Max effort LS7 Cam suggestions needed
05-31-2013, 01:00 AM
#42
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Mast heads are awesome heads on big bore motors due to the nature of their huge intake runners, you'll need something like the PRC 265 heads with TI valves. Otherwise.. Port your stock casting heads and bump up the compression to 11:5 with full bolt ons and the right cam, you are over 600rwhp
06-04-2013, 11:47 PM
#43
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Fast102 with NW 102 TB
1 7/8 ARH
Akrapovic KB
MAST 305 heads 68 cc
06-05-2013, 08:39 AM
#44
You can achieve a lot with the stock castings. I've seen some aftermarket heads actually make less power than ported LS7 heads due to the heavy stainless valves in some aftermarket heads. I would run titanium intake valves in whatever heads you choose. If the valve train isn't stable at higher rpm's then you'll never achieve the power that you expect.
06-06-2013, 07:44 PM
#47
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Trying to decide on heads/cam as well. I had a QM 600 in my last z06 and it lost too much power down low. Then I did a big LG cam and heads package that made 600whp and trapped 138 in Texas heat. I don't do any drag or highway stuff anymore. Mainly street driven with 6-8 HPDEs a year.
Bought a spare set of ls7 heads. Trying to decide between Richard at WCCH or Darin Morgan to port the heads. opinions?
Also, was thinking of the 231/247 comp cam. I really dont want to give up power down low as 95% of the car's life is on the street. Heck, the only reason I bought another z06 was because I missed the torque. Was going to do the BT spring package. Maybe I will buy a cam from Brian as well.
edit: hope TS doesnt mind me posting in his thread since it's on topic
Bought a spare set of ls7 heads. Trying to decide between Richard at WCCH or Darin Morgan to port the heads. opinions?
Also, was thinking of the 231/247 comp cam. I really dont want to give up power down low as 95% of the car's life is on the street. Heck, the only reason I bought another z06 was because I missed the torque. Was going to do the BT spring package. Maybe I will buy a cam from Brian as well.
edit: hope TS doesnt mind me posting in his thread since it's on topic
Last edited by kumar75150; 06-06-2013 at 07:49 PM.
06-07-2013, 03:19 PM
#50
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I loved it so much, I sold it and he built me another one:
https://ls1tech.com/forums/generatio...8ci-build.html
https://ls1tech.com/forums/generatio...8ci-build.html
06-07-2013, 04:55 PM
#51
Trying to decide on heads/cam as well. I had a QM 600 in my last z06 and it lost too much power down low. Then I did a big LG cam and heads package that made 600whp and trapped 138 in Texas heat. I don't do any drag or highway stuff anymore. Mainly street driven with 6-8 HPDEs a year.
Bought a spare set of ls7 heads. Trying to decide between Richard at WCCH or Darin Morgan to port the heads. opinions?
Also, was thinking of the 231/247 comp cam. I really dont want to give up power down low as 95% of the car's life is on the street. Heck, the only reason I bought another z06 was because I missed the torque. Was going to do the BT spring package. Maybe I will buy a cam from Brian as well.
edit: hope TS doesnt mind me posting in his thread since it's on topic
Bought a spare set of ls7 heads. Trying to decide between Richard at WCCH or Darin Morgan to port the heads. opinions?
Also, was thinking of the 231/247 comp cam. I really dont want to give up power down low as 95% of the car's life is on the street. Heck, the only reason I bought another z06 was because I missed the torque. Was going to do the BT spring package. Maybe I will buy a cam from Brian as well.
edit: hope TS doesnt mind me posting in his thread since it's on topic
I have a line of torqueMAX cams for the LS7 now as well. They follow the same guidelines as our ever so popular cathedral port head TorqueMAX camshafts do if you're worried about power under the curve.
IMO the larger the split from I/E in duration and the wider the LSA the more power you're going to lose under the curve. If that is your goal, I wouldn't suggest a large I/E duration split unless it has a fairly tight LSA.
06-07-2013, 06:14 PM
#52
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06-07-2013, 07:55 PM
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Darin Morgan.
I have a line of torqueMAX cams for the LS7 now as well. They follow the same guidelines as our ever so popular cathedral port head TorqueMAX camshafts do if you're worried about power under the curve.
IMO the larger the split from I/E in duration and the wider the LSA the more power you're going to lose under the curve. If that is your goal, I wouldn't suggest a large I/E duration split unless it has a fairly tight LSA.
I have a line of torqueMAX cams for the LS7 now as well. They follow the same guidelines as our ever so popular cathedral port head TorqueMAX camshafts do if you're worried about power under the curve.
IMO the larger the split from I/E in duration and the wider the LSA the more power you're going to lose under the curve. If that is your goal, I wouldn't suggest a large I/E duration split unless it has a fairly tight LSA.
a popular grind for the road race guys is the Katech Torquer: 220 244 on a 110lsa. so im thinking the 231 247 on a 113 is in the ballpark for what i should be looking at.
06-08-2013, 04:38 PM
#55
Typical Intake Valve Close point for a LS7 427 with 270-280cc port volume and a 2.200" valve will be around 50-52 degrees ABDC. That means the piston is almost 1/3 of the way back up the bore on the compression stroke before the cam is at .050" lift, which is .090" at the valve. The same engine using 245cc cathedral port heads with 2.10" intake valves may stand a IVC of 54-56 degrees ABDC, and with 305cc heads using 2.250" valves it may want a IVC of 47-49 degrees.
The smaller the port volume and valve diameters are, the longer the port will exhibit forward flow during the intake cycle (compression stroke), and vice versa. Larger ports and valves will exhibit less velocity, so therefore the forward flow of air will stop sooner in the cycle, which requires closing the intake valve sooner as to not loose too much average power.
It's difficult to gain top end power using larger heads on a engine when using a long runner EFI intake like the stock LS7 or Fast, but it's very easy to lose low end torque as the heads get larger.
If larger heads were the key to making more power, then all LS3 and LS7 heads would make more power than all of the cathedral port heads. But when you look at back to back head testing like the Hot Rod cathedral port head shootout, you see the largest heads did not make the most power.
The smaller the port volume and valve diameters are, the longer the port will exhibit forward flow during the intake cycle (compression stroke), and vice versa. Larger ports and valves will exhibit less velocity, so therefore the forward flow of air will stop sooner in the cycle, which requires closing the intake valve sooner as to not loose too much average power.
It's difficult to gain top end power using larger heads on a engine when using a long runner EFI intake like the stock LS7 or Fast, but it's very easy to lose low end torque as the heads get larger.
If larger heads were the key to making more power, then all LS3 and LS7 heads would make more power than all of the cathedral port heads. But when you look at back to back head testing like the Hot Rod cathedral port head shootout, you see the largest heads did not make the most power.
06-08-2013, 06:04 PM
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WCCH has done the most by far. Seen two guys with Darin's heads that picked up power over WCCH heads but that could just be a fresh valve job. I had Advanced Induction heads on my last z06. Seemed to do well. LMR just came out with their CNC program. It seems to me that all ls7 heads are within 15 hp of each other.
07-09-2013, 10:20 AM
#57
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I'm thinking about going solid roller on my ls7 build after reading about John_B's monte. Does anyone have any information/links about what needs to be reworked/machined for a solid roller set up? just so i can understand what all goes into it.
07-09-2013, 10:35 AM
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You may also ask Patrick G for his input on the Ls7 cam.
07-09-2013, 10:42 AM
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I am just finishing the build of a solid-lifter 451 cubic inch LS engine.
I am using Isky's lifters - 937K150EZMAX and bushings - KLB-937. By going with a solid lifter camshaft, you have the opportunity to use the .937 inch lifters, which are preferred by top NASCAR engine builders. The .937 lifter will also give your camshaft manufacturer more latitude in designing his ramps.
Here are three pictures of the ISKY .937" EZ MAX solid lifter:
The EZ MAX lifter does not use needle bearings. It is built with a high load bushing for improved durability and load carrying capability.
Please note the offset pushrod location. These lifters offset the pushrods 0.150" outboard for both the intake and exhaust. This allows the use of 7/16" tapered pushrods for improved valve train stiffness.
The final picture shows the locating tab on the body of the lifter. These tabs keep the lifter aligned in the bushing.
Good luck with your decision.
Last edited by Pumba; 07-16-2013 at 12:51 AM.
07-15-2013, 12:28 PM
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Gentlemen,
I posted earlier that if you choose to use solid roller-lifters you can use the preferred .937 inch size.
Two other benefits are the offset you can build in the .937 inch lifters. The following is a picture shows the lifter-pushrod assembly, with 0.150-inch offset for both intake and exhaust:
The advantage of being able to offset your pushrods outboard are two:
1) Your pushrods will clear the intake ports on the better, high-flow cylinder heads.
2) You can spec and install larger diameter pushrods.
The next picture shows a comparison of a 7/16", a 5/16", and a 3/8" pushrods.
I am using the 7/16" pushrods shown in the above picture. These pushrods are significantly stiffer than either a 5/16" or 3/8" pushrod. This added stiffness adds to valve train stability and accuracy.
I posted earlier that if you choose to use solid roller-lifters you can use the preferred .937 inch size.
Two other benefits are the offset you can build in the .937 inch lifters. The following is a picture shows the lifter-pushrod assembly, with 0.150-inch offset for both intake and exhaust:
The advantage of being able to offset your pushrods outboard are two:
1) Your pushrods will clear the intake ports on the better, high-flow cylinder heads.
2) You can spec and install larger diameter pushrods.
The next picture shows a comparison of a 7/16", a 5/16", and a 3/8" pushrods.
I am using the 7/16" pushrods shown in the above picture. These pushrods are significantly stiffer than either a 5/16" or 3/8" pushrod. This added stiffness adds to valve train stability and accuracy.