Yup, by my pic i was hoping twin plenums and throttle bodies.


https://cimg3.ibsrv.net/gimg/www.off...f59e7be37.jpeg

Like kinda similar to Holley’s Snioer intake for the LS’s. Oh well. :(


https://cimg7.ibsrv.net/gimg/www.off...18cab6ef5.jpeg

more like "gay dolphin porn" :D :D

My favorite. :thumbs

could always buy some intake tubes and start tig'ing a manifold together.

https://www.williamsenginedesign.com/intake-runners/

Was wondering why Valako or others haven’t been fabricating them. On a larger scale at least.

I wonder what the details on the 'Modified plenum chamber shown on manifold base 540-572" are?? I have extensively modified 500 efi manifolds, other than carrying hp on a 540 to 670/680 range flat to about 5600/5800 with a big torque tradeoff (but I never finished true testing of limits with a 9.5 or 10-1 engine). I have seen either a AZSM 500efi style upper with upper dividers removed in one random internet pic (or it was done by lingenfelter or innovation) but never seen anyone mention using one. Is this a pic from old advertising or something recent?

https://cimg0.ibsrv.net/gimg/www.off...4f0897bf7f.jpg
aside from the 500 lower I personally modified, first time Ive ever seen one like this, found it searching those images that were uploaded, I see it was something flagship offered from AZSM in 2009, havent ever seen it anywhere else and I dont think it caught on or maybe didnt work great. My testing with similar gave mediocre results, big tq loss but did carry rpms, hp higher, Smitty

supposedly asm did the r&d and owned the manifolds and mercury paid a fee to them for use of it...

I see Engine Masters mentioned on this thread and I’m a huge fan.

The guy that runs the dyno (sorry, don’t remember his name) often mentions motors he’s built for race boats, and I think specifically offshore.

Anyone know of him?

Seems like a very sharp dude.

He often catches what the other guys miss or are stumped by.
(Dulsich is also very sharp)

Steve Brule, sharp guy

Brule has worked at Westech Dyno for seemingly for ever, The Hot Rod and etc msgaxines had used them for long time too. Freiburger worked for thise mags seemingly forever too.

Anyone know of Brules race boat motor building?

The Engine Masters TV series started as a magazine story which became an annual event.

I think in Popular Hot Rodding.

Then its own magazine series.

Was very cool.

Each yr they devised new rules for the season.

I.e., OE iron small blocks, any head, any cam, sgl 4 brl NA.

Anyone could enter.
Saw some cool packages.

Now morphed into the TV show.

Tons of history in that dyno cell.

I just never heard of Brule, or his race boat motor building until seeing him on TV.

The other guys have been around forever.

Steve Dulcich wrote for all the old Mopar muscle car mags I used to read.
Very sharp dude.

I believe that to be true,in my collection of 500/525 intakes , one has ribs on top plenum and am pretty sure that is the version aszm personally sold. But the upper normally has a divider and lower divider goes up square to meet the upper, this picture I found off a modified 500 efi lower actually ever being marketed, modified is first Ive seen and I been chasing these mods for quite a while. heres a stock one vs one i modified
https://cimg3.ibsrv.net/gimg/www.off...1c70cff83c.jpg
stock intake
https://cimg5.ibsrv.net/gimg/www.off...60496a8002.jpg
one i modified

Brule is the brains behind all of that. Incredibly smart guy when it comes to tuning.
Freiburger just retired from the magazines after 30 years.

https://cimg1.ibsrv.net/gimg/www.off...76f11d8cde.jpg
Our finished 525 throttle body.
https://cimg2.ibsrv.net/gimg/www.off...1a73de6180.jpg
Spacer to extend throttle body out to help #1 short radius.
https://cimg4.ibsrv.net/gimg/www.off...e3eecb0e58.jpg
525 liwer ported.
https://cimg5.ibsrv.net/gimg/www.off...494e2e7f44.jpg
Lower with big injectors installed.
https://cimg6.ibsrv.net/gimg/www.off...b224385fa5.jpg
525 stock throttle body.
https://cimg7.ibsrv.net/gimg/www.off...2c6e6b1654.jpg
525 intake top with stock plate cut off.

We were able to achieve 700 hp, 700 lb ft. With these intakes.
565 cu in. 9.3 comp. But they were done. Came to the conclusion it would be much better and cheaper to just have intakes made to what we wanted. The nice thing about sheetmetal intakes is you start with a clean sheet of paper.

This thread has certainly peaked my interest. I have warmed up 500efi's, making 625hp. Aluminum Promax heads, 509ci, cam, bigger injectors and porting to intakes. Wonder if theres any gains left on the table with a tunnel intake? Kwright, really dig your build and read your resto thread in fountain section, well done.

Agreed, eventually you hit a wall and it becomes futile, but none the less you're still 100 hp up from where you started. good thing for boats is they make a ton of down low tq..

Probably some but NA 509’s your nearing full potential (within reason) unless you were gonna turn it 6k plus. Where did you peak with current builds/mods? I’m sure many would disagree however I’d target in on stroking them. Then at least you knew going into it you’d see a 75 hp gain min without spending a bunch more money. Just a guess but cost of the tunnels PLUS some costly porting$$$. Could probably stroke for under 3k a side.

The short answer is yes. But at what cost, and what final results are you looking for. Fortunately for me, two of my good friends own a speed shop. Fully equipped with CNC's dyno, and all the machine shop equipment it takes to develop and build engines. 10 years ago when we set out to see how much hp we could make out of a 525 efi based engine we had no idea. We were lucky Dustin was interested enough to tune the computers for us. After many hours modifying the intakes and countless dyno pulls, we cam to the conclusion the intake runners were too long, plenum was too small and all the modifications in the world was not fixing that design. So we went with the Hogan intakes. After about 30 more pulls and having plenum stuffers made we achieved the results on our current dyno sheets. To be honest we could got the same results with the 525 Whipple kits. And a hell of alot cheaper. If you are intent on building NA engines with a 500 efi your first bottleneck is the intakes and throttle body. Just won't flow the air needed. Once you get beyond that cu in. I personally wouldn't go any bigger than 565. Then cylinder heads is going to make you your big numbers, find yourself someone who can support their claims. It definitely is not cheap, but their comes some satisfaction from running away from those 700 stage lll boats.

I was at 640hp/670tq w AFR 315 heads, 741 cam w double swap,bigger injectors,asm mono blade but i had 8:1 compression, you can prob get a little more by bumping that

Problem is with 500/525 motors regardless of heads If were still talking lightly modified factory intake (tb, port matched), runner length, size and plenum volume kills ability to carry hp, rpms. Going to a 540 will give you more tq, it will also "runout of intake sooner". Light mods/cam, good heads get most of them in that 620 range, putting a cam in that would raise peak higher normally raises rpm tq peak happens at but hp barely goes higher up since intake is the limiting factor. some different schools of thought, some successful builds around these intakes focus on making great tq, ie, this 660, 680 range with hp falling flat at 620, 630. a cam size increase that would normally raise peak another 400, 600 rpms and gain 40, 60 hp is lucky to gain 10 and torque tradeoff is much greater. Im still torn on which way to go with my own 500 style engines, a edelbrock proflow intake will take one instantly from 620 to 680/690 hp BUT with its 5.5, 6" runners give up signifigant tq. These custom intakes if sized properly with medium length runners is real answer if its in someones budget, ie, a 6' runner makes mediocre tq, a 14" runner makes great tq but dies on top, a 7 or 8" runner thats also extended into plenum another inch or 2 would be pretty cool, Smitty

Blappppp ! lololol
Just playing here...
Choose throttle size, Make runner length per app, and then Put a flame arrestor on top. LOL
Kinsler, now owned by Holley.

https://cimg4.ibsrv.net/gimg/www.off...09d9b7b34c.jpg




https://cimg8.ibsrv.net/gimg/www.off...a3c27f5d7d.jpg
https://cimg3.ibsrv.net/gimg/www.off...ac6582239d.jpg

https://cimg0.ibsrv.net/gimg/www.off...f9201c7062.jpg
https://cimg1.ibsrv.net/gimg/www.off...36fa34f44a.jpg
the first dyno pull is with RFD bb3 CNC'ed heads 1 7/8 primary headers.
Second one with RFD 24b CNC'ed heads with 2 1/8 headers.
same cam, compression intake and throttle body. The only other difference is second one is dry sump running 10 inches of vacuum.
alot can be said of increased cylinder head tech in the last few years.

To bad mr chinaman didn't make one of these partial intakes for the bbc. Would make it much easier to make a plenum for each side and run two tbodies.
https://cimg4.ibsrv.net/gimg/www.off...9317f46a70.jpg

I have one of these kinsler style intakes on a 572 we’re putting in a pro touring style 69 camaro. Real cool setup with Holley hp controller.

Anyone remember that guy with the orange 50 hustler with triple 600+ cu engines? He made some nice intakes out of tunnel ram base. I can’t remember his name or find pics.

I'm doing stack injection on my 572 for my gasser, im using the borla kit. their manifold has all the vacum underneath so it gets a cleaner look and less lines to run. also no remote thermostat and filler.
https://cimg9.ibsrv.net/gimg/www.off...190a3f7e2c.jpg

That is a bad ass setup $$$$$

The stacks have been great....been running this with the Holley HP for about the last 9 years. Bought the Enderle stack from Alkydigger - had the injector bosses cast in and integral thermostat housing. I'm not sure if you can still get them or not. I had to make the vacuum manifold, but did it all under the intake so you can't see it. I have a thread on here somewhere detailing the whole conversion from carb to efi.


https://cimg0.ibsrv.net/gimg/www.off...6f70735370.jpg

Gettrdun,
Not sure on the exact numbers. I dont have the dyno sheets. Motors were done when I bought the boat. Not really interested in opening up motors to stroke them. Im i know im over simplifying it, but figured if there was a decent gain by just switching intakes and tuning, why not.

Well just figured out how to multi quote. Lol. Anyway, lots of good info here. I know Im over simplifying it, was thinking it would just be cool to have 700hp by just switching intake and tuning. Not sure my exact numbers, I dont have the dyno sheet. Motors were done when I bought the boat. I know Eddie Young tuned it, might be worth a phone call to him, and pick his a brain a bit. Ill probably just leave it alone. Then Ill have to address the bravos.

I believe Motortrend did an Engine Masters episode on the stack EFI manifolds recently and even played with stack lengths, but it was on a 350-ish ci SBF I believe, so not quite in realm of what I'd think the stacks would be optimal on (big inch motors). Results were very underwhelming compared to a more conventional intake setup surprisingly.

Please PM me how to multi quote! 😂. I always screw it up.

its easy,hit the multi quote tab on every post until the last one you want to quote,that last one you hit the quote button and they all get quoted.

Oh 🙄. Like the button right next to! Wtf is wrong with me. Tks though. I needed a kick in the azz. 😂

Btw No raaammm’s for getrdunn johnny! Or shaft rockers. I can’t gamble the timeframe on either. T&D claims they don’t have a direct figment for such regardless.

we run the crower stainless rocker shafts. If I were to run a rocker arm it would also be their stainless one. JMO.

Same heads? If so I’ll ck them tomorrow. Tk u