Valve seat pressure

Heaten m90

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What is the recommended valve seat pressure when running 25+ PSI of boost and 8k RPM? Further what type of issues will i encounter running agressive springs? Has anyone seen the crank gear fail? Ill be running billet tensioners and guilds, i know the ratcheting tensioners can "stick" but im going to be beating the shit out of this engine its entire life. And i dont think with a increased pressure oil pump the oring will hold up on the plastic unit.... Any thoughts?
 

groundpounder

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"What is the recommended valve seat pressure when running 25+ PSI of boost and 8k RPM?"

I'd say a daily prayer to Jesus and also a baker's dozen of other deities. Or you could make a deal with the devil. Either seems like the only way to tame such a beast?
 

drive_55_not

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Mark from Bullet Cams recommended 120# seat pressure for 20+psi when I spec'd out a turbo cam from him ..

The heavier seat pressure is going to wear the softest part faster ...

The more rpm you run, the more unstable the valve train becomes, I don't think the OE parts will survive long up there under heavy boost ... Jesel makes aftermarket lash adjusters/cam followers their stuff's $$$$.

There are a couple billet crank gear's available, I'm running the MMR one and the MMR guides ...


.
 

eighty6gt

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This build will never run for more than a few minutes.
 

702GT

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What is the recommended valve seat pressure when running 25+ PSI of boost and 8k RPM? Further what type of issues will i encounter running agressive springs? Has anyone seen the crank gear fail? Ill be running billet tensioners and guilds, i know the ratcheting tensioners can "stick" but im going to be beating the shit out of this engine its entire life. And i dont think with a increased pressure oil pump the oring will hold up on the plastic unit.... Any thoughts?

There's really no need to run higher oil pressure than OE. Every built motor I've had my hands on (2v, 3v, 4v) we had the machine shop set all the tolerances to OE spec, and ran OE grade oil (5w20). One of the Teksid blocks we built we had to run 5w30 in because the block had to be so worked we would have had to run custom bearings to spec for 5w20, was easier just to run 5w30 and he ran the same oil pressure as stock. Higher oil pressure at high rpm is going to make for bad voodoo. What you want is flow. The plastic timing tensioners will be just fine in any power level build. Ratcheting tensioners will likely reduce the life of your timing components at that rpm.

Again with the 8,000rpm bullshit. What, in your mind, makes you think the 3v heads are going to flow at 8,000rpm that they won't flow at 7,000rpm with less chance of failure? I really hope you'll reconsider, but the dyno will show you the truth.

Drive_55's got you covered. As for how much seat pressure, any spring manufacturer will help you if you call and ask them what you'll need based on your build. Or you could hit the archives and look up some of the builds that have been done at that boost level and see what's been run.

This build will never run for more than a few minutes.

MMR? If it runs for more than 10 seconds, the warranty is void and the build is a success in MMR's book. Because the engine ran, it voids MMR's warranty as abuse, the part was not designed for use in a running engine.
:yaoface:
 

eighty6gt

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Just have a look at all of the builds that put demands orders of magnitude less on the parts. The S197.com trail of tears. Should be a sticky thread full of links.
 

RED09GT

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Just have a look at all of the builds that put demands orders of magnitude less on the parts. The S197.com trail of tears. Should be a sticky thread full of links.
How many 1000 rwhp build have actually yielded running cars? LOL

Worst part is I never seem to have cash when the part-out threads come up...
 

Bingo

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I can think of a few screen names.

3-valve builds? I can't. I love the 3V as much as anyone, and it can be really solid and reliable, but when it's pushed into territories that are way outside of its envelope, shit is just not going to work very well.
 

46addict

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3-valve builds? I can't. I love the 3V as much as anyone, and it can be really solid and reliable, but when it's pushed into territories that are way outside of its envelope, shit is just not going to work very well.

Any of these names ring any bells?

05stroker
swflastang
retfr8flyr

Also look up Mo Makki on FB. And raredesign is on his way there I believe. Terry's car is close to 1k wheel.

If the blocks are good to 1000whp I don't see how that is way outside the envelope. The only envelopes you're pushing at that level is budgets, traction, octane, and will power. People quit because they run out of money or the willingness to build, not because the parts can't take the abuse.
 
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05stroker

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Any of these names ring any bells?

05stroker
swflastang
retfr8flyr

Also look up Mo Makki on FB. And raredesign is on his way there I believe. Terry's car is close to 1k wheel.

If the blocks are good to 1000whp I don't see how that is way outside the envelope. The only envelopes you're pushing at that level is budgets, traction, octane, and will power. People quit because they run out of money or the willingness to build, not because the parts can't take the abuse.
Im only about 940rw on the last motor so I dont count! Lol

Most loose interest before they get the car there. I dont care if its a 3v, 5.0, or LS based setup. 1000rw plus is a HUGE goal in the real world and not on the internet or a go for broke shop car.
 
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05stroker

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To the OP, if Im reading you correctly on your threads, you trying to do a big turbo build that can road race, drag race, go to lunch, and take the kids to school with 1400 bhp, 8000 rpms, 40 psi, and maybe some odd mix of fuel. All I can say is, good luck. I hope you have a 50k build buget.

As to your question here, I had good success with the Comp cams and springs, I ran the 127550 cams with the correct springs recommend for them, I forget the part number, but is on there site. I spun them to 7550 without issue for an entre season. Consider them wear items at this point though.
 
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swflastang05

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IDK if I'm at 1000rwhp yet either, but my new motor might be pretty damn close, time (and time slips) will tell soon! In any case I've been running PAC 1533 Nitrite coated springs on my motors with great results. I don't think I've ever spun it above 7300 rpm though. L&M Engines has some customers that have 1000+ rwhp 3 valves, so they're out there for sure.
 

702GT

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I'm certainly not saying 1000whp+ isn't possible, I'm just saying you don't have to spin to 8,000rpm to achieve it, nor would it be doing the valvetrain any favors. I am saying the heads are a huge flow restriction to overcome due mostly to valvetrain complications and overall head design. 3v's are great responders to a point, can trump a 2v head with little effort and hang with some stock 4v heads, but the 3v is a limitation when it comes to making big numbers. It's much easier to address a 3v build when aiming for a E/T goal. But when it's balls out dyno queen, the 3v lacks compared to other avenues. I'd rather stretch cubic inches than try to scream more CFM through the heads by reving the piss out of everything.
 

Heaten m90

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Fucking hell i just wrote like 6 paragraphs trying to explain my fixation with RPM, and how i believe its possible to achieve a 305/210 CFM 3v port. But it shitout or something when i went to post it.

My pimps pushing hard for me to move to FR500 heads but with cost and complexity i cant cant justify it. If my rods/pistons ever find a way to escape, ill cash out my 401K, start selling crack and build a 5.8 stroker. Some dudes build cars to enjoy them.... thats cool, but mines going to be a purpose built racecar, the goal is winning. This is just my first big build, and im not going to be a pussy about it.

I'll be in the test cell with my buddy from work next week for his big block. I'll pass along the recommended part numbers and specs to the builder, thanks guys.
 

01yellerCobra

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If it's a purpose built race car I'd follow PSF Racer's lead and go big block.

Misspelling brought to you by Tapatalk
 

46addict

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I forgot NoviBlownGT's car traps 150+mph too. I'd say if you are trapping 145+ with little to no weight reduction, it's close enough to 1k whp.
 

702GT

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Again, just my $.02 going out. I have a hard time following it being a purpose built race car if you're focused on squeezing your goals out of a 4.6 3v. 281 3v's are remarkable motors with loads of potential and variety of applications, but like any powertrain, they have their limitations. Pushing on limitations takes away from reliability. Most everyone here isn't knocking your goals, just trying to keep you informed and convey to you what's already been successful, why it was successful, and what failures and hurdles are to be expected along the path you're taking. I've seen many people get halfway through a build and decide to change directions with the build because of unforeseen complications with the build, there's no disgrace in that. You act like you've got something to prove with this build, but this forum has seen most of it done. Consider the opinions and weigh them against your goals. If your car is truly a purpose built race car, focus on the purpose, and the means to getting there won't become so static as they are now.
 

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