454 cam upgrade questions/opinions..
 

I am rebuilding my 400HP 454's this winter, I have a set of Merlin heads to go on, with a small runner single plane intake,9.0:1 compression, and 454 CI.

I want to try to get the most I can from them, my 400/420 cam is decent but would a cam change be worth it? what cam have guys been running with a combo like this? I am not looking to go roller at this time, not in the budget this year, any suggections would be great, thanks..

Exhaust??
 

Tell us more, what exhaust are you running?? Aftermarket?? Wet or Dry??

Well, that is a tricky one...
Right now I have an old school 3" stainless marine setup, I plan to go with GIL or IMCO but I need to do the hull work and engines first, then see if the money is there for the exhaust, I figure I can run these one season if I have to, I know I will not see a good gain until the exhaust is done but I want to do cams while the engines are out.

Here is what I have now, some guys say it may not be that bad but it cannot be great! these were done in 89, back then this must have been a upgrade!

http://i36.photobucket.com/albums/e4...g/105_7518.jpg

Like I said, I know the exhaust is going to kill it if I use these for another year, but I cannot do the cams in the boat, and I have the engines out now...

WOW, props to the heilarc guy. I imagine these pipes are not the best for water reversion, so being there wet, i would not get crazy. Even on some of the new, good stuff, if its a wet system, with any sort of mixing in the tailpipes you have to be careful. With a wet system and a hyd. flat-tappet, I would go with something around [email protected], .525-.540 lift and a 112 LC. Although we have been able to use some larger hyd. roller grinds with wet systems with great success. As large as 244 and .600+ lifts with no problem. Mainly due to the function of a roller design. I know you said you cannot go that route now, but if you can swing it, you'll be far ahead of the game. It sucks there are not any reasonable hyd. lifters for an older style block. This is were the cost is really incured. You figure $200 at best for a reg. hyd cam&lifter kit. The roller cam alone is $250, then the retro lifters if your using a gen-4 block, these are $375 alone. You would then need shorter pushrods to complete the swap. And a cam button of course. Triple the cost, but money well spent, as far as performance, reliability, and clean oil goes.

If you're not going to go to a roller cam, then the cam you have is pretty decent. Changing to roller cam will cost you at least $1000 per engine.

The stock cam is a .530/.551, 228/236 on a 114 lobe sep.

Kind of at I am thinking, the roller just cannot happen this year, maybe in a 2-3 yrs, I will prob refresh again, then do roller cams, The 420 cam is a decent cam, I just wondered if going bigger would not really be worth it.

How important is it to make sure all the flat tappet lifters stay in order? I had them sitting in order then knocked them over, is it really that big of a deal?
I did a small block years ago and did not keep them in order, it did not hurt nothing then, but with the boat it is more involved if there is a problem..

I would just replace them for the $150. Its not worth the headache of wiping out the cam.