NA 1.6 weight reduction: Upgrade to 1.8 water pump and alt tensioner: Save 1.5 lbs
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NOTE: The 1.6 block doesn't have a threaded hole for the timing belt tensioner, you'd have to fill and tap the unthreaded hole on the 1.8 pump.
1.6 guys, next time you change out your water pump, think about this. The 1.8 water pump has an extra tab on it for a differently designed alternator tensioner. I think the newer design is far superior.
Here's the breakdown on alternator tensioner brackets, based on me going out and looking at mine.
The tensioner bolt assemblies are the same.
![Name: DSC_0412.jpg
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Size: 137.1 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197232d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0412.jpg)
Both brackets are made of pressed steel.
Draw your own conclusion here. I couldn't measure how much the tab on the 1.8 water pump weighs, but that probably isn't even 2 ounces.
1.8
![Name: DSC_0414.jpg
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Size: 67.4 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197233d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0414.jpg)
1.6
![Name: DSC_0413.jpg
Views: 366
Size: 63.5 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197234d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0413.jpg)
And while you're at it, drill a hole in the tensioner block bolt and add a paperclip. That way you won't ever lose that assembly on the road again. You also gain more space to reach your hands into that area to work on things compared to the 1.6 bracket. Total weight savings: ~1.5 lbs.
1.6 guys, next time you change out your water pump, think about this. The 1.8 water pump has an extra tab on it for a differently designed alternator tensioner. I think the newer design is far superior.
Here's the breakdown on alternator tensioner brackets, based on me going out and looking at mine.
The tensioner bolt assemblies are the same.
![Name: DSC_0412.jpg
Views: 454
Size: 137.1 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197232d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0412.jpg)
Both brackets are made of pressed steel.
Draw your own conclusion here. I couldn't measure how much the tab on the 1.8 water pump weighs, but that probably isn't even 2 ounces.
1.8
![Name: DSC_0414.jpg
Views: 362
Size: 67.4 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197233d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0414.jpg)
1.6
![Name: DSC_0413.jpg
Views: 366
Size: 63.5 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197234d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0413.jpg)
And while you're at it, drill a hole in the tensioner block bolt and add a paperclip. That way you won't ever lose that assembly on the road again. You also gain more space to reach your hands into that area to work on things compared to the 1.6 bracket. Total weight savings: ~1.5 lbs.
![Name: DSC_0409.jpg
Views: 490
Size: 94.5 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/197235d1501236064-na-1-6-weight-reduction-upgrade-1-8-water-pump-alt-tensioner-save-1-5-lbs-dsc_0409.jpg)
Last edited by Bryce; 05-29-2010 at 04:01 PM. Reason: Added note at top
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I liked. Weren't you the one that put the NB starter idea in my head? That's anoth 5# or something like that. I already got rid of the little bent bracket that has the nut welded on, this'll be next once I source one. Thanks!
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I added the note at the top of my first post. This won't work without a little modification to the water pump. You'd have to fill and then tap the hole for the timing belt tensioner (on the 1.8 water pump) because the 1.6 block doesn't have a threaded hole for it.
This fact probably makes the mod not worthwhile.
This fact probably makes the mod not worthwhile.
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