Thread: Johnson "70mod"

  1. #321
    Team Member hupiveneilija's Avatar
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    Quote Originally Posted by LittleCharger View Post
    I believe he has raised his exhaust port height so there is a difference
    1.382 from deck.

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    Quote Originally Posted by hupiveneilija View Post
    1.382 from deck.
    Is that Bridge port or oval port? That's higher than any mod Bridge port I make and if it's an Oval port that's still high even in the middle of the port. Remember the higher you make the port, the less ECR is, so you need to correct that with the head.
    ECR= Effective Compression Ratio. Always reference this when modifying any engine.

    Set up your ports to gain torgue, not RPM. High reving engine is bad, not over 7800 , high Torque pulls bigger props = faster.

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    Team Member hupiveneilija's Avatar
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    Its bridgeport. I only have chamfer on sleeve area, havent raise the roof. Yes im aware of ECR, might go up a little in that. I have to find prop to take rpms down to ~7500 in wot.

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    not so sure exactly what you are now saying..
    so the clear this up a bit . are you saying
    1/ this port height is 1.382 the top of the chamfer to the deck ?
    or are you saying
    2/ the actual top of port height is the 1.3820 not including chamfer ?

    sorry for the confusion, but something is not translating right here.

    .

  5. #325
    Team Member hupiveneilija's Avatar
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    45* chamfer on sleeve area, upper edge 1.382 from deck. Port roof untouched.
    Attached Images Attached Images  

  6. #326
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    I never make the chamfer to the deck less then 1.400. The real port is lower yet. I don't raise that at all. I leave stock and do all the work with the chamfer. Raising the root of the port kills bottom end. The engine will rev great with that so going higher only reduces torque.
    Phil could not get your message. email wpt1mike@gmail.com
    Thanks johnson60 thanked for this post

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    I wish I knew how to make an attachment, I could supply drawing or photo.

  8. #328
    Team Member zul8tr's Avatar
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    Quote Originally Posted by Mike Wienandt View Post
    I wish I knew how to make an attachment, I could supply drawing or photo.
    Mike

    If you have a photo or sketch on your computer in a folder you can easily grab it. When you make a post on lower right is a Go Advanced tab left click and a screen opens, scroll down for Manage Attachments and left click, in upper right is a (+) Add Files tab when you left click than left click Select Files at the bottom than you can browse to the location on your computer for the picture or sketch PDF file. Make sure pictures are not too many Mb keep JPG pictures less than 0.488 Mb and PDF sketch less than 2.38 Mb.

    Hope this helps?

    Pete
    " Three may keep a secret if two of them are dead" Ben Franklin

    Location: SW Orlando, Fl

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    ah you only put a chamfer on the sleeve and not raised the original port height .

    I see.

  10. #330
    Team Member hupiveneilija's Avatar
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    Quote Originally Posted by Mike Wienandt View Post
    I wish I knew how to make an attachment, I could supply drawing or photo.
    I cant either with computer.
    This is why i do all forumwork with my Honor7, everything goes like snap of a finger😂😂!

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