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MILD THUNDER 02-17-2017 08:20 PM


Originally Posted by getrdunn (Post 4530134)
Hey now....

It is kinda funny though when your think of a tunnel ram 565 with 236/244 much smaller than 252/252 yet pulls peak hp at 6k. Port velocity??? Valve timing??? Wonder what peak hp woulda been with some 315 cnc heads. Btw I did end up with cams that even make yours look small. Lol

Main thing is , He doesnt have a tunnel ram, fully ported aftermarket heads, 2.3 plus intake valve, 1.85 ratio rocker arms, and 700ish lift with solid lifters on hyd lobes.

Like i said earlier, rpm capability, can be affected by valve lift, valve diameter, head flow, and so on. If his velocity was crapola, i dont think hed be making more torque at lower rpms than bcks smaller headed, smaller cammed, 10:1 548 with 305 afr heads.

Change the camshaft lobe, and valve size, and your velocity can go way up, or way down. It all plays a part. Thats what "custom" cams were meant to do. Design a cam for the engine package the customer has.

MILD THUNDER 02-17-2017 09:03 PM

Getrdunn, just entering some information in pipemax.

With tahoe's specs, his cam, and 2.25 valve , it shows the intake system, is good for 5760rpm

By simply adding a 2.3 valve, with .700 lift, it raises to 6019 rpm. A 2.35 valve, with .730 lift, goes up to 6159 rpm.

Thats adding 400 additional RPM to the intake system, without a single change to the .050 duration.

By adding 1.85 rocker arm, which would increase his lift to roughly .685, his intake system went from 5760, to 5928 rpm.

While its just a computer program, seems pretty dam close to me, suggesting the engine would run out of steam with that combination of lift, duration, and valve size at 5700, and his dyno sheet seems to agree. Pretty neat stuff.

getrdunn 02-17-2017 09:16 PM


Originally Posted by MILD THUNDER (Post 4530150)
Getrdunn, just entering some information in pipemax.

With tahoe's specs, his cam, and 2.25 valve , it shows the intake system, is good for 5760rpm

By simply adding a 2.3 valve, with .700 lift, it raises to 6019 rpm. A 2.35 valve, with .730 lift, goes up to 6159 rpm.

Thats adding 400 additional RPM to the intake system, without a single change to the .050 duration.

By adding 1.85 rocker arm, which would increase his lift to roughly .685, his intake system went from 5760, to 5928 rpm.

While its just a computer program, seems pretty dam close to me, suggesting the engine would run out of steam with that combination of lift, duration, and valve size at 5700, and his dyno sheet seems to agree. Pretty neat stuff.

That's pretty amazing data. If I had that software I wouldn't get anything done. Lol..

getrdunn 02-17-2017 09:24 PM

It is just interesting how cam duration always gets discussed where people want to make their peak power at a said rpm yet heads, valve size and induction can change it in a hurry with the same cam. Combo, combo....

HaxbySpeed 02-17-2017 10:35 PM

1 Attachment(s)
Looks like you could've pulled a few jets out for sure. For cam duration vs cylinder head comparisons, here's a very similar combo with a lunati 238/248 114. Same cubes, same heads, a little less comp. 1 7/8 ID headers with 3" exhaust and mufflers. No accessories. Vic Jr. Hp950

[ATTACH=CONFIG]564863[/ATTACH]

Tahoe540 02-18-2017 07:20 AM

Yes for sure going to lean it out a little, you have great numbers as well. Very similar. Here is the complete pic of the Dyno graph.

http://i393.photobucket.com/albums/p...psaynqua8k.jpg

HaxbySpeed 02-18-2017 08:34 AM

Looks great. That should work very well for you, and I bet upgrading to a quick fuel 1050 4150 carb or something similar down the road will pick up a fair bit more power too. Nice build.

MILD THUNDER 02-18-2017 09:07 AM

1 Attachment(s)
Heres Tim's 540. 9.6:1 , 1050 quick fuel, AFR 325 heads, 241/246 112 680 lift madera cam. Stainless marine exhaust with accessories.

ICDEDPPL 02-18-2017 10:33 AM

So AFR heads and custom cam same power as 088 GM heads and off the shelf cam.
Marine Kinetics really killin it! :D

TruxtonFox 02-22-2017 04:36 PM


Originally Posted by Tahoe540 (Post 4530215)
Yes for sure going to lean it out a little, you have great numbers as well. Very similar. Here is the complete pic of the Dyno graph.

http://i393.photobucket.com/albums/p...psaynqua8k.jpg

What are you looking at to know that its running rich?


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