Page 1 of 1
#1 Oil Pressure/Ignition Switch
Posted: Sun Mar 14, 2021 9:05 pm
by JPowers
Hi,
I'm putting the pieces back onto the engine of my 1966 4.2L FHC. The engine is not original and comes from a later 2+2 (block was cast in May of '66) and never had the block-mounted switch for the ignition/oil pressure warning lamp. I do have the wiring for it however (brown w/ black fabric coated wire from ignition warning lamp.) The bolts along the oil gallery on the right side of the block are intact and appear to have always been so. According to all of the available wiring diagrams, I should have originally had this switch. Can I remove the bolt closest to the motor mount on the right hand side and install an ignition/oil pressure lamp switch where it would originally have been mounted?
#2 Re: Oil Pressure/Ignition Switch
Posted: Mon Mar 15, 2021 7:56 am
by christopher storey
Yes , any of the positions will do. Just make sure you don't lose the copper washer which should be under the bolt
#3 Re: Oil Pressure/Ignition Switch
Posted: Mon Mar 15, 2021 2:09 pm
by JPowers
Ok, great.
Thanks for your help
Jim
#4 Re: Oil Pressure/Ignition Switch
Posted: Wed Apr 14, 2021 11:40 pm
by mtnjag
Is that port BSPT, BSPP, or unlikely 3/8” NPT?
If it takes a washer s/b BSPP.
#5 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 8:00 am
by Gérard A110
it is in Withworth BSW, UNF , like all others on engine.
#6 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 12:57 pm
by mtnjag
Is BSW the same as the BSPP?
#7 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 1:14 pm
by mtnjag
I see, same as UNF. Typical fine thread found in US hardware.
#8 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 3:19 pm
by mtnjag
Well, pretty close anyway.
#9 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 4:14 pm
by Tom W
UNF isn’t the same as Whitworth or BSPP.
UNF uses a 60 degree thread form, whilst Whitworth is 55 degrees. BSPP uses a Whitworth thread form.
1/4 BSPP is 19tpi. 1/2” UNF is the closest dimensionally, but is 20tpi. So over a short length they may appear compatible, but they’re not.
Edit: The plugs are described as 1/2” UNF by the usual parts suppliers.
#10 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 4:22 pm
by mtnjag
So for the sake of the original question from a Member in the US, what adapter would he use in the oil galley to get to a typical US 1/8” MPT?
Would a male 1/8” BSPP adapt with washer to 1/8” FPT work?
#11 Re: Oil Pressure/Ignition Switch
Posted: Thu Apr 15, 2021 4:39 pm
by Tom W
The bung is 1/2” UNF, so the hole in the block will be 1/2” UNF.
So the adapter will need to be male 1/2” UNF to whatever suits the available pressure switch.
Or use a 1/2” UNF pressure switch.
#12 Re: Oil Pressure/Ignition Switch
Posted: Fri Apr 16, 2021 12:22 pm
by mtnjag
So i had always thought the nuts and bolts on the block, except perhaps the sump drain and water jacket bung which i thought were BSPP, were UNF and have always used such for replacement when needed.
It is mentioned in a post above that they are BSW and UNF which are close but are not the same.
Where have i been wrong?
#13 Re: Oil Pressure/Ignition Switch
Posted: Fri Apr 16, 2021 1:21 pm
by christopher storey
The parts list shows the plugs as C2352, and the copper washers as C2296/3 . The list does not give size or thread, but I am pretty sure that , like virtually all the cast iron threads they will be UNF. I cannot think of another fastening/closure on the car which uses BSF , and the only Whitworth fastening I can think of is the timing chain adjuster locknut which is from memory 1/2" Whit
#14 Re: Oil Pressure/Ignition Switch
Posted: Fri Apr 16, 2021 1:26 pm
by christopher storey
The parts list shows the plugs as C2352, and the copper washers as C2296/3 . The list does not give thread, and the SNG Barrett website merely sizes them as 1/2". I cannot think of another fastening/closure on the car which uses BSF , and the only Whitworth fastening I can think of is the timing chain adjuster locknut which is from memory 1/2" Whit . If I get a chance I will take one out of one of my cars and check its thread