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Discussion Starter #1 (Edited)
Putting my combo together and running a little tight on the PTV setup.

Stock, untouched bottom end
TFS170 58cc
Custom cam w/ 73925k2tw springs
1.6 RR
9333pt head gasket (0.047” compressed)

The checking was done with light springs

Exhaust clears by miles, but intake is tight. I did the clay method and dial indicator method.

Degreed cam mulitiple times and within 1/2 degree of where I need to be. Verified all the provided timing events. They are spot on. The fact the exhaust clears by so much makes me second guess this, but it checked out fine

With dial indicator, I reset and performed measurement multiple times and get 0.060-0.065” on my closest approach around 10 ATDC.

Clayed it a few times, and measure around 0.080”. Im testing with the 9333pt gasket but only snugged down, not torqued. Only checked on one piston. Should I check on more?

What should I do here about being 0.015-0.020” less than where I should be. Would deflection with the real springs make that up?
0DA9650B-D97B-4DC3-B1B2-FA95BC0F884B.jpeg
 

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I would run it. Now if you missed a shift and floated the valves, then maybe it would be an issue.
 

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Does your timing set have keyways to allow 2 deg. adv/retard ?
Could play around with the timing events to pick up more clearance.
 

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Discussion Starter #5
Does your timing set have keyways to allow 2 deg. adv/retard ?
Could play around with the timing events to pick up more clearance.
It does not. Just 4 degrees advance/retard. Could certainly buy one.

I’m going to degree the cam again just to make sure. But how much clearance would 2 degrees retarded gain me? Another 0.010”?
 

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Shouldn't be a problem. You would be shocked at how tight we've run some stuff.
 

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I have your exact setup with a Lunati 20350711 cam right down to Ed's valve spring kit you are using (73925k2tw).
Same clearance, .060 to .070 on the intake valves and ultimately decided to run it. Been about 2 years and maybe 2000 miles with no issues. A few spirited 6000 rpm pulls thrown in there.
The intake valve is chasing the piston, so it should be OK. Those springs should keep things in check (valve float etc).
 

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Discussion Starter #8
Thanks, I feel better about this. I’ll still do some checks to make sure before I button it up for good, but everything I’ve been reading suggests I’ll be fine.

Now, if this was an e7 head with tired 150k mile original springs and a new cam coming up with that sort of clearance on the exhaust side.....I wouldn’t be so eager to run it like that.
 

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Putting my combo together and running a little tight on the PTV setup.

Stock, untouched bottom end
TFS170 58cc
Custom cam w/ 73925k2tw springs
1.6 RR
9333pt head gasket (0.047” compressed)

The checking was done with light springs

Exhaust clears by miles, but intake is tight. I did the clay method and dial indicator method.

Degreed cam mulitiple times and within 1/2 degree of where I need to be. Verified all the provided timing events. They are spot on. The fact the exhaust clears by so much makes me second guess this, but it checked out fine

With dial indicator, I reset and performed measurement multiple times and get 0.060-0.065” on my closest approach around 10 ATDC.

Clayed it a few times, and measure around 0.080”. Im testing with the 9333pt gasket but only snugged down, not torqued. Only checked on one piston. Should I check on more?

What should I do here about being 0.015-0.020” less than where I should be. Would deflection with the real springs make that up?
View attachment 1053638
Don't worry about it. I had .065" on my intake valve and .300" on my exhaust. I was worried as well and reached out to Ed Curtis who ground the cam. He wasn't concerned with it. As long as you're degreed properly and have the right springs you'll be fine.
1053758
 
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