Offshoreonly.com - Cam and valvetrain longevity....??? low duration high lift...

Offshoreonly.com (https://www.offshoreonly.com/forums/)

- General Q & A (https://www.offshoreonly.com/forums/general-q-20/)

- - Cam and valvetrain longevity....??? low duration high lift... (https://www.offshoreonly.com/forums/general-q/341258-cam-valvetrain-longevity-low-duration-high-lift.html)

Quote:

Originally Posted by check300 (Post 4486272)

Oh we found quite a bit more torque before we were finished..:)

Even better, was that was an engine that actually ran on the water. For quite some time too. She was no dyno queen

Quote:

Originally Posted by check300 (Post 4486269)

https://www.youtube.com/watch?v=Y6EcyKygxTg Just for fun...... full marine dress with Dana Marine manifolds. This was just getting it tuned. We eventually pulled it to 6500.

That would fit nicely in my ski boat. ;)

Quote:

Originally Posted by check300 (Post 4486269)

https://www.youtube.com/watch?v=Y6EcyKygxTg Just for fun...... full marine dress with Dana Marine manifolds. This was just getting it tuned. We eventually pulled it to 6500.

Were the exhaust housings on the turbos water cooled?

The housings were not water cooled but there were water cooled heat shields over the top of them.

Quote:

Originally Posted by bck (Post 4482776)

I ask myself that all the time, but the question still goes further than that. This engine architecture has been around for a long time. Computer development is pretty advanced. Why does anyone ever ask 4100 or 4500? Spacer or no, if so which kind and how big? Anti reversion plates? A dozen different intake choices another dozen head choices. There HAS to be one combination of parts that works best. If I say I want a 700 hp 540 there only needs to be 1 combination of parts yet apparently from all these types of threads no one is sure what that exact combo is.

From an engine builder in Long Island who does some offshore stuff. The RHS heads he mentions, are the Engine Quest iron heads now. He doesnt mention cam specs though

Have a number of similar units out and running for some time now.

Dart S/D, 540", RHS 320's, Comp retro-hyd-roller, 9.75:1 C.R., 2527 Edel, and a 4500 Holley. Bolt-together build, absolutely no HP chasing at all!

All off the dyno at/above 730 HP @ 6200 and 700 Torque @ 4500. Have many of these still in service after 15 years or more, not a single problem to date an any!

These are tested without any accessories however.

Thanks, Gary in N.Y.

P.S. With a change to a solid-roller, some very minor head work, and 10.5/10.75:1 C.R., we see above 775 HP/725 Torque, very similar RPM band. The RHS heads flow 375/275 @ .700" from the boxes. Just tested some recent "brand-X" heads we took on for a line, and still see just above 700. The cost on these heads is about 1/2 price!

Quote:

Originally Posted by MILD THUNDER (Post 4485963)

I believe that engine , had profiler cylinder heads, and I want to say, a good sized cam in it. Wanna say it was a solid roller as well with over 700 lift . Either way, it was a stellar build!

That had pretty big camshaft you can watch the screen on the holley and see it did not make much vacuum at idle.

Do you know what heads they where?

Quote:

Originally Posted by 14 apache (Post 4486304)

That had pretty big camshaft you can watch the screen on the holley and see it did not make much vacuum at idle.

Do you know what heads they where?

I wanna say, 370cc . Don't hold me to it though. It was a fairly long duration solid roller, with a decent amount of lift if I recall.

Price difference isn't much btwn profilers and rhs. Valako is adiment about me getting the 320 profilers due to the extra thickness above the runner. We never discussed rhs but I always seem to hear and read great things about them.

Typically, if you are going to have heads ported, you get what your head porter wants you to. Doesn't mean you can't battle alittle. LOL. IMHO.

Quote:

Originally Posted by SB (Post 4486341)

Typically, if you are going to have heads ported, you get what your head porter wants you to. Doesn't mean you can't battle alittle. LOL. IMHO.

The only time we disagree is with the very same subject were on "cam selection". He always *****es cause I tend to wanna over cam everything. I understsnd his reasoning with his ported heads.