I have 548 ci blocks bore 4.5
Merlin heads 30630 119 cc 2.3 and 1.88 valves
je /src pistons #257943
crank 4.25 stroke
rods 6.38

The compression ratio appears to be 8.5 to 1 is this correct? if so or if not will I need to change out the pistons?

The plan is to put a dart intake and carb ...the one that came on the 500 carb engines...(not sure what size to use)

and a a hyd flat tappet cam in it (dont want rollers due to price) dont know which one to use

I'm looking for input here what hp would these be? I'd be happy with 500 to 600 hp as the boat origionally came wit 500's and ran 88 (dont want to pop the bravo's 88-98 mph is good for me)

I was looking at the merc website looks like the bulldog is aprox 8.5 to 1 also

is this a viable build? im trying to save what I can and not put the wiand 250 blowers back on

I would like to keep in the low octaine fuel due to not knowing what you get these days

hope this makes sense with what I am asking

with a 119 cc head, piston in the hole .010 and a ,041 head gasket compression will be at or near 8.4 to 1,the hp500 is 8,75 to 1,so you are close,i would not use a flat tappet cam,go with a crane 741 hyd roller and you should be close to 500 hp.if you install the blowers it will really wake up.

I did a 540CI, Merlin 320 Iron Heads, 9:1, 741 Crane hyd roller cam, single plane dart intake, 1050 Holley. Right around 600HP and 615ft lbs.

I hate to say it but Bite the bullet now and put the Hyd Roller cam in it.
Skimp on something later like new gauge bezels, painting the dash or taking the girl/wife out for dinner a few times.

I agree . Sometimes you can find a crane 741 cam cheap here , or the 525efi cam. Those are gen vi cams though I believe and you'll need a gen vi timing set. The 525efi cam is the 741 but on a 114Lsa rather than a 112

I have 2 complete 500 EFI roller cam sets for sale.

you are pissing in the wind trying to run a flat tappet cam anymore...the core they are ground on are junk..no quality control...call Bob M. @ marine kinectics...he will set you strait...listen to him...nuff said

Give Bob a call on a cam and he can get you taken care of. Worked with him on mine, 548 tall deck, AFR 305's 9.2:1 comp and his cam and we are making a nice 650hp/675 lbft

rollers it is then, I make the GF take me to dinner any way LOL

That`s two shots for anyone reading this thread btw!!