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eliminatorbuild

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Driveline/spline question
« on: June 14, 2020, 03:10:16 PM »
I had my intake replaced with one with a shoe and ride plate. My pump now sets about 3/4” lower then it did. I put the engine back in where it was to see how far out the drive line was. To me it doesn’t look all that bad but I’m wondering if there’s something I’m missing. Please help!!!!! 


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76Mantra455

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Re: Driveline/spline question
« Reply #1 on: June 15, 2020, 07:35:20 PM »
I read on here on a post  but  angle from the shat of the pump to the flywheel should be like 1 degree 2 degrees max.....The post was ...setting up motor mounts... hope this info helps
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Flusher

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Re: Driveline/spline question
« Reply #2 on: June 16, 2020, 06:34:47 AM »
The intake/suction sits lower now?

The engine appears low in your pictures, but I don't think it would be a problem.  If the former intake setting was indeed higher, it is better now.  However, 3/4" is huge and something, either then or now, would be terribly wrong.  Is your oil pump hitting any of the front six intake bolts?  If your intake is truly set higher, you will run out of clearance in a hurry.

On short drivelines, such as in jet boats, I prefer to keep the angle between 1-3-degrees per joint, not zero.  Ideally, for driveline optimization, the pump shaft and crankshaft should be parallel.  Here is a really good video explaining U-joint phasing .

I can't tell if you have a 4-point mount or a rail kit from your pictures.  The bellhousing looks a little 4-pointish.  Assuming that you have a rail kit, you could raise the engine by installing shims between the rails and motor plate blocks.  With a 4-point, what you have is what you get.

Something I can't empathize enough:  Make sure that you have 1/8" - 3/16" clearance between the slip yoke and bottoming out anywhere on the pump shaft.  If it bottoms out, it will destroy your engine!
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angermgmt

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Re: Driveline/spline question
« Reply #3 on: June 16, 2020, 07:59:18 AM »
I think you’re good.


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eliminatorbuild

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Re: Driveline/spline question
« Reply #4 on: June 16, 2020, 11:58:26 AM »
The intake/suction sits lower now?

The engine appears low in your pictures, but I don't think it would be a problem.  If the former intake setting was indeed higher, it is better now.  However, 3/4" is huge and something, either then or now, would be terribly wrong.  Is your oil pump hitting any of the front six intake bolts?  If your intake is truly set higher, you will run out of clearance in a hurry.

On short drivelines, such as in jet boats, I prefer to keep the angle between 1-3-degrees per joint, not zero.  Ideally, for driveline optimization, the pump shaft and crankshaft should be parallel.  Here is a really good video explaining U-joint phasing .

I can't tell if you have a 4-point mount or a rail kit from your pictures.  The bellhousing looks a little 4-pointish.  Assuming that you have a rail kit, you could raise the engine by installing shims between the rails and motor plate blocks.  With a 4-point, what you have is what you get.

Something I can't empathize enough:  Make sure that you have 1/8" - 3/16" clearance between the slip yoke and bottoming out anywhere on the pump shaft.  If it bottoms out, it will destroy your engine!
Thank you for your feed back.
I have seen this question asked a lot on here but I haven’t seen it answered. Where on the pump is parallel with the shaft to check from? And where on the engine is parallel with the crankshaft to check from?  I’ve read some use the oil pan on the engine but not much has been said about where on the pump.


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Flusher

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Re: Driveline/spline question
« Reply #5 on: June 16, 2020, 06:31:57 PM »
What tool you are using will dictate what surfaces you are able to measure from.  Basically any machined surface of the block will be either parallel or perpendicular to the crankshaft centerline.  Cast surfaces are not true enough.  The carburetor pad is typically machined at an angle, so not viable.

The outside diameter of the bowl is cylindrical and concentric with the shaft.  I find that a convenient place to measure shaft angle.  You could also measure off of the front bearing cap of the suction, if you needed to.  The suction to intake surface should be machined parallel to the pump, unless some pump guru altered it.

Usually I have the luxury of having the bowl removed from the jet, when I build a rail kit, so I measure directly off the shaft.  I use a mock-up block and I made a plate that spans the tops of the China walls, over the lifter valley.  The pan rail is my second option, if i can easily get to it.  Often, the oil pan is in the way.
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Flusher

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Re: Driveline/spline question
« Reply #6 on: June 16, 2020, 06:50:13 PM »
I'm going to 2nd angermgmt's very thorough and well thought out reply of, "I think you're good."

The only thing that I would do is verify that you have 1/8" - 3/16" clearance, for the yoke to slide on the shaft.

Ignorance is bliss.  With a 4-point mount, you aren't going to be able to change it without re-rigging everything.

If you are really worried about it, verify that you don't have any mechanical binding and run it.  It really doesn't look bad.
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Flusher

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Re: Driveline/spline question
« Reply #7 on: June 16, 2020, 06:52:45 PM »
I do wonder why you think the intake is installed drastically different than before.
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eliminatorbuild

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Re: Driveline/spline question
« Reply #8 on: June 16, 2020, 07:10:54 PM »
I do wonder why you think the intake is installed drastically different than before.
The guy that changed the intake told me he had to lower it. I’m guess about 3/4” because when I put he pump back in it I had to drill new holes for the transom cover. And the new holes are about 3/4” lower then the old holes. I will check the clearance to make sure I have 1/8 to 3/16.


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eliminatorbuild

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Re: Driveline/spline question
« Reply #9 on: June 16, 2020, 07:17:58 PM »
The guy that changed the intake told me he had to lower it. I’m guess about 3/4” because when I put he pump back in it I had to drill new holes for the transom cover. And the new holes are about 3/4” lower then the old holes. I will check the clearance to make sure I have 1/8 to 3/16.


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If you zoom in on the picture you can see the old holes just below the blue tape.



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Flusher

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Re: Driveline/spline question
« Reply #10 on: June 17, 2020, 05:16:25 AM »
That may or may not have changed the jet height at the yoke
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