KAAMA

iTrader: (1)

You have stock Merc cast iron exhaust manifolds with an IMCO stainless riser/tail pipe? If you do, then it would be slightly better than Merc's stock riser exhaust system.

Also, it would be interesting to know what type of heads you have on your engines and have them bowl/pocket, shortside radius work done to them, call RMBuilder/Bob Madara for a cam selection and better breathing exhaust system like GIL or Stainless Marine would get you near the 500hp range. The engine has to breath well to make good power in a 454...and it always begins with a well breathing exhaust system. Have fun.

Pat McPherson

Hey Mike,
To convert your new 454Mag to a 500HP is going to cost quite a few $$.
Better exhaust than the stock cast stuff is a must.
Your heads can be worked/ported to flow better and you will need new valve train componts.
There is a GM cam that will work pretty well with your stock lifters, push rods, and rockers. It is not the best cam but there are quite a few people running them, the ZZ502 cam.
I bought one to install in a 454 Carb engine but them ended up going with a different engine all together.
$75 pluss shipping...
Believe me this is not a sales pitch and I'm sure we'll see some post that will tell you that this cam or that cam are better. Yes, the facts are there are better and more " marine freindly" cams, but to go after market will cost a lot more $$...

Plane Silly

Is it a Bravo drive? You may try a stern jack to give you some bow lift. I have heard that they work well on the Baja's.

AIR TIME

I got stainless marine exhaust dry and it helped when I had a merc 502, you can go with a 2'' imco shortie for about 2,000. or SM exhaust from 1800 t0 3700 depends on what model. I have made 6 motor changes in 17yrs on my 24 ol 88. call me if you want as of last fall I got 83.2 gps with my set up and ran out of prop. theres a 81gps 25ol with a 525 its all set up not just hp without set up ,I HAD56OHP and wouldonly hit 74 gps. the 2'' shortie gave me aprox 3 to 4 mph. if you go cam go hyd roller cam thats about 1200 to 1500 kit form. if your motor is new it might have a hyd roller in it then you need just the cam if you have low hours thats 300 to 400.give me a call at 617 833 3327

AIR TIME

oh I have a trubo 24p 3 blade it ran about the same speed as my 25 mirage but was quicker mid range and 200rpms higher was faster than my 23 mirage to when I was running the carb 502merc. so the 24 with a chip for your rev limiter that should be more like 5300 that way you might see a lot more speed at 5100 or 5200 rpms. if its a hyd roller set up you won't float until 6100 to 6300. my set up is set for 6000 and will run between 5600 to 5800, my max tq is 4800 637 hp 670 at 5900 and drops at 6300. I MAKE 600 AT 5050RPM WHICH IS NICE MY CAM IS A ISKY SET UP ABOUT THE SAME AS A CRANE 741. OH the prop is for sale 200, and next time you need a new one or labbed go to BBLADES BRET HE;S ONE OF THE BEST. ART

AIR TIME

any pics did you go with the '' raised box and shortie??

KEPP

I have been reading your posts since they started and I think the advice about the props has been great. AIR TIME hit it on the head buy going to BBlades. They know their stuff. If you really want to get to 70mph we here at KE can get you to your mark but how much are you looking at spending? As most everyone here can attend to 70mph isn't cheep. If you are really interested you can call us at (386) 446-0660 or e-mail me back at [email protected].