I need some help with motor options, I have a 1989 311 with 502's which I blew one up. having both rebuilt but not sure which way to go since I have trs drives what hp can these handle.And has anybody built up a 311 if so what motor package and speeds? any info would be helpfull..thanks

Mine did 70 with 502 MPI engines and Bravos and over 72 with HP500s and Bravos but I haven't got the right props on it yet. The TRS should be able to handle 500 HP pretty easily but you won't get as much speed since the gear housing is not as hydrodynamic and you lose some power through the transmission.

Are they carb 502's? A nice cam, a little headwork, some other goodies, and 550-575HP is not hard to do. If you have the motors out, now would be the time to refresh the trannies, and have them add a extra plate...The trannies can take alot if built properly.....the TRS drives, can take 600HP a side in a 31ft boat. Just dont abuse them. Easy on holeshots and don't get carried away launching off waves...


Where you located? Lots of good MARINE engine builders around...be careful with car guys rebuilding your motors....Depending on where you are, we can recommend one..

yes they are carb motors I was getting 73mph on gps motors were pretty much stock besides good exhaust and msd ignition. Trannies were already beefed up because there were blower motors in the boat before.I was thinking about je ultalight pistons comp cams and roller rockers and lifters port and polish heads and a hardin marine intakes, all new gauges .well pretty much redo the whole boat!!!!!!!!!just like the looks and the ride of formula boats. will be posting picks of the build..Im hoping to get around 550 to 600 hp

forgot to add Im in virgina just south of Richmond Thats for the replies

Cool..if you wanna send your heads out, have Jim valako in grand rapids Michigan go thru your heads. He is very reasonable, and flat out awesome with heads. He knows what areas to work on, to get results, rather than just a general port job.....he also is now casting his own marine heads...

does he have a web site?

My HP 500's are at Jim V's shop right now. They are now 509's,with new comp roller cam, new comp roller rockers, Jims port work on the heads, and some other little tricks. Also running 9.5cr, they should be making 600 a piece.

Ive been working on mine getting everything rewired painting the bilge, drive and all motor brackets lots of time and work!! waiting on machine shop now.(been there since january) but o well. I would be real happy with 600hp.

Ted something does not seem correct, I get just at 70 GPS as does my buddies (69mph) with 420's and TRS drives.