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Thread: vortec 8.1 engine,information

  1. #1
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    Default vortec 8.1 engine,information

    any information on how this motor has been in 25 ft jetboats,I know thunderjet used it.has it been reliable also i heard it's no longer being used,thanks

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    Member Dupont Spinner's Avatar
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    It's one of Mercruiser's most popular engines.

    As far as jets go most started to go to the 6 liter, not to far off of the big block hp/tq at a lot lighter package. Inboard/outboard and performance inboards are also repowering with the 6.0.

  3. #3

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    Quote Originally Posted by gmoose View Post
    any information on how this motor has been in 25 ft jetboats,I know thunderjet used it.has it been reliable also i heard it's no longer being used,thanks
    Just received word that the 8.1 is no longer available. North River's commanders will be standard with a Kodiak C350 with optional 6.0L and will soon have a optional 6.2L. All gassers are now supplied with catalytic converters. The 250hp diesel is also an option and soon a 300hp version.

  4. #4
    Member Music Man's Avatar
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    No problems with mine, and a friend has one in his airboat with no problems.
    When seconds count, the cops are just minutes away.
    '08 24' HCM Granite HD "River Dog"

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    GM discontinued the 8.1 in ALL marine and truck applications. Can't even get a big block in a pick up
    The 6 liters have taken it's place in various power levels up to the supercharged LS9 which puts out over 600 hp.

    The 8.1 HO puts out over 500 foot pounds of torque at approximately 3,300. The big difference between the 6 and 8.1 is the 6 has to be run at higher rpms and this usually means higher fuel consumption. Still, they are lighter, take up less room and weigh a little less. No doubt they will be engine of the future for a long time.

    Have the standard 8.1 in our Sea Sport and doesnt seem to matter how much weight we put in the boat we still average 2 to 2.2 mpg when cruising. Our Thunderjet has the HO (425 hp) version and it also does pretty good on the fuel until it it loaded down heavy. Lightly loaded it will use 8-10 gph or roughly 3 mpg. But when you have 3,000 pounds of gas and gear on the deck you can double that.

    Some people on different forums state they have upwards of 5,000 hours on these motors without having to rebuild anything. So, if you run 100 hours a season the motor will last 50 years
    Tennessee

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    Forgot to add, we have not had any issues with either 8.1 in our boats.
    Tennessee

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