Is my cam pushing it?

[metrogdor22]

I had a custom ground cam recently installed and the specs are 226/240 .637"/.620" 113+4. I wanted something relatively mild to avoid any problems, and I'm wondering if that cam is pushing what I should be running on stock rockers and lifters. The shop that spec'd the cam and did the install is a reputable local shop that does almost exclusively LS engines.

Compare it to a BTR Stage IV for example (233/250 .618"/.596" 113+5) - it has a bit less duration but a lot more lift. BTR also has this disclaimer for that cam: "Lift approaching .650" or more while using stock 15 degree rocker arms with too much open spring pressure can damage valve tips long term. We recommend maximum lift of .630" and maximum open pressure of 400 lbs when using stock rocker arms." The shop also installed BTR .660" platinum springs, which hit that 400lb maximum.

The car drives fine; idles at 750 RPM with only a little surging and only starts to buck below 1500 RPM. Any thoughts from experienced cam guys and gals?

[ecreps]

Originally Posted by metrogdor22

I had a custom ground cam recently installed and the specs are 226/240 .637"/.620" 113+4. I wanted something relatively mild to avoid any problems, and I'm wondering if that cam is pushing what I should be running on stock rockers and lifters. The shop that spec'd the cam and did the install is a reputable local shop that does almost exclusively LS engines.

Compare it to a BTR Stage IV for example (233/250 .618"/.596" 113+5) - it has a bit less duration but a lot more lift. BTR also has this disclaimer for that cam: "Lift approaching .650" or more while using stock 15 degree rocker arms with too much open spring pressure can damage valve tips long term. We recommend maximum lift of .630" and maximum open pressure of 400 lbs when using stock rocker arms." The shop also installed BTR .660" platinum springs, which hit that 400lb maximum.

The car drives fine; idles at 750 RPM with only a little surging and only starts to buck below 1500 RPM. Any thoughts from experienced cam guys and gals?

It's on the bigger side, but I think you're fine. Do you know what lobes it uses?

lots of LS guys running larger cams in stroker motors with more duration and lift on stock rockers. It probably isn't 100% ideal, but it seems to work ok.

[frankwjr]

I recommend upgrading the trunnion's to one of the brass style...other than that should be good.

who spec'd and ground the cam? and who did the tune? peace

[Dbunch9]

You would poop your pants if you saw the cam I'm putting in next week lol

[sixty9fordkiller]

Originally Posted by metrogdor22

I had a custom ground cam recently installed and the specs are 226/240 .637"/.620" 113+4. I wanted something relatively mild to avoid any problems, and I'm wondering if that cam is pushing what I should be running on stock rockers and lifters. The shop that spec'd the cam and did the install is a reputable local shop that does almost exclusively LS engines.

Compare it to a BTR Stage IV for example (233/250 .618"/.596" 113+5) - it has a bit less duration but a lot more lift. BTR also has this disclaimer for that cam: "Lift approaching .650" or more while using stock 15 degree rocker arms with too much open spring pressure can damage valve tips long term. We recommend maximum lift of .630" and maximum open pressure of 400 lbs when using stock rocker arms." The shop also installed BTR .660" platinum springs, which hit that 400lb maximum.

The car drives fine; idles at 750 RPM with only a little surging and only starts to buck below 1500 RPM. Any thoughts from experienced cam guys and gals?

also, the BTR Stage 4 cam specs you referenced will require flycutting on the exhaust valve side of the stock LS3 pistons if the exhaust duration on the cam is 250 and you're using stock LS3 heads

[sixty9fordkiller]

Originally Posted by Dbunch9

You would poop your pants if you saw the cam I'm putting in next week lol

LMAO!!!!!


Let me guess........

Cam Motion LLSR?

[Rich2010]

Originally Posted by sixty9fordkiller

also, the BTR Stage 4 cam specs you referenced will require flycutting on the exhaust valve side of the stock LS3 pistons if the exhaust duration on the cam is 250 and you're using stock LS3 heads

Negative on that, I’m running it now. Stock untouched bottom end, with BTR springs, pushrods, and stock trunions.

[sixty9fordkiller]

Originally Posted by Rich2010

Negative on that, I’m running it now. Stock untouched bottom end, with BTR springs, pushrods, and stock trunions.

What was the ptv clearance?

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[acammer]

Originally Posted by Dbunch9

You would poop your pants if you saw the cam I'm putting in next week lol

Likewise - there are definitely off the shelf grinds that offer even more lift and duration on a tighter LSA that still have acceptable PTV clearance. The GPI stick going in my car this month has more lift that OPs cam, and more duration than the BTR STG4 on a tighter LSA than either of them. Still maintains acceptable PTV clearance on stock heads without the need to flycut.

It's what I would consider a "max effort" without pulling the heads kind of cam that doesn't absolutely shred the valve-train. GPI has a proprietary cam lobe that is designed to work with the stock lifters/rockers and BTR .660 Platinum springs. So - all that said to really say that the cam the OP has isn't a monster stick, and shouldn't be a major concern for tearing up the valve-train - just keep an eye on the springs.

[lazerlemonta]

Roller Rockers are your friends....................

[metrogdor22]

Originally Posted by lazerlemonta

Roller Rockers are your friends....................

Any recommendations on brands?

[lazerlemonta]

i have had good luck with YellaTerra, harland sharp and crower. A non adjustable would be fine for your set up and stick with a stock 1.7 ratio. I use 1.85s and when and if i do a cam i will reduce my lift to accommodate them.

[Rich2010]

Originally Posted by sixty9fordkiller

What was the ptv clearance?

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Had a local, very reputable shop install it so I don’t know. There’s enough that when I’ve bounced the 7000rpm limiter on a few occasions there wasn’t an issue 😬.

[Punisher_ATX]

Low lash solid on Stock Rockers here. Seems okay to me haha