Building a Chevy 427 by scratch

[Dave Koehler]

What about the plugs on the side? Have those channels been cleaned out and new plugs installed?

[Harleyboy14]

What about the plugs on the side? Have those channels been cleaned out and new plugs installed?

Yes.

[Harleyboy14]

Got a little work done today. Installed oil pump with a Milodon pick up #16810. Spot welded both sides of the pick up for piece of mind. Prepped Miloden stock style oil pan with 320 wet n dry paper and cleaned with Acetone and painted the very quality pan with three coats.

[Harleyboy14]

Moving along on build. Got the bottom end all sealed up. Flipped 427 over and installed Brodix Race Rite heads with Fel Pro 1037 head gaskets. I took cautious time to figure out how to get the correct push rod lengths. I ended up purchasing a set of 12'' dial calipers off e-bay to get a accurate measurement. I did the valve adjustment by firing order starting at #1 cylinder TDC compression. Adjusted both valves on #1 cylinder then turned crank 1/4 turn and moved through firing order repeating the process.

[levisnteeshirt]

Alot of people don't even consider these anymore, plenty for a real street car , and not near as expensive to build a sbc that makes the same HP/TQ

[Schurkey]

Notching the bore to unshroud the intake valve going out-of-style? I spent some time with that on my 454.

Are you measuring your pushrods the same way your pushrod supplier measures pushrods?

[Harleyboy14]

Notching the bore to unshroud the intake valve going out-of-style? I spent some time with that on my 454.

Are you measuring your pushrods the same way your pushrod supplier measures pushrods?

I used adjustable pushrods with the light weight springs as pictured. The lifters were right out of the box not pumped up. Just lubed outside of lifters. Started on #1 firing on TDC. Used layout die on valve stem tops. Adjusted push rods till all up and down movement was out. Turned over a couple times and checked. Then repeated process till roller tip was center of valve tip.

[Schurkey]

I took cautious time to figure out how to get the correct push rod lengths. I ended up purchasing a set of 12'' dial calipers off e-bay to get a accurate measurement.

Are you measuring your pushrods the same way your pushrod supplier measures pushrods?

I used adjustable pushrods with the light weight springs as pictured. The lifters were right out of the box not pumped up. Just lubed outside of lifters. Started on #1 firing on TDC. Used layout die on valve stem tops. Adjusted push rods till all up and down movement was out. Turned over a couple times and checked. Then repeated process till roller tip was center of valve tip.

1. Adjusting pushrod length to get the rocker tip at the center of the valve tip is poor practice. You'd be better-off to adjust for minimum sweep distance on the valve tip, even if that is somewhat off-center.

2. Once you have the adjustable pushrod set up for minimum sweep, do you measure the adjustable pushrod the same way the pushrod supplier does? There are (at least) three ways to measure a hollow pushrod.
From Comp Cams, click on the "Measurement Techniques" tab.
http://www.compcams.com/Products/CC-%27 ... %27-5.aspx

If you're measuring pushrods with a 12" caliper, you're probably getting the "middle" measurement--which is NOT how Comp Cams measures pushrods. I don't know about other pushrod suppliers.

3. When I do this, I'd turn the rocker nut 1/2 or 1 turn tighter than "zero lash" so that the rocker pivot is at the same height as when the engine will be running. If the lifter plunger is not depressed into the lifter body during pushrod-length testing (which is the way you describe your process), this means the pushrods will be too short by the amount of lifter preload I want. I have to add some length to the measurement to allow for lifter preload. I typically add at least 0.035, or a bit more if that gets me to the next shelf-stock pushrod length.

4. All this assumes that your intake, and your exhaust valve tips are at the same height. Throw a straight-edge across the intake valves, and across the exhaust valves to verify that they're reasonably close to the same height.

[Harleyboy14]

At this point on my build. The valves are adjusted and motor being per oiled. At this point what would your recommendation be to check for correct roller rocker arm geometry. I'm moving slow and cautious on this build, no hurry.

[CharlieB53]

My eyes are not what they once were. In the original post the second picture showing the cyl deck I am confused by the image as it appears as there is a 'step' machined into each of the cyl bores at the top.

I am familiar with machined steps like this for the installation of cyl sleeves, but this build appears like it is finished honed. So this step leaves me puzzled.

The only other question I have is was any correction needed to the lifter bores?

[Schurkey]

At this point on my build. The valves are adjusted and motor being per oiled. At this point what would your recommendation be to check for correct roller rocker arm geometry. I'm moving slow and cautious on this build, no hurry.

Install your checking springs on #1, re-mark the valve tips with whatever dye you're fond of--I use a Sharpie magic marker. Adjust the rockers for zero lash plus whatever your preference for preload is. Roll the engine over and see how wide the pattern is. Narrower is better. Keep an eye on the lifters to verify that the plunger isn't depressing as the valve lift increases.

If it's good...you can check more cylinders or you can just be done. If it's not good, I'd check with the adjustable pushrods until you see how narrow the sweep can be made, and how the final pushrod length differs from your existing pushrod length.

If your lifters can be pumped-up and not leak down, maybe you don't need the checking springs. My lifters always bleed down too fast.

My eyes are not what they once were. In the original post the second picture showing the cyl deck I am confused by the image as it appears as there is a 'step' machined into each of the cyl bores at the top.

I am familiar with machined steps like this for the installation of cyl sleeves, but this build appears like it is finished honed. So this step leaves me puzzled.

Pretty sure you're seeing the piston rings (pushed into the bores so the ring gap can be verified and corrected as needed.) One photo has a feeler gauge in one of the cylinders.

[Harleyboy14]

My eyes are not what they once were. In the original post the second picture showing the cyl deck I am confused by the image as it appears as there is a 'step' machined into each of the cyl bores at the top.

I am familiar with machined steps like this for the installation of cyl sleeves, but this build appears like it is finished honed. So this step leaves me puzzled.

The only other question I have is was any correction needed to the lifter bores?

That was a picture of rings in the bore after I fitted them.

[MadBill]

The pushrod determination procedure Schurkey mentions works fine and is pretty well goof-proof. Another approach that gives the same result but which I find a little more precise is to use the adjustable pushrod in conjunction with the lash adjustment device to position the valve at 1/2 of net max lift when the rocker arm centerline (center of fulcrum pivot to center of roller tip) is at exactly 90° to the valve stem. A small straightedge across the retainer provides a good reference, especially if its width is such that the top edge lines up with the centerline.

[77cruiser]

This is good viewing.
https://www.youtube.com/watch?v=o5is9BsH5OU

[Newold1]

Nice input Schurkey and MadBill. Nice of you Harleyboy 14 to pay attention to the input these guys are sharing with you and to take your time to do it right! Wise men never stop learning or listening.