ol school 272
 

Does anyone on this thread run an early 80s smallblock 272LS.Im restoring an 84.

We did a lot of work on one for a friend of mine it is a 84 LS as well, nice boat. Good on fuel but uses a lot of beer!!!!!!!

I have a 83 272 with small blocks. I pulled motors and transon assy 13 yrs ago to paint bilge and look at things ect. Put corsa
captain's call exhaust on. Wife won't let me upgrade because boat has been a good one. What questions do you have?

What kind of speed do you get? what props do you use? Are the engines stock. Does yours have k planes if so how does it effect the ride. the gimbals on mine were rough just picked up a nice freshwater set. Are your drives counter rotating. How are they set up, rotating out? thanks Paul.

Brought the boat with 260hp. the motors have lasted 13yrs plus the owners hours before me. Did run 60mph but now 56.Cleaver 21props, not counter, bennett tabs. Friend has same boat 300hp tempest motors running 70 on good day. Had the chance to go counter but rode on two other boats with counters and saw little to no difference. I have a spare drive to fit either side and did not want to worry about finding props.

Thanks for the info mine has 330hp vortec engines that are being massaged right now. When I talked to Formula they said 62. but also heard that wasnt realistic on such a heavy boat. Mine has counter drives with merc mirage 21p props.

Paul, do not understand why 62 is not realistic. 300 tempest motrs were pumped up. My motors have center bolt valve cover head which raise comp ratio a little. 5800lbs dry is weight. the hp to lbs ratio verses big blocks/TRS is going to help. Small hp gains show more. 272 did 57mph w/260 when new if I remember. Anybody else have input?

In 87 a buddy of mine bought a new Cobalt Condurre 27 set up the same way it could hit 60 under the right conditions. Probably a reliable 55 all the time. Through talking to folks I heard the 272 SR1 big block version was a 70mph boat. I would be thrilled with 65. Im hoping for 400 ft.lb. of torque out of the engines. My 30' Scarab had 330/454s with trs drives that was an honest 65mph boat. Just fishin for info from someone who has a proven setup.

my 87 272 i had ran 59.9 GPS with 260's only upgrades were MSD coils K&N arestors and locked timing @35 degrees. 648 HRS

4800 rpms spinning 23 Mirages was 59.9

3500 cruise was 40.1 GPS

hey car biz do you mean no advance straight 35 off the pick up only?

Yup. Ran the motors up to 3500 (advance was all in at 3200 though) set it @ 35 tighten up dist. done.

Timing
 

The reason Im asking is because I just put a 355 together for my 21 and its a little flat on top. I have been conservative with timing due to the compression 9.7 I have also been battling with a weber 750 that wasnt very cooperative so I put a new Holley on it but had to winterize before I had a chance to run it. It has Dart heads with vortec chambers that are supposed to be more forgiving on higher compression due to the chamber design. I may try a single plane intake as well.

My previous boat : 1988, 272 ls1 ,twin 250 prop HP alpha 1.5-1, 23' mirage props, GPS 59-60.0 mph4450 rpms. After adding the 350 mpi/300hp and counterrotating alphas 1.47-1 ran GPS 60.0 mph. We needed to cut 1' pitch out of props to get in rpm band and 60 mph. The counterrotation did nothing for top speed nor did the added power but easier backing up and noticeably more torque /acceleration especially when many aboard. Must need big blocks to get the torque for top end?My2 cents

Thanks Pat It looks like im gonna have to get the hp/tq up to get the speed up there.