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Turbo Lines

Started by mister.x · 7 May 2017 · 6 replies

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mister.xArchived member
After reading almost every post about turbo lines on Calaisturbo and probably half of SAU I am still stumped. The water feed hole on my block is smaller than 14mm, It has an ID of about 12.4mm Has anyone else seen this from factory?
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Duke57TTArchived member
Quote: Originally Posted by mister.x [View Post] After reading almost every post about turbo lines on Calaisturbo and probably half of SAU I am still stumped. The water feed hole on my block is smaller than 14mm, It has an ID of about 12.4mm Has anyone else seen this from factory? You sure you've got the right hole? It is towards the back of the block and it is absolutely M14x1.5.
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mister.xArchived member
Quote: Originally Posted by Duke57TT [View Post] You sure you've got the right hole? It is towards the back of the block and it is absolutely M14x1.5. Pretty sure I have, its the one marked as coolant feed eye bolt on the image below? Im going to drop the coolant and compare it to the one in the car at the moment will take an actual photo and upload it. Some original photos have not been recovered yet.
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CurlyArchived member
M14 doesn't mean the internal thread will have an ID of 14mm. Looking at this reference chart, http://www.carbidedepot.com/formulas-tap-metric.htm, an M14 x 1.5 thread is tapped from a 12.5 mm hole which lines up with what you have mentioned above.
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mister.xArchived member
It's definitely not m14x1.5 I have a m14x1.5 banjo that I have triple checked and it's too big for the block. From the measurements I've taken and the using the thread gauge it looks to be 1/4 npt. I'm going to pull the bolt out of my current engine this weekend which I'm hoping is the right size and will prove I'm not crazy.
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Duke57TTArchived member
There is no NPT on the engine from what I can remember. You sure you don't have an early RB30 block? I can't remember but it may not have the water feed etc The return thread is 3/4 BSP.. 3/4 NPT threads in OK as it is the same TPI.
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mister.xArchived member
Quote: Originally Posted by Duke57TT [View Post] There is no NPT on the engine from what I can remember. You sure you don't have an early RB30 block? I can't remember but it may not have the water feed etc The return thread is 3/4 BSP.. 3/4 NPT threads in OK as it is the same TPI. Yeah I know. So today I pulled the plug out of my other engine and it was normal. So I have no idea what the go is with this block, my only thoughts are it could be one of the old blocks that someone has tapped out to the wrong size will just have to work with it. Thanks for your help anyway duke.
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