Mild build questions

[Zeb]

If you really don't want them to fail again go with the harlandsharp or Warren diesel setup. But be sure your sitting down when you price them out.

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You’re thinking rockers. There is absolutely no need for Harland Sharp (which have fitment issues) or WDI’s setup on a motor like the OP is building.

 

[alwaysdiesel]

Everything is coming along good, got almost all my parts ordered and block/heads are finished now. Pretty well stuck to my original plan, WDI 205/30s, Gear*ead tunes, Kc stage 2, BD mani's, Colt stage 2 cam, RCD valve springs, Oringed heads, pushrods...etc etc

Machine shop just finished up with everything so I'll be picking it up on Monday, but I had some questions about pistons. A few cylinders had 0.005-0.007" wear and a deeper gouge made them bore 0.020" over. Mahle .020" pistons run about $900 a set, so I was thinking of spending a little more and going coated, possibly 0.050" flycut since I am running a bigger cam, I know it isn't necessary but they don't cost much more. I know the coating helps dissipate the heat. Can anyone shed some light, what is the limit for stock pistons?

 

[Zeb]

Everything is coming along good, got almost all my parts ordered and block/heads are finished now. Pretty well stuck to my original plan, WDI 205/30s, Gear*ead tunes, Kc stage 2, BD mani's, Colt stage 2 cam, RCD valve springs, Oringed heads, pushrods...etc etc

Machine shop just finished up with everything so I'll be picking it up on Monday, but I had some questions about pistons. A few cylinders had 0.005-0.007" wear and a deeper gouge made them bore 0.020" over. Mahle .020" pistons run about $900 a set, so I was thinking of spending a little more and going coated, possibly 0.050" flycut since I am running a bigger cam, I know it isn't necessary but they don't cost much more. I know the coating helps dissipate the heat. Can anyone shed some light, what is the limit for stock pistons?

The money you spend on coating on the pistons is an absolute waste, imo. If you were to have the motor apart in a couple thousand miles, you absolutely couldn’t tell they were coated.
As far as fly cuts, I prefer to avoid them on a small cam. On a larger cam, (Stage 3 or 4 it’s almost impossible to avoid it). I prefer to keep the top of the piston flat. I usually take 0.015”-0.20” off the top of the piston (depending on deck height, etc) and roll the bowl lip back, but don’t totally eliminate it.
Stock pistons are plenty strong enough for 700-800 hp. Nitrous, a lot of rpm, or something else stupid is what’ll kill them.

 

[alwaysdiesel]

So I've working out of town since November and the engine progress has been slow. I got my bottom end all together and mocked up a cyl head but have ran into some issues. I am running test springs on #4 cyl and clearances are tight. Originally I had tack welded a couple old lifters to avoid having my plungers collapse and give me false readings, but my exhaust valves ended up contacting the piston towards the end of the exhaust stroke.

So I've swapped back to hydraulic lifters and rechecked my clearances. At TDC compression stroke, there is only 0.054" intake clearance and 0.052" exhaust clearance, Confirmed valves are fully closed. During valve overlap, clearances don't get any tighter than 0.051" on exhaust or intake.

My setup is Colt Stg 2 cam, Motorcraft lifters, RCD pushrods (0.007" shorter) factory rocker assemblies, 120# RCD springs, Motorcraft head gasket, Mahle 0.020" Over pistons
The block got machined, and I am sitting close to MAX piston protrusion (rough 0.030-0.032") Heads got fully rebuilt, and they say everything was done to "spec" although I've read that most machine shops air on the side of caution and set the valves deeper (0.020" average) They did say they topped the valve stems to account for valve depth but did not give me specific numbers. I will try contacting again this week.

I also checked lifter preload, at TDC compression, It took 0.098" to bottom the lifters. I checked max plunger travel and got 0.200", so that would give me 0.102" preload. From what I've read this is fairly normal?
Thoughts?

 

[Zeb]

So I've working out of town since November and the engine progress has been slow. I got my bottom end all together and mocked up a cyl head but have ran into some issues. I am running test springs on #4 cyl and clearances are tight. Originally I had tack welded a couple old lifters to avoid having my plungers collapse and give me false readings, but my exhaust valves ended up contacting the piston towards the end of the exhaust stroke.

So I've swapped back to hydraulic lifters and rechecked my clearances. At TDC compression stroke, there is only 0.054" intake clearance and 0.052" exhaust clearance, Confirmed valves are fully closed. During valve overlap, clearances don't get any tighter than 0.051" on exhaust or intake.

My setup is Colt Stg 2 cam, Motorcraft lifters, RCD pushrods (0.007" shorter) factory rocker assemblies, 120# RCD springs, Motorcraft head gasket, Mahle 0.020" Over pistons
The block got machined, and I am sitting close to MAX piston protrusion (rough 0.030-0.032") Heads got fully rebuilt, and they say everything was done to "spec" although I've read that most machine shops air on the side of caution and set the valves deeper (0.020" average) They did say they topped the valve stems to account for valve depth but did not give me specific numbers. I will try contacting again this week.

I also checked lifter preload, at TDC compression, It took 0.098" to bottom the lifters. I checked max plunger travel and got 0.200", so that would give me 0.102" preload. From what I've read this is fairly normal?
Thoughts?

To get proper clearance readings you have to have a pair of solid lifters and a pair of adjustable pushrods. Anything else will NOT be accurate.

From my experience, 0.030”-0.032” piston protrusion, a Colt Stage 2, and valve recession less than 0.020” will run closer than I am comfortable with.

I like to see piston protrusion in the 0.020”-0.024” range and valve recession in the 0.025”-0.028” range with a Colt Stage 2 cam.

 

[alwaysdiesel]

To get proper clearance readings you have to have a pair of solid lifters and a pair of adjustable pushrods. Anything else will NOT be accurate.

From my experience, 0.030”-0.032” piston protrusion, a Colt Stage 2, and valve recession less than 0.020” will run closer than I am comfortable with.

I like to see piston protrusion in the 0.020”-0.024” range and valve recession in the 0.025”-0.028” range with a Colt Stage 2 cam.

Rechecked all measurements:

Piston protrusion checked with dial ind= 0.033"
Valve recession = 0.025"
Head thickness = 3.735"

I've made myself a set of solid lifters using round stock and shims, and bought some comp cams adjustable pushrods. Set pushrods to zero valve lash, and rolled it over. On valve overlap, intake clearance is 0.015", and exhaust clearance is 0.025" at tightest points. So pistons came back out to get machined down. Question is, how much can I take off? Spec is 0.008" minimum protrusion out of deck, but can I run them slightly below deck? I don't care about losing some compression, I just don't want anything touching.
At this point, I can take 0.025" off and be at minimum heigh spec but would prefer to take closer to 0.040" off and increase my intake clearance to 0.055"

 

[Zeb]

Rechecked all measurements:

Piston protrusion checked with dial ind= 0.033"
Valve recession = 0.025"
Head thickness = 3.735"

I've made myself a set of solid lifters using round stock and shims, and bought some comp cams adjustable pushrods. Set pushrods to zero valve lash, and rolled it over. On valve overlap, intake clearance is 0.015", and exhaust clearance is 0.025" at tightest points. So pistons came back out to get machined down. Question is, how much can I take off? Spec is 0.008" minimum protrusion out of deck, but can I run them slightly below deck? I don't care about losing some compression, I just don't want anything touching.
At this point, I can take 0.025" off and be at minimum heigh spec but would prefer to take closer to 0.040" off and increase my intake clearance to 0.055"

Minimum factory spec on piston protrusion is 0.024”.

Geoff at Colt says 0.030” piston to valve clearance is sufficient. I agree, especially with stiffer springs like you have.

I have run 0.015” piston protrusion to get valve clearance where it needs to be and that motor runs just fine, even tho the compression ratio is surprisingly low at that point.

I would take 0.020” off the pistons if I were you.
If you take 0.040” off the pistons, and they are delipped your compression ratio will be under 15/1, iirc.

 

[alwaysdiesel]

Minimum factory spec on piston protrusion is 0.024”.

Geoff at Colt says 0.030” piston to valve clearance is sufficient. I agree, especially with stiffer springs like you have.

I have run 0.015” piston protrusion to get valve clearance where it needs to be and that motor runs just fine, even tho the compression ratio is surprisingly low at that point.

I would take 0.020” off the pistons if I were you.
If you take 0.040” off the pistons, and they are delipped your compression ratio will be under 15/1, iirc.

Thank you for the reply, it's reassuring hearing that number from Geoff as well. I've read in a few places that min protrusion is 0.008", so thats new to me. If I take off 0.020" off the pistons, that will leave me with 0.013" protrusion and bump my intake clearance to 0.035"

 

[alwaysdiesel]

Update

Pistons got milled down, 0.020" got taken off them all. Clearances are now between 0.040-0.050"
Engine is about 75% assembled, waiting for a front cover to come in so I can finish up the the rest of it.
Does anyone own or have the ability to get their hands on a rear main seal installer? I would like some dimensions to make my own since being in Canada there is no easy rental and no chance Im spending $600 to use it a handful of times if that. I have access to a lathe

PM me if can help out.

 

[Zeb]

Update

Pistons got milled down, 0.020" got taken off them all. Clearances are now between 0.040-0.050"
Engine is about 75% assembled, waiting for a front cover to come in so I can finish up the the rest of it.
Does anyone own or have the ability to get their hands on a rear main seal installer? I would like some dimensions to make my own since being in Canada there is no easy rental and no chance Im spending $600 to use it a handful of times if that. I have access to a lathe

PM me if can help out.

I have one. I can get measurements/pictures in the morning.

I’d even risk shipping it to you.

 

[alwaysdiesel]

I have one. I can get measurements/pictures in the morning.

I’d even risk shipping it to you.

That would be amazing if you can get me some measurements! I appreciate you considering shipping it, but I'm probably further ahead to make my own, and have in incase I get my hands on more 6.0/6.4s. The trend is that this won't be my last... haha

Feel free to text the pictures if you still have my phone #
Thanks!

 

[Zeb]

That would be amazing if you can get me some measurements! I appreciate you considering shipping it, but I'm probably further ahead to make my own, and have in incase I get my hands on more 6.0/6.4s. The trend is that this won't be my last... haha

Feel free to text the pictures if you still have my phone #
Thanks!

There is quite a few measurements you are going to need.

I’d be more than game to ship it to you and let you copy it.