• If this is your first visit to the iboats.com Boating Forums, be sure to check out the FAQ. To post a question or comment, begin by signing up. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement Module

Help Tip: If you have a question that has not been answered to your satisfaction in the archives, it is always best to start a new thread of your own. By starting your own thread, you will receive the maximum number of views by forum members.

Below are some additional forum policies in hopes of all iboats members will follow, Thank you.

1. Please do not reply to old topics or hijack existing topics. Old topics of a technical nature are like a library book, Please do not write in them.

2. Old topics should be considered archives and used for reference only. Please do not reply to them.

3. Do not take over someone elseís topic (aka hijack) with your own question, even if it is similar. If you have a question that has not been covered to your satisfaction in the archives, it is always best to start a new topic of your own.

4. If you have a question for the original poster (OP) and the topic is over 30 days old, send the OP a PM, he may not even visit the forums any longer, or may not notice your question in the old topic.

5. By starting your own topic, you will receive the maximum number of views by forum helpers that may not even notice your question when itís posted at the end of someone elseís topic. And those answers will be specific to your particular issue.

6. Please do not post to topics that have been inactive for more than 3 months unless you are the original poster. We have very active forums and any topic that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old topic.

7. Posting at the end of any topic is considered to be hijacking the original posters topic which in turn subjects the topic to be closed if it continues to happen thus not making it fair to the original poster in the future had for some reason he/she needed to return for additional information or provide an update of the problem solved which is always welcomed within a reasonable amount of time frame.

8. Please note that you should see a red banner pop up near the bottom of each inactive topic asking you not to reply to old topics. The Red banner will read: Please note this topic has been inactive for 90 days. For the best results, please start a new topic.

Thank you all in advance for doing your part in helping iboats run a smooth ship.

Additional forum rules linked below.
See more
See less

454 Magnum

Page Title Module
Move Remove Collapse
Conversation Detail Module
  • Filter
  • Time
  • Show
Clear All
new posts

  • 454 Magnum

    I'm researching different types of long blocks for my Wellcraft. I have 1995 Gen V 7.4L in their now. I have been looking at US Engine at their website about 454 Magnum motors with 2" rectangular ports that have 55 more hp and torque in the 1500 to 4000 rpm range and use 20% less fuel than the original mercs. I have a Magnum in my other boat and I love that engine and it's performance. My question is will this in any way affect the Hurth transmissions I have in my boat and will I have to reprop as well? Any advice would be appreciated.

  • #2
    Re: 454 Magnum

    First I don't believe their claims about horsepower and especially efficiency. Otto cycle technology (throttle and spark plugs) just doesn't support efficiency swings like that. If they are that good they should be building engines for GM

    What model Hurth? Specs? What hp rating in there now? Carbed 310?
    Keep the faith!!! We'll be back stronger than ever


    • #3
      Re: 454 Magnum

      They are Hurth HSW630V1-1.55 Gear C. That's all the information I can find on them. The motors are 310hp I believe and are carbed.


      • #4
        Re: 454 Magnum

        That's one sweet motor but I would need two and a much larger cheeckbook!!


        • #5
          Re: 454 Magnum

          Looks like they'll be fine: http://www.simplicity-marine.com/ZF/.../Technical.htm

          I am getting 1.56 ratio though. Not sure why.
          Keep the faith!!! We'll be back stronger than ever


          • #6
            Re: 454 Magnum

            Thanks for the info QC it may not be as expensive as I thought!! HA HA!