Getting Bored need something more...

[j o n]

Originally Posted by frenchsquared

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Why are shops so dead set against installing a cam in a LS7 and not spending $5,000 in the heads? I really don't want to do the heads at this time. There is a big different in a $2,500 cam and tune VS a $7,200 cam and heads package. After the headers I'm at $10,000.

I thought the LS7 in the Z28 did not have the valve issue?
Has anyone done just a cam?

Yes, LS7 is great for cam only (my brother did cam only in his c6 z06 and was at 550 hp to the tires). The heads flow great and support an upgraded cam. However the valve guides are questionable. You can get them changed out in your current heads for durability sake. Easy enough testing can be completed to asses your current status. Given your high track miles it is only wise to get them tested and taken care of if need be.

[SSEssence]

For 10k, wouldn't it be more cost effective to add a blower?

[j o n]

Originally Posted by SSEssence

For 10k, wouldn't it be more cost effective to add a blower?

Blower = heat/cooling issues and weight

Still have potential head reliability with valve guides

[frenchsquared]

Originally Posted by SSEssence

For 10k, wouldn't it be more cost effective to add a blower?

Blower makes to much heat and makes the car useless on 105 degree track days. Even the ZL1 and Z06 over heat and go into limp mode ever 4 to 6 laps. I bought the Z28 because it doesn’t need a blower to reach 600hp. Very few people really understand blowers on heavily tracked cars.

[pat_t]

Originally Posted by frenchsquared

Back to more useful talk...

I thought the LS7 in the Z28 did not have the valve issue?
Has anyone done just a cam?

I just have cam, headers, full Titanium valvetrain and tune. Redline Motorsports in Florida (sorry nowhere near you).

578rwhp, 511rwft-lb. Cam specs are on page 1 of my thread.

FWIW I have never had issues with wheel hop on trackdays or 1/4mile or standing mile race events. I think you know I drive my car hard like you do

Interested to see what you do next.

[frenchsquared]

Originally Posted by pat_t

FWIW I have never had issues with wheel hop on trackdays or 1/4mile or standing mile race events. I think you know I drive my car hard like you do

Interested, my hope is terrible. Cool mornings on cold tires you have to pay attention just driving around or it hops in 1st and 2nd gear. I wonder if something might be wrong on my car. Or if the alignment is contributing.

[Livernois Motorsports]

Hey guys just wanted to show you an installed package we do that will put you around 600rwhp. We usually see on our dyno between 580hp-610hp to the ground. Now we are not local to you as we are in Michigan right outside the motor city but we do offer transport also. Also we can make it faster as well but I know you were saying you wanted 600 to the ground.Please contact me back with any questions. My number is 313-561-5500 ext 126 my name is Jake. Thank you and here is the link. https://www.livernoismotorsports.com/product/LPP0108519

[aris]

Originally Posted by frenchsquared

Yes, thats about all I do with the car.

personally I wouldn't do a cam and long tubes without addressing the valve guides in the heads. If you're at it, why not do the heads as well? Cheaper than dropping a valve at the track and blowing the motor.

[pat_t]

Originally Posted by aris

personally I wouldn't do a cam and long tubes without addressing the valve guides in the heads. If you're at it, why not do the heads as well? Cheaper than dropping a valve at the track and blowing the motor.

I'm gonna respectfully disagree.

1) I think GM have sorted the heads on Z/28s since the original LS7s in Corvettes.

2) The cam and headers doesn't really stress the valvetrain a lot more. If anything you rev the engine a bit less with the additional torque most of the time. I'm staying in 3rd gear out of hairpins at 3-4k revs, wherein a standard car with 450rwhp I'd probably drop it down to 2nd and be revving it 6-7k and wearing the engine out faster!! Likewise you get closer to the traction limit of the tyres with the extra torque sometimes, so you short shift going up which is also stressing the engine less.

Just my 2p - but I do design engines for my day job

[j o n]

If you're a car dealer and able to move your current z/28 and work well with other dealers...

This is smokin15's previous car with mast heads, cam, mad intake, nick Williams 102, built by vengeance. Less the 3k no on car. $48k asking price
https://www.autotrader.com/cars-for-...lerId=68860933

[MX621]

Originally Posted by pat_t

I'm gonna respectfully disagree.

1) I think GM have sorted the heads on Z/28s since the original LS7s in Corvettes.

There is no evidence gm did anything differently on our engines. Do enough research on the corvette forums and you will find this is not the case. Nothing changed, Plenty of cases later ls7’s with guide issues/dropped valves. Gm claimed to have went to 100% inspection at some point, but ls7’s still have the problem. I bought my Z/28 100% knowing I need to address the heads. I’m not here to argue, ive just not seen any evidence the problem is solved on the z/28 ls7’s.

[z28rox]

Had mine done at Wyospeed your pricing is a tad off...I have about 10k parts, labor and dyno. Super conservative tune since is all I do is track the car. 560WRHP. Mast 305cc Heads, MSD Intake, Cam Motions custom cam (spec'd by Mast), I had purchased the American Racing Headers (no cats) previously so those are not included in the 10k build. Car is for sale $45k. 7000 miles.

[Livernois Motorsports]

Originally Posted by frenchsquared

Back to more useful talk...

Why are shops so dead set against installing a cam in a LS7 and not spending $5,000 in the heads? I really don't want to do the heads at this time. There is a big different in a $2,500 cam and tune VS a $7,200 cam and heads package. After the headers I'm at $10,000.

I thought the LS7 in the Z28 did not have the valve issue?
Has anyone done just a cam?

Ok check this link out https://www.livernoismotorsports.com/product/LPP0108518 our standard price is $3150 with no head work. There is almost no difference in the early 7L and the later ones as far as heads go. So doing the guides and being proactive is not a bad thing. We can do this package and include pulling the heads, installing valve guides, valve job, mill and finish in the $4K range. I think its smart to at least talk about doing this while your getting work done. Its minimal when we have it apart.

Let us know we are happy to help

[aris]

Originally Posted by pat_t

I'm gonna respectfully disagree.

1) I think GM have sorted the heads on Z/28s since the original LS7s in Corvettes.

2) The cam and headers doesn't really stress the valvetrain a lot more. If anything you rev the engine a bit less with the additional torque most of the time. I'm staying in 3rd gear out of hairpins at 3-4k revs, wherein a standard car with 450rwhp I'd probably drop it down to 2nd and be revving it 6-7k and wearing the engine out faster!! Likewise you get closer to the traction limit of the tyres with the extra torque sometimes, so you short shift going up which is also stressing the engine less.

Just my 2p - but I do design engines for my day job

Fair enough - we can agree to disagree. I'm still not about to touch that motor without addressing the heads.

I think it ultimately comes down to how much risk you're willing to live with. I've personally been witness to 3 cammed LS7 w/ stock heads, all in C6 Z, and all with under 50,000 miles, pop at track events in the last 2 years. All three of them had the same issue of excessive valve wear.

For a primarily street driven car that's driven peacefully in normal street conditions, I'd say go for it. No significant risk whatsoever. There is however more than enough documented evidence to suggest that there is an issue with the stock heads/valve guides, which has been addressed directly by Chevrolet, as well as multiple reputable engine builder, including Katech. Given there is documented evidence of an issue with the stock heads even in low mileage cars at stock power levels, I'd be hesitant to push the limits of motor in a track environment with any level of confidence.

Here's one article by Jason Harding of Katech that discusses the causes of the excessive valve wear issue:
http://read.uberflip.com/i/834132-july-17/77?

So like I said, personally, if there is even a 10% increased risk of popping my motor prematurely as a result of not addressing the valve guides, then I'd much prefer doing all the work at the same time to ensure that I actually have a reliable race motor, rather than worrying about it every time I take the car out.