possible upgrade.
 

I am by no means a motor guy so maybe yall can help me out.

what can be done to a motor that has 10-1 compression to get more power?

can forced induction be used.

basicly i want to get more power but dont want to have to buy bigger motors.

any input would be appreciated.

Can't add boost with that compression.

thats what i thought

....Unless you add methanol injection.

or lower compression to around 8 to1:party-smiley-004:

Better heads/intake would seem to be the likely option.

yep also cam, carb drive height all adds up to speed I got 8mph gps by a 2'' shortie and carb change prop was small at that point but Iwent in for surgery came out drive carb steering msd boxes all gone and more Ithink there was another 2 or 3 mph left.:angry-smiley-038::angry-smiley-038::angry-smiley-038::angry-smiley-038:

I have added a Whipple to 10:1 engines on several occasions. I actually build my 750's with the same bottom end as my larger, supercharged engines for that reason. You note only have to limit the amount of boost, but you have to have a really spot on tune. Obviously, I assume you have aluminum heads. The exact amount of boost will be largely determined by the camshaft. It's going to depend on cylinder pressures. As a general rule of thumb, you should be able to get away with 3-4 psi. I have squeezed out as much as 6 psi. You could always run a little more boost with some higher octane fuel added. You could add say 30-40 gals. of 110 octane to a 100 gallon tank, for example.
You have to be really careful on a carb engine without any form of knock protection. It can be done but the exact amount of boost will be determined by the rest of the combo. Let me know if I can help.
Eddie

I agree, you can add FI on an engine like that if you have aluminum heads, keep it fat, run relatively low boost, and spray meth. Forged pistons would be a must. Race fuel would work as well, but it isn't feasible for most people to run daily. Ideally you'd want to lower the compression though...

Look up magnum machine in phone book. Call and ask for Curt. H has done lots and lots of performance marine engines in the area.

The season is coming to an end and i have a ton of cosmetics to do on the boat and would like to get more power, but im not sure i want to run something as temperamental as a high compression boosted motor sounds like it can be.

It seems as if i would be putting a time bomb together. ??

The boat runs good now but like everyone...
when it aint broke we still wanna go faster.

it sounds as if it might be worth it to lower compression on what i have or look for some long blocks to work with.

Young: would there still be any reliability with packages like this? obviously if dialed in and tuned correctly?

Bill: are they local? i haven't heard of them. have they done work on your stuff. I know u always do it rite.

Like I said, the setup is key. It would be better to lower the compression obviously. I just wanted to point out that it can be done, assuming you have access ot 93 octane fuel. Yes, it can be reliable.
Eddie

I agree that most of +MPH opportunity is not in the engine compartment. If the X is still as it was set in 1999 with 3-blades. Spend you $ on a re-rig. Big job, but more MPH and less $ that two new engines. If you have #3 or Bravos, neither will likely last in a 38' Cig with big torque.

i apprecaite the input... i run 94 octaine in it now.

That was also another concern is that the X dom. is low but i have heard people having mixed reviews on shorties and or boxes on straight bottom guns.

when u say re-rig do u mean filling the transom and raising the drives and motors?

looking at the bullet of the lower in comparrison to the bottom of the boat it seems low... i guess a good first step would be to try some shorties and see how it reacts.

Yes, In Chesapeake close to Priority Chevy. Did work on my motors after Joey Griffin screwed me. Also has done work for LOTS of local guys. He is good and reasonable pricing.

I think the comments you have seen on over raising the X are about X's on boats that the X was already set up for 4-blades. They started higher and then went too high. You would have to see where you X-was set in 1999..
It should be pretty easy to find the ideal X for a 38 TG straight bottom that was dialed-in for Bravo 1 4B's. This should be one of the last straight bottom Cig's. If you can't find the answer on OSO, call Phil at Lip-Ship.
The re-rig will include replacing most of the transom, paint/gel, raising the engines, reworking the tail pipes, misc hoses, etc.
Great winter project :drink:

yeah. phil knows the boat pretty will from what i understand. it would probably be easiest to call him.

I think no matter what route i go motor wise i will look into the x dom. or atleast shorties.

haha.. yea a great winter project. A friend did all u listed in my shop a couple of years ago. actually didn't seem as bad as one would think. but im not sure i want to get into all that.

i was considering the obvious and getting a newer stepped #6 boat but am still a little upside down in mine so im gonna keep workin on mine till i am ready financially.

Kinda what I was thinking... get into a T/S TG and you'll be running faster right out of the box. Like you, I'm afraid my drives are going to be my next weak link. Either way, good luck!

bravos will always be the weak link on these big heavy boats.

its crazy how much anything to do with drives cost too...

I would certainly think that your boat would benefit from some shorties and props considering it's an older straight bottom gun. I haven't put shorties on that exact boat, but I have never had an older straight bottom boat that didn't go faster with shorties. I did a pair on a 31' Cig Bullet years ago and it picked up 7 mph. That was defintely on the higher end, as most were 2-4 mph gains.
As a side note, if you don't already have full hyd. steering, you'll want to get before adding the shorties.
You may also want to check the bottom to be sure it doesn't have even a slight hook. That can cost you quite a bit of speed. Depending on how much faster you are looking to go, you may be able to find it all in setup alone, as mentioned earlier. Sometime there is a bunch of speed left on the table.
Good luck and let me know if I can help.
Eddie

I agree 100% and think the things you have mentioned..

can i check the hull myself?

I do have external MM steering.. it origonialy had 700 zuls in it (blower motors)

have about 600 a side rite now and will run 76ish @4900. with 3 people and full fuel.

Like you said i feel there is speed left on the table, mostly due to the fact the boat was rigged and set up 13 years ago.

Tres Martin is the guy to talk to on straight bottom (ts) guns also! Got tons of good info from him.