2007 CTS-V Build Thread..nothing new but new to me.
#281
What attracts me the most is the promise of good idle quality and better drivability even with big nasty cams. If I'm reading correctly, without the large plenum area of the typical single TB intakes, one can run cams usually reserved for the carb setups..like 250s duration and 106 LSA.
I'm not jumping right in to the deep end of that pool but am looking forward to seeing how it runs with the new bigger cam I decided on. Was about 225/235 (116+4?) and now 233/246 113+3. This cam should at least make more noise even if it doesn't make any more power.
#284
Dibs on FAST recorded. Note that I am an incurable parts hoarder. Just because it doesn't perform as well doesn't mean I won't try to convince myself to keep it for some non-existent future project.
#286
A little eye candy. These should flow a *little* bit of air. Gigantic compared to the stock cathedral stuff.
Here's a head on with a used LS2 gasket. Checker springs installed on #1 and valve drop(from closed to touching piston) @ TDC is .184" intake and .226" exhaust. This is because the intake valve is so much larger(2.165") than the exhaust(1.59"). Kip @ Cam Motion was nice enough to come over to my little sweat shop and show me the basics of the degree wheel and then how to find true TDC and check valve drop.
Here's a head on with a used LS2 gasket. Checker springs installed on #1 and valve drop(from closed to touching piston) @ TDC is .184" intake and .226" exhaust. This is because the intake valve is so much larger(2.165") than the exhaust(1.59"). Kip @ Cam Motion was nice enough to come over to my little sweat shop and show me the basics of the degree wheel and then how to find true TDC and check valve drop.
#287
Kip was also kind enough to run the numbers for me since I don't have near long enough pushrods to run the thing all the way around and truly check PTV. First pic is -9 degrees, second 9 degrees.
Exhaust clearance is .0828 and intake is .0440. This I would likely check again once final assembled and still run(if I were happy with 10.4:1 compression) but I want to be over 11:1 compression.
I am currently aiming for Cometic C5751-040(4.060" bore, .040" thickness) and about a .024" mill on the heads to bring those down to 64cc from 68cc and give me about .035" quench cold. With the expansion of the Al block, I think this will give me a (safe?) quench of around .038"-.040" hot.
I'll be fly-cutting about .040" I guess. Ordered the cutters from Lindy.
In CM's calculator(free for Windows on their website) I'm looking at 11.49:1 which should make some real nice power.
Exhaust clearance is .0828 and intake is .0440. This I would likely check again once final assembled and still run(if I were happy with 10.4:1 compression) but I want to be over 11:1 compression.
I am currently aiming for Cometic C5751-040(4.060" bore, .040" thickness) and about a .024" mill on the heads to bring those down to 64cc from 68cc and give me about .035" quench cold. With the expansion of the Al block, I think this will give me a (safe?) quench of around .038"-.040" hot.
I'll be fly-cutting about .040" I guess. Ordered the cutters from Lindy.
In CM's calculator(free for Windows on their website) I'm looking at 11.49:1 which should make some real nice power.
Last edited by Mercier; 10-20-2016 at 05:35 PM.
#291
Well we are fly-cut. Made lots of scary sounds and had me sweating it until I was done but it turned out pretty good. I started the first piston with the one of the cutter tips sitting on the piston so it was positioned further up. The others I started with it sitting on the piston in between cutting points, so a little further down when I set the stop. Basiclaly piston #1 is about a .060" relief and the others .080" but I'll even that up tomorrow or so by just cutting another .020" on the first one.
Dipped the stems in a bottle of oil each time I moved them from one cyl to the next, vacuumed as I went, and oiled the cutter head and piston with WD40 as I went. Turned out better than I thought but I think with more patience and experience, it would be even a little smoother.
I did position the pistons at about 9 degrees below TDC(very slightly down in the bore - maybe .040") when cutting which is where max interference is.
Dipped the stems in a bottle of oil each time I moved them from one cyl to the next, vacuumed as I went, and oiled the cutter head and piston with WD40 as I went. Turned out better than I thought but I think with more patience and experience, it would be even a little smoother.
I did position the pistons at about 9 degrees below TDC(very slightly down in the bore - maybe .040") when cutting which is where max interference is.
#292
Ended up ordering Fel-Pro MLS 4.100", .041" head gaskets:
https://m.summitracing.com/parts/fel-1161l041
And the heads are at the machine shop being milled .025" to get me down around where I want. Will cc after and report back. I hypothesize that the accepted .006/cc formula for cathedral port heads is more like .005 or less for rectangle port heads, at least for the first .010-.015 since the chambers are wider and taper in a bit. So my guess is that .015" will take about 3cc off and the next .010 will take another 1.5cc.
In the end, we will be .025" closer from the milling and .010" from the gasket so .035" closer and .080" reliefs. Should give me room for when I want to try a donkey-d!ck cam with that ITB intake.
https://m.summitracing.com/parts/fel-1161l041
And the heads are at the machine shop being milled .025" to get me down around where I want. Will cc after and report back. I hypothesize that the accepted .006/cc formula for cathedral port heads is more like .005 or less for rectangle port heads, at least for the first .010-.015 since the chambers are wider and taper in a bit. So my guess is that .015" will take about 3cc off and the next .010 will take another 1.5cc.
In the end, we will be .025" closer from the milling and .010" from the gasket so .035" closer and .080" reliefs. Should give me room for when I want to try a donkey-d!ck cam with that ITB intake.
Last edited by Mercier; 10-24-2016 at 10:27 PM.
#296
Most of the bigger chunks fell in the engine. That's what the filter is for right?
That pic must have been after I vacuumed off some of the bigger bits...or one where most of the bits stuck to the head. It is a mix; larger shavings at first, and then when you get to the bottom of the cut and speed up the drill, smaller pieces.
That pic must have been after I vacuumed off some of the bigger bits...or one where most of the bits stuck to the head. It is a mix; larger shavings at first, and then when you get to the bottom of the cut and speed up the drill, smaller pieces.
Last edited by Mercier; 10-25-2016 at 03:57 PM.
#300
New, even bigger solid roller from Cam Motion to take advantage of the ITBs..
238/250 @ 110LSA. This will be interesting. This cam would fall on its face in a big car with a FAST and single big TB.
As Steve pointed out, 23 degrees overlap. The ITBs should settle it down idle-wise but I am interested to see what it smells like.
238/250 @ 110LSA. This will be interesting. This cam would fall on its face in a big car with a FAST and single big TB.
As Steve pointed out, 23 degrees overlap. The ITBs should settle it down idle-wise but I am interested to see what it smells like.