Question for engine pro users...

[SappySE107]

I have the flownumbers on the site under pushrod>flowhseets. I will cc what I can for you. I have the combustion chambers, intakes, and exhausts all cced for 3400 and 3500 but not the lower manifolds or plenums.

[SappySE107]

Just remembered you were asking me about how I setup the head for flow. I use a clay bell shaped entrance for the intake and a 4.5" long, 1.69ish diameter tube for the exhaust. It gives me more consistant numbers and without these devices the flow numbers hit a wall real fast. This is an extreme case showing how the manifold works with the head.

[EspanolaGuitarista]

Cool. thanks...

...How would a 3400 .080 over sound with a 3500 top end. That would be 3.5L exactly. Do you measure just flow or velocity too. The sim puts out the theoretical velocity which is helpful. Also, when putting in the flow charts for the different heads you need to also put the spec for port length. Volume cc's won't be accurate if we do know that dimension. Thanks. Great job on your all your hard work. It's appreciated.

[SappySE107]

That would be the 3500 bore for the most part but I don't know if the cylinder walls will be thick enough to handle any power or last. Sleeving it would be best at that point.

So you need to know the length of the port in the head as well? Kinda confusing cause of the shape of the port but the software to go at it like that costs thousands (hundreds of thousands likely).

As far as velocity, I have taken measurements inside the port and can plug them into my flowbench software and it gives me velocity. I don't have the pilot tube type setup with manometers to test velocity at a given depression. I need more money to build the test bench I want but I work with what I got (and do as much as I can). I appreciate the help with simulations. Id love to know what dropping 5-10cc on the 3500 heads would do for power.

[EspanolaGuitarista]

Well....

...The length of the port would be from the valve face to the exit of the port going down the centerline with a peice of stiff wire. As close as you can get would be ok. I have 4 inches and that seems to work well for the 3400 head. I think that is what you suggested initially. I will use 4 inch port for the 3500. Also can you get me the valve cant and angle of the port if possible?

[EspanolaGuitarista]

I inputed the 3500 heads....

....They seem to make about +15 hp, +20 ft/lbs torque conservatively. This particular setup can make with a 206/206 cam and headers, around
230-240 hp / 240-250 ft/lbs. Going more than a 206 cam seems to not pay off unless you increase the compression. 300 hp/320tq is possible with these heads but you need port the intake side and leave the exhaust alone. This is true with the 3400 and 3500 head. I went to a flow coefiicient of .65 on the intake side and made more and more power. .6 flow coeffficient is around 245 cfm on the intake side. So there is a limit. But don't touch the exhaust side is my advice.

[SappySE107]

Is that with the same throttle body?

What happens if you increase the exhaust and the intake? I can send you some of my "beta" flow numbers if you want to test that. I haven't got the angles of the valves but I can try to figure out something.

[EspanolaGuitarista]

Sorry, House thieves wiped me out....

....on New Year's Eve. When I catch up with that guy, I'm gonna kick his a$$ from one side of the city to the other. Got my Gibson and Jackson guitars, my computer, mountain bike, amplifiers. Oh well, I know what my New Year's resolution is; get new stuff!

[SappySE107]

omfg! Yeah, id be kicking some ass too if I had my guitars stolen and my computer and other stuff. Wow, that really sucks. Does your software take a dongle for copy protection? Mine does so if that got stolen id be screwed. I hope you find the low life that stole your stuff. I hate thieves.