articfriends

And on the topic of the 695 hp 502 6100/6200 peak w open dry headers (and virtually no decay in power at 6300, bsfcs didnt get ugly until 6300+), 5800/5900 with mufflers and 5700 ish with the EMIS. Top end numbers on dyno looked excellent on this, I had hoped to see 640/650 ft lbs tq (9.8-1 w Oval ports and mini tunnel ram) but saw in the 630s in open headers trim, 620s muffled and 618/620 w Emis. In the boat (A real HEAVY POS Envision) motor feels like a turd in mid range. IF I was doing it over, I would have spent my customers money on a 4.25 crankshaft fwiw, torque moves things, Smitty

articfriends

The boat the 509 went in needed to be dragged to a landfill and crushed but heres a pic.

hogie roll

farmo83

Awesome info !

hogie roll

SB

Yup. The Diamond Performace/KE Thunder-N-Lightning have 1 3/4"x 34" pirmary runners. Collectors are 4" and you make the collector length.Collector length starts on the Diamond marine/KE's where from where tail bolts to manifold and then ends on outside end of transom exhaust tip., Most marine 502's-540's want 18-20"collector lengths.
http://www.diamondperformanceparts.c...age=1&featured
See Diamond Marine pic under this dimension info.

Here is Pipemax on a 502 i entered with a Crane 741 cam and 5800rpm max rpmpower.

--- Single Primary Pipe Specs --- for 502.176 CID from 3800 to 6300 RPM
Diameter= 1.899 to 2.024
Length= 33.7 to 36.7 inches long
--- 2-Step Primary Pipe Specs ---
1st Dia. inches= 1.899 Length= 16.9 to 18.4
2nd Dia. inches= 2.024 Length= 16.9 to 18.4
--- 3-Step Primary Pipe Specs ---
1st Dia. inches= 1.899 Length= 16.9 to 18.4
2nd Dia. inches= 2.024 Length= 8.4 to 9.2
3rd Dia. inches= 2.149 Length= 8.4 to 9.2

--- Header Collector Specs (Conventional Straight Tube) ---
Diameter= 3.466 to 3.716
Tuned Lengths= 19.4 best and also 9.7 or 38.8

--- Header Collector Specs (Megaphone or Diffuser Cone Shape) ---
Diameter= 2.966 taper to 3.966 Megaphone/Diffuser Length= 19.4 inches

Best HP/TQ Tuned Collector Lengths= 19.4 , 38.8 , 77.6 , 155.2 inches long

Worst HP/TQ Loss Collector Lengths= 29.1 , 58.2 , 116.4 , 232.8 inches long
Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness

---- Primary Pipe's Harmonics ----
1st Harmonic = 149.4 inches long ... typically never used
2nd Harmonic = 56.5 inches long ... longest recommended
3rd Harmonic = 33.7 inches long ... highly recommended , best Torque Curve
4th Harmonic = 23.4 inches long ... shortest recommended
5th Harmonic = 17.5 inches long ... typically never used
6th Harmonic = 13.8 inches long ... typically never used
7th Harmonic = 11.1 inches long ... typically never used
8th Harmonic = 9.2 inches long ... typically never used

---- Collector's Harmonics (includes Intermediate, Muffler , TailPipe) ----
1st Harmonic = 155.2 inches long ... longest with Mufflers and TailPipes
Note: Worst = 116.4 inches long for HP/TQ Loss
2nd Harmonic = 77.6 inches long ... longest recommended with Mufflers
Note: Worst = 58.2 inches long for HP/TQ Loss
3rd Harmonic = 38.8 inches long ... more bottom-end Torque
Note: Worst = 29.1 inches long for HP/TQ Loss
4th Harmonic = 19.4 inches long ... highly recommended , best Torque Curve
5th Harmonic = 9.7 inches long ... reduced Torque , more top-end HP sometimes
6th Harmonic = 4.9 inches long ... reduced Torque , not recommended

Tinkerer

smitty - does anyone make a manifold like that for a tall deck. I have EFI and would love to go to a tunnel ram style manifold. I am going to try adding twin turbos this winter and I think that would work great and look good also.

articfriends

Aside from the big $$$ ones that are pretty much custom built (CFE/ICEMAN/HOGAN), not that I know of. Even for this project, I wish there had been something with longer runners, bigger plenum, bigger throttle body mounting. I will say, this one was a like new, used oval port intake I bought on Ebay because Edelbrock discontinued making the oval port 5 years ago (this whole build revolved around trying a set of 300 cc oval ports from AFR). My hp/tq goal was 640/640, I came up slightly short on tq and as mentioned exceeded my hp goal by 40+ which is rare. Between THAT and the BSFC being real nice to 6300 I liked this intake so much I bought a square port version of it to try on dyno with some other stuff I have brewing (a 13-1/12.8-1 515 or 522) that IF I like the results on, I will duplicate and stick in my 33AVS. When the Rectangle port version showed up (NIB) , it has about 3/4 to 1" longer runners, what appears to be a slightly bigger plenum and better TB mounting surface with dual patterns so Im excited to see how it works when I get to this project, Smitty

hogie roll

articfriends

E85, going to build one and dyno it to see IF i can get the BSFC reasonable with the compression increase. My theory is, a 500 efi on my dyno is at about .580 at wot, most whippled 2.3/3.3 93 octane motors i dyno head towards .680 on top. IF i can build a compression motor that has bsfcs in the .450 range on 105 gas and bsfcs in the .620 to..650 range on e85, the range of my boat won't really be much less than if I went with whipples. We'll see!