Offshoreonly.com - Off the shelf cam options for marine engines

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Quote:

Originally Posted by Trash (Post 4408363)

The port velocity won't break the sound barrier.

It was it bit of a joke :stooges:

Quote:

Originally Posted by phragle (Post 4408364)

You just need to up the boost to something like 4000% overdriven, This can be accomplished by adding a 63 speed overdrive transmission to the blower.

Also, an intercooler the size of the boat. Sorry, back on track here....

Quote:

Originally Posted by GPM (Post 4408110)

Hard to say on the Chinese metal, I could do without it. I just bought a custom solid flat from Bullet for an LS6 454, hoping to get it on the dyno in the next week or so.

I just did a LS7 454 for my street car this summer and wanted to stay with a solid flat tappet, looked at all of the blueprint LS7 replacement cams from Crane, Lunati, ect.ect. but was afraid of all the flat tappet cam failures so I bought a GM NOS LS7 3959180 cam and used the Crower solid lifters with the .024" EDM hole. Hopefully I won't have any problems when I break it in.

Quote:

Originally Posted by kvogt (Post 4408293)

Ports never go past the speed of sound. But that is variable based on localized density and temperature..

About .52 mach is all the air a port will handle before it gets unstable.

I'm guessing this really isn't helping Haxby's cam sales.

Quote:

Originally Posted by Lee (Post 4408395)

I haven't done many flat tappets, we use mostly solid rollers. There are times when the old style fits the bill. I've read the horror stories, seems like the lack of ZDDP is the killer. Just for fun my brother is changing out his 33 year old hydraulic flat tappet for a new solid flat, I guess we'll see. Good luck with yours !!

Quote:

Originally Posted by Lee (Post 4408395)

i just last week finished a 1970 396/375.i tried to talk the owner into a hyd roller of similar specs but he insisted on the flat solid.we got the cam from comp and used the crower lifters with the .024 edm hole in the bottom.i broke it in with brad penn 5w30 oil and the comp cams zddp break in lube,i also removed the inner springs and ran it at 2500 for 15 minutes.then i replaced the inner springs and sent it down the road.i forgot to mention the crane extreme pressure molly lube coating the cam&bottom of the lifters.from what i have been told the problem with the flat tappet cams of today is cores not properly heat treated.

Some say the cores of recent are crappy and others say it's the lack of ZDDP.
Pretty sure there are only a few core suppliers, so one cam company is really no better than another.

a tech at comp told me they make their own cores because the ones they were getting had a large failure rate.i guess time will tell.

Quote:

Originally Posted by vintage chromoly (Post 4408543)

Some say the cores of recent are crappy and others say it's the lack of ZDDP.
Pretty sure there are only a few core suppliers, so one cam company is really no better than another.

P55 cores are made by Engine Power Components, wonder if they are still around. Been 8yrs or so since I;ve gotten a flat tappet.