IRONMAN

Storm, I was using a 25 mirage plus and a labbed bravo1 26. I am changing the drive this winter and will have to wait for ice out to get data with the bravo drive. I prefer the mirage when running alone and the bravo when the boat is loaded more.

Stormrider

Ironman, forgot you were running the TRS. Sorry.

Dangerous Dave

Hey T-Mone
Is 84 the best YOU got out of it or the best I got out of it? Just kidding dude. When are you coming down here? Hopefully I'll have my rat trap in the water soon, I'm going with 2 whole new Stainless Marine exhaust systems (business has been good)

Jo,
After that day I went outside with you and Anthony (4'-6' at least) it made more of a believer out of me than even before. It is unbelievable how well a boat that size handles rough water.

Stormrider

Would you guys think w/ a 240 duration cam, I would be OK w/ Stainless Marine manifolds w/ long risers?

Pat McPherson

Storm,
Reversion is caused by the vacuum created during the intake stroke with the exhaust valves still open. Cam duration @ 0.050 lift is not the only factor. The Lobe seperation angle and cam profile play a big role. Cams with a lot of "overlap" need long risers or even dry exhaust...
Are you having your engine rebuilt with a roller cam?

Stormrider

Pat, flat tappet cam.
Builder thought I'd have no problem w/ the long risers.
I only heard one person mention a problem in the tech section and thats it.
This is not a radical rebuild, so I can't imagine long risers not being enough.
I should have the cam specs in a day or two.
I'm just reading up on cams so this stuff doesn't sink in too quickly.

Pat McPherson

Storm,
So long as your builder is familiar with a marine application, he'll likely pick a good cam for you...
With a roller cam, the profile can be more agressive so the duration and overlap could be less.

Stormrider

Pat, all he builds is marine.
JC Perf... may sound familiar to you from the board.
He does the assembly work for Zul and has his own shop.

He knows his ****.
I'm in good hands, but I'm just learning about this stuff so I'm pretty curious.
I'll start a new thread about the rebuild once it gets more involved.

IRONMAN

If you can spring for the roller then do it, 240 duration will be no problem with that exhaust it might be with silent choice though. The best flat tappet cam that I used in any 454 was the crane 228/236 .540lift but I never had any 454 with more than 9:1 compression. For a roller go with the crane -731 226/234 similar to the HP500 cam. There is a lot of good stuff in the Dennis Moore book also. good luck.

Stormrider

Ironman, thanks... I might be wrong w/ that cam.
My builder knows what he is doing, so the most I can do is discuss
what is being done, not tell him what to do.
Like i said, I'll post more on the rebuild in a new post, when I have more to post.
thanks again guys...