Go Back  Offshoreonly.com > Technical > Do It Yourself, Boating on a Budget
502 with side mount Whipple >

502 with side mount Whipple

Notices

502 with side mount Whipple

Old 05-01-2020, 08:52 PM
  #1  
941
Registered
Thread Starter
 
Join Date: Oct 2019
Posts: 42
Received 12 Likes on 9 Posts
Default 502 with side mount Whipple

This is my first boat! My wife got it for me last Christmas so last season was my first time running this or any boat... The idle was not confidence building when trying to dock so I decided to look into it and have a look at what's going on in the engine bay. I know my way around an engine so why not take a swing at it?? So I found a modded 502 lower manifold on this site and got the wrenches out. Everything went smooth till it came time to get her running, need a scan tool to set tps and iac count. turns out a buddy's friend has just that tool. I find out my tps is not returning to the same number every time. I went with the Holley EFI tps and boom returns to the .47v every time. now I sweep the throttle to wot. To my surprise it was only going to 78.5%! I see Youngs performance is the go to guys with this setup so I call them. They were very nice and helpful and they told me that the tps needs to see 99.1% or better. The man I was speaking to was so nice and helpful it was refreshing, here I am asking him for information on how to work on my boat and taking time away from him billing for his time. Big thanks.



So I take off the throttle body and start looking at it. I see the linkage can be set two ways. The way it was setup, both blades open at same time which would make it fall on its face. the other way lets the first blade opens a40% then opens the second blade. this tb is so big there is no way this engine needs all the air it can deliver.




Bill added for size reference.


So after playing with the tb for a while I got it all squared away and now it get over the 99.1% at wot. Does anyone know what throttle body this is?

Tim
941 is offline  
The following users liked this post:
brett fiddes (05-02-2020)
Old 05-02-2020, 03:07 PM
  #2  
Registered
 
Join Date: Jun 2011
Posts: 1,101
Received 53 Likes on 42 Posts
Default

I can't comment on that throttle body specifically, but the factory 2 stage TB that Merc motors of that era came with were linked progressively. In other words, the first or primary TB blade opened with throttle until around 50% TPS then the second TB blade would begin to open, usually at a much faster rate. I would hazard to guess the second way you connected the linkage would be the correct way.
Trash is offline  
Old 05-05-2020, 07:06 PM
  #3  
941
Registered
Thread Starter
 
Join Date: Oct 2019
Posts: 42
Received 12 Likes on 9 Posts
Default

I put the boat in the water yesterday and it was sooo lean...
I had a lambda of 1.14 getting on it. All I did was fix the 78.5 wide open throttle (now 99.6) and change the intake manifold to a modded lower I bought here on this site. It must make a huge difference on a boosted motor. So I called Young performance back up... I was told to add two 80# injectors to the TB and how to run the fuel system. So this morning I got the trailer and pulled the boat out and got to it!!! next daying the ecu to Young's tomorrow!! Pics of course or it did not happen..





Tim

Last edited by 941; 05-05-2020 at 07:09 PM. Reason: spell check
941 is offline  
Old 05-05-2020, 09:19 PM
  #4  
Registered
 
Join Date: Oct 2000
Location: Lakewood, NY, USA
Posts: 3,353
Received 221 Likes on 117 Posts
Default

Eddie is a great guy.... He will take care of you.

Padraig
Padraig is offline  
Old 05-06-2020, 08:36 AM
  #5  
Registered
 
Join Date: Jul 2009
Location: Newburgh, IN/Grand Rapids, MI
Posts: 533
Likes: 0
Received 10 Likes on 5 Posts
Default

I had the same 502/side mount set up several years ago and mine was a disaster when I bought the boat I took it to Eddie and he fixed all the issues, if you are taking your boat to Eddie ask him about a return fuel line to the tank to prevent vapor locking. The first season I ran my boat it vapor locked constantly leaving us stranded for a hours on more than one occasion. Mine was a 252 Baja and when running strong it would hit low 70's on GPS. Mine also had an older MEFI computer that eventually malfunctioned on the next owner and damaged the engine.
bigredbaja is offline  
Old 05-06-2020, 10:02 AM
  #6  
Platinum Member
Platinum Member
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
Posts: 775
Received 20 Likes on 13 Posts
Default

Originally Posted by bigredbaja View Post
I had the same 502/side mount set up several years ago and mine was a disaster when I bought the boat I took it to Eddie and he fixed all the issues, if you are taking your boat to Eddie ask him about a return fuel line to the tank to prevent vapor locking. The first season I ran my boat it vapor locked constantly leaving us stranded for a hours on more than one occasion. Mine was a 252 Baja and when running strong it would hit low 70's on GPS. Mine also had an older MEFI computer that eventually malfunctioned on the next owner and damaged the engine.
Unfortunately most of these systems are advertised incorrectly. They make them seem like a simple bolt on when actually they are quite complex, as mentioned above, fuel lines, new injectors, re-flashing the ECU. and nobody says the drive wont last! Most motors will need a rebuild after a season to get the parts that can handle the additional stress. Speaking from experience and the tuition paid to learn to do it all right the first time or you may be disappointed!
RBeyer is offline  
The following 3 users liked this post by RBeyer:
941 (05-06-2020), articfriends (05-06-2020), Gimme Fuel (05-07-2020)
Old 05-06-2020, 11:37 AM
  #7  
941
Registered
Thread Starter
 
Join Date: Oct 2019
Posts: 42
Received 12 Likes on 9 Posts
Default

Originally Posted by RBeyer View Post
Unfortunately most of these systems are advertised incorrectly. They make them seem like a simple bolt on when actually they are quite complex, as mentioned above, fuel lines, new injectors, re-flashing the ECU. and nobody says the drive wont last! Most motors will need a rebuild after a season to get the parts that can handle the additional stress. Speaking from experience and the tuition paid to learn to do it all right the first time or you may be disappointed!

Learned All this when I owned a car shop, Everybody wanted a bolt on turbo or supercharger kit. This engine will get dialed in and left as is. I am building a Dart tall deck for this boat, block is at machine shop now. What sub section should I post that in??


Tim
941 is offline  
The following users liked this post:
ph1971 (05-06-2020)
Old 05-06-2020, 11:18 PM
  #8  
Platinum Member
Platinum Member
 
RBeyer's Avatar
 
Join Date: Nov 2003
Location: Antioch, IL
Posts: 775
Received 20 Likes on 13 Posts
Default

Originally Posted by 941 View Post
Learned All this when I owned a car shop, Everybody wanted a bolt on turbo or supercharger kit. This engine will get dialed in and left as is. I am building a Dart tall deck for this boat, block is at machine shop now. What sub section should I post that in??


Tim
Sounds awesome. Hopefully you will post the progress to be followed.
RBeyer 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 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.