I'm taking it to our local machine shop since CNC dude doesn't do automotive machine work. The local shop here has built a couple of SBC's for me in the past and they do really good work, I just have to show him the numbers and the math so they can see that it will take more than .30 off the head to get my compression into the target range.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Sealed Power is the name applied by Federal Mogul to their after market / service parts,, FM is a world wide OE manufacturer, typically a top shelf supplier, the materials used will be very close to what Chrysler spec'd originally.

here is an informative article on the materials used in engine valves

http://www.enginebuildermag.com/Item/11 ... gines.aspx

Never heard of any problems at all. They will only be enlarging the existing seat by @ .060. I would go ahead and get the engnbldr valves and install them. Many of us are running them right now.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Hardened seats anyone?

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'72 Duster 198 stock cam, 3:23's Hookers on jack stands for 8 years in the driveway
'79 Maxivan 360 Offy Qjet Comp RV cam/rusting in the driveway.
93 D350 160HP Cummins Auto Dually Clubcab needs a injector pump
2005 Golden Couch Buick

I think the engine is an 85 so it should have hardened seats. I may be totally wrong too!

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Jeb, has this piston crown been peppered with fragments, or is it flaked carbon? If it has been peppered, what caused it? Does it mean there is deeper damage somewhere?






regards,Rod

It would have it...but experience has shown that the hardening isn't that deep, if the machine shop regrinds the seats you get to play russian roulette...

Not so bad on the intake side...but at a minimum I'd ask for new hardened or stainless seat on the exhaust sides...

-D.Idiot

It's an 82.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

And the speckled piston top ?

regards,Rod

I have no idea what caused the speckled piston top. I'm thinking a piece of casting flash (that intake has LOTS) might have broken loose inside the intake and got sucked into that cylinder. The cylinder walls look good and aren't scratched or gouged any. Plus I have a screen under my carb to catch any air bleeds or other foreign objects I might drop.

As for the head, the machinest is going to clean it up so I can CC it and do a mild port/polish job on it. We are sticking with stock sized valves (sealed power) and he is going to backcut them for me. He also said the seats are shot so it's getting a new set of stainless valve seats on the exhaust side. The guides are pretty well gone too so it's also getting bronzewall valve guides.

The tenative plan is to deck the block to .110 and get the chambers in the 54-55 CC range. That will give me exactly 9.0 static and 8.0 dynamic with cam installed straight up. But we are not cutting or milling anything until I find out exactly my chamber sizes are.

Other than the head he was impressed with the condition of the engine. It barely has a wear ridge at the top of the cylinders and the bearings look very good. Goes to show what frequent oil changes can do.

I gave him the specs of my build and he said that upping the compression and doing some bowl work on those god awful exhaust ports would help me more than anything else.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Just a quick update, I've been doing a mild port job on my head and CC'd out the chambers. Surprisingly they all came out to 59 CC's. So it looks like the plan is to deck the block to .110, bore it .030 over and get the chambers down to 55 CC's. That will give me 9.0 static and 8.0 dynamic using the KB calculator. According to RB calculator, my dynamic will be 7.95 with a cranking pressure of 158 psi.

So if .066=1CC, then I need to take .60 off the head, correct?

I also noticed while I was porting the heads that the #6 exhaust runner is actually shifted over to one side about midways and smaller than the rest. I assume this is because of the air injection passage that exits next to it.

I plan on using the custom cam that Dadtruck used. 212/206 @ .50 with .443/431 lift, 45* overlap, and 105 LSA. What kind of idle quality can I expect with this cam? Will it be rock solid smooth like the stock cam or have a little burble at idle (which would be nice).

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

The correct number is .0066=1CC
59-55=4CC x.0066=.0264

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks Charlie, so it's .0264 off the head?

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Finished up my light head porting today. It's going back to the machine shop tomorrow to rejoin the block.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

So, I'm butting heads with the machine shop again. I told him I would like new stainless steel exhaust seats installed on all six exhaust ports but he says I don't need them. I also told him how thin the actual induction hardened seats are and that a valve job will probably wipe them out. But he still says that hardened seats will still be there after he does the valve job.

The seats I had picked out are sealed power 24514371. Dimensions are 1.442" OD; 1.25" ID; 0.216" Depth

So, what do you guys think? This ain't no damn Chevrolet and I'm having a hard time getting people to think otherwise. I'm also having a hard time getting them to understand that this is not a stock rebuild.

Also, How likely is he to hit water when (and if) he cuts for the new seats? I know there isn't much "meat" in that area.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2