Twins with Twins, Anyone?

2004LB7

Well-known member
Dec 15, 2010
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^^ 2x

This info is tuning gold that could easily be lost in a 20+ page thread. Maybe copy it to a new thread instead of moving it
 

kidturbo

Piston Tester
Jul 21, 2010
2,539
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Somewhere On The Ohio
www.marinemods.us
Thanks much. Will post testing updates over there shortly.

For now, belt routing. Comments?

LB7 tensioner with a smaller pully looks to be our winner..

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PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,496
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Central OH
Ideally you want the tensioner directly after the crank on the slack side, otherwise an accessory driven in between the two may slip. If the belt is tight enough, it may not matter
 

kidturbo

Piston Tester
Jul 21, 2010
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I agree best spot is directly after the crank to absorb majority of the slack. But the space is tight, and I was worried about how it would act with 80% of that crank pulley in contact. So here is how it would look if tensioner was sprung the other way.

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kidturbo

Piston Tester
Jul 21, 2010
2,539
1,375
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Somewhere On The Ohio
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Then I looked at belt routing of my old Ford 6.0, and may have found the correct answer to both questions..

Seems Ford has no issue with placement or belt wrapping clean around the crank. And gonna say that tensioner is best fit I've found to date. Being it's off a equal size diesel, it should have enough spring rate for this setup. Will pick one up Thursday and give it a try.. Until then, Happy New Year to all !!

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kidturbo

Piston Tester
Jul 21, 2010
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After much much searching, finally found the right tensioner for the job. And it's GM..

04-09 Cadillac CTS has a 2.5" swing radius with correct spring direction and pulley. Backset is close enough to line up by shimming the base or removing some meat behind the pulley.

Both Advance and AutoZone have me blacklisted for returns. Don't know why, I only purchased and returned 9 tensioners last week. . .
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PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,496
477
83
Central OH
Blacklisted :rofl:

Were some of them special order? I don't see why they'd be mad, unless that was sarcasm and I haven't woke up yet
 

kidturbo

Piston Tester
Jul 21, 2010
2,539
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They were all special order... LOL

That doesn't include the PS pumps I returned also. Looks like 87 Sunbird is the winner on the type 2 remote resivour pump design. They actually don't seem to mind all these returns. Advance and AZ are across the street from each other, so they know I'm screwing both equally..

Now it's down to finalizing acc bracket and coolant resivours, then she's ready to to pump some water.

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kidturbo

Piston Tester
Jul 21, 2010
2,539
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Last week was another one step forward two steps back on accomplishments.

The PS pumps I purchased with remote reservoir tubes were about 1/4" thicker depth than my mock up pump. Which made the belt 1 rib off. While all Saginaw II pump bodies may look the same, they are not....

According to all the internet, only diff in type II pumps was shaft dia and reservoir attachment type. Here to tell ya that the internet is wrong... The early model .662 dia shaft also has a taller main body that limits how far back the pulley can be mounted.

The GM pump I used for mockup and fit perfectly was off a 97 Saturn. Which is like finding an 07 Duramax with a manual transmission now days. So when I noticed the 87 Sunbird pump was a no go, it left me digging for other options. Best guess, something from a more common engine same year.. And winner is, 3.1L v6 Grand Prix pump with .750 shaft. You can see the slight diff in pics below. About one belt rib in height. In fact the 3.1 pump has enough clearance to push the pulley even one rib to far down as I did in pulley comparison between it and the Saturn pump on right below.

Now any suggestions on how to fix a return line tube or AN fitting would be helpful.

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2004LB7

Well-known member
Dec 15, 2010
6,992
2,147
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Norcal
Seems like a return fitting off a 2005 to 2009 Grand Prix power steering pump 8 CYL 5.3L would work

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