Building an LQ9 with 243 heads and using a Tick SNS stage 3 cam with the milder lobes. Has anyone ran this combo and checked PTV clearance? I'm thinking about sending the heads out and having them CNC. Not sure how much they will flat mill them, just don't want to run into any trouble.

 

Nobody has ran this combo?

 

Hi, I can help by using EAP.

I would need the cam specification, a Cam Doctor/Andrews lobe file.

Lance

 

I'm sure someone has ran it before, but no two setups are going to be exactly alike. The best way, and only way to know is to check for ptv clearance yourself. Just like pushrod lengths, the only way to know for sure is to measure your own setup. It's a pain, but if it's worth doing, it's worth doing right.

 

Do you have the LS1 SNS3 (234/242 | .61x"/.61x" | LSA111+2)?
or
Do you have the LS2 SNS3 (238/242 | .61x"/.59x" | LSA111+3)?

Either way, I would not recommend that you mill the heads at all with either of these cams. They are both pretty tight of piston-to-valve clearance.

 

I understand it needs checked, was just hoping someone has measured it before with this combo. Just seeing how close it is. Just gone to clean up the heads a little maybe
010.
Tick has the cam as 238/242. Lift they have 61x and 59x so not actually sure the last number. LSA 111+3

 

Yep, the LS2 version.

 

That camshaft is very tight on the intake side. I think you will find about .035"-.045" of intake valve to piston clearance on an LQ9 with stock heads.

 

When you say stock heads are you talking about the 317 heads or 243? That sounds pretty tight. Should I not run them?

 

Either of those heads will have the same piston-to-valve clearance if they are not modified from stock. While the 243s have smaller combustion chambers, the valve locations are the same.

Lots of guys are running those cams without issue. With that said, I would not reduced the piston-to-valve clearance any further.