yota

iTrader: (3)

I'm trying to decide how to set up my valvetrain on the build I'm working on. Basic setup is a 346 LS6 with Katech rod bolts, PRC 5.3 stage 2.5 heads with a Tick SNS Stage 3 cam (235/243 | .62x"/.62x" | LSA111+2), and ~200hp shot of nitrous via a plate kit. I've already purchased a set of Harland Sharp adjustable rockers. My questions are mainly related to springs, lifters, and pushrods.

First off, springs. I'm currently torn between keeping the installed springs that came on the PRC heads and swapping them out for Brian Tooley .660" springs with Ti retainers. I don't want to have to worry about valve float or dropping a valve, both of which I have seen with the PRC installed springs recently.

Lifters, I'm trying to decide between BTR SLR or Morel 5274. Are the Morels worth the extra $3-400? I understand that using link-bar lifters allows you to ditch the plastic trays, which is supposed to aid in oil drain-back and overall lifter performance.

What size (diameter) pushrods and wall thickness? I don't want to lose valve lift or have poor valvetrain harmonics due to pushrod deflection.

One more thing... Would it be worth it to replace the intake valves in the PRC heads with a set of turned down LS3 hollow stem valves to save on weight? My thoughts are that if I end up swapping for the BTR springs with Ti retainers, that would be the time to upgrade the valves as well if I am going to do it.

My goal is to have the most robust, well balanced and QUIET valvetrain possible without completely breaking the bank, while still keeping in mind that this is a street car and a weekend racer. I'm well aware that I could just slap it together with a set of stock rockers, LS7 lifters, and keep the current springs and valves and get out "cheap", but I want to optimize the setup as much as possible before slapping it together and feel that the valvetrain would be a smart place to spend a little extra time and money.

Thanks in advance for any input, and please feel free to correct anything I have posted that isn't exactly correct.

soundengineer

iTrader: (16)

sounds like a good start...but personally, I am not a fan of Harland Sharp rockers... they are heavy over the valve and they are not the best for valvetrain harmonics which contributes to broken rockers or broken valve springs


I have not used either of the springs you have listed...but both have had pretty good results that you can read all over this site.
the key to valvetrain setup is to shim the springs to within .060 of coil bind for ideal spring pressure and maximum performance....
but... this can be too close for comfort as it puts you really really close to coil bind when you get lifter toss and when you have thermal expansion of parts making that value smaller.
so I like to shoot for a little larger.
good valvespring pressure is the key to good valvetrain control...
too little and you have no control, too much and you have great control but you sacrifice a few ponies from friction....too much pressure can also cause some valvetrain wear....you end up beating up the valve tips and guides(especially ones made with brass)




its worth it to get the Morels.....the oiling holes are in a better spot, they hold up to more abuse, they help with oil drainback if you get the link bar lifters... you gain stability from the link bars and an overall better lifter

the thicker you can go, the better....
I dont know if your heads are set up for 3/8 pushrods.. but you can call Texas Speed and ask them
I dont believe they machine them for 3/8 pushrods....but if they are off, you can easily modify them yourself.
otherwise, consider getting a set of 11/32 pushrods... I suggest a set of Manton 502 series 11/32 pushrods in whatever length is appropriate to your setup.
since you have adjustable rockers that you want to use... be sure you buy a pushrod with a Tool Sttel ball on one end for the tool steel adjuster on the rocker....otherwise you will tear up pushrods pretty quickly and suddenly you will have serious valve lash issues and lots of broken parts to follow shortly after.


if you are trying to spin it more than 7500 rpm on a regular basis.... then you might consider it....but you are going to need to change a bunch of things to do that anyways....the springs you have in mind probably arent going to be the right ones for the job...you will need to go to a lighter rocker, and titanium retainers/locks/lightweight valvetrain stuff...plus a set of 3/8 pushrods...
you are going to need a good ATI balancer, and you will need a very very well balanced forged crank

if you arent going to spin it that high, then I really wouldnt worry about changing valves...spend your money on other parts that have more bang for the buck






you are correct...no such thing as cheap and robust...its one or the other..

the key is you really have to decide just how much you are willing to spend and how robust you really need it...
you can easily spend several thousand dollars on your valvetrain...but just spending a few hundred might be enough to get to your goals and have more money to spend on other parts of your vehicle

maintainence is also part of the equation....
adjustable rockers do need to be checked once in a while to make sure they havent worked their way loose....(check them at every oil change)
valve springs need to be replaced at regular intervals (a lot shorter than most people realize)
ocassionaly lifters need to be replaced (not often,...but you will know it if one fails..LOL)


hope all this helps

99Bluz28

iTrader: (35)

Get at least 11/32"(better) , or 3/8" double tapered(best) pushrods.
Really good PR info here:
https://ls1tech.com/forums/17549747-post22.html
https://ls1tech.com/forums/17549751-post23.html
Yes, lighter valves are a good idea.
With you running a 200hp shot, I'd say get the Morel 5274 over the BTRs.
IMO, I'd consider going with the stock rockers w/trunion upgrade over the RR's. The stockers are going to be more stable at the upper rpm range, and most likely make more power than the RR's and quieter.
Good luck with you build!

ls1 1990 VN

DO NOT USE THE HARLAN SHARP ROCKERS.

They are way heavy on the valve and will cause you issues like they did with mine.
See my now sig
Stay with OEM rockers & Trunnion upgrade.
I stayed with my installed springs....WRONG! Valve float, I had to go with BTR .660 Platinums.

Mine is still not quite right & if I new then & had the money then yes LS3 valves would now reside in my heads. I believe the stainless valves in my heads are too heavy.

I am using LS7 Caddy race lifters, good for 8k-8.5k rpm with no issues what so ever, I am using LS2 trays.

Yes as stated get a ATI super damper

JakeFusion

iTrader: (7)

Agree with what everyone else has said.

Manton 11/32" .120" wall pushrods will fit and are a nice upgrade. You provide the overall length to Manton. And they can provide pushrods down to the thousandth of an inch. I ordered 7.572" pushrods for my build from them.

Don't use the HS rockers. Stock with trunion upgrade or CHE bronze bushing.

The stainless valves and PRC .650" springs are okay. The EHT .675" is a bit overkill. Shim them up for the most control.

Morels or Johnson Short-Travel lifters. Though, the BTR SLRs are actually a very nice upgrade over LS7s, and I'd recommend them over the Street Morels, but not the big boy Morels or any short travel lifter. The short-travel lifters are good for 400-500 RPM over other hydraulic lifters with everything else being the same. They act like a solid lifter at high RPM and would help increase the RPM range of a well sorted combo.

This comes from Comp on the advantages of short travel:

Short Travel Hydraulic Roller Lifters are the perfect choice for use in mandated hydraulic roller racing classes and high performance/race applications . The limited plunger travel extends the usable rpm range by up to 500+ rpm but still remains a hydraulic lifter while staying as close to a mechanical lifter as possible.

• Designed to perform at higher engine speeds
• When equipped with hydraulic lifters, high rpm is limited by improper position of lifter’s internal piston as lifter “pumps up”
• Improper location results in open valves that lead to lost power and possibly engine failure
• Minimize internal movement to allow higher engine rpm

yota

iTrader: (3)

Wow, thanks for all of the feedback so far. While some of the answers aren't what I was necessarily hoping to hear, there seems to be a lot of really solid advice here.

So what I have gathered so far is that for the best results, I should set this up as follows:

Morel 5274 link-bar, or short travel lifters (~$550)
3/8 double tapered Manton pushrods (~$250?)
Trunion upgraded stock rocker arms (~$200- I have to buy stock rockers and upgrade them)
BTR .660" Platinum springs with Ti retainers ($350)

And if I have money left over- turned down LS3 intake valves

So, without new valves, I'm looking at approximately $1350 into the valvetrain. I'm guessing for turned down valves, I'm looking at another $3-400? ($25/valve plus machining costs) That puts me at a high end of around $1800 for a fairly well thought out valvetrain. Not too bad considering everything involved.

The good thing is that my heads are still in the box and have never been installed, nor has my cam, etc. and my car has been down for over a year now, so I'm already used to not driving it lol. Looks like I know where my tax money is getting spent come January!

Again, thanks for all of the input so far!

97camaro383

iTrader: (31)

btr srings are $299 on Tick Performance's website

yota

iTrader: (3)

Good call. I wasn't seeing them with the Ti retainers, but I didn't realize they had a drop-down menu to select them. I've got a few other things I need to buy from them already, so that works out since they do free shipping over $400. Thanks!

JakeFusion

iTrader: (7)

Keep the PRC springs. That's not a smart use of funds.

Put the 299 toward something else... and even the 3/8" double taper pushrods aren't guaranteed to fit. Plus they are $400.

The 11/32 will fit and are $200.

yota

iTrader: (3)

Just curious how the BTR springs aren't a smart use of funds? I've known several people personally who got valve float using them, and zero who had problems with the BTR springs. Not saying you're wrong, just want to know why you feel that way about them.

Thanks for the figures on the pushrods. I didn't know the double tapered ones were that pricey. Seems like a lot of money for a small gain vs the 11/32" .120 wall ones

soundengineer

iTrader: (16)

The 502 series manton pushrods 11/32 with a tool steel tip on 1 end were $350

Big difference between 3 series and 5 series...
You might only need a 3 series... but if you call and talk to them...they will tell you the differences...both in mechanical terms and a strength percentage.

JakeFusion

iTrader: (7)

PRC .650 springs are 144lbs closed and 402lbs open @ .600" lift.

BTR are 155lbs closed and 380lbs open @ .600" lift.

You get a little more seat pressure. But you could get that by shimming the PRC. They aren't a bad spring.

Have you used them yet? Do you have valve float? I suspect most people using them are doing so with heavy valves and LSK lobes or some other funky combination.

I actually have Series 4 from Manton for my pushrods...

soundengineer

iTrader: (16)

Keep the prc's...higher spring rate per inch (430# per inch)....and the seat pressure wont be enough difference to putz with.

The btr springs are only a 375# per inch

There's plenty of seat pressure on the prc's...they are already on the heads...no extra work needed.

Spend the money on other parts

soundengineer

iTrader: (16)

Series 4 are designed to be used with guide plates....
Series 3 and 5 are designed to be used without guide plates

It was one of the many questions I asked when I bougt mine..

Also...Series 5 gains you almost 100% stiffer than series 3

Series 4 was somewhere in the middle...
But again...they told me you should use guide plates with the or they will wear very quickly.

Burken01

iTrader: (88)

Series 3 are $180
Series 5 are $250

$60 extra for the special heat treatment

JakeFusion

iTrader: (7)

I went with what Tony Mamo and the crew at Manton thought would work best for me. All Comp/Trend pushrods for example are hardened to be used in guideplates and are installed in the LS1 all the time. It's just the hardened procedure. As you say, 4 is somewhere between 3 and 5, where the surface of 3 and 5 would not take the abuse of scrubbing a guideplate.

yota

iTrader: (3)

So the consensus for stability, longevity, and overall performance seems to be:

Morel 5274 link-bar, or short travel lifters
11/32" Manton series 5 pushrods
Trunion upgraded stock rocker arms
Installed PRC springs
turned down LS3 intake valves (potentially... not needed, but it's a little thing that will help overall)

Am I missing anything? Glad to see a good conversation about this stuff. Thanks guys!

Burken01

iTrader: (88)

that looks pretty solid, just make sure PR length and proper preload are in spec and your golden..

ls1 1990 VN

OP In your inital opening thread you didn't state if the heads are new or not!
Are the valve springs new or used?
Your call if they are used & you decide to stay with them, then have possible float!
Above all of us who have been there & done that....Please please check with Martin, 'Tick' it may well save you some heart ache & Dollars.

yota

iTrader: (3)

Post #6, I posted that the heads and cam are BNIB. I have Martin on speed dial lol, I just felt like this is an area where doing my own research would benefit me more. When it comes to in depth cam discussions and how overlap and valve events affect an engine, you might as well be speaking Russian to me so I call him up and let him do his thing. Valvetrain stuff is all geometry and materials based, combined with making it all actually fit a defined space, which is much easier for me to understand!