Valve to piston clearance

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If a fly cut will fix it, it's not as hard as you probably think. You can easily do it with the engine in the car. Finding the proper size cutter(valve stem diameter, and notch diameter) usually isn't too difficult. Determining notch depth and piston thickness will be the most difficult part.
 
I will definitely look into the valve relief cutting. I think piston dome is +5
 
dartlove said:
I will definitely look into the valve relief cutting. I think piston dome is +5
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If you are not 100% sure how to degree the cam with that gear drive PM me and I'll walk you through it. It's not hard. In fact, it's so easy once you get how to do it, you'll laugh at how simple it is.

BTW, gross or net lift has little affect on V/P clearance. It's valve opening at TDC and just after TDC that makes clearance issues.

I'm betting you are off a bit on cam timing. The Milodon instructions are a bit on the vague side. I was going to do a video on it, but, like lots of other ****, I never got around to it.
 
yellow rose said:
If you are not 100% sure how to degree the cam with that gear drive PM me and I'll walk you through it. It's not hard. In fact, it's so easy once you get how to do it, you'll laugh at how simple it is.

BTW, gross or net lift has little affect on V/P clearance. It's valve opening at TDC and just after TDC that makes clearance issues.

I'm betting you are off a bit on cam timing. The Milodon instructions are a bit on the vague side. I was going to do a video on it, but, like lots of other ****, I never got around to it.
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Yes the milodon/wesmar/shaver/sommers drives aren't as crystal clear as Jesel, ect. Nice of you to offer to help him. It's the whole package as you know. Lift, event timing, piston profile/thickness, ect all play a role. There's usually enough room to play with.
 
Find someone local that can show you how to degree your cam. Or pay a machine shop to do it. I bought a cam degree wheel kit and planned on learning to do it. I mocked my 360 up and couldn't figure out how to degree it. It didn't make any sense to me and I didn't know anyone that could do it. So I assembled it.

To make things worse I timed my engine wrong (long story). The engine spin over by hand no issue without the lifters pumped up (another stupid mistake). So I put it in the car and fired it up! It ran, and I even drove the car but it was REALLY low on power. Ended up having all of the intake valves hitting the pistons and eventually broke one and destroyed my new engine.

Whatever you do, make sure you have proper clearance.
 
yellow rose said:
If you are not 100% sure how to degree the cam with that gear drive PM me and I'll walk you through it. It's not hard. In fact, it's so easy once you get how to do it, you'll laugh at how simple it is.

BTW, gross or net lift has little affect on V/P clearance. It's valve opening at TDC and just after TDC that makes clearance issues.

I'm betting you are off a bit on cam timing. The Milodon instructions are a bit on the vague side. I was going to do a video on it, but, like lots of other ****, I never got around to it.
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You are correct, the milodon destructions are vague. I read them several times but never quite understood. I even bought a DVD from milodon, that I am going to watch again. I really appreciate the help and info. I work out of town so it won't be until next weekend, but I think I will just PM you and get this right.
 
dartlove,
Your location says, northern Ca. where more specifically? I'm considered NorCal too. It would be my pleasure to lend a hand.
 
yeah... you're 2 1/2 - 3 hrs north of me.. too bad. God's country up there!
 
just for info, here's the cutters I mentioned:
Isky Piston Notching Cutters PNT-218

I've done it this way before. It's very time consuming but, you're ensured the 'eyebrows' will be in the correct spot, cause even changing head gasket thickness will change the location slightly.
If your pistons have existing valve reliefs, it's easier to stick the pistons in a piston vise and re-flycut them. I've done both ways.
The problem with these cutters is that they're probably too small for your application, depending on your valve size, of coarse. The relief needs to be at least .080 larger than the valve diameter, the parameter of the relief is as important as the depth.
So, with say a Ferrea 2.14, the Isky cutter will have to be at least 2.22" dia. So there's a limit to their use..
 
My pistons were made to accommodate my heads. Intake 2.190 exhaust 1.760 & cam specs. I had to edit to be specific
 
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OK! with a little faith, the reliefs are positioned correctly.. Once the cam phase has been verified, maybe a little flycut is all you'll need.
But I can't imagine someone cutting a set of pistons without enough relief in them, with those heads in mind... Especially with a 286 roller..
I wish you the best !!
 
You're not in over your head, but here are somethings to consider. You say you're hitting the exhaust valve NOW. Ok, so as Roy pointed out, .100 on the exhaust and .080 on the intake is the norm minimum. So, if you're hitting on the exhaust now, you're obviously going to need MORE than the .100 minimum. So yeah you see you're out of gasket territory as far as being able to fix that. How much is anybody's guess. First thing "I" would do is pull it down and find out how thick the piston tops are in the area of the valve reliefs.

There's no sense in finding that info out first without a tear down, because that's what you gotta do to fix it. So get busy with that.

Man like Roy said, that's a LOTTA cam! lol

I'm not sure I wouldn't prep another block. It's always an option. That mess would always be in the back of my mind.......no offense.
 
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SGBARRACUDA said:
You need a clearance of .080 intake and .100 on the exhaust. No way your going to do it with head gaskets. You need to fly cut the pistons. If you have enough material.
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^^^^^^^^^ and , if u do it w/ head gaskets , ur going to lose ur quench, making the engine need higher octane ----
Ur duration has a lot to do with the timing events in the engine too , like rrr said , tear it down , unless u got the cam timing way the heck off !
 
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dartlove said:
My pistons were made to accommodate my heads. Intake 2.190 exhaust 1.760 & cam specs. I had to edit to be specific
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Who made the pistons? Part #? maybe a pic?
Your cam is about in the middle of the road, when it comes to racing applications. Nothing unusual there.. I been around cams much bigger than that.
I don't see the reason to re-invent the wheel, without knowing what we have first.
 
dartlove said:
This is my first build of this magnitude. First time using milodon gear drive. (Still don't quite understand) . Thought I had it. When I did the clay neither valve touched. Also wasn't quite getting valve lift on intake according to cam card. It wasn't until I put all together prime and rotate that I run into problems.
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Those gear drives can be tricky to setup. There are no dots like a chain to get you in the ballpark. Your comment that you had clearance the first time is telling.
Re study the instructions on how to setup the drive. Make sure you understand how to do it. When you get it right you may be ok for clearance.
Here's a link for you to read on the milodon drive setup.
Installing a Milodon Gear Drive on a Big Block Chevy - OnAllCylinders
 
dartlove said:
Pistons were made by race tech. I will have my son look for the info .
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Like I said, PM me when you are ready and if need be I can call you and walk you through degreeing a cam with a gear drive. It's actually easy once you get the hang of it.

BTW, I know engine builders who have been at it for decades who can't degree a cam with a GD.
 
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