kings or clevites . Brass freeze plugs , Fel-pro gaskets . Melting oil pump , comp double roller time set . Is there anything else I'm missing ? Yeret you seem to be knowledgable . Looking for ward to your replys .

Yeret · May 8, 2017

Sounds pretty good for a stock rebuild. I had my engine "freshened" with pretty much all the same parts (Fel-Pro, Clevite). Just make sure that if you have someone build the engine for you, they won't keep it apart on a table for three months and then you ultimately have to tear the engine half apart to fix their screw-ups...

MAKE SURE that if you pull the distributor, you have the fuel sync set with the aid of a DRBIII scanner. I have yet to have this done to mine and it runs fine but it has kind of a weird "wave" when accelerating between 1,500 and 2,000 RPM at light throttle. It's not like a misfire, just kind of a smooth up and down "wave." It's kind of hard to explain.

Take your time, follow the torque specs and try not to be tanked when doing stuff. Buzzed is okay but when you're flat drunk, that's when the little things get missed.

Oh, and definitely get a plenum repair kit or at least a revised gasket. You will NEVER have a better and easier chance to do it than while the engine is out.

Mopar_Fire · May 9, 2017

It's a bare block now . Nothing but pistons and a crank are in it . I'm going to do my damned to get my parts soon . But damn does that price add up and I'm also doing going he 1/4" alum plenum repair .

Sent from my iPhone using Tapatalk

Yeret · May 9, 2017

Only thing cheap about building an engine is the thirty-pack of Busch Light you drink while building it, LOL

dapepper9 · May 9, 2017

+1 for the Busch :pepper:

But to be serious, whats been posted so far is pretty much solid. Only thing i would change is not even mentioning hemifever and only mentioning Ryan. There's literally no comparison between the 2. Wouldn't even consider hemifever

Yeret · May 12, 2017

Yeah, mentioning Hemifever here is a little like going to an AR-15 forum and bringing up an AK-47. I was just mentioning him for example since half the sigs on pretty much every Dodge forum contain "Hemifever tune" somewhere, so now OP knows what the hell that means.

But yeah, when you research, you find that Hemifever is kind of rocky. If I remember reading it right, Ryan (Flyin' Ryan) actually started off by "fixing" Hemifever tunes. I have no idea what needed to be "fixed" but I am curious to know (here's looking at you, Pepper). Knowing little about the "ick" of Hemifever, I will say that Ryan's tune was the best money I spent on performance. I would totally do it again and if I ever actually do something radical with my engine (stroker, blower), he'll be the guy I turn to. :happy107:

dapepper9 · May 12, 2017

Yeret said:
If I remember reading it right, Ryan (Flyin' Ryan) actually started off by "fixing" Hemifever tunes. I have no idea what needed to be "fixed" but I am curious to know (here's looking at you, Pepper).

He likes to run too much timing and too much fuel. Would over fuel builds running 5000rpm or more because he doesn't know how to adjust the rpm scale. Final fuel/timing adjustments would hold that same bit steady to whatever rpm customer wanted to run. Bigger injectors were often favored here even on na stock displacement builds, in which factory is plenty. Idled like **** and pig rich, would seem to fall on its face after it would shift.

Ryan fixed all of these and more

Yeret · May 12, 2017

I see. A cool thing about Ryan's tune is the engine behaves pretty much the same as it did before, which is smoooooth. The difference is it just pulls so much better and doesn't feel like it's pulling a boat anchor. With the death flash, the engine felt so flat and poochy with any kind of real throttle input. Now, I can turn onto the highway with other vehicles nearby doing 65-70 and before they're even a full-length ahead of me, I've matched their speed and still accelerating and pull right ahead of them.

My personal favorite is turning onto the highway via on-ramp with someone right behind me in a new car and they immediately turn into the passing lane to go around me as if they're thinking "outta my way, slow old truck." Then I go about 3/4 throttle and they never see anything other than my shiney chromey bumper. The cherry on top is when I see their blinker turn on in my rearview mirror and they slink back into the righthand lane.

I honestly wish the same thing would happen with someone in a Camaro or something and were being serious. I know that I'd get my ass kicked but boy, it'd sure be fun trying to hang with 'em! I've never truly tested the limits of my setup anyway...

Flyin' Ryan tune + bolt ons = :Rock on:

goodtodoo · May 12, 2017

Thanks for the rply, so how much power are we talking using theSCT X3 on a stock 5.9.

Yeret · May 15, 2017

I honestly have no idea what the gains would be with stock engine. I don't think it's so much an increase in power as much as it is an "allowance" of power. That is to say, the tune lets the engine utilize it's full power potential as opposed to it's potential being dynamically suppressed by the "death flash."

Let's not kid around. The MPI Magnums are NOT powerful engines by any means in stock form. They're total low-end grunt engines and they perform excellent as such. Unless you plan on spending a ton of money, it's best to leave them as such. Bolt ons and a tune will enhance mid-range power significantly without impacting low-end power much but if you think a tune is gonna turn your Magnum into a 300 HP Triton-killer, you're gonna be disappointed.

But the engines do behave like a truck V8 shoud once you ditch the ******* "death flash" update as well as address the plenum problem. If you really want to make power, you're gonna have to swap the heads/intake/cam which will cost money and you WILL lose your low-end grunt. It really depends on what you want.

Me, I'm gonna stick with the kegger and factory-spec cam with my tune but eventually install Harland Sharp 1.7's and some Gibson shorties then rebuild the axles with 3.92 or 4.10 gears and call it a ****ing day. I'll grab a V8 Camaro or Mustang or something down the road if I really need to satisfy my need for speed.

Or maybe money flows a little better and I'll get a 440-powered Road Runner. Who knows what the next day will bring...

dapepper9 · May 15, 2017

Peak gains of 19whp/30ish wtq on trucks with only a muffler swap. Doesnt sound like a lot but the real magic is:
A. Death flash delete, brings more timing back into play where it was pre-update. And that's before advancing
B. Deletion of tq management, exactly like how it sounds
C. The re-mapping of your entire curve. The real gains aren't at peak output but everywhere else in the curve

Mopar_Fire · May 15, 2017

Marty fletcher will be tuning mine !

Sent from my iPhone using Tapatalk

dapepper9 · May 15, 2017

Marty is a decent in between to Sean and Ryan. Not as good as Ryan but better than Sean and more readily available for custom tunes.

Flyinryan · May 19, 2017

Google KRC Performance.

regularcab2500 · May 19, 2017

You guys here are great..theres only a couple things i want to add..

Make sure you DO NOT buy your rebuild kit until youve had your block machined. .030 is probably more of an over bore than you need but say you buy .001 crank bearings and you needed it turned .010, then you have bearings that in most cases you cant return or exchange. Plus if youre using the stock rods they will need to be checked and balanced (new ones would too but i'll assume youre going for budget) so you'll want to wait to see if those will require undersize bearings.

Anything else specific this motor im not much good for unless you decide to put a flat tappet cam and carburetor on it :crazy:

these things make excellent power for a small block with the way the magnum heads flow and the right induction setup.

Sent from my SM-G930V using Tapatalk

Motor Build

Junior Member

The Village Drunk

Senior Member

Senior Member

The Village Drunk

Junior Member

The Village Drunk

Junior Member

The Village Drunk

Senior Member

The Village Drunk

Senior Member

The Village Drunk

Senior Member

The Village Drunk

Senior Member

Junior Member

Senior Member

Member

Senior Member

Similar threads

Forum statistics

Share this page