I'd love to see someone who's got a good, modern software dyno application to put together a "Modern" TPI engine that involve bolting together a few off-the-shelf components, just to show what is possible today vs. in the 80s / 90s.

406 SBC Shortblock: 4.155" bore x 3.750" stroke; 6" rod
Something like Mahle PowerPak shelf D-dish -16cc pistons -thin 1.2mm rings (10.4:1 static CR with a good .035" squish)
EITHER AFR 195cc race heads or Speier Racing's 205cc Street Head (I already have an airflow file that I can share for both), but +300 CFM at about 550" lift.
FIRST Fuel Injection aftermarket TPI intake with free 1050CFM large throttle body option (Flows 294CFM on the worst runner 300+CFM on the rest)
Sequential Fired Injection (assuming modern EFI system control)

1 3/4" headers -with open headers (Something like American Racing's amazing 1 3/4" off-the-shelf headers with a proper merge collector with merge spikes). 28.7" -31.3" long (tuned length that balances torque vs hp)

Aggressively lobed hyd roller cam: Here's mine for giggles, but on a more ideal LSA than mine: I'm certain it's not optimized for this engine but not terribly far off: Seat to seat durations: 280/286, adv duration: 273/281, 0.050" durations: 230 /232, Lift: .600"/.576", LSA 107, ICL 105 (+2 advance ground in) -Vizard's formula for max perf on a 2.08" intake-valved 406 SBC recommends a 105.5 LSA, for what that's worth.


Even reducing the flow #s of the heads down to 294 on the intake side as the maximum because the FIRST intake OOB restricts flow there on the bad runner, I get 510ft lbs and 515hp or there abouts.
My app does NOT support wave tuning calculations, but I'm considering picking up a copy of DynoSim6 and running it again WITH a wave tuning calc.

I modeled a similar 383 combo on Pipemax and it was recommending opening the runners from a 2.4" area (1.75" inside diameter) to 2.35-2.64", so the runners would surely need to be ported to not be a restriction at the upper end. -I think when I looked at Extrude Honing it was like $1000+ and it only opened up the are like 0.1" with every pass, so how to get more runner area on the cheap IS a challenge, but I'm not convinced that a bunch of and drill speed and time with the right sized ball hones couldn't make it happen.


500 hp out of a "top shelf", bolt together, pump-gas aftermarket (FIRST intake + Aftermarket EFI) TPI build is totally doable in 2022!
"11 times the power" AND can be just purchased and bolted together. -Thanks Technology!


Adam

 

Eh you need a very advanced program and very accurate measurements on all crucial data points for sims to work well. Else they likely over estimate. Engine analyzer pro aint bad if you have the 500-700$ for it. I had a trial copy and I wasn’t sure it was modeling boost correct but seemed ok on some rough na combos i knew of. Been a few yrs since i used it tho.

500/500 however doesnt need a super long runner to achieve.

https://www.thirdgen.org/forums/alte...m-low-rpm.html

low comp boat motor. 218 cam. Short runner miniram. 475/500. Big more cam compression and few more inches of runner, it could be easily 500/500

 

Yep. BadSS on here was nice enough to model my lowly 350 FIRST-based build with EA Pro -just modifying his similar build for what was different in my combo and came up with 440 hp and 470 ft lbs. An extra 56 cubic inches with +.155" of bore and +30 CFM of airflow makes a bolt together 500 HP long-runner TPI style engine very much possible.

Even Dynosim6 ($150) now includes intake wave simulation and seems to be the cheapest cost of entry for the feature now.

500hp with shorter runners on an SBC hasn't been an interesting challenge in DECADES.
A bolt-together 500 HP 19" runner NA TPI engine is WAY more interesting to me, and would definitely make more average power under 6,000 RPM than a miniram.

-It's funny to me that so many old threads of "I want to build a 500 hp TPI engine" ended in ridicule and significant "correction" of the original poster in decades past, and folks have theorized "any day now, someone's going to come along with a 500hp long-runner TPI build" and it's quite possible with bolting together some nice parts today.

RCS Racing sells their 460 HP FIRST TPI 383 crate engine with a WARRANTEE. An extra 23 cubic inches and +.125" more bore, a step better head and cam and you've cleared 500 hp as easy as falling off a log.



Adam
P.S. That Throttles build is cool too. Those guys are amazing!

 

I engaged over on the Corvette forum about 2 months ago and think the two links I posted below are similar to what you're looking for.
https://www.corvetteforum.com/forums...post1604823933
https://www.corvetteforum.com/forums...post1604845864

 

its always been a number that gets thrown around. 500. Everyone wanted 500 hp at one time. Maybe they still want 500. Lol most dont seem to build sbc anymore and just ls swap it. I just think a lot of ppl just dont really know how much 500 is and what it took to get there, especially years ago. Today there are better parts and knowledge so to speak, better efi systems to help with tuning, even tho stock ecm could do it

tpi certainly makes it difficult. Runner length makes it hard to get the air mass required. The runners and radius can only be so big before running out of room. So could a 500 hp tpi exist? Yes it has already been done by 1989gtatransam in his long runner project and 369” sbc. Think it got to 440 whp.

but it wasnt like he bolted parts together and it wasnt a out the box intake. If it was so easy to get 500, kinda have to wonder why it isnt more common and results posted.

Regardless a healthy 406” sbc with a first tpi would be fun

 

I spent several hourse measuring and inputing data on Engine Analyzer on my 383. Just an 11:1 383 with a ported L31 truck manifold and 80mm throttle body.

 

Just truly outstanding content! Doesn't get better. I couldn't read past post 170 on my phone because CF on my phone just EATS memory and crashes my mobile browser. Finally getting caught up on that thread today.

BadSS, your contribution is SUPER appreciated there.

Adam

 

did you get dyno numbers to compare?

 

No but I do have airflow numbers from the MAF, a known injector flow rate and injector duty cycle values and its not hard to get a fair estimate of power and thus torque. GMS/SEC airflow multiplied by 1.2 is pretty close to crank HP. 422.28 x 1.2 is ~506 hp.

 

I can't tell what the FIRST combo with the "more appropriate cam" reached for peak torque from the chart exactly, but looks like 545 ft lbs @ 4,000 and then an hp peak of 492 HP @ 5,200 RPM.

I AM super curious what the cam specs looked like on that cam, if it's something you're willing to share.

-We also know from BadSS's early assessment of the ideal runner area / min CSA that it's possible to move a 383 FIRST combo's torque and HP peak "further to the right" a couple hundred RPM, which even on the 383 combo would surely clear 500 HP. -Another +23 cubic inches and .125" of bore area, and stepping up from a 2.055" intake valve on a 4.030" bore to a 2.080" valve (or from a heavily shrouded valve to valve with plenty of valve to cylinder wall clearance), surely makes 500 hp SIGNIFICANTLY easier.

(Although honestly, I think the more compact chamber and the faster piston speed and quench velocity from a 396 would help avoiding knock around the torque peak more than a larger bore 406 with less stroke...) -Getting the extra airflow on the 4.030" bore, the big cost jump to go to a forged crank, and the extra stroker-clearanced rods to avoid going to a reduced base circle cam makes a 406 cheaper and easier to get to 500 hp, even if a 396 might be more knock resistant.


@BadSS I know you've got a TON of time in collecting all the details necessary to simulate these FIRST combos in EA Pro, but I have to ask whether you'd be willing to share the dyno file to let someone else try out a few modifications to the combo. (I'm definitely interested in seeing what a solid roller cam is worth and how it might allow a bit more RPM while keeping the DCR the same, and also swapping out the AFR 195cc heads for the Chad Speier SFactor 205cc and his 220cc heads, or seeing what the AFR 195cc comps are worth; the Speier / Profiler exhaust ports are behind AFR by quite a bit and would need more exhaust side duration, I'm almost certain...)

-Totally understand if you've just got too much time in the sim to share those, though. (EA Pro is totally outside my price range, but I've been considering either the standard version of EA or DynoSim 6 from Larry Atheron. Larry has highlighted that wave calculations in DynoSim 6 are QUITE basic and I don't think it's going to do a "good enough" job for evaluating long runner stuff.)

I just upgraded my PipeMax license to the new version, but I'm still trying to figure out all the changes to v4.0 -like the critical "% VE loss from induction system" value -which seems like pure guesswork...


Adam

 

I didn't model these in EA Pro, it's too complicated to guess at a lot of unknowns. I use EA Plus for anything I post on the internet when I'm not actively involved in the build. EA Plus does a really good job and gets really close, but doesn't have enough coding (due to the price) for it to be very accurate under 2500 rpm. It's very good at hitting peak power numbers and peak RPMs though and the curves from peak TQ to peak HP are pretty dang accurate. If you're looking for a moderately priced simulation, I'd highly recommend it.

You said you were having trouble access the later posts, but here are the specs on that combination, including sharing the cam used in the simulation.
396, 10:1,
Miller's head specs:- estimated intake volume of 205cc, 2.05/1.6 valves
0.1 - 84/56
02 - 157/120
0.3 - 220/171
0.4 - 267/199
0.5 - 297/218
0.6 - 308/223

Stock length FIRST runners (15.5" plus 5" head runner length = 20.5"), ported to 1.825" - time consuming but not that hard to do (1.75" stock), stock FIRST base (1.85" is stock but would need to gasket match at the heads and do mild porting/blending about 2"),
Custom Comp Cam 112 Lobe Spread +2 Advancement



Headers: 1.875" diameter, 30" Primaries, 10" collector, uncapped.
Simulated with production water pump, typical windage, lower friction pistons, STD correction factor

Simulation estimation below - 570lb/ft @ 4200 and 528HP @ 5400 RPM


Changing to a solid roller to get lift up and giving up 1" of vacuum gets you about 10lb/ft and 25 HP (580/553) moving peak HP up around 5600.

Simulated 406 adds about 8lb/ft and 5HP,,,, everywhere - peaks are the same as the 396.

 

Wonderful! Those really ARE great heads!
Another couple points of compression let you keep the same cylinder pressures with a couple degrees more duration and move that curve to the right to target a 6,000 RPM HP peak, I'd expect it to make a couple more numbers.

If you were going to build a 406 from scratch and didn't already have heads, a 2.08" intake valve would flow a couple more CFM at every lift point and I'd expect the move to a simulated 406 with the 2.08" intake valve to gain more over the 396 with the 2.05" valve.

I'm not saying they're remotely budget or inexpensive, but the Speier Sfactor 205cc heads are very similar to that Miller guy's heads. Chads' site says they were flowed with a 2.055" intake valve and on only a 4.000" fixture, but he sells them with a 2.08" intake valve as the stock option so I'm not sure what to make of that...

Both Mike Jones and Comp have slightly more aggressive hyd lobes that can get you to .600" of intake lift, too.
-So again, it's not CHEAP but a "bolt together" 500 hp FIRST-based SBC 400 is quite possible -with the exception being that you'd have to open up the FIRST runners. (Ken will CNC the exit to your choice of Felpro gasket sizes included in the price.)


http://speierracingheads.com/205cc-street-factor.html
2.30in² MIN
​Straight Plug
64cc chamber
1.320 x 2.230 opening
Fel Pro 1206 (trim)
2.35in² AVG CSA
5.33 port length
205cc runner
2.055 intake w/32º BC
1.600 exhaust
4.000 fixture
.200 147/115
.300 208/149
.400 256/183
.500 289/202
​.550 300/209
.600 303/216
.650 305/220
.700 306/224
.800 310/230
.900 312/234
1.00 314/237

Why haven't we seen it done? -My take is people generally think it's impossible and any discussion that a long-runner / TPI-looking build could POSSIBLY approach such power is immediately and repeatedly shot down, so folks with the will and the wallet think it's an impossible quest and call it off...

One person doing it, proving it, and documenting the "recipe" opens up the possibility in people's minds and one of them being built opens the door to more of them being built.

Adam

 

The heads on my 383, ported by Lloyd Elliot to match stock vortec intake and exhaust gaskets in both size and location are not that far off. Flowed on a 4.030 jig and with a 2.02/1.60 valve. Lloyd knew my setup was for torque and a lift of 0.578. Mine are right at 210cc.

.200----------138-------107
.300----------192-------138
.400----------241-------164
.500----------274-------183
.600----------291-------193
.700----------295-------199

 

The Speier SFactor 220cc heads have a 2.08" valve and were flowed on a 4.155" bore for a 406, so not but they're outflowing the AFR 220cc competition head for about $300 less. If you want the best performance with "regular" SBC rockers and you've got the cubic inches and RPM, they seem great. The only potential downside is that the exhaust ports are WAY behind (almost embarrassingly so..) the AFR heads, so you'd need more exhaust duration with the Speier heads, but they're standard height exhaust ports so no header fitment issues...

2.40in² MIN
​Straight Plug
64cc chamber
1.320 x 2.230 opening
Fel Pro 1206 (trim)
2.46in² AVG CSA
5.45 port length
220cc runner
2.080 intake w/32º BC
1.600 exhaust
4.155 fixture
.200 147/112
.300 202/143
.400 257/173
.500 298/194
​.550 314/203
.600 326/209
.650 328/215
.700 329/221
.800 331/226
.900 332/230
1.00 333/233

10 CFM ahead of AFR @ .600" lift.
http://speierracingheads.com/220cc-street-factor.html

Adam

 

It's fairly easy to get big flow numbers just by making the port bigger, which can be counterproductive. Jump to 5:26

 

Thanks for the reminder! I've heard Chad say it before, and Darin Morgan before him, in his now taken down prior blog (I guess Reher Morrison made him take it down?), that you shouldn't evaluate an exhaust port based upon flow bench numbers, but I'm still never quite sure what to do with that tidbit in the real practical world...

Darin's quote before the blog got taken down was ""The pressures the exhaust port has to deal with in the running engine are hundreds of times greater than the flow bench could possibly simulate. Ask yourself this: why would you design a port using 1 PSI test pressure at 70°F, when it’s actually flowing at 500PSI+ and 1300°F?". He also talked about evaluating how quiet the exhaust was on the bench just like Chad does in that video...

But as far as I can tell, a head with a worse-flowing exhaust still requires more duration on the exhaust side and eventually that leads to reduced torque in the midrange right?
-I'll definitely take a better intake and a slightly worse exhaust port over a slightly worse intake and a slightly better exhaust port, but when the exhaust ports get SO FAR OFF, I can't help but think about the downsides...
(The standard Profilers with their raised exhaust ports are better than the standard height casting that Chad's using in the Sfactor linup, but even those flowed considerably worse vs. the AFR exhaust ports. -At what point DOES the exhaust port's flow still matter?)


I just can't fully get away from the air bench #'s on exhaust ports... Darin and Chad drop that bomb that you can't use the flow bench to evaluate an exhaust port, but then we're still not left with an alternative and there's obviously a point at which the exhaust port becomes a factor limiting power -what is it? -This new revelation came without a guideline, so it's really hard to know what to do without it... "Just trust us, it sounds good on the bench", doesn't feel "good enough"; anyone can say that...

It would be awesome if SuperFlow came up with an exhaust bench that pulled 100" of vacuum and used 500F air temps to more accurately evaluate an exhaust port (or some flow meter that runs in a standardized header collector on a running engine or something..), but until such a thing exists, how ARE you (and cam designers) supposed to evaluate a heads' exhaust port and it's potential impact on power (very real question cause I haven't a clue)?

Adam

 

I actually read an engine masters artice where the engines performance was better across the board running 1.3:1 ratio break in rockers on the exhaust. Exhaust flow is probably the least important aspect of a cylinder head. Also I have had very good results in numerous engines with a single pattern cam. I only used the split pattern in my 383 because my heads are stradled with the stock vortec exhaust port size and location along with 1-5/8" primay tri-ys flowing into cats. With a 2,800 rpm stall converter and deep rear gears was less concerned with low-end torque.

 

Wow. 1.3:1 is extreme; surprised by that. I definitely noticed that the newest generation of cams finally have exhaust lobes where the exhaust side has less lift than the intake. One more reason that friends don’t let friends run comp XE flat tappets: the exhaust lobes have more lift and duration than the intakes because they’re just reusing the next size up intake lobe on the exhaust side; you can see it in the master lobes catalog. They can’t even be bothered to put an actual exhaust lobe on the cam because why do they need to? People will buy them anyway…

1 5/8” tri-y’s very nice! Doug’s / Thorleys or Stans or ??? I honestly really wanted a decent TRI-Y for my car and Stans is out by me but their design is definitely dated and limits upper rpm power AND they want almost $1000 for their mild steel header for my car; for $1,100 I can get actual stainless steel with race style merge collectors and merge spikes from ARH. I do wish there were more tri-y shelf headers…

This is on your van right? (Perfect app for small tri-y.)


Adam

 

But "anyone" isn't saying that. Two of the performance Industry most accomplished induction airflow management technicians are saying it. And if you take the time to sift through some of the older indepth technical posts from back in the day at speedtalk you're going to find that many experts have eluded to the same thing. I suppose the question you have to ask yourself is who are the people pushing the boundaries of 23° sbc heads in this day and age, and if you can't take their word at face value then who can you believe? And another thing, who else of their caliber is willing to share the technical information that they have? And at end of the day you're not talking about a highly competitive class engine, you're talking about a max effort street car engine build. Maybe splitting hairs for the hp per cubic inch results you are seeking? I mean, until you buy the best block money can buy, pay for above industry standards machine work and attention to detail while assembling and leave no stone unturned in your search for power.. debating if they are being upfront about a 220-230 intake runner 23° head is kind of silly isn't it? I have no dog in the fight, but I have noticed that Chad Speier doesn't speak often, yet when he does those that are in "the know" have almost never stepped up and made any attempts to contradict what he says. To me that says a lot about the man, and his integrity. Further, I have not heard of a single person that has worked with him and purchased his products in an attempt to make their program faster, more consistent, etc have anything to say except to sing praise. Literally not one person with something negative to say after purchasing his products. And please don't take this the wrong way.. but who the f#$k are you to question what he has said? I mean, has your extensive experience and years of development and testing shown you a different outcome? I'm not trying to make you look bad, rather point out the obvious thing which is.. if it looks like a duck, walks like a duck, and quacks like a duck.. it's usually a duck my friend. At the end of the day it's a dang 23° sbc. Work with someone you trust to get you the results you seek. But seriously if Darrin Morgan or Chad Speier aren't on your short list there isn't going to be anyone you trust.MBE maybe? And I get your meaning, that it is hard to take things at face value for a thinking man, and you weren't attacking them either, rather you posed a question of when do exhaust port flow limitations begin to matter. Because you are on a quest to expand your own personal understanding of the forces that determine maximum output. Further, I know you weren't attacking anyone. I can offer this, if you are a paying customer of Chads he will take the time to explain things to you, I drove him bonkers asking questions when he helped me with my project a few years ago. You'll find him very honest and forthcoming. I'm sure Orr and others who have been a customer of his in the past will agree with that. The man knows cylinder heads and induction systems better than most. He is humble too, often makes reference to his friendships with industry leaders and late night conversations picking their brains in the ongoing attempt to further his understanding and skills in interviews he has given. A true professional is always learning. So I wouldn't be so quick to lump him into a discussion where you state "he says, but anyone can say that" I suspect the questions you are asking are starting to tread into areas that they may be reluctant to discuss indepth due to them running a business and trying to maintain a competitive edge above others. In the speedtalk threads where indepth technical discussions were occurring they seem to hit a point and then get quiet, as I'd those involved stand back and say I have said to much already. It's their life's work, how they feed their families so to some extent that is to be expected.

 

it really isnt that simple imo. A better header on a slightly lower flowing port may ultimately be better than a good port with a undersized or restricted header. Cam timing needs to go along with the exhaust design. The best designed header for best scavenging may not work if cam exhaust timing is not in tune with what the header is trying to do. Sometimes good scavenging needs less exhaust lobe. So it may not mean less torque or power.

Typically you want the exhaust port sounding good on the bench, as stated by darin and chad. Then i would say compare the port size and flow on two heads if both have a good port that sounds good on the bench lol. But like said, flow is not as meaningful here. Its under high pressure, so it will get out. Chad has stated he has purposely made exhaust ports smaller and reduced flow and engines made more power and accelerated quicker on dynos. Not the first engine guy i have seen say something like this.

also, in the lsx world, i have seen a number of torque cams where there is a wider duration split than you would think is necessary. So more exhaust duration isn’t necessarily a bad thing for power production as long as the rest of the components support it

 

Then again in the LS world seems only a few are now flirting with tighter LSA cams with shorter duration. Summit measures the cams they sell in house. The Truck Norris is a single pattern 212/212 on a 107 LSA and 0.554 lift. It has more average power than several of the other hot truck cams. I mean it made more power than a Stage 1, Stage 2, or Stage 3 truck cam and never lost torque anywhere.

As for cylinder heads, Lloyd basically said the same thing to me. The exhaust is going to get out. If you look at most of Lloyds grinds they have less intake/exhaust split and a tighter LSA than most of the off-shelf cams. Shorter exhaust duration and tighter LSA still gets the job done with overlap and does not blow as much torque out of the tailpipe.

When I ran my 383 on the stand at my shop, my neighbor made the comment it was unusually quiet even with open headers. I told him it was because the engine was not blowing all the combustion pressure out of the exhaust ports before it pushed the pistons. His turbo LS stuff is pretty radical and without the turbos, downright loud.

 

Right. The earlier you open the exhaust the higher the cylinder pressure is, so you have more volume of gas coming out at higher pressure so it should be noisier.

tighter lsa while keeping intake center the same just opens exhaust later. Get more combustion time and work applied to piston. Wider lsa stuff is earlier so makes sense

always was surprised why lsx guys never went very tight on lsa. Part of it probably was because piston to valve clearance with no reliefs. Other part was the better the cylinder head, typically dont need a lot of overlap and tight lsa. 11-15 deg factory heads flow well so makes sense, and being efi, its nice to have abit wider for idle manners.

 

I think I'm doing a bad part getting my point across, based upon your reply.

I don't quote Chad Speier or Darin Morgan or explicitly look to what they say because I DON'T trust what they say; I seek out and quote their advice, because I DO trust it.
-I'm not saying that I wouldn't believe Chad or Darin if they say that a head has a good exhaust port.

My concern was: "How is a normal person supposed to know which heads do an DON'T have good exhaust ports?" You can look at the CFM flow on a bench on the intake ports at a given average and min CSA and get a good idea on an intake port. But there's no objective data available for knowing whether a head you're looking at has a good exhaust port before you purchase it or not in this new paradigm. -Except to have some top-tier head guy tell you "Yep, that's a good one."

I guess that IS actually good enough, but I'm mostly just mourning the loss of some objective measure of "how good an exhaust port is" that can be evaluated by a mere mortal...
"dB of exhaust port @ 28" depression" -Even that would be a reassuring objective #.

Numbers are warm and comforting. ;-)

Adam

 

I get that, but it's good to keep hearing it over and over so maybe it sinks in. I've definitely seems some very good fast headers throw fuel out the exhaust and understand that less exhaust duration could be warranted.
-My concern is just how a "normal guy" evaluates whether a head has a good exhaust port or a garbage exhaust port, now that this new paradigm means that there's no objective data that can be used to make the decision.
It just feels like we move back into a place where marketing departments just get to make wild claims and there's no objective way to prove whether they're right or full of it.

Adam

 

its like anything else in life. Unless you have direct experience, have been trained in the discipline, etc, you wont know what you are doing and need to consult expert opinion. You go to a doctor to diagnose whats wrong with you. People have experts do the work on their vehicles, their homes, their yards/lawns etc. some learn the trades to do it on their own, but you need to have experience built up and to work with it to gain understanding of what you are doing

so yeah, heads are the same way. You can look at port measurements and numbers and think about what they mean. But unless you run the heads and compare how they run with others, you wont really know how they stack up. So you need to talk with engine builders and head guys on what heads work best for what you are doing.

 

Sorry for belated response, I get the impression for them to talk about it in-depth with explanation is either treading on proprietary, or above the understanding of anyone who doesn't have extensive experience with port work and the equipment. They could explain it, but without a bench, pito tube, etc it would Be difficult for you to put a number to "that's a good one" we are fortunate today to have professionals that disclose the info they do. Wasn't 25 years ago that porting was some black art well kept secret. At least we have the Darin Morgans, Chad Speiers Eric Weingartner s, David Vizards of the world disclosing the things they do.