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I'm talking to Kip. I also have a few grinds from Tooley in my head. And of course Chris Frank.
Several options on the table using LLSRs:
244/258 113+4 (mild option)
248/262 113+4 (higher peak - could go to a 112+4 to bring it down some at the expense of a more rowdy cam)
255/265 110+4 (a **** ton of overlap)
I'd aim for about .700/.680 on the lifts.
I may tighten up the exhaust some, but Tooley is of the mindset that extending the exhaust duration adds power. Geoff Skinner believes in this as well. Their testing shows this to be the case as well.
But the 248/262 113+4 ends up around 24 degrees of overlap when you take into account the lash of the solid roller and may be the best overall cam. The 244/258 113 is ~20 degrees. Which would be a decent driving cam in a 416.
I would look at your options in valve events instead. It will be easier to see the differences:
An average EVO for a 416 would be 60-65 degrees BBDC, and average EVC would be 8-15 degrees ATDC, average IVO would be 8-15 degrees BTDC, and average IVC would be 48-53 degrees ABDC with EVO and IVC being the two most important points.
The cams I have it down to are the 248/262 113+4 and the 255/265 112+4 (recommended 112 anyway - was trying to push the IVC down).
Events look like this (smaller on left):
IVO 12 16.5
IVC 50 52.5
EVO 65 65.5
EVC 11 13.5
Overlap 23 30
So both fall in the range and both have the same EVO. IVCs are off 2 degrees... and overlap is the difference. The 248/262 113 would probably be everything I need.
The IVC was 48 in Chris Frank's hydraulic cammed 408 example, and it still peaked at 6900 in a Hydraulic application. Pushing that to 7200 or so would be fine with the Solid Roller. Also has similar overlap 23 vs 24.
Tooley is of the mindset that extending the exhaust duration adds power. Geoff Skinner believes in this as well. Their testing shows this to be the case as well.
I would say there are limits to that and those limits are dependent on the exhaust flow you are working with. Obviously, the sooner you open the exhaust valve, the more pumping losses that you eliminate, but you also have to consider the overlap cycle. A very high flow exhaust scenario is going to affect your ovelap timing. If all of your exiting exhaust velocity is spent before TDC, it will have an effect on your cylinder scavenging.
What did your last build make? I'm curious how much you expect to gain from your current setup
I plan to get it on the dyno once I stop traveling for work. Wanted to do it back in April after I got the fuel issues resolved and never found time at the dyno when it was free, and I was available. I do need to go and clean up the tune over 6000 though.
Originally Posted by Know It All
I would still run the LS7 heads. Last time I checked, the LS7 heads were going faster than the LS3 style heads.
Plus I'm pretty sure some people have put the LS7 heads on a 4.070" bore already. The exhaust valve is a little tight, but it still fits and makes really good power with a 4" stroke crank under it.
No. Not when I can run a head with smaller valves, similar port size, and a good bit more CFM... for less money. Though, the LS7 heads are insane and worth it on a 434+ cid motor.
No. Not when I can run a head with smaller valves, similar port size, and a good bit more CFM... for less money. Though, the LS7 heads are insane and worth it on a 434+ cid motor.
The FRH LS3s are serious heads.
I've seen assembled LS7 heads on here for less than $1k. The parts and labor for fixing the exhaust valve issue is less than $500. Further ported (than OEM) they made over 800fwhp on a 4.065" bore.
First, is a 239/247 114+4 Comp LSL cam with TEA Stage 2 Heads, 1.7:1 Roller Rockers, FAST 102, and 1-7/8" Headers on a 408 with 11:1 CR. Power is 620/555 in a pretty mild setup on a SuperFlow 902.
Next is a 427 with 12:1, a 248/262 112+4 Cam with 1.8:1 Roller Rockers, FAST LS3 102, 2" Headers, and TFS LS3 255 heads. Power is 645/580.
There's a difference of 25/25. Some of that is compression and added CID. The rest is probably the cam. I'm willing to bet if the compression of the 408 was 12:1 and it had a slightly larger cam... say 243/251 113 it could close the gap another 15HP or so. Then you have to look at the cost involved. To me, this leads me to trying to optimize my heads and spend the money on the LLSR and the new shortblock vs going to a new head and combo. I've seen solid rollers on these kinds of combos pick up 20-30HP. If I could hit 650 with a 93 octane, solid roller, with the TEA heads I have... yeah.
I hear you there. Those heads you have a very good, and with the right cam and bigger cubes, can still support a lot of power. Have you considered sending them out for some additional work?
I hear you there. Those heads you have a very good, and with the right cam and bigger cubes, can still support a lot of power. Have you considered sending them out for some additional work?
I agree with Phoenix you can always upgrade heads later on after its build on down the road
I agree with Phoenix you can always upgrade heads later on after its build on down the road
It sure doesn't hurt to see how well they will do. If these were any less of cylinder heads, I wouldn't opt to go this route, but the TEA ported heads more than hold their own.
It sure doesn't hurt to see how well they will do. If these were any less of cylinder heads, I wouldn't opt to go this route, but the TEA ported heads more than hold their own.
Talked to TEA today... they do have a Stage 3. Hand blending, updated VJ, and 2.08/1.60 valves. 30cfm increase... while keeping the port size around 229cc.
Is there something wrong with your current motor? If no then why not just put a 150 shot on it and get some use out of your current setup? If I am not mistaken you have just recently got the all the kinks ironed out and the car is running good now no?
07-14-2015, 06:11 PM
