I am going to remove the stock wieand 177 blowers from my merury 525s.c.'s and replace them with a pair of 250 B&M blowers and chillers. I am also going to change the cam and lifters over to a roller. I am wanting a recomendation on cam shafts. I need to know the part numbers by the way. Also is it worth the expense to put aluminum heads on these engines? What sort of h.p. increase is realistic with the blower chiller and cam change? and if I did do aluminum heads what additional h.p. would I expect? What would you recomend for initial jetting in my dominator carb? Thanks!

There a lot of threads on this. Do a search here. I would be interested in one of those old blowers for a spare, if you are going to sell them.

I will see if I can find any of those old threads, I will probabally sell both set up's.

I would give comp cams a call on the cam, as far as the heads are concerned H/P going to deoend on which alum heads you run....many choices there....but the same head in aluminum will not add H/P, what boost are you running now ? what are you planning on running....thats going to detrimine a lot on the power, but remember at a price, jetting is just going to be a tuning issue, just have to run 1 min 3000 rpm runs read the plugs and jet the primaries, then wot runs and jet the secondaries......Rob

If you've got the hatch clearence, I'd go with a pair of 671's & Superchillers. Give RM Builder (Bob Madara) a call for the cams and associated parts. I'm running same combo, Bob is a wizard on cam selection

ezstripper,

I will give comp cams a call, but would like to hear from someone who has gotten or used the cam, just to be sure and get all the info. I currently have a stock 525 s.c.'s, they make 5 lbs of boost and I have no chillers. With the bigger blowers and chillers I may try 8 lbs of boost. As far as the heads go I am probabally going to go middle of the road something I can run out of the box and not spent $2800 per engine. On the jetting I was just looking for a first try. I would assume that the current jetting would probabally be safe to try.

what kind of fuel are you planning on running ? running 8 psi is going going to give you about 11.5 static compression ratio...the chiller will help but it's still going to be on the extreme for marina pump gas...most only 89 at best....I was going to run 7 in my setup but now staying with 4.5-5 in case have to fuel up on the water. the stock jetting would be ok to start, may have to play with a colder plug to help to, I'm running there blower specific cam(comp) but do not have it together yet...issues with the short block and time !!!