:drink:

That is what I thought too 670 lbs of torque at 3700 is not to shabby. I know how this works in a car but how does this torque work down low with an outdrive? Will this benefit in getting the boat up on plane quick?

Boat motor or tractor tailer? Lol

I just picked it up and they used 1 3/4 primary tube headers on this so the exhaust was crap. He also told me to go down one jet size all the way around.

I've seen some AFR headed 540 combos here on oso, that didn't make that kind of low end torque , with smaller CC heads, and smaller cams.

Are those heads using the stock 2.19 intake valves?

Certainly. It should be a nice combo for a 30ft single engine boat. Some larger headers would have helped , esp in the upper rpm band. 1.75 is small for that build.

I think your cam guy did a good job. I'm sure most were thinking, that cam was way too big, and not enough split, but I think it could have used a bit more cam. Hence why I said it will make more TQ, than HP.

This should be Getherdones favorite build. But he`d use a smaller cam for even more TQ .

:lolhit:

They are 2.25 now. The cam was reground by this guy my machinist uses in socal. He has reground one of my solid drag race cams but I have not used it yet as the clay smith I had custom ground works so much better than the Erson I had in there. Good people over at Clay Smith.

I know everyone talks about HP numbers breaking outdrives but what does high torque down low do to them. I will state I am not planning on hole shots and abuse on the outdrive. I have already bought a spare one just in case.

Well I was within 1 hp but off with rpm. I woulda though even advanced 2 deg it woulda peaked out higher. Nice build

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 OP's peak hp woulda been with some 315/325 worked over heads with 2.30 valves.

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.

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..

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....

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]

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

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.

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.

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

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

Gotcha, missed that pic