I'm thinking about ordering the G5X3 with a 113 LSA. This will be installed with stock LS6 heads on a Z06. Later on I plan on AFR heads.

I've heard from a few people (even LGM) that the G5X3 with a 112 LSA will work without flycutting pistons, but it's very close....almost too close. How much clearance would I lose by going with a 113 LSA vs. a 114 LSA? Or better yet, how much clearance would I have with the 113? I haven't been able to talk with Lou about this yet because he's on the road racing.

 

Too close for comfort. With such a big cam, I would give it all the room it needs.

 

I'm running it on a 112, WITHOUT flycutting. It WILL work...you might want to measure, and remeasure again, but FLYCUTTING IS NOT NECCESSARY...although there are many people on this board that will tell you otherwise...Now if you end up milling the heads later on down the road, then hell yes, you better cut.

 

What was the value of your PV clearances?
Int
Exh

 

g5x3 114 lsa no milling works fine. i got it. i havent had the money to get it tuned right so im not happy yet. we will see

 

EDIT...I was able to find the old post when we measured the valve drop.

https://ls1tech.com/forums/showthrea...light=g5x3+112

Good question, I wrote them down on the box that my heads came in and I have since then thrown it away...I've had the cam in for about 8 months now, so I do not recall the exact values...FWIW...it was real damn close, but it was within the tolerance that Lou gave me, and that was good enough for me. We used the clay method, and could not come up with a good # so then we used the valve drop method. If I remember correctly I think Lou said he recommened at the very least .070 clearance (please correct me if my decimals are not in the right places, I'm too good with this math ****), which would mean we we would be good with .030 valve drop. I'm thinking we were at about .021 or .020 which would have left a safe clearance of .080. I then called Lou back with my measurements and he told us that it would be safe. (Now this is to my recallection, so if I'm spouting off wrong #'s here then I apoligize, please check with Lou for your application, he is very helpful on the phone)...Also I think we oly measured one side...I can't remember if it was exhaust or intake, but it was the one that Lou recommended...I'm almost positive that it was the exhaust side, since it had the higher lift.


DISCLAIMER CHECK YOUR **** 1ST DON'T JUST TAKE MY WORD FOR IT...THESE ARE JUST MY EXPERIENCES. MY EXPERIENCES ARE NOT THE GOSPEL FOR THE X3 CAM...I'VE JUST SEEN A LOT OF INCORRECT INFO FLOATING AROUND ABOUT THIS CAM AND HAVING TO FLYCUT. I THINK IF THE CORRECT INFO WAS OUT MORE PEOPLE WOULD BE RUNNING THIS CAM.

Matt

edit...to correct my numbers...here is the post back from Jan-Feb, were I posted the original valve drop #'s....
https://ls1tech.com/forums/showthrea...light=g5x3+112

 

TTT for my edit!

 

What is flycutting? Sorry to sound like such a newb, thanks

 

Flycutting is actually putting notches in your pistons so that you have enough room for a big cam, so the valves won't hit the pistons.

 

Thanks WS6snake-eater

 

He told you .07 was Ok? I would call that extreeme limit and not on a DD.
0.1 should be a minimum without playing with a time bomb, one miss-shift or overrev and the motor is toast.
IMO that is pushing the envelope.

 

Like I said I don't recall the exact #'s...I did post them here back in Janurary or February...I'm going to do a search and see if I can find them. I think the #'s that I quoted in my previous post are wrong.

 

https://ls1tech.com/forums/showthrea...light=g5x3+112


Here is a link to the clearance we had....I'm going to go back and edit my original post...sorry for the mis-information, and thanks for picking up on it. Also BTW I think the reason he said that .07 was ok, was beacause he knew I was running an A4 and would not be able to over-rev.

 

https://ls1tech.com/forums/showthrea...light=g5x3+112

In post #16 WS6snake-eater says he had 0.210" clearance.

 

Thanks torch...I went back and read that post...and edited. my #'s above...

 

Hey Predator-Z....are you running this cam? Just curious if you are, if you would like to swap some tuning info?

 

Nope, that is a great cam only provided your bottom end can take it but a bit too radical for me.
I'm in the "small" category. LOL...

From what I read around, a mail order tune by LG is a good base to fine tune it to your application. The reason being Lou doesn't release the specs and makes it more difficult to get the right parameters to tune.
Best of all would be to dyno tune at LG of course.

 

Yeah I've got my tune pretty much nailed down..I was just looking for something to compare to.

 

So if a customer was to doctor the cam, then it wouldnt be a problem for a competitent tuner? Didnt LG give the specs to the G5X3 to some people that bought it?

 

You need ~ 200 thou plus VALVE DROP. Search Valve drop and you will find may posts about it. I am simply clarifying what WS6 Snake eater said.

we have run them as tight as .055 before on extreme applications. the T Rex cam is right at ~ .070 clearance which is fine, as is anything more than that.


Now, if you are running through the gears, and grab 2nd instead of 4th, dont expect any cam to have enough clearance.

Hope that helps.

Louis