Largest cam w/59cc 243 heads??
Thread Starter
Le Mans Master
Joined: Feb 2001
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From: West "By God" Virginia
CI 7-8-9-10 Veteran
Largest cam w/59cc 243 heads??
I have P&P stage 2 ls6 heads milled to 59cc, and have been thinking about going with a bigger cam. Anyone have experience running big cams with a setup like this? If possible, I would like to avoid flycutting!! Let me know what's out there??
Supporting Tuner
Joined: Sep 2004
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From: ================== Houston, Texas www.englandgreen.com ================== Necessary Evil™ __________
CI 6-7-8-9-10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Keep it under .595 lift and you should be fine.
Stephen
Stephen
Burning Brakes
Joined: Jul 2006
Posts: 968
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From: Regina Sask
Max lift won't affect the PTV, the duration, lobe separation and intake center line does.
I have ported LS6 heads milled to 62 cc with 2.02/1.57 valves, and used GM MLS gaskets.
With the LG G5X3 114 camshaft installed on a 110 intake centerline, I only have .057 intake
PTV and .112 exhaust PTV.
Measure your valve drop at TDC, as most cam manufacturers list the lobe lift at TDC.
Russ Kemp
I have ported LS6 heads milled to 62 cc with 2.02/1.57 valves, and used GM MLS gaskets.
With the LG G5X3 114 camshaft installed on a 110 intake centerline, I only have .057 intake
PTV and .112 exhaust PTV.
Measure your valve drop at TDC, as most cam manufacturers list the lobe lift at TDC.
Russ Kemp
Le Mans Master
Joined: Jun 2006
Posts: 6,979
Likes: 31
From: Wichita KS
Max lift won't affect the PTV, the duration, lobe separation and intake center line does.
I have ported LS6 heads milled to 62 cc with 2.02/1.57 valves, and used GM MLS gaskets.
With the LG G5X3 114 camshaft installed on a 110 intake centerline, I only have .057 intake
PTV and .112 exhaust PTV.
Measure your valve drop at TDC, as most cam manufacturers list the lobe lift at TDC.
Russ Kemp
I have ported LS6 heads milled to 62 cc with 2.02/1.57 valves, and used GM MLS gaskets.
With the LG G5X3 114 camshaft installed on a 110 intake centerline, I only have .057 intake
PTV and .112 exhaust PTV.
Measure your valve drop at TDC, as most cam manufacturers list the lobe lift at TDC.
Russ Kemp
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Pro
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From: Richmond VA
You sir, are a friggin' moron. The man you're mocking knows more about corvettes than everyone you know put together. Perhaps you should do a little research and figure out what the he!! you're talking about before you go making comments on this forum.
Pro
Joined: Mar 2007
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From: Ashland Kentucky
Actually if he knows so much he wouldn't have referenced lift when discussing ptv. That out of the way, yes just flycut. There is no reason to not do it.
Thread Starter
Le Mans Master
Joined: Feb 2001
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From: West "By God" Virginia
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Pro
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From: Ashland Kentucky
You'll hear all kinds of internet wannabe know-it-alls say you can't. But they can't tell you one person who has ever had a piston fail at the flycut. The ringland always goes first. How much you gonna spray? I had no issues with a 100 shot on my .075" flycut pistons on my old car.
Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
I think once you exceed the low to maybe mid 220's on duration you are going to be too tight with those heads. Lobe design will also play a role in the PTV. If you are planning much more duration then that, measure but be prepared to cut (plan enough time in just in case).
Thread Starter
Le Mans Master
Joined: Feb 2001
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From: West "By God" Virginia
CI 7-8-9-10 Veteran
You'll hear all kinds of internet wannabe know-it-alls say you can't. But they can't tell you one person who has ever had a piston fail at the flycut. The ringland always goes first. How much you gonna spray? I had no issues with a 100 shot on my .075" flycut pistons on my old car.
I have a 100 wet shot. I use 1, maybe 2 bottles a summer.
I think once you exceed the low to maybe mid 220's on duration you are going to be too tight with those heads. Lobe design will also play a role in the PTV. If you are planning much more duration then that, measure but be prepared to cut (plan enough time in just in case).
Pro
Joined: Mar 2007
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From: Ashland Kentucky
I had to flycut to use a G5X3 on a 112. 243 castings milled .030. Stock sized valves and GM 3 layer MLS gaskets.
Well, that is to get the recommended min clearance of .080 intake and .100 exhaust.
Well, that is to get the recommended min clearance of .080 intake and .100 exhaust.
Le Mans Master
Joined: Sep 2001
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From: State of Confusion.
You'll hear all kinds of internet wannabe know-it-alls say you can't. But they can't tell you one person who has ever had a piston fail at the flycut. The ringland always goes first. How much you gonna spray? I had no issues with a 100 shot on my .075" flycut pistons on my old car.
As long as you don't get greedy with the juice, you'll be fine. Alot of N20 mishaps happen because of other things. If you're going to spray, make sure you've got adequate fuel to support the extra power and make sure your tune is on the money or the above problems could happen (broken ring lands, burnt pistons, etc.) This mostly happens when using a bigger shot, but in my opinion, you can never be too safe, especially with the cost of parts when/if they break!
Please remember, Everything is good in Moderation!
Good Luck!
Team Owner
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From: At the beach in little Rhody
Personally, I would do the heads first to see where that puts you. I would also closely examine the torque curve you are trying to obtain.
Race Director
Joined: Oct 2002
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From: Gone
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St. Jude Donor '03
And...if those heads were milled down from 64cc to acheive the current 59cc...I don't see any upsize in cam being advisable.
If they were the welded-chamber 59cc Patriots, different story.
Chad, I'd just flycut it and open your options to whatever cam you want.