87 octane 636hp 499 stroker

There is not too much detail in what the specs are in this engine combo. I am curious as to how one can build so much power and run 87 octane. The static compression is 10.5 and has Victor heads but it doesn't state the cam specs aside from its a roller with .600" lift so we don't know its timing events. Any thought on how someone would make a similar build and how much power was left on the table by building towards 87 instead of 91+ octane. For me the thought of 600+hp and 87 octane seems too good to be true.


https://www.enginelabs.com/news/running-on-87-octane-636hp-mopar-big-block/

They make 10 to 1 800 horse aluminum headed strokers motors all the time. Catalogs are full of them that run on premium.
I had a 30 over 318 that made 477 horse on 91 octane
Knock 1 point of compression out of it...... is what 3%-5%..... not sure of this combo, but those figures didnt make me raise an eyebrow.... at 500 inches with a roller cam

Big help: small advance until 3,000 RPM

What are the key components and specs to achieve 600 hp on 87 octane? Most of the 500 stroker builds I see posted in the 600+ how range all run 91-93 octane. If it's easy to get 600hp on 87 I would think more would be building towards this method. If a roller and a solid tappet cam have the same lift it would be easier to do with the roller because of the decreased duration for the roller compared to the solid allowing for an increase in cylinder oressure correct? I've been trying to read about cylinder pressure and dynamic compression but but it's not clicking in my brain on what is required to prevent detonation.

Yeah I can see that happening, especially if the engine builder has some experience with that type of combination. If I was building it I'd use a flat top piston near zero deck with a 0.036 Cometic gasket. Put a reverse dome in the piston to get the compression ratio in the low to mid 10's and you should be there.

Running on 87 octane wouldn't be a big problem on a dyno since you have cold water, lots of airflow around the engine and usually start the pulls above 3000 rpm. Having it run on 87 in a car might be a different story.

EFI would help a bunch, especially if the EFI controls the ignition timing. It would take a pretty good tune to get a Dominator and a spring and weight curve distributor to survive on 87 octane on the street.

Seriously doubting these results on this build. Peak TQ and HP occur at awfully low RPM's considering the Victor heads. Like Andy said 87 for a dyno pull = BD. In car is different ball game. J.Rob

Along with the big intake and carb.

The fender well headers do lower the peaks, but 5300 seems a bit too low.

I dynoed a 505 last fall with a small hyd cam, rpm heads, and an original torker(which is not a high rpm manifold), and even that very mild combo made peak power at 5100.

542 with EZ heads, 440-3 manifold, and 1-7/8” fender well headers made peak tq at 4500 and hp at 5900.

i was thinking the same... i mean, i have doubts in such results on that build... or maybe there's something i can't understand?

I thought it sounded too good to be true but I just curious if it could be done. Around 2010 I bought a 505 kit and non-cnc ported heads from 440 Source for my 65 coronet. The kit i got is a 4.250 stoke 4.35 bore -27CC piston I figured my compression would be around 9.7 if I mill the heads down to 80CC. Back then I was saving money to get the heads cnc'd and for the rest of the components for the build then I bought a house,then got married, then had a son, and am about to have my second son so so all my car money went to better causes. I am finally in a spot where i can work on obtaining parts for my car again. This started my journey into octane requirements and if I could tweak the rest of an engine to run on 87 swill and still make good power. I haven't been able to find much about any engines running on low octane and saw this guys build and figured I'd see if it was doable. I appreciate everyone's input!

I would look at what results you want from the stroker motor and how often you drive it
Are you willing to sacrifice some performance for better gas mileage or are you willing to buy the better pump gas for better results

My 505 makes 600 HP and sips pump swill 87 with no problems.

CNC ported stealths, 10.63 CR and very mild hydraulic roller.

I was more interested in big torque for the street.

I try to run 91 no ethanol in it most of the time, though.

My yard equipment won't run on 87 here in CA. Won't run on 91 either...
As seldom as I drive my old iron, I don't mind obtaining good gas. It ain't cheap anymore but it's way more fun!

First thing to understand about stuff like this is that a magazine article is just a single data point. I write magazine articles and we're limited on time and budget. Magazine articles are not the same thing as OEM testing. The guy who wrote the article probably put 5 or 10 dyno pulls on the engine and printed out the dyno sheets and wrote the article. I doubt that he fabricated the numbers and I'm sure they put 87 octane in the fuel tank. But that doesn't mean that engine will run on 87 octane in a 4000 lb car in the middle of the summer going up a hill. That wasn't the test condition. The dyno test was probably on a nice cool day with big fans blowing on the engine and cold water in the water tank. So yeah, the article is probably right but it doesn't mean that the engine in your car will run on 87 octane fuel.

A 9.7 engine with 440 Source heads (good quench pad) should run on 87 octane IF the pistons are correct. You need to be close to zero deck (0.005 down or so) and 0.036 or 0.041 head gasket. If you do that it will work. Then you can play with cam timing and ignition curves and stuff like that but it should work.

Cool, thanks for the information Andy. I don't need a max build. The car will mainly street driven I would love to get into bracket racing but know that would be down the road a ways. I have no plans of ever putting a cage in the car so I do not need gobs of power. Im aiming for a fun easy on parts and maintenance street machine. Figured a cam like Hughes/Howard's around 242/246 .564"/.576" with 1.5 rockers would be a good fit but will probably consult with a professional and get a customer when it's time. I do find myself occasionally drifting in thought and going more aggressive... sell the stealths go trick flow 270s and start shooting higher!

Yeah, me either! That went out the window... With that combo, 11.50's are pretty easy. My second time out I went 11.30's with a smaller cam than what you have listed.

For street driving you do not need a big cam, even in a 505. A 242 @ 050 is plenty big, you could go a few degrees smaller and still have enough power to roast the tires in all gears. If you aren't going to race it then keep the cam small so you can enjoy the car while driving around with the wife and kids.

Ill have a dyno pull in a week or so with a stroked 440
10:1 and 240 trick flows , hydraulic rollers and cast manifolds and six pak
Cant wait to see - hope for 500 .. builder thinks 7.
594 lift , seems high , but I guess the roller deal tames it. Not sure
how it all works — i hope it idles like my ol bob k cam
Everyone involved says it will be tame and super reliable

GY3, could you tell me more about your build? What kind of suspension are you running? What tires? How do you like the hydraulic roller? Did you bush your lifter bores? I was leaning towards a solid flat for ease of use and cost but I'm still open to other alternatives. It seems every cam has its positives and negatives and people get pretty passionate about it!

AndyF, I need to go back and read you stroker cam shootout and your book again. I remembered you saying you don't need much cam for a street build. I've probably getting a little wrapped up in reading other people's posts who do more true street/strip!

Nice! Look forward to seeing you post the results! You'll have to let us know the street manners once you drop it in! What kind of lifters did you go with?

Sure!

Cam is Howards 288/294 (235/241 @ .050"), .545/.545 hydraulic roller. I did not bush the lifter bores. CNC Stealths, Crane ductile iron rockers, Manton pushrods, Molnar 4.25 crank and 7.1" rods, Mahle pistons, 2800 stall Turbo Action converter, fwd pattern Cheetah mvb, Dana 60 with spool and 3.54 gears.

3 way CE shocks up front with 6 cylinder bars. Cal-Trac setup with their 9 way shocks out back. ET Street Pro rear tires. Weighs 3600 lbs. with my 210 lbs. behind the wheel.

I went with a hydraulic roller after having a flat tappet MP.557 go flat. I absolutely love it! Very quiet valvetrain.

The low deck 470 that I had 20 years ago was 10:1 compression with HP manifolds and Edelbrock heads. It just had a Mopar 0.528 flat tappet cam in it. That engine would roast the tires in the first 3 gears and would run high 11's in a 3800 lb B body. If you are really just driving on the street then you don't need much more than that. If you are racing then sure, turn up the wick but then you have to live with the downside.

I ran that .528 MP cam in a 440 with 3.23 gears and loved it!

We used
Morell Hydraulic Rollers