stroked 409 RPM limitation

[Ishiftem]

What are you trying to accomplish? You can make 625 hp with out spinning it past 6500 so why would you want to build a engine that is going to be very peaky where it makes its hp at 7500 rpm? Especially with only a 3.36 gear?

 

[Skip FIx]

Yep with 3.36 you want a broad torque curve which most strokers are going to give you.

 

[Iowa 409 Guy]

Me too. I don't understand where 7,500 rpm and 3:36 gears and a stick trans all marry up. Am I missing something here? If you have a 26" diameter tire you may be in the 196 mph range.

 

[61 Bubble]

I like the ease of a free Erving engine. Plus on a chassis limited street style car, I want the higher revs for less tire spin and bit more ease to the frame. One can accelerate to a higher RPM and therefore the weight is already under x amount of force. And with engines having equal hp and tq at 5252, I can launch the car and the hp can take over after that.
Now the 3.36 was what's in the car now. Good for highway. But with the same first gear in the trans with the 5 speed, I don't need to invest in 4.56/4.88's for some spirited stop light fun.

 

[models916]

Fuzz logic for me. 3:36 gears need low RPM grunt that high RPM power can't supply.

 

[61 Bubble]

Guys, please don't forget, a motor that one runs to say 7500 RPM should max power about 7100 RPM. And given that "most" cam are designed for about 3500 peak operating range, this motor should be right in the sweet spot from 2600 to 7100, and shifting around 400 RPM past peak Hp.

And the 3.36 gear with the Nash 5 sp is like a T-10 and 4.88/5.13's. I 11.289 first gear ratio where as a 2.20 first gear 4sp with 5.13 is just about the same at 11.286. I you have basically the equivalent to a 5.13 I the first 4 gears for city, bang 5th and your back to a 3.36. That's the nice thing about the Nash, well that part anyway.

 

[poison ivy]

my experience has proven on the dyno, that most engines don't make power over 7000 rpm, it takes a very good combo, cam,intake,heads, etc to work. the heavy, lop sided pistons of our engines work best up to 6 to 6500. above that requires careful planning as well as professional assembly.sometimes built to last is better than half fast.

 

[61 Bubble]

See, I'm just trying to see if these W motors can get close to what we do with a 468 pump gas BBC that still retains OEM LS-6 castings, ported and Stock ported dual plane intake? I know we will probably never get close to the tq the 468 has, but hoping to get hp close to a OEM dual port intake headed pump gas 468????

 

[Skip FIx]

My head porter and place we dynoed my 470/409 where quite impressed with HP and TQ said it was on par or a hair better than many of their 496 BBC combinations they dyno with comparative cams.

Look at the head flow and port CC and cross section of a BBC port-that is why they can turn more RPM.

 

[61 Bubble]

Skip, I see from your sig. your motor makes around the 600Hp mark. I don't know your build on much about it. But it does make 600hp and that seems pretty respectable.

My questions and way of thinking was brought about by this engine listed below was done back in October 2015. It's a pump-gas 468 with LS-6 heads, OEM 163 dual plane intake with about the same cam that's in my 409 (that surely doesn't mean my cam is right for my 409, but Jims a good guy and does know what he's doing, so it's certainly not way out in left field, you can bank on that!!). I just think these W motors need the RPM's to help them make the power???

I'm thinking this is the bar I should be working with as a goal:

NOTE: it made a bit more power then this, just NOT allowed to give that info out. Hint, as you can see, the HP1000 ran out of air @ 6100

 

[MRHP]

I would doubt your sweet spot is as broad as 2600-7100. I am sure it is in there somewhere, just not everywhere. I also don't think the engine will like loafing with 3.36 gears for cruising.

 

[61 Bubble]

I would doubt your sweet spot is as broad as 2600-7100. I am sure it is in there somewhere, just not everywhere. I also don't think the engine will like loafing with 3.36 gears for cruising.

These BBC seem to do ok with 3.31 and 275 tire for 800 mile trip!

 

[MRHP]

Good luck!

 

[jim_ss409]

That's a very impressive 468. I think just getting within 50 hp of that with a streetable 409 would be pretty neat.

It seems like you can make about 650 hp with the 690 style heads and still have something you might call streetable.
The stroked 348 that Joe Sherman built made 650 hp at 437 ci. It would run on pump gas but it was getting close to the edge of what you would call streetable.
http://www.hotrod.com/how-to/engine/hrdp-0911-chevy-w-series-engine-build/

I know several racers have made quite a bit more power. I think both Dave Mills and Carl Bucks have run 9.60's or 9.70's with 690 heads. So I guess there is certainly more power available.


I think the factory Z11 heads had a lot more potential to make some high rpm horsepower, not quite in the same league as the LS6 heads, but pretty respectable just the same. It's too bad they didn't use the Z11 heads as the regular high performance head from 63 to 65. They would have been a lot more plentiful and I think there would have been a lot more interest and speed equipment available for these engines.

I think Russ Campbell ran 9.20's with ported factory Z11 heads. I don't think that would even be possible with the 690 style heads.
Lamar Walden built a 409 with about 436 ci for Pat Lobb with factory Z11 heads and it made 745 hp. I'll bet with a little less cam and compression that engine could come pretty close to making 700 streetable horsepower.
http://www.yellowbullet.com/forum/showthread.php?t=564294&highlight=lamar

 

[61 Bubble]

Thanks Jim. MANY MANY things to think about. Just doing some research for the future. I look back at the Sherman add quite a bit and it's saved in my favorites too! Did you ever flow the heads off that motor? With and without intake? We can always make the best of whatever once the know factors are determined and addressed in the way that needs to be done.

Who have EVER thought the 468 pump-gas motor with a OEM dual plane intake would make what we have done! And there was quite a bit of power found after that dyno sheet. My ZL-1 should be around the power your Al. 511 makes. Again it will be ran on pump-gas with OEM heads and dual plane intake. I think it too will run out of steam around 72/7300RPM. Were just not sure the block is up to it?? Modelling that we do on these seems to work out well and is usually quite accurate IF everything is done and holds up well.

So after listening to the guys here, and some other research, I might be changing a bit on direction as far as RPM operating range. Tq seems to be a bit harder to come by with this motor design? Both the Sherman and the BES didn't kill the tq. The YB Z-11 didn't mention RPM's either?? I'm actually leaning towards a tq converter trans instead of a stick?

JIM, you gave a ton of info posted above, THANK YOU. I have no ambitions of running like Russ, Dave or Carl. 9-ANYTHING is not what I'm looking at doing with this, but guess I could get caught up in all that too. It seems like these cars/frames can handle 9's with some tweaking. I still want to be able to jump in this and drive 3 hrs down the highway.

 

[jim_ss409]

Did you ever flow the heads off that motor? With and without intake? We can always make the best of whatever once the know factors are determined and addressed in the way that needs to be done.

I think Sherman got 329 cfm out of those Edelbrock heads. We never had them tested ourselves but that seems pretty much in line with what a very good head porter can get out of them. I think a well ported 690's might be about the same or at least pretty close, especially if you used a bigger intake valve. I think a 2.25" valve will fit.

I just bolted those heads on to a new engine we're building for the 55 Chevy. This engine will be 481 ci and it will also have the homemade tunnel ram that we've been using. It'll have about 13.3 to 1 compression and the cam will be similar to what was used on the stroked 348 that Sherman built. I'm not sure whether or not we'll dyno it, but if we do, I'll post the results.

 

[Skip FIx]

I think mine minus intake were about 329 or so CFM. Ported Edelbrock heads-2.25 intake valve custom Manley, 1.72 Fererra exhaust(cut down Pontiac 5.09 length) as Edelbrock valves not guaranteed for roller spring tension. 1.7 Comp SS roller rockers Comp solid roller lifters, 251/251 @ 0.050 Ultradyne lobe from Bullet-standard firing pattern(Comp only had 4-7 swap blanks), Edelbrock dual quad ported to match some plenum clean up. 1" 4 hole spacers . Dual Edelborck 600 cfm carbs jetted one step leaner(per Ronnie Russel). 10.25 :1 measured by CC block and heads JE pistons, 4.00 Eagle crank, 6.385 Eagle rods. Crank had to be turned 0.010/0.010 too much journal taper. 2-2 1/4 Jardine Tri Ys. Pretty streetable idle vacuum on dyno we'll see once it goes in a car, but I ran a bigger solid roller in my 78 TA in a 455 on the street.

As far as operating range-dyno tells you! You can do computer sims, run formulas nased on head flow, runner/header length but the dyno tells no lies! IF it is calibrated right and not "generous" like the Westech dyno in the magazines. A good dyno will "run the numbers" at the track mph/weight.

 

[409 lever]

westech dyno numbers are always laughable.

 

[61 Bubble]

westech dyno numbers are always laughable.

Steve Schmidt's was that way too. My NHRA P/S motor made 100Hp more then then it did at Fj Smith's??
We put it down to the Canadian to US conversion rate lol!

 

[Skip FIx]

Yea Car Craft had an article a few years back on a BBC they built for a Chevelle and had gobs of HP 600ish at Westech but was maybe only mid 11s at the same weight my only 525 on the dyno here 455 in my TA clicked off high 10s!