Go Back  Offshoreonly.com > Technical > Do It Yourself, Boating on a Budget
Baja 272/502 mpi new to me >

Baja 272/502 mpi new to me

Notices

Baja 272/502 mpi new to me

Old 01-08-2021, 07:19 AM
  #1  
Registered
Thread Starter
 
Join Date: Jan 2021
Posts: 18
Received 0 Likes on 0 Posts
Default Baja 272/502 mpi new to me

Introducing myself and asking some questions for clarification after searching.

as luck would have it i was surfing through Craigslist seeing if ther was anything i couldn't live without. Fortunately/unfortunately i found a 1995 Baja 272 with a no running 502, being not very smart i purchased said project. Not one to just rebuild the 502 as both head gaskets were blown and they failed to de water the motor.
my plan is a stockis rebuild with a mild cam, some mild porting the intake and heads , computer tune and 496ho exhaust. From what I've read the exhaust is fairly Straightforward and will work with my "captins call" Exhaust.
3 questions
1 other than dealing with making brackets what am I missing
2 is this worth the headache for more hp
3 best source for exhaust parts new or used

Thanks in advance
carnutsx2 is offline  
Old 01-08-2021, 09:57 AM
  #2  
Platinum Member
Platinum Member
iTrader: (6)
 
F-2 Speedy's Avatar
 
Join Date: May 2012
Location: Midwest & T-Rock
Posts: 7,785
Received 608 Likes on 309 Posts
Default

Id try to find a low hour drop in ready 502 mag mpi and go boat,
F-2 Speedy is offline  
The following 3 users liked this post by F-2 Speedy:
1BIGJIM (01-08-2021), 92nsx (01-08-2021), Kefurr (01-10-2021)
Old 01-08-2021, 10:58 AM
  #3  
Registered
Thread Starter
 
Join Date: Jan 2021
Posts: 18
Received 0 Likes on 0 Posts
Default

Thanks, I originally was looking for just that but I have a machine shop that has built several motors for me in the past. My problem is I can't put things back to stock. If the boat ran 25mph and I've got to rebuild it I would like 26mph when I'm done.
carnutsx2 is offline  
Old 01-08-2021, 01:19 PM
  #4  
Platinum Member
Platinum Member
iTrader: (6)
 
F-2 Speedy's Avatar
 
Join Date: May 2012
Location: Midwest & T-Rock
Posts: 7,785
Received 608 Likes on 309 Posts
Default

have you had the block magna fluxed, de water the engine ? didnt drain or winterize..its really a waist of money to try and port those 088 or what ever heads
F-2 Speedy is offline  
Old 01-08-2021, 11:43 PM
  #5  
Registered
 
Join Date: Mar 2020
Posts: 116
Received 43 Likes on 15 Posts
Default

One of the concerns I'm having with building a stock 502 is the oil cooling. I've read a number of threads stating the oil cooler is just adequate enough for the 415 HP it produces. Not to mention the oil hoses are pretty small in diameter.

When Merc built the 500HP (same size 502) they completely redid the oil cooling. Much larger oil cooler and larger diameter oil hoses. So keep that in mind
xlint89 is offline  
The following users liked this post:
carnutsx2 (01-09-2021)
Old 01-09-2021, 12:41 AM
  #6  
Registered
Thread Starter
 
Join Date: Jan 2021
Posts: 18
Received 0 Likes on 0 Posts
Default

The previous owner had a bad mechanic work on it swapping the heads and it blew head gaskets on both banks- never seen it before bot it was blown between each bore .
after spending the day doing research i think its going back stock, maybe a slightly hotter cam. Ill do some pocket porting just because I've got free time and some say not very smart
carnutsx2 is offline  
Old 01-09-2021, 01:13 AM
  #7  
Registered
Thread Starter
 
Join Date: Jan 2021
Posts: 18
Received 0 Likes on 0 Posts
Default

The previous owner had a bad mechanic work on it swapping the heads and it blew head gaskets on both banks- never seen it before bot it was blown between each bore .
after spending the day doing research i think its going back stock, maybe a slightly hotter cam. Ill do some pocket porting just because I've got free time and some say not very smart
I'm still in the hunt for 496 ho exhaust
carnutsx2 is offline  
Old 01-10-2021, 01:26 AM
  #8  
Registered
iTrader: (1)
 
Join Date: Oct 2013
Location: SF Bay Area
Posts: 2,806
Received 94 Likes on 66 Posts
Default

Fun boat! The factory package is pretty tough to beat and small mods really aren’t worth the trouble. Did the ‘95 have MPI already? Bumping up 50hp will give you a 2 maybe 3 mph gain and $1000 in new oil cooler and plumbing and then the EFI mapping won’t be up to snuff, and then you’ll need a different $600 prop. It never ends once you stray from factory. But, some good exhaust manifolds and dumping the stock Corsa exhaust tips really give you some good bang for the buck.
Baja Rooster is offline  
The following users liked this post:
bajaman (01-10-2021)
Old 01-11-2021, 10:46 PM
  #9  
Registered
Thread Starter
 
Join Date: Jan 2021
Posts: 18
Received 0 Likes on 0 Posts
Default

Its got MPI . I'm very familiar with the concept of scope creap but thats hot rodding.
Last night I drove the neighbors crazy running the pressure washer until after dark but the bilge is clean. This morning I started to pull the bottom end apart , everything was covered in a light chocolate milk shake or rust. The only surprise was its a gen 4 502 so its a flat tappet hydraulic cam , according to Delta Cam the local cam grinder says the cam is .507.505 lift 223 223 duration on a 116 lob sep.
now on the hunt for 496 manifolds.... so if anyone knows of a pair hit me up .
Tomorrow ill start packing stuff up for the machine shop and clean up the grease spot in the garage.
carnutsx2 is offline  
Old 01-13-2021, 08:01 PM
  #10  
Registered
Thread Starter
 
Join Date: Jan 2021
Posts: 18
Received 0 Likes on 0 Posts
Default

Well I Just pulled the trigger on a Comp roller retrofit kit, the extreme marine 218/224 @.050 and .510/.510" lift , I have a set of 496 exhaust to replace the logs that came on it and Ill put an O2 sensor in the so I can have a reasonable input for the tuner. It came with 1.7/1 no name roller rockers . With a fresh crank , resized rods, new bolts and forged pistons it should be good. The cam is a little smaller than I wanted but I would rather have too little than too much cam.
carnutsx2 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.