D9HP

Hello all,

I am trying to decide which set of cylinder heads I am going to run in my ERL 454ci build.

It will be a solid roller system targeting a 7.5k RPM red line. Most of the engine's life will be spent between 4-7k on the track.

The titanium valve upgrade through Mast is a skull crushing $800 on top of an already steep entry price. With their solid roller setup the price tag starts creeping up towards $5k, which just seems prohibitive for me.

The PRC 285cc heads have a $400 adder for the titanium valves and it seems like I could get those assembled with the correct springs and on my doorstep for under $3,500, which is still steep but more reasonable given the flow numbers they claim.

I would just like some feedback on how important going Ti will be in either heads at the RPM levels I'm shooting for and any take on the respective heads.

Also would be open to hear of other equally performing heads that would come in cheaper with Ti valves and ~.750-.800" lift beehive spring setup.

All appreciated!

Gray86hatch

iTrader: (83)

Look at what TI valves are being used. Not all are the same quality.

On that engine you will want the big heads for big power at that rpm.

Tim

Jimbo1367

TSP had good reviews/power on LS7 head swap a mag did a few years ago. If you call TSP, they might be able to e/m you the article or at least let you know what magazine and date of the issue. I remember being impressed their head did so well.

I also agree with Grey86hatch about the quality of ti valves.

D9HP

Mast just lists them as "Mast Titanium Valves". I assume they are pretty solid performers.

I have seen some good reviews on their heads and their published flow numbers are actually higher than Mast's...but I haven't ever read a poor review of Mast's 305cc heads.

Does going solid roller vs. hydraulic reduce the overall benefit of going with Ti valves due to the reduced weight of the valvetrain?

Currently leaning towards the 305cc heads without the valve upgrade. Using the Mast solid spring option I might get out the door around the $4k mark which would keep me happy.

Do the Mast castings already have provisions for shaft mount rockers? It looks like their rocker stands are for pedastal (stock) style rockers.

I'm going to run the Crowler LS7 shaft rockers so I would have to add that cost to the PRC heads, I imagine.

Gray86hatch

iTrader: (83)

With that big of a valve you want Ti.

Tim

D9HP

Would you say that the solid stainless is acceptable for the exhaust?

dckmn52

This.

I would call everyone and kick over what you are running in your combo. Call TSP, Mast, and maybe WCCH a ring too for reference.

The Crower rocker LS7 setup is 1200 roughly IIRC. Youll have to check each head and see how each one is set up out of the box.

dckmn52

http://www.superchevy.com/how-to/140.../spintron.html


Spintron says no.

Violence.z06

iTrader: (3)

that lift and solid roller i would lean away from beehive springs also.

D9HP

Great read, Thanks!

This is raising the cost of the heads considerably but they are definitely where all the power is sitting in this build so I'd rather wait a few months longer and have it correct out of the gate. This engine is going into a 2 year project car so I can handle the wait!

Mast also offers inconel exhaust valves but I don't have much information on them. Any comments on those?

Thanks for all the input, everyone.

D9HP

You vote double springs? That Katech article seems to prefer the Beehive option.

All ears - would rather get it sorted now before I've spent money on the wrong option for the application.

Violence.z06

iTrader: (3)

Me personally, im no pro engine builder but valvetrain stability is a good thing. especially with solid roller. I have never been a fan of beehive springs. I would run dual springs over beehives anyday. my build will run triple springs.

just my 2 cents

blackonblacksls

iTrader: (1)

With the mast heads and a large diameter, High pressure springs stainless valves are fine..

You aren't spring limited like on stock ls7 heads. So the valve weight thing isn't as big of a concern in my opinion.

Rise of the Phoenix

iTrader: (27)

You might want to also check with Chris Frank of Frankenstein Racing Heads and see if he has something that would work well for what you're planning.

KCS

iTrader: (20)

I agree, especially with a solid roller setup. I would probably just run a nice soft lobe and a good spring and be happy with it. There might even be a hollow stem option. They're not as expensive as titanium and not as heavy as the solid stem valves.

D9HP

Both valves would be fine being SS or just the smaller exhaust valve, in your opinion?

His stuff looks incredible and he is absolutely on the list I just haven't seen any prices so I figured it was north of Mast.

Great points - Mast offers an inconel exhaust valve but no hollow stainless options that they show online.

Thanks!

Rise of the Phoenix

iTrader: (27)

MAST may if you give them a call. I'm sure they would do whatever possible to make those heads work for you.

KCS

iTrader: (20)

Inconel is HEAVY. That material is generally used for severe duty in big boost applications where the EGT's are ridiculous. Stainless steel should be okay for you.

blackonblacksls

iTrader: (1)

Both valves stainless should be fine is my opinion.

And it is also the direction I decdied to go with my build.

2.2 diameter valves and some big Manley Springs. 1.55 diameter. Solid roller stuff

Millenium Z06

My car just got done, ERL 434 M2 bottom end and PRC 285's with a ported stock LS7 intake. Made 575 / 505 thru the LS7 intake, cats and 1 3/4 headers, 66-67 chambers I believe.