LETHL 03

iTrader: (4)

I have some 243 port and polished heads that are milled .028" and was wondering if anyone knows what my piston to valve clearance would be? Cam specs are 231/242 .617"/.592" 112+2. I would be running stock head gaskets .051"

Just trying to figure out if I would be ok with such cam or no

black sky

iTrader: (3)

Just from my own experience, I would say that's a little to big for that much mill. I have 243's worked over by AI. They were milled .020 and they suggested something in the area of a 228- 232 or 230-238. Of course type of valve job and a few other factors play in. Your mill is .008 more so that cam might be a tad big. If you haven't installed those heads yet you could always flycut and run whatever size cam you want. Maybe someone else on here who has more experience could chime in also.

LETHL 03

iTrader: (4)

Yeah I'm trying to avoid having to fly cut. Might end up with a torquer V2 cam and measure to make sure it clears before firing up

mikes87ss

I put a set of PRC heads that were cut .017 with BTR stage 3 cam in my 02 TA.I didnt measure for ptv clearance.BTR said it would be close but that I should be ok.Runs like a scalded dog.Installed a ported FAST intake and throttle bodyand it put down 448/400.I'm happy.

black sky

iTrader: (3)

I think comparing a GM 243 factory casting to a PRC casting would be a bad idea. Especially when considering ptv clearance. PRC heads are cast with a thicker deck than 243's from the start. More material to mill from means more PTV. You have to be a bit more mindful of how much you mill 243s because the lack of extra material. Both sets milled to a say......62cc combustion chamber will give very different ptv measurements. To the OP,,,,,that's cool if you are not into flycutting. Well if you are dead set on that cam, I would either consult Brian tooley and get his feelings or clay your heads to see if it hits. I'm going with a new cam motion cam myself and will go through the same process.

henery97

853s with a btr 3 here. Heads were milled slightly just for cleanup and I measured .080" clearance with a stock ls9 hg. I would say you are going to be tight with your 243s milled .028.

ragtopz28

iTrader: (57)

My BTR III fit with a .015 mill. Brian told me the Stage IV would not fit if ANY milling was done, which is why he sent me the Stage III. I did not want to fly cut either.

nskyline34

iTrader: (2)

Not the same cam, but for ref: Stock deck 243 heads, OE head gaskets, 235/240 .629/.615 lift on a 111 LSA and I was at 0.100" and 0.080" on a stock bottom end with 14k miles. I'm approx 0.020" under the "normally accepted" PTV clearance. Car turns 6800-7000 RPM quite often and sees a road course about 20-30x a year...

jtotheizzo

While you didn't say what engine I thought I would add to this info for anyone putting this in an LS2.

I put the BTR stage III in a 6.0 LQ9 with 243 heads (basically an LS2) that are milled .020 with LS9 gaskets. My measured P2v at the closest point in rotation is E= .076 I= .067. I was concerned that this was too close but both the guy who ported and milled my heads and BTR said that this should be fine and that the cam would benefit from the bump in compression. Mind you this didn't come from Bryan himself but one of the people in his shop.

I haven't started the car yet so I can't say but I figured the measurements may be helpful for someone who is going down the same road.

07NBSChevy

iTrader: (1)

I know for sure the Torquer V2 .600 Lift version works with 61cc (milled 0.022") 243 heads. May be a good basis for yours, I do not know how much clearance tho it had. Engine builder, at the time, said I could have got away with 60cc heads as well with that cam.

jalex0858

Wondering how your build turned out...in the process of choosing to mill the heads with the same cam at the moment. Any dyno numers or track times?