272 with twins how to go faster?
 

I am looking at a mid 80s 272 with the 260's Does anyone have one of theese that runs 75 to 80 with modified small blocks. OR Would I need to change everything to get the speed up like 502 mags and bravos?

Re: 272 with twins how to go faster?
 

You won't see 75-80 in that boat with small blocks unless you can get like NASCAR type hp out of 'em (750 :eek: )

That's a fairly big heavy hull. Even with 454 Mags back in the day, 70-72 was tops.

Re: 272 with twins how to go faster?
 

A local guy has one with the 350/260's and alpha drives (EEEW!). I seem to remember him saying 63/65 on the speedo. (GPS would be lower). A good friend had one with 454/330's that were bumped to around 375-400hp that pulled 73-75 on speedo. 3rd 272 just brought to the area has 2001 500efi's and ran 83 GPS but couldn't hardly get on plane (props too big). Props were changed which increased overall performance and boat hits 78 GPS now.

Re: 272 with twins how to go faster?
 

I wouldn't change that over to big blocks/ Bravo's - 272's w/ that package sits very azz heavy.

One trick is to swap the port Alpha drive (or change the gears yourself) for a counter rotating one as that boat most likely has both RH drives on it. With the right props that could add another 5+ mph. If you threw some small superchargers on there I'd bet that would get you mid 70's.

Re: 272 with twins how to go faster?
 

Has anyone switched one to a single? Looks like some major stringer work though.

Re: 272 with twins how to go faster?
 

Plus it's a heavy boat for a single unless you have some MAJOR power. I have t/540s and see mid to upper 80s :cool:

Re: 272 with twins how to go faster?
 

Mopower, I hope your putting some hours on those bad boys, hopefully a trouble free summer :D

Re: 272 with twins how to go faster?
 

Masi,
Pretty much trouble free this year. Still have a slightly rich problem which wasn't there on the dyno. I have an Innovate Air/fuel meter and at cruising speed I'm running 10.9/1 A/F and plugs dark brown. Better safe than sorry. Adjusted floats again and have to try again. My engine builder says it could also be the exhaust in the boat causing it to go richer too. Other than that it runs like a raped ape :D
Also have a set of 30" Bravos to try. Got 28s on there right now and turning 5600/5700 rpms :eek:

Re: 272 with twins how to go faster?
 

Is it very stern heavy with the 540's?

Re: 272 with twins how to go faster?
 

Nope.
Aluminum heads , intake , and exhaust manifolds. They are Merlin blocks and they are heavier but Merlin heads are near 80 lbs each , my Canfield alum. are 38 lbs each. Merc cast iron exhaust manifols and elbows will tun your face red trying to lift them. My Imco Power Flows can be handled with one hand. And the Team G intakes are probably near 1/2 the iron Merc intakes were :cool: .

Re: 272 with twins how to go faster?
 

I may be wrong here, but I remember hearing that the stringers are setup different in small block vs. big block 272's, therefore making very difficult or not possible to swap from one to the other.

Anyone else know about this?

Re: 272 with twins how to go faster?
 

Never heard of that before. I tend to doubt there would be any difference. Motor mount location on the stringers may be different but I really don't think the stringers are different.

However, I don't really know for sure.

Re: 272 with twins how to go faster?
 

I did this conversion on my last boat, 85 272ls. From 260's to T340's I converted a pair of blue water inboards. Could only get that heavy puppy up to 59 on the gps. The big blocks made the boat handle badly in rough water. To much weight! But It was all cast Iron back there. The guy with the 540's has the right idea. Lighten those big blocks up so they are at least the same weight as the 260's were. But we do have three of them in my club and none can break 60mph. These boats are made for a good ride, it is an expensive proposition to try to get the to go real fast...

Re: 272 with twins how to go faster?
 

AND HOW...just ask me about it. :rolleyes: