Help with my first engine build (5.9 Magnum)

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Look like there aren’t any cracks in the heads. So that was nice to confirm.

Last night my pistons came in! Now I can take all my parts into the machine shop this week. Excited to get the ball rolling on that. There is something pretty cool about fresh speed parts!

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Are those KB 107's if so you are going to have alot of compression.
Choose a camshaft wisely, detonation with iron heads is one issue I foresee.
 
They are KB107s, maybe I made a mistake by buying them? My cam isn't too extreme, what ways can I avoid detonation with these pistons? Aside from aluminum heads...
 
Find a cam with a late intake closing, I had to on my 5.9 mag build with aluminum heads.
Or run race gas, or E-85
 
I was at 11.37 with aluminum heads measured.
 
Comp cams has a desk-top dyno that you can plug their cams into.
Its free, run it and see how the numbers come out.
I ended up using the 20-612-9 in my engine, it preformed exactly as the desk top dyno print out.
I built the engine for torque, because it was going in a truck.

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Tonight’s progress, lapped and installed new stainless valves, valves seals, and springs. One head down, one to go!

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I was lucky enough to find another machine shop to do some work to my block. I was fully planning on putting the motor together as is, however this family owned shop quoted me a price of $7-800 for all the work I mentioned above (minus crank balancing, all they can do in house is polish and mic it to be sure its in spec). After talking with the guys at the shop, they told me that I won't need to get the rotating assembly balanced, as long as I'm not racing the motor. They said if its not living up above 6000 rpm it isn't necessary. My plan is to simply drive this car, but not race it. It rarely should be up at 6000 rpm.

Do you agree guys with their opinion about balancing? Or am I asking for trouble?...
 
The kb107 piston change will require balancing. You’re asking for trouble by NOT doing it.
 
X2 you will have to balance the KB pistons, there is a weight difference.
My machine shop told me anything with 10 grams difference needs balanced.
 
Motor is back from the machine shop! Finally... I excitedly put it on the stand and got to work. First thing I did was check the main bearing clearances with plasti gauge, they all were right at .003". I've heard some say it's fine with that clearance, other sources say its too much... what are your guys' thoughts?
 
ValleyRat said:
Well I called my local machine shop... I was surprised what I was told. For the following...

Cylinder boring
Decking the block
Cam bearing install (I provide bearings)
Crank polishing
Crank balanced to new pistons (I provide pistons)
Hanging the new pistons on the rods

it came out to $2090... I haven't ever had machine work done before, but is that a reasonable price? To me it sounds pretty high, makes me think more about sourcing another block... what do you guys think?
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That's more than we charge here, you could ship it to me, get the machine work done, and ship back probably cheaper
 
replicaracer43 said:
And if your machine shop didn't ballance it, they are hacks.
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The small local shop I got my block bored at doesn't have the capacity to balance... seems to be common around here in Alaska (not many machine shops around). They told me I didn't need to balance the rotating assembly with the new pistons if I'm not spinning it up to the 6500 rpm range constantly. I don't really believe that... Its frustrating, but the only shop that balances around here quoted me $1140 for a crank grind and balance...
From what I've read, it needs to be balanced, just a bummer that the one shop has such a monopoly.
 
Yeah, that definitely sucks. Chrysler factory ballance jobs are notoriously inaccurate, the piston your using doesn't weigh the same as the stock ones anyway, it will run tho
 
And while plastigauge isnt 100% accurate, it does give you a indication, and .003 on the mains is a bit to the high side unless it's a race engine. Again, it will work tho
 
I'll measure it will calipers too, try to be as accurate as possible. Good information, I appreciate it!

At that cost ($1140), knowing what you know about the importance of balancing a street engine, would you still have it balanced or run it as is and hope for the best?
 
I wouldn't pay 1100 dollars for a ballance job, but a QUALITY ballance job makes a very noticeable difference, and the bearings will live longer also.
 
I hope it's not too late and I didn't read the whole thread to see but are the factory roller lifters in good shape? If so I'd highly recommend reusing those with an aftermarket hydraulic roller cam. If you get a "retrofit" roller cam it'll have the extended snout to run a mech fuel pump. Flat-tappet cams work but if you can use a roller cam without having to buy all new lifters that's the way to go IMO.

The engine in my Duster (avatar pic) was a high-mileage 5.9L Magnum I pulled from a truck at the local junkyard. There was a tiny bit of wear on the cylinders where the crosshatch was more faint near where the head bolt bosses are but overall looked great. All I did was replace the rod bearings as they were showing copper and "sent it". Majority of the money I put into it was for the top end (heads, cam, intake), reused pretty much everything in the short block including lifters and had a roller cam custom-ground by Jim at Racer Brown. That was about 4 years ago, still runs like an absolute champ with minimal blowby and put down 290 HP at the wheels, uncorrected at 5000' elevation. I think 450 HP at the crank at sea level would be a safe estimate.
 
MopaR&D said:
I hope it's not too late and I didn't read the whole thread to see but are the factory roller lifters in good shape? If so I'd highly recommend reusing those with an aftermarket hydraulic roller cam. If you get a "retrofit" roller cam it'll have the extended snout to run a mech fuel pump. Flat-tappet cams work but if you can use a roller cam without having to buy all new lifters that's the way to go IMO.

The engine in my Duster (avatar pic) was a high-mileage 5.9L Magnum I pulled from a truck at the local junkyard. There was a tiny bit of wear on the cylinders where the crosshatch was more faint near where the head bolt bosses are but overall looked great. All I did was replace the rod bearings as they were showing copper and "sent it". Majority of the money I put into it was for the top end (heads, cam, intake), reused pretty much everything in the short block including lifters and had a roller cam custom-ground by Jim at Racer Brown. That was about 4 years ago, still runs like an absolute champ with minimal blowby and put down 290 HP at the wheels, uncorrected at 5000' elevation. I think 450 HP at the crank at sea level would be a safe estimate.
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Great comment, I appreciate it! I think I did save the roller lifters, but just pulled the trigger on a new stock set of roller lifters. I thought it might be smart to replace them, rather than try to reuse the old ones with 144k miles on them... I can still cancel the order, what do you think?
My build sounds very similar to yours, hopefully I get some of the same results!
 
ValleyRat said:
Great comment, I appreciate it! I think I did save the roller lifters, but just pulled the trigger on a new stock set of roller lifters. I thought it might be smart to replace them, rather than try to reuse the old ones with 144k miles on them... I can still cancel the order, what do you think?
My build sounds very similar to yours, hopefully I get some of the same results!
Click to expand...

If you already ordered them I'd probably just go that route. Reusing the stock lifters just saves some money but my main point was to take advantage of the provisions in the Magnum block for roller lifters. What brand lifters did you buy?
 
I bought a set of Melling Factory Hydraulic Roller Lifters, JB-2225. I guess it won't hurt to have a backup set (the used ones).
 
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