NPT yes...NPTF no, it seems. Is that why gauges and adaptors are advised to not be left in place? Are your elbows NPT with tape to seal them? Thanks. Sent from my iPhone using Tapatalk
Connections are 1/8” NPT. No tape necessary, just nip ‘em up on the taper and they seal. Mine are 90* on the front, 45* on the back, so it points straight at the carb. Could put in the gauge adaptor, but it is another point of potential leakage. You only measure the pressure once in a blue moon.
Thanks. It got confusing as different suppliers are stating different things. Some selling the blank version as being NPTF (product code: FPR008F). Malpassi state the blank version to be NPT (different codes). As are all the fittings they sell - so they (you ) must be right. “...once in a blue moon...” answers another question. Sent from my iPhone using Tapatalk
Having geeked out on the difference between NPTF v NPT, pros & cons, interchangeability yet fundamental differences rendering them not compatible...then deciding on a preference given that both options are available. I contacted a supplier to confirm that their Malpassi was in fact NPT (not stated on the website), to which was replied it was NPTF - ensuing debate about the differences. I was then put in contact with their supplier, who I queried as to the origin of their NPTF version considering throughout the Malpassi website they only ever mention NPT. Response was swift. It’s a typo! So confirmation folk. They are all NPT, no matter what seller’s with the code FPR008F are stating...it’s just a mistake passed on in association with a companies internal product code. To think, I was going to ask my Italian ex to call Malpassi to see if there was some mystery product or knockoff out there. That’s the long story. Short one: I’m ordering it tomorrow! Sent from my iPhone using Tapatalk
Will your engine ever be finished ? NPTF is a very obscure thread. All similar fittings are NPT. My motor is slathered with them.
If it were just the engine and all associated with it, possibly a month would finish that off. Unfortunately it’s absolutely everything else also needs doing. I subscribe to my cousin’s eloquently phrased philosophy of... “Better slow n right, than rushed n Marmitee!” ...but not by choice. Slathered. Sent from my iPhone using Tapatalk
To confirm, before ordering, it’s the 6mm connectors I need, right? I ask because the engine builder has used an 8mm T connection between the carbs: Hoses say 6mm (Gates brand) when i’ve read they are supposed to be 5.6mm ID. I seem to have hijacked this thread. Sorry. I’m sure all the info will be useful to others at some point. Sent from my iPhone using Tapatalk
Because they operate on fairly low pressure, the usual thing is to have 8mm back from carbs to pump to increase flow which is what ultimately matters, so low pressure big holes. Up to the pump it doesn't matter and it's usual to use the 5.6mm because... it fits the tank outlet. The rotary elec pump we nearly all use and the filter it came with have 8mm fittings so it's normal to step from 5.6mm up to 8mm between tank and pump. I use a cheap plastic filter for that which is also handy for catching the crud where I can see it - if there ever was any. If you were using a stock pump, the sooner you step up to 8mm after, the better because the 8mm flows more so you can have lower pressure. 5.6mm has x-sectional area 24.6 sq mm 8mm is 50 sq mm - twice the size in reality.
Brilliant. Thank you. That explains the varying sizes of hose on the old setup: It had been stepped down again, after the pump, to 5.6mm. So I am actually better off taking 8mm ID hose from the pump to Malpassi and connecting to 8mm unions rather than squeezing on to 6mm? Continuing to use 8mm to the carbs. All of this still rings true on Kadrons requiring only 1.5-2psi? I just took a hose off one to see what the barb is like. Possibly also 8mm. This is a 6mm drill bit offered up as a comparison: Cheers. Sent from my iPhone using Tapatalk
Don’t try and squeeze 6mm hose onto an 8mm union. It’ll split. Either use an adaptor in the pump hose (blue Tefen nylon ones are fine), or get an NPT fitting to the Malpassi that accepts 6mm hose (as mine does).
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Aha yes - with a regulator you can start the 8mm after that instead of after the pump if you want. i.e.5.6 from pump to reg, 8 from reg onwards. Yes those look like 8mm on your carbs. What size fittings are on your regulator? It's true that some people just see all those different sizes as a hassle and bodge it together with whatever they have. heathens!
Heathens. Ha ha I’ve not yet ordered anything to do with the pressure regulator as wanted to understand all the hose aspects better first. Grasping it now. So since i’ve already got 8mm unions on the carbs and on the fuel pump, it makes sense for me to get 8mm unions for the Malpassi. That way i’ve got the big bore, flow assisting hose throughout the system other than the step-up (via filter) soon after the tank before the pump. Sent from my iPhone using Tapatalk
Yes, 8mm all round except for off the fuel tank. So might as well match that, in & out, on the Malpassi. Via an electric fuel pump. Sent from my iPhone using Tapatalk
