Chemicalblue Posted June 2, 2008 Share Posted June 2, 2008 Does anyone know what the pipe thread type and size is for the head coolant return line (at the back of the head by #6 cyl L28et). I busted a heater hose while at the track this weekend and I would like to use a nice AN fitting there but its not a NPT fitting. I did a search but nothing really came up on the subject. Tnx in advance Tommy Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted June 3, 2008 Share Posted June 3, 2008 good idea but i have no clue. i'd like to know as well now that you mention it. Quote Link to comment Share on other sites More sharing options...
MONZTER Posted June 3, 2008 Share Posted June 3, 2008 What is not a pipe thread? The head or your fitting? I'm pretty sure the head is a 1/2 NPT at least my N-42 and P-90 is Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted June 3, 2008 Share Posted June 3, 2008 yeah ive got the p90a head that sounds about right monz. im planning on refitting most of the lines in there for stainless and AN Quote Link to comment Share on other sites More sharing options...
KiwiCowboy Posted June 3, 2008 Share Posted June 3, 2008 All of the tapped holes in a Z engine are metric, both machine screw and BSP (British Standard Pipe). Like American pipe threads, there are taper (NPT) and straight (NPS) pipe taps and these "almost" the same as the BSP pipe taps. The difference between NPT and BSP is Threads/Inch. Here is a list of the them: Size TPI (NPT) TPI (BSP) 1/16 27 28 1/8 27 28 1/4 18 19 3/8 18 19 1/2 14 14 3/4 14 14 You can see, starting with the 1/2", the TPI are the same. Beaware, that a NPT fitting will screw into a BSP threaded hole a few turns when the TPI are not the same. This could damage the threads if not careful. Quote Link to comment Share on other sites More sharing options...
Chemicalblue Posted June 14, 2008 Author Share Posted June 14, 2008 Well this is what Ive found so far. Here is a link to a site that has BSP to AN adapters. http://www.pegasusautoracing.com/productselection.asp?Product=3230 I'm still trying to find the exact size. Ive had several people tell me to "just re-tap it to npt". That sound great until you try and do it, If the engine was out of the car Id say sure. But really $15 for the adapter is way less expensive than just the tap and not to mention the time involved and B**** factor of doing it. I'm thinking of going with the -10 line size, It seems big enough. Anyone else have any thoughts? Quote Link to comment Share on other sites More sharing options...
MONZTER Posted June 15, 2008 Share Posted June 15, 2008 I have used a 1/2 NPT to -10 on mine, no problems at all Quote Link to comment Share on other sites More sharing options...
pcs Posted June 23, 2008 Share Posted June 23, 2008 I think you will find that it is 1/2" BSP. pcs Living in the land down under. Quote Link to comment Share on other sites More sharing options...
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