articfriends

iTrader: (1)

Can anyone tell me from there experience what kind of power my motor is making? 2000 baja 272, had a 502 w/merlin 320's,procharger,lightning headers, 8psi boost boat went 79 mph w/28 pitch merc 4 blade,5200 rpm's trimmed up, Built a 540,same top end,.628 hyd roller,same blower pulleys,made 638 hp/5200 rpms,695 lbs torque 4400 rpms on tyler crocketts dyno ,he assured me those were good numbers and that prochargers claims of 685hp on 502 were a little generous (i was expecting 750-800 from 540) dropped motor in boat w/no changes,same prop,76 mph/4900 rpms!!!! Called Tyler,suggested more boost,called kip at cam motion,suggested more ign timeng,put 4 more degrees timeng in,4psi more boost (had only made 5-6 psi w/pulleys that made 8-9 on 502)boat goes 83 mph now 5900 w/28 pitch,85 mph w/30 pitch lab 5600,HOW MUCH HP IS IT MAKING? My buddys laughed at me when i showed them the dyno sheet (so much for bragging rights),these speeds were on gps and boat does have full hyd steering and yes it is a little out of control,thanks,Smitty.

cobra marty

So before you had 502CID 9lbs boost and 79MPH, then
540 CID 5 lbs and 76 MPH with 638HP and 695TQ, then
540 CID 9 lbs and 85 MPH and ?? what HP and TQ?

You gained +9MPH so you are now making 100-135 more HP.

Is this a magMPi EFI motor or a carb motor?

articfriends

iTrader: (1)

The intake and plenum are original 502 mag mpi (2000) w/stock injectors,tyler crockett has p/w opened up in program to close to max and 75 psi fuel presure under boost.

kennyo

Why aren't you turning a bigger prop? I run a 30p on a 502 w/5# boost and run 80-82 mph(gps) turning 5000rpm. Also has a stern jack(I wonder how much that helps?) Wear that kill switch cause they do get squirrelly.

articfriends

iTrader: (1)

kennyo,what size is your baja? w\28 pitch,boat pulls good to 5600,trimmed to max builds to 5800,w/30 pitch,pulls 5400,trim to max slowly builds to 5600,30 makes boat sensitive to fuel and pasenger load,boat will go 83 w/28 3/4 tank gas,4 people w/o too much effort,the max trimming makes boat the fastest but pretty squierrly,stern jack must help. tried 110 race gas and 11-12 psi w/30& 2 more deg timing only picked up .3 mph (85.2)but think i'm at limit of fuel system and don't want to detonate motor.

zt260

Your most likely making 750+Hp to get 85mph I would say you are really pushing the limits of that injection system. Don't bother with race fuel unless your ready to upgrade the injection system. If you want more you need solid lifters, AFR 357 heads and a new injection system. You could make up to 900hp at that point. I have these heads on my 540 and they make 50Hp more than anything else.

articfriends

iTrader: (1)

kennyo,i see now looking back at your reply you have boss 272 also,mine went 62 stock 502 loaded,64 lightly loaded,76 with 502/lightning headers/5 psi boost w/26 pitch/5200 (before i started getting really carried away). Was stern jack on your boat when you got it or did you put it on and see a gain (was wondering about the 4-6 mph difference when comparing my old 5psi set-up compared to yours). Is stern jack co still around,i don't see them advertising anymore and never seen one on anyones boat (figured it was just another gimmick part that came and went),thanks,Smitty

jspeeddemon

There is no doubt that your heads are killing you on the power. I know the 500 HP responds well to supercharging because of the head upgrades. As well you can figure motors make @ 1.2 HP per cubic inch naturally aspirated. Increasing the ci to 540 would net you about 45 hp with the same top end running it naturally aspirated. Adding the cubes to a Procharged motor would give an additional 65-70 HP. It takes 125-150 HP to pick up 10 mph by rule so that would be inline with you 6 mph increase. You are going to have to step up to better heads to go any faster, AFR, Brodix, Dart or Canfield all make good selections, I would pay for the CNC option. To go from 85 any faster it wil take even more hp per mph.

articfriends

iTrader: (1)

jspeeddemon,i am running merlin 320's with 322cfm@28in/.600 lift intake/202cfm28in/.6oo ex,when i was building this motor tyler crockett reccomended against anything bigger,i was game for a set of 340-350 cc runner heads. I'm currently using all my spare money to repair yet another beefed up xr outdrive so i have given up on putting anymore power into the motor but was wondering where my power is with current set-up,thanks for your input,Smitty

GEOO

Your 502ci was making around 700hp @ 8-9lbs, 540ci 760-770hp @ 9-10lbs.