Durs96TA

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MyLS1Hauls:
<strong> If your dyno sheet looks like the one posted, then the shop is completely wrong. That dyno shows absolutely no signs of valve float. Looks like someone wants to make some cash on valvespring swaps! Especially if your car is an 02, which has the valvesprings shimmed an extra .020" to increase the load, they shouldn't be floating. I've only seen a few isolated incidents where a stock motored car had valve float issues at stock rpms. I'll have to see if I can dig through my dyno sheets to see if I have one saved from a car with floating valves.

Brad </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Can you explain what a dyno sheet with valve float would look like?

NHRATA01

iTrader: (10)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jay 95WS6:
<strong> gm has notoriously used "weak" valve springs for 2 basic reasons, fuel economy, lower tension springs cause less rotational friction which increases economy. the second reason is warranty lighter spring will lose their tension quicker and lessen the useable RPM will lessen the RPM related failures. i'll get the actual spring rates tomorrow and post them here

Jay </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I'd imagine the weaker springs would put less of a beating on the valve seats, helping long term durability (100k+ miles) and also fewer customer complaints about valvetrain noise. IIRC, when I had my cam installed, my 918s were 129#'s, the stock ones I believe were in the 70-80# range. I remember the 918s having close to twice the seat pressure of the stockers.

Jay 95WS6

here are the specs all @ 1.80 installed (GM Spec)

97-03 vette LS1
98-02 F-car LS1
closed press 76#
open Press 220#

01 ZO6
Closed pressure 90#
Open pressure 259#

02 ZO6
closed pressure 90#
open pressure 294#

i hope this helps

jay

Durs96TA

My dyno sheet looks really weird towards the end. Take a look, and let me know what you think.

http://community.webshots.com/photo/...62051148VOhVtD

DavidBusch

Well, here goes the scam.

We had more than 40 cars on the dyno that day and I will try try and recall all the cars.

1st I made recommendations based on a quick evaluation of a given car based on experience, sound of the engine, dyno graphs, 2 pulls to be exact, and mods or lack of mods on a given car.

2nd I never gave a price unless asked for one.

3rd At no point was there a sales pitch or demonstration.

I would like to thank everyone who came and wish I had more time to meet everyone and answer any questions they may have had. We offered a free dyno day to bring everyone out during this cold winter to have some fun on the dyno and meet new people.

Now I did recommend upgrading to 2001 ZO6 springs on a car that is stock and our dual springs only if you plan on an after market cam in the future.
I quoted 5 hours labor @ $65 an hour and parts. Our springs, titanium retainers, seat locaters, and valve seals, are $320.00.

There is a couple of different things that can cause the graph to fall off, Lean AF causing detonation, too much timing for the load causing detonation, Bad gas causing detonation, ignition problem, and yes weak valve springs. When the valves float the graph usually falls off as the valves lose stability causing a loss of power whereas when it detonates the graph drops down around 5-10 HP then continues with a normal arch not dropping off severely. We had more than 5 cars with audible detonation and the graph reflected it. With the car in question I heard and felt a deep moan which from experience, felt, sounded, and looked like valve float.

My experience is, working with LS1 cars from 97 to present day, 15 years as a mechanic, 3 years performing machine work with heads, EMIC training for FI, Working on and driving a 10.90 H&C car, a 9second fuel injected small block Camaro, 9.33 410 NOS powered LS1 Camaro among others, and countless hours of hard work.

I'm amazed at what happens to someone asking a question and how people who obviously know more than the rest of us, have to instantly try to accuse a shop of trying to take advantage or lie for more business. Everyone who visited our shop will tell you how busy we are and won't recommend any unnecessary work. We would rather work with a customer and his or her budget to help achieve they're goals. We test products all the time so our customers don't need to waist money on something that doesn't work.

And I guess your rite, nothing in life is free. So how many free dyno days have you given and what makes you an expert or is your screen name say it all "chicken" <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

And now for some words from the experts,

Dave

Durs96TA

Dave,

First of all I would like to thank you for the free dyno day. It was a great experience and I got to meet a ton of new people (even if I did have to get up at 4am to be the first ones there w/Pete). If you read back in the post, you will see that throughout it I have never once accused you or your shop of wrongdoing. I also have not accused you of trying to drum up business, or giving me a sales pitch. When you told me I had valve float I was concerned, I have owned this car for only 6 months. I spoke to you at length about my options, cost, and what would be the best route to take. Throughout that time you were nothing but helpful and courteous, giving up your time to speak with me. I posted this question merely to get a second opinion, from people who I believe know there stuff. I'm not saying that you don't, however before I go and spend $400+ on a job, I want to be sure I need it. Like you said, you guys were packed that day, so you could've misdiagnosed my car. Do not think that I in any way was trying to say that you were scamming me or anyone else with this dyno day. I look forward to good relations with you and your company, as I have had good experiences in the past.

Dave

Max@Cartek

Dave,
I thought I made it clear in my post, I am not posting against you nor was my post meant for you. I said it is amazing how some people want to take your request for information and turn it into shop bashing. I was glad to spend some time talking about your cars problem. I know that all LS1 heads have a spring locater not a shim and the thickness has not changed after all these years. I also did recommend 2001 ZO6 springs 1st and when you asked if we could recommend any other options I then told you about the springs we use if you planed on a cam in the future.

Dave

Durs96TA

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Wide Open Throttle:
<strong> Dave,
I thought I made it clear in my post, I am not posting against you nor was my post meant for you. I said it is amazing how some people want to take your request for information and turn it into shop bashing. I was glad to spend some time talking about your cars problem. I know that all LS1 heads have a spring locater not a shim and the thickness has not changed after all these years. I also did recommend 2001 ZO6 springs 1st and when you asked if we could recommend any other options I then told you about the springs we use if you planed on a cam in the future.

Dave </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Dave,

I just wanted to be sure you knew where I stand. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> But I do agree, some people took my thread looking for advice and turned it around to something else. Thanks again for the dyno day. My buddy is ATAPing my car this weekend to see if anything else is going on before I do the springs.