xfactor_pitbulls

iTrader: (16)

Well I have done the calcs for my clearances and it appears I am going to lose .0239" from going to the 2.05" intake valve. I am trying to get the compression up as much as I can due to the fact I deshrouded the combustion chamber pretty agressively to help with low/mid lift numbers. Right now I will flycut if I cant get to my 11.2:1 goal with a .040 gasket and some mill if any. Anyway my exact specs are 228/232 .578/.584 114+4. Does anyone out there have a pretty closely speced cam and their exact PTV measurements laying around. How about anyone that had a G5X1, pretty damn close to that one.

Brandon

bigdsz

iTrader: (1)

I'm in the process of a CC xer 228/230 .588/.591 112+2 and I have to notch the pistons. This is with AS 5.3 heads, 2.02 intakes not milled. I only have .045 clearance at 8-10 ATDC. Hope this helps

xfactor_pitbulls

iTrader: (16)

I appreciate the reply. However that doesnt sound right. What gasket are you running? .045 clearance with that size valve and unmilled just doesnt seem right. I dont disbelieve you, but are those verified numbers or what a shop told you?

Thanks

Brandon

bigdsz

iTrader: (1)

Jay at AS liked to hang the intake valves out on the edge of the seat, this is one of the ways he got such good flow. The cam is in and it has been degreed. Yesterday I clayed the #1 intake, it clearly indicated ~ .045 clearance. Also prior to this I came up with a method that appears to be fool proof to mechanically measure P/V clearance. I took the distance from the intake valve to the head deck, this measured .125, compressed graphite gasket thickness .052 is added to make .177. Set up your dial indicator on the rim of the #1 intake lifter while it is on the base circle zero it out .Turn your degree wheel to 10* ATDC where the piston is closest to the valve and take a measurement of lobe lift inmy case it was .094, the multiply that by the rocker ratio of 1.7 and that gives you valve lift of .160. Now deduct the.160 from the .177 head/gasket clearance and you are left with .017, to which you must add the distance the piston is in the hole by measuring with a feeler gauge, in this case it was in the hole .025, adding that to th .017 you come up with closest P/V clearance od .042. The only oter adjustment to be made is tha the valves a angled 18* of the perpendicular to the piston which requires a 3% correction factor. In my case it adds.001+fora a total of .043 clearance.This method seem to be idiot proof, what do you think?

xfactor_pitbulls

iTrader: (16)

Well, I do appreciate you giving me your method to figuring PTV. Stll though look at the specs of different cams out there and what measurements people have gotten. I just have to wonder how off people are when they arent actually claying. I had kinda planned on flycutting anyway, this just sets the nail in the coffin. Oh well I guess I will cut .080 and go for 11.5:1

Thanks

Brandon

bigdsz

iTrader: (1)

Finally, I'm getting my pistons notched tomorrow. I'm going for .050 on the intakes and .025 on the exhausts. Another guy and I were prepared to do it ourselves, but the guy that owns the Isky Tools and 1/4 head is going to do it. This way i'm more confident there will be less chance of a screw up. Now I wish I'd gone for a bigger cam.

xfactor_pitbulls

iTrader: (16)

Sell it, get a different one. Alot of these guys change cams several times a year. Dont forget someone is always looking for your spec cam. Actually I would think your specs are pretty appealing to alot of people nowadays.

Brandon

bigdsz

iTrader: (1)

Good advice, but I just want to get the car back on the road it's been down for a month and a half. Terry at Racetech is making me some +.025 titanium retainers so my 978 springs won't be too close to coil bind, when I receive those I'll be good to go. FWIW Terry really knows his heads etc.

xfactor_pitbulls

iTrader: (16)

Well I hope your setup works out well. Who nows though, you could post that cam for sale and have it sold in a few days, then have another one in another few days. Either way I bet you make great power.

Brandon