Proper Order for Block Machine Work?

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Jul 28, 2003 | 06:37 PM

No Go

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Melting Slicks

Joined: Jun 2000

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From: Tampa Florida

Proper Order for Block Machine Work?

I try to make things as simple as possible, but once I lay everything out for a "better than standard" engine assembly it gets somewhat frustrating...:)

I'm using a OEM 400 block to construct a 407 CI with Scat 4340 3.75 crank and their 5.7 H beam rods and SRP flat top pistons (5 cc valve relief).

I want to use AFR 210 heads.

Once CR is determined, it seems the proper order to machine a block is:
-take block to shop to bore the block to figure if .020 or .030 is required
-order pistons
-finish hone pistons to block using pistons for measurement
-take block home
-install crank/rods/pistons to measure for preferred deck height (my case 0)
-take block back to shop for deck machining!

Lots of trips to shop seeing it is 1.5 hours round trip. :)

Does this all make sense?

Talked with AFR...7 to 8 weeks for delivery...kind of think that will be optimistic, but my car isn't going anywhere anytime soon. :)

My original 407 didn't take this much time/effort, but then again it only made 340 HP...:D

Jul 28, 2003 | 08:54 PM

427Hotrod

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Re: Proper Order for Block Machine Work? (No Go)

That's pretty much how I did mine. You could use the BHJ gauge to measure deck height and do calculations, but I like mocking it all up and getting real #'s when you are dealing with tight quench areas.

And if it ends up a couple of .000's OUT of the hole...even better!!

What is it with AFR and the length of time it takes to get heads? Has it always been this bad?

JIM

Jul 29, 2003 | 11:06 PM

arnold

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Re: Proper Order for Block Machine Work? (No Go)

Quote:

Once CR is determined, it seems the proper order to machine a block is:
-take block to shop to bore the block to figure if .020 or .030 is required
-order pistons
-finish hone pistons to block using pistons for measurement
-take block home
-install crank/rods/pistons to measure for preferred deck height (my case 0)
-take block back to shop for deck machining!

Lots of trips to shop seeing it is 1.5 hours round trip. :)

Does this all make sense?

Ah, in a word, no! Even without the proper 'homework' done B4hand, it should be one trip there, and one trip to pick it up.

The overbore necessary will be determined with checking equipment to determine the amount of cylinder bore wear, prior to any boring.

It is a good idea to check deck hgt. with an original piston/rod assembly. This, plus the specs for new crank, rods, piston specs, and head gasket to be used, will determine what you can expect to remove from deck to obtain the quench hgt. you want. A good shop won't agree with the jerking around to take the block back and forth for unnecessary checking. Armed with the specs of the rotating components, and head gasket specs, they can/will determine the correct [crank centerline to block deck dimension] you need for the quench hgt. you are after. The shop will then remove correct amount of material from deck, cuz their cutter is set to a predetermined reference hgt. from crank centerline. You can then compare what material they will remove, with the calculations you made to assembly prior to delivering the block to them.

Jul 30, 2003 | 11:49 AM

clem zahrobsky

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From: delmont pa

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Re: Proper Order for Block Machine Work? (No Go)

if the shop uses a deck mounted boring bar you must first deck the block to make sure the deck is parallel to the crank centerline or the rebore could be out of square to the crankshaft centerline. if they use a boring setup that mounts the boring bar on a table that holds the block by the main beaing journals this is not a problem. :chevy

[Modified by clem zahrobsky, 11:50 AM 7/30/2003]

Aug 1, 2003 | 06:24 AM

black bart

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From: La Fontaine Indiana

Re: Proper Order for Block Machine Work? (No Go)

Depends on how close to flush you want to get. Since your new rod & pistons will vary in length from one to the other. The shop that does my machining has a fixture that holds the rod piston assembly with a dial indicator on top to check overall length. I had Ross to build custom pistons and I told them the block was taller than it would be. After I got them and checked them for aol then the block was decked to where we had to cut a couple thousands off the pistons. When the shortest rod piston combo is flush put it in the fixture take a reading and then measure all the others and machine them off till all fit perfectly flush with the deck then balance everything. This is time consuming but since the rod piston combo varys in length by a few thousands it is necessary if you are going to get it right. I only have .033 head to deck clearance. Also I would use 6 inch rods instead of the 5.7 with a 3.750 stroke the 5.7 has a poor rod-stroke ratio. :cheers:

Aug 2, 2003 | 10:32 AM

No Go

Thread Starter

Melting Slicks

Joined: Jun 2000

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From: Tampa Florida

Re: Proper Order for Block Machine Work? (arnold)

I have the capability of only checking piston deck height using a micrometer and bridge. Would have with this block, but I bought it with no rotating assembly.

The process I outlined I guess seems to make sense for my application with my tools. Wish they could do it all at once, but that is basing stuff on many assumptions. :)

Thanks!

Also I like the 5.7 rods vs the 6 inch to avoid the oil ring supports that are required. I'll give up a bit of hp to avoid a possible pitfall of oil burning...

[Modified by No Go, 9:35 AM 8/2/2003]

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