272 x dimension
 

I'm in the process of restoring a 1984 272 l s .I'm going to be installing a couple of stroker small blocks .I know that the formulas had a conservative x dimension and can get more speed from running shorty lowers, but these are alphas..Is there a problem with just raising the x dimension .I know this involves re-doing the transom and bringing the entire drivetrain up. Does anyone know how far up I could bring them without running into problems. Problems= Running, and clearance issues. I do business with a pro glass shop that will do the transom for me on a tit for tat trade. My end of the trade is just doing what we always do.Thanks in advance for any input

I would just do a bravo swap. No glass work involved. Stronger drives for stronger motors and you can run shorty lowers. If it doesn't work out easy to go back to regular or spacers. A lot more options that way then trying to redo transom just to keep alphas.

Appreciate the input ,but i'm not trying to keep Alphas ,i'm going to keep Alphas. In fact I own a couple bravos and transom assemblies but don't want to throw them at this boat .For the amount of power i have, well built Alphas will work .Take the work/money part out of question on transom. I think I'd like to raise assemblies 1" to 2" inches but would like to hear from someone that has done this .My thinking is if 2" shorty's work on a Bravo to speed boat up, why not just raise x dimension a like amount.........But ,I was wrong once before .

Your good, I have been wrong lots of times. Heck, after 18 years of marriage, I do not remember what it is like to be right! Yes, raising the drives will help from what I have read. You need to contact sprink on here about his old 272 that he had. Scratch that, sprink needs to post a thread recapping all the info he has about his old boat into one spot.

Anyways, he had a 272 with stock mercruiser motors that had fuel injection back then with alpha ss drives. Guess this gave the boat a rated 320 hp per side, counter rotation and the drives were shorter, mayby by 2"? Definately picked up speed. I would like to know what the motor specs were internally to compare to what we are building today. Was it really only 320 hp? Or was it the rpm they were built to spin? Never got around to pestering him about it.

If I end up keeping this old bird long term or getting a newer fastech, I would love to do some newer generation motors to get the rpms up there as compared to what I run now and shorter drives. Seems there is speed on the table from what some have run. Good luck, will watch for where this goes.

Brian

I would like to see the results of 2" shorties on a 272. A friend of mine put an Imco shorty on his 242 w/ HP500 and gained exactly NOTHING. Loaned it to another friend with a 26 Sonic and he gained almost 5 mph!

I'd like to try a set of shorties on my 303

I'd certainly hate to go to the trouble to do transom and gain nothing .I'd think , by pulling more drive out of the water ( vertically ) and propping accordingly ,it's bound to be a little faster .I just don't want to go so high I have problems staying hooked up. That's why I'm looking for input from anyone that has done this to a 272.I thought I had read somewhere on this site about a guy running shortys and gaining speed. Maybe a hallucination...Can't find it now.
Never had a chance to see these drives running in the water at wot or any throttle for that matter .Bought the boat as is where is without even trying to start motors. They do run, but boat is now stripped to bare transom ....

Mopower ,just saw you had a 272 with two 540's .How much power per motor and how fast is your boat .I've always been a bb guy but I'm wanting to try a couple little motors in this boat ...just because.

I would think a single 525 would be nice in a 272, anyone try that?

I had that thought also, convert it to a single bbc. Bt now that I am as far in my current boat as I am, I will not rip it apart o start over and doubt I would get rid of it to do the same boat again.

Hum...single 550 -600hp bbc Bravo....gets the wheels turning. I may look into that as a possibility. There would then actually be some room in the engine room.

Trust me...I have seen that tried...these are heavy boats and need 600+ horsepower and 800# of torque to run well. It's easier to accomplish with twin SBC's since you are already rigged for it. If you decide to mess with the transom...spread the centers to 34". Then you have the twin BBC option.

Diego in this forum has an '87 with twin 454's bone stock 330 horse motors running about 65. He's changing the stock exhaust to Stainless Marine performance as I type this. With a bit of carb tweaking and prop selection he may see 70.

I would like to see a strong pair of 383's in one of these...Diego has a fresh pair that made 400 horse and 460 ft lbs...he may be in a position to sell them.

I'm putting twin 400 horse 355 Vortec Roller Cam motors in my 255 as I write with Bravo drives, The 255 is a similar boat to the 272 maybe 200 lbs lighter with higher free-board. I'm running stock X and will possibly see 70~75 if I push it...top end isn't my goal...long runs (4+ hrs) at 50~55 are. I went for the Bravos for a variety of reasons but mainly for long distance ocean running durability.

My '86 272 had Alpha SS drives behind 320 EFI/TPI Mercruisers...23" stainless cleavers. We had no GPS in that day but pitot speedo was 74~75 at 6000 RPM. Those motors were strong and made power all the way from idle to 6000. I ran that boat 60 for 2 hours once which was about 4800 RPM...that 272 was a strong running SOB in smooth or rough water. it brought me home many times thru weather and seas that I should not have been in. The Alpha SS was strong. I used to catch air with that boat and spun the hubs out of several props...never had a drive issue. Take that back...I hit something right outside of Port Everglades one afternoon in 40 ft of water. Bent the starboard prop and the prop shaft. Mechanic went all thru the drive and tried to talk me out of it. I watched him the whole time to make sure i didn't get the upper swapped for a standard Alpha...I know the SS gears and bearings had to be heavier...6000 RPM on a standard Alpha...no way!!! The SS handled it. The only other boat I ever saw them on was a '86 Formula 242 SR-1 with twin 320 EFI's. Owner told me he saw 80 once after driving thru a chine walk...said he saw God!!

I never did check the X on those drives but I know I could get on a plane in 4' of water with no skeg drag!!

If you are looking for strong Alphas check this guy http://rlcboats.com/triple_digits/pr...pledigits.html

I think someone will break 100 in a 272 with LS motors based on GM 6.0/6.2 architecture I think it will take 1000 horsepower to do it....with twins. A single engine will run too deep based on hull configuration regardless of dive length....unless someone builds a pad into the hull...interesting to theorize.

I love these old boats...think about it...they still turn heads and hold their own in the performance boat world 25~35 years later....that speaks volumes.

Good luck with your project. Remember that the Formula hulls weren't built for top speed but moreover for the ability to slice thru rough seas at high speed.:cool:

Nice write up John.

This is the Sprink I was looking for threads from,i think. My initial thoughts with this boat was to pull the stock 260's and replace with a couple 383,s with good heads and exhaust .These days it's not hard to get 400 hp out of one of these strokers.Then I started wondering about the possibility of raising x-dimension to get some drive drag out of water .I was sizing up boat yesterday as to possibility of single bb and was wondering about how high or low to run single Bravo .what you said makes sense about drive to low ....Needs a notch or pad ,,,or both .But this boat will get neither.Do you think the stock alpha x dimension is high enough for some decent speed with 750-800 hp..I really only care about getting it somewhere in the mid 70's...This certainly isn't a race boat .Main reason for wanting decent top end numbers is to be able to "motor" in the 50's with motors happy. Not super concerned with Alpha reliability. Set up tight and not beat on too hard ,they should be alright .And if one comes apart ,I have more drives and drive parts .Obviously my easiest path is to leave transom alone ,since it is solid, and get some motors in this old bird.....Thanks for reply

Ls motors=out of budget for this old boat...would be fun though