LET'S TALK TECH-317 HEADS- THE BEST FOR BOOST?

SHOULD EVERY TURBO LS MOTOR BE RUNNING 317 HEADS? THEY FLOW WELL AND DROP COMPRESSION-SOUNDS LIKE A BOOST HEAD TO ME! LET'S TALK ABOUT THE RECENT VIDEO ON 317 HEADS.

[@kylemilligan752]

Mr Holdener, I agree. Years ago I tuned a bunch of stock rsx type s 11:1compression with Greddy turbo kits, 6psi on 93octane. They made around 260whp dynojet with around 8-12 degrees total timing at max boost/rpm. Exhaust gas temps were absolutely unbelievable, but they were safe and reliable. Put forged 9.0:1 pistons in one, wanted 6-8 degrees more timing on the same 93 octane, and made the same 260whp dynojet, while egt's dropped more than you would believe.Tuned it to 13psi on 93, around 320whp where the little turbo cried uncle and started laying down up top. I agree with Mr Holdener, when limited by fuel octane (93), lower compression, allowing more ignition timing, lowering exhaust gas temps, makes a far more reliable combination

[@richardholdener1727]

egts do get high with low timing

[@lukeb.8478]

I know the limiting factor is the turbo, so if you have twins does limit on hp double equally . 500hp single with 2 1000hp ?

[@richardholdener1727]

if one turbo supports 500, then two will support 1000

[@mistermonkey5842]

we all know the limitation is really not running a turbo cam. 😂 Okay, now that we've had a good chuckle, if a single turbo makes 500, twins may not actually make 1000 if the fueling or flowrate aren't designed to support. In the old days, just slapping a 1250 dominator on your 2 bolt 9:1 350 didn't grant you 400hp even if the carb "could" support it. If Saint Richard has taught us anything it's that the engine is a system and everything effects everything. Twins can however play games, one vaned for quick spool for low RPM power and the other for high flow high RPM. And other silly games.

[@richardholdener1727]

if 1 turbo supports 500 hp, then can support 1000-what you do with that potential is another story

[@mistermonkey5842]

@@richardholdener1727 Speaking personally for myself, I would prefer an abundence of power and have the limiting factor be elsewhere. But alas I own a 3.6L wrangler so having too much grunt AND too much snort isn't really my problem. I'm against a fairly solid wall of transmission input torque. Running the boosted power math a force fed 3.6 and 6M offers the higher developed power per pound of driveline and power per liter on par with the big V8s. But heaven forbid you drive torque, the 6M wants to a ferometallic liquid.

[@baby-sharkgto4902]

Is what you are calling a “sloppy stage 3” a 238/242 .595/.595 on a 112? If so that is an excellent cam for a 6 liter or bigger. I’ve also used that cam in a boosted 427…still good. But obviously it depends on what you are looking for.

[@abdullaalameri90]

I really would like to see the effect of boost leak on power at different boost levels. Maybe start with 0.5" boost leak hole and step up in 0.5" increments to 2" hole. And then try different boost levels. A simple turbo setup single would be best. Would really love to see that. Thanks.

[@richardholdener1727]

a turbo will overcome the leak-better to illustrate with a blower

[@abdullaalameri90]

@richardholdener1727 agree, but given that the leak will cause the turbo to spin faster. Back pressure pre turbine will increase, yet boost level will remain the same by the wastegate. More back pressure will be less cylinder charge filling. There will be a loss of power on a turbo due to the boost leak, but will it be 5% or 15% power loss?

[@richardholdener1727]

how will back pressure go up if boost is the same?

[@abdullaalameri90]

@richardholdener1727 what I understand is that boost leak will affect turbine speed to achieve the same boost of a non leaking system. The higher the turbine speed the higher the back pressure. To be Frank am only speculating. I only know that peak power will be affected with a boost leak.

[@hondatech5000]

It’s really whatever you have. I got mine running with 241’s on my 4.8 just because it’s what was on the blown up 5.3 I had 😅 for real if I upgrade I’m going 53 and whatever heads it has…

[@chipcurrey653]

It isnt really logical to say the 317s or any of the cathedral port stuff is "the best for boost" in 2023 unless you get an engine with them for free. On ebay the price difference between a square port 6.0 and a cathedral port 6.0 is less than the cost of even a tbss intake for the cathedral 6.0. Compare 07 lq4s to 08 ly6s from wrecking yards like lkq and they can even be the same price. That square port engine is basically the same as the cathedral port engine with ported heads, a fast intake, and a bigger throttle body from the factory.

[@th600mike3]

🤫 🤫 🤫 DONT let people know. cathedral 317 the best! 😗🎶

[@richardholdener1727]

see the ly6 testing vids

[@kylemilligan752]

For budget N/A 6.0 guys, a 317 head with TBSS intake vs L96 rectangle port heads and truck intake would be a good data point/comparison. Under boost, it doesn't matter. Give it another psi or two

[@richardholdener1727]

that test was done-rec port makes more

[@kylemilligan752]

Mr Holdener, I have a wildcard question for you. In 1999-2000 gm made a 873 casting # cast iron head for 6.0 LS engines that folks say flow the same as a 317 head. If the aluminum head does experience a "lifting/bending" force blowing head gaskets, how about giving the cast iron 853 cathedral head a try?

[@Mattvardaman]

I believe it’s the bolts that stretch when the head lifts not the head itself. I have a set of those heads that I pulled of my dad’s 99 2500. When I installed a camshaft (summit 8718), I also installed a set of rebuilt 317s.

[@Mattvardaman]

I would love to see him run a set. Just to see if they actually have the same flow/performance.

[@jmflournoy386]

FYI did some checkin of that 06 3valve mustang for a screw blower KB said recertifying call back 3 mo, otherwise try Magnuson reseller in FL Whipple kit is DC any other choices?

[@richardholdener1727]

ford racing

[@jmflournoy386]

@@richardholdener1727 Thanks I thought ford racing was a roots not screw I'll check BTW centrifugal takes about the same power as some small CVT vehicles has anyone done a CVT for a blower (Germans did in WWII all we did was a two speed)

[@Mattvardaman]

Richard, putting a pump on your truck will make a huge difference. Over time the bypass valve wears and gets stuck. Mine had lower than normal pressure for quite some time before the bypass valve stuck open and pressure went to zero. Luckily it was at idle went pressure went to zero. Only 1/2 trucks with a 6.0 have a 4l60e (4l65/4l70). Most 6.0’s were in 2500’s with 4l80e. I have a turbo 5.3 daily with original 4l60e with minor modifications. So they can live with timing pulled on shifts. It’s so quick that you don’t feel it.