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506 BLOCK WORTH ANYTHING?

spdgofast

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I figured I'd start a short thread to try and figure out what to do with the 506 engine that I removed from my Burb to make room for the P400. So the engine that came out of my 94 K2500 Burban only has about 50K miles on it and never pulled anything heavier than 3000 LBS. It was a warranty replacement somewhere around 1997 I believe. I believe the only issue it had was I stretched the head bolts (I believe). I have not had the block cleaned and checked nor the heads yet either. I ran Amsoil synthetic in it for about 43000 of the 50K on it. So if it checks out with no cracks in the block I was thinking of honing the cylinders, polishing the crank and installing new rings and bearings. I also have the valves from the P400 I could use along with the rocker assemblies. I also have 3 different turbos GM 4, HX 35 & Super HX 40. I have a new DS4 IP with 500 miles on it along with the DB2350- PE340 IP with 1500 miles (maybe) that I just took off the P400 (don't think I'll use that one on it). So is it worth it to do this? I don't have the accessories like manifolds and bolts and front cover and I don't have anything to put it in so it may just be a waste of my time because anyone would want a guarantee on buying a rebuilt engine I would guess. Any suggestions?
 
At least $50-75.00 at the scrap yard. :p

Do not polish the crank. It's induction hardened. Pull it apart and see what failed including a good crack check. Then you can decide if it's worth "fix what broke" repair. How long did it sit with coolant contaminated oil? Er, remind us how/why it failed?
 
Yep, dont touch the crank. Ifnit has issues it needs replaced. There are proper ways to repair or work the crank, but it is cheaper to replace with a new scat or optimizer crank instead.

Do you just want a backup engine for zombie day or do you have another ride to put it in?
Are you thinking fix and sell?

If you just have to do new tty bolts and headgaskets, and get it to running status on test stand then you could sell for best money, but how much is a wild guess. Seen some go for a few hundred, others advertise for couple thousand. But imo figuring the take out optimizers from Teds, Boyce, etc- you can’t expect a ton because those places offer a basic warranty and they are optimizers.

Definitely pull it apart and clean it up to see what you have for sure.

I have a good 506 centermount engine that I bought for the turbo and manifolds. I kept it because I have the room and cant expect a lot of cash for it. Been thinking about picking up some extra parts just to sell as a runner, but it is bottom of the list.
 
Oh yeah! I was thinking you had a line on a used one you were going to buy.

Never sell a geared timing set until you are out of the 6.5 world or if you are reducing ownership like down from 3 trucks to 2.
 
I didn't install one in the P400 when I put it together because I was reading about ill harmonics and such but now I understand if I'm pushing the IPs limites that it puts more stress on the timing chain so I may put the gears in it since its apart. I would like to get the 506 block apart next week just to check it out. I wonder if I should have Chris coat the 18:1 pistons. He only coats the tops of the pistons though correct? Now I just need a Skat crank and a girdle kit, LOL
 
The harmonics thing was an issue I looked into and heard a lot about it on the 6.5 forums. Mind you, I had timing gears custom made before for my racing mess years before. I found such AMAZINGLY contridictory info it was unbelievable. Once I realized that last statement, it hit me- some of it was unbelievable for a reason. It was amazingly false.

I didnt pull together all the info unfortunately or I would want to have a book Inplace of a thread. At the time there were a few prople that had different view points and people were hard dug into their stance.

In the end a few items that helped me decide. Flat out asking for pics and proof of longevity vs early death. Never did get a single picture showing early death. Stepping out of theoretical ip death on chevy’s vs long ip life on fords. Most chevy guys still think 150,000 miles is a good run on a db2. Ford guys get pissed off if the ip needs rebuilding just because the piston rings and valve seals are painting the hiway behind them. Hmm.

I had a few people contact me behind the scenes that pointed out parts sellers who only profit from selling chains were quick to point “faults” of gear drive, and gear drive resellers didn’t fight it back to often, if ever.

When the majority of the argument turns to harmonics into the ip through the out of balance set up becomes the biggest issue- it took me back to when my gears were custom made- and some of the guys helping with this crazy hot rod diesel idea back in the 90’s were big names in racing, so theory wasn’t theory- it was proven knowledge as fact.

We had the gears made a little lighter than dsg or Leroy’s current ones are. Basically narrowed in the middle. But even back then we talked about should we lighten it or make it heavier on purpose. The fact that it is slow rpm, small diameter, etc means lightening it doesn’t help that much. Cut weight in half at 4,000 rpm could mean a potential 0.25 hp. Yeah- big savings huh? So we had wide gear surface for applied load, knowing we were giving some up to drag, but still comparable to chain drag. Anyways the vibration issue was less concern because race engine vs daily driver. But the gears only transmit the vibrations so redoing my dd had me worried. Right?

If chain: Timing chain means gear only is cam vibration. So forget that. Your applied spring tension and valve smacking friction is the issue there, and until 5,500 rpm that doesn’t even record input.

Crankshaft is legitimate vibration. Assume gear drive And at specific harmonic rates can amplify. But the 2:1 ratio changes the rate by a factor down, not in half. So if your crank is out 12 grams, the gearing cut makes it 4 grams. But if your crankshaft really is out 12 grams, it will break in 3 months anyways- haha. Seriously thats like an unbalanced aftermarket crankshaft! So yeah, real engine death is a concern there. But to continue if you have your crank at factory horrible spec of 4 grams, one gram at the cam and ip is possible. Now this factor is affecting the alplitude of the vibration. The frequency will stay the same.

The chain slap is supposed to ease up the vibration and only stretch the chain faster. Makes sense. But why do pumps live longer on fords?

The vibration transfered in through the gear to the cam has so much less than the valve spring slamming up and down on the cam at all time cause their own vibration. Harmonic dampers were once made for camshafts for this issue but were abandoned because the advance and retard action of it was more counter productive than any vibration savings they made. Know what else has advance and retarding action? Timing chain slap and timing variations every time the engine goes
From deceleration to maintain or maintain to accelerate.

That got me to looking at which is more damaging slap vs crankshaft relayed vibration. Cams shatter so easy when you drop them- As hard as possible and as little deflection as possible by design. But carburetors and gasoline injectors dont need an ip. Vibration into a camshaft from the crank isn’t even thought of in most engines.

So if the number one vibration creater is valve chatter & springs to the cam aside from MAYBE the relayed crankshaft, and I was worried about vibration into the ip... the cam vibrations are still into the ip, regardless of timing chain being able to absorb the crankshaft issue the valvetrain created vibrations should be killing the ford ip- but it isn’t!

Rip apart any ip. Look at the worn out components. Rotational wear. Contamination causing scoring and erosion. Try, just try to find evidence of vibrations related wear in any ip. Show me how much worse it is in a gm vs a ford which if you didn’t already know or figure out by now, uses gear drive not a chain drive. Why does Ford? Same reson EVERY OTHER DIESEL mfr does. It works. Know how many big rig engines have a kazillion miles on them? Know how many of them use timing chains?

Why? Why the confusion / discussion on gm diesel boards?
Misinformation driven by profit market share is why. Do some people honestly believe the chain is better- I am sure there is some people that were convinced of it. It’s ok, errors can be corrected.
 
The new 5.0 Cummins uses a chain. Maybe they only want 159 k not million out of the engine.
That may be more of a noise issue in the cabin than anything else. Look at the 5.0 Cummins's application - light duty truck car-substitute predominantly boulevard cruiser with a little bit of half-serious towing once in a while. Interior noise levels are much easier to tame with a relatively quiet chain vs. the whine of gears with variable pitch with change in speed.
 
Not by a long shot. Ask MoPar about stupidity. Nylon cam sprocket teeth with the timing chain set just so the small block motors would run quieter? Guaranteed to get brittle and start breaking teeth off at 90-100K miles. Then the chain starts jumping teeth back and forth. Replaced a couple on my 360 powered 72 D100 Adventure Sport P/U.
 
Well I just realized the Fluid Damper I have on the P400 is for a crank gear with a reluctor on it and the one on my 506 block is for a DB2 setup so I would need a different damper, it would be cheaper to buy a new gear set.
 
Don’t quote me on this but don’t you use a spacer or washer on one pump but not the other. If yours has the ring and you are going DB pump I think all you do is remove the ring or washer or What ever it is. Or it might be the other way around.
 
There is a core charge because Leroy has to cut the reluctor off for reuse, and iirc a slight difference in price for db2 vs ds4.

@Burning oil Maybe he can sell you the other parts required to use the ds4 timekeeper on the db2 rig.

And on that subject- everyone remember, please dont just throw away your old timing gears, they are needed parts- not just for Leroy but by you fellow 6.2/6.5 owners. Leroy, what parts are you looking for on those as a reminder?
 
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