| Author | Message | ||
     Chris Miller Grand Master Username: cjm51213 Post Number: 434 Registered: 5-2013 |
Hi Folks, I had a slow leak which has recently increased to a small torrent. Today I tracked it down. It was the oil pressure sender adjacent to the oil filter. Does anyone know of an alternative part available in California? I don't have immediate access to Brian Vogel's resources list, and I am under a bit of a deadline. Thanks for the help, Chris. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1396 Registered: 5-2012 |
Hi Chris Brian's resource file lists the RR part (UE33647) as Standard Motor Products PS12 or PS12T. Also NAPA part ECH OP6610. They are from 1973 Chevys and GM cars. Geoff | ||
| Chris Miller Grand Master Username: cjm51213 Post Number: 435 Registered: 5-2013 |
Hi Geoff, Thanks very much. I got the ECH OP6619. I don't know if ECH OP6610 is a typo or a different part, but in any case, the guy at NAPA found what I needed. It fit, but just by a RCH, and I had to remove a bit of grime from a structural member to get that RCH clearance... (-: Chris. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1398 Registered: 5-2012 |
Hi Chris Yes, Brian did specify OP6610 however he did mention by implication other units would work. Does the OP6619 part you bought have one or three terminals? The OP6610 has three. I was wondering what the other two are for. BTW - I had to look up RCH in the urban dictionary  Geoff | ||
| Chris Miller Grand Master Username: cjm51213 Post Number: 436 Registered: 5-2013 |
Hi Geoff, ECH OP6619 has one terminal. As a speculative guess, the other terminals might be for some sort of cutout for the engine. I think low oil pressure is a catastrophic condition justifying extraordinary measure, like halting the engine for its own good. > BTW - I had to look up RCH in the urban dictionary Yeah, ... That's where you'd find it... It is a very fine gradation, but a coarse term, only used in the finer garages. (-: Chris. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 1115 Registered: 5-2015 |
Austin Metro | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 364 Registered: 4-2015 |
Chris... Just for clarification, what is the year and chassis number for your car? Are you referring to the oil pressure gauge sending unit, or the low oil pressure warning light sending unit? They are both right near the oil filter. I was recently trying to find a substitute for the warning light sender (not the gauge) and never did get a satisfactory result. Thanks | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 337 Registered: 10-2008 |
Christian, if it is the same as a 1970 Shadow ( my son has just fitted one to his ), or a 1981 Spirit, then a Morris Minor oil pressure switch will fit. I believe this switch was also fitted to some Minis and other BMC "a" series engine cars. Mark | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 365 Registered: 4-2015 |
Mark... Thanks for the tip, but an exact part number would be even greater. Back when I was on that pursuit, I found that there are two similar, but not exactly the same, threads but contacting the retailer to determine "which" was on their product was always either a dead end, or an ingored request. I was never even able to determine which of the two threads is on the OEM part. Buying an OEM part, or using the old part, and a bunch of substitutes seemed to be the only "if you want it right, you have to do it yourself" solution, and I did not have either the time or patience for that exploration just to get a workaround substitute for a $50 OEM part. Someone knows, but no one would tell. P.S. FWIW...in my case it was concerning an early chassis #CRX2541 (1966) | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 338 Registered: 10-2008 |
Christian, this is the part my son used: http://www.ebay.co.uk/itm/GENUINE-LUCAS-SOB104-CLASSIC-CAR-OIL-PRESSURE-SWITCH-MINI-JAGUAR-MORRIS-MINOR-/221402021267?hash=item338c96bd93:g:BEQAAOxy4eJTMr3W Mark | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 366 Registered: 4-2015 |
Mark... Excellent! Thank you! The listing also included the thread as being the 27 per inch rather than the 28 per inch. | ||
| Kelly Opfar Prolific User Username: kelly_opfar Post Number: 113 Registered: 7-2004 |
Christian, 1/8"-27 NPT is a tapered pipe thread designation. I'm not sure of the item you described as having 28 TPI (Threads Per Inch), but 28 is only the pitch of the UNF series 1/4" cap screw (bolt). If you saw a fitting that specified 28 TPI, most likely it is a typo or it refers only to the fasteners, not the screw-in fitting itself. It is possible that a fitting could be made with straight 1/4"-28 threads and sealed with a crush washer (similar to the high-pressure fitting on the top of the ACV's), but I don't think you are talking about that. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1401 Registered: 5-2012 |
Thanks for the link Mark. I've just ordered one. Geoff | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 367 Registered: 4-2015 |
Kelly... I certainly cannot pretend to know even a fraction as much as you do and am easily confused. The reference to 1/8x28 was for BSPT and ISO that are referenced at this link previously provided by Russ: http://www.wellsve.com/showall_ds_oil.php In that same thread, Russ had referred to a "1/8x26" (sic) that I had assumed to be a typo and as confirmed by that link where no "26" tpi were shown, only 27, 28, and many others. From this, I surmised that it was at least "possible" that the fitting could have 1/8x28 BSPT threads rather than 1/8x27 NPTF threads. Perhaps I was reading too much into what seems to be a very confusing topic (for the novice) by correlating the "British" of BSP, and the "British" of Rolls-Royce (pre-BMW!!) As the owner of various PreWar and EPW cars which have a variety of British threadings, Whitworth, et al...I suppose that I am always skeptical of what is going on, threadwise. That skepticism is compounded by my GMC pickup truck that has an unpredictable (to the novice) combination of both "Inch" and "Metric" fasteners sprinkled throughout! | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 339 Registered: 10-2008 |
It appears that Lucas SOB101 and Lucas SOB103 are also 1/8 x27 tpi but with different switching pressure. The switch in my link is ,from memory .6 bar, approx. 10 psi. Kelly, is 1/8 BSP 28 tpi ? It seems to be Common ( bad ? ) practice in the UK to use 1/8 NPT fittings in replacement of obsolete 1/8 BSP units. Mark | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 368 Registered: 4-2015 |
Mark... ...and compounding the problem is that I have read that the transition occured in approximately the early 1970's and thus affects early Shadows and later Shadows as well as the subcomponents created by other suppliers...radiators, for instance. My early MPW had the original circa 1966 Marston Excelsior radiator and when the drain petcock needed replacement, it immediately became apparent that a standard 1/8x27 NPT was the wrong thread and the proper replacement is actually the 1/8x28 BSPT. That experience has created a bit of "uncertainty" whenever the use of a 1/8x27 NPT fitting is alleged to be proper and leaves open the possibility that on the earliest Shadows, in line with other British industry at that time, still tended to use BSP prior to the transition to NPT. We must always remember that the Early Shadows are in many respects different that the later models and this may be another instance. I still have the original oil sender and eventually will take it to a hydraulic fitting shop in the hopes that they will have a known BSPT fitting or other way to determine once and for all the threading. Until then, I suppose that it is an unresolved issue. | ||
| Kelly Opfar Prolific User Username: kelly_opfar Post Number: 114 Registered: 7-2004 |
Well, time for the ceremonial eating of the crow. Please pass the humble pie. The BSPT pipe thread designation is obviously a hole in my thread terminology knowledge. Despite having a classic British car, I have never heard of the BSPT thread series. But the 1/8" BSP fitting does indeed have 28 tpi. I just went in the garage and checked my original fitting on my '76 Shadow and it has 27 tpi. Mark, I would never suggest to anyone that a 28 tpi fitting be screwed in a 27 tpi hole. If the fitting was screwed in 1/4", there would be .008" of lateral thread deflection. That is almost guaranteed to tear off threads and cause a leak. An adapter with a male 1/8" BSPT and female 1/8" NPT could easily be made by a machinist. I was at a hardware store a couple of years ago and I overheard a gentleman asking the 18 year old employee what kind of bolt he could put in his radiator to replace the leaking petcock. The employee handed him a 1/2"-20 bolt and announced that the threads on it looked the same as the 1/4"-18 NPT valve in his hand. I politely waited for the kid to leave and suggested to the man that he go to the auto parts store and get the right petcock. The man wasn't rude to me but he told me that the bolt was close enough. He left and I wondered what more I could have done without being a jerk. I'm sure the guy's next stop was the Toyota dealer for a new $300 radiator. | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 340 Registered: 10-2008 |
Kelly, I too am learning and stand corrected! The original switch on my Shadow was 27 tpi taper, as is the BMC "A " series. On my S1, I had to fit a BSP 28tpi to NPT 27 tpi adapter. Crewe part UE 33647 appears to be fitted to all Shadow 1 and therefore I presume all cars are 27 TPI NPT. The sender for the oil pressure gauge where fitted appears to be BSP! | ||
| ross kowalski Prolific User Username: cdfpw Post Number: 115 Registered: 11-2015 |
Hi all, I have been a little busy as of late so I haven't been up on the latest threads. It sounds like I made a typo somewhere if I said 26 TPI on a little taper. As far as I know there is 27 and 28. Most big tap and die sets come with both taps. Never saw a 26 ever. A source very close to me has used these two thread tapers interchangeably for years. The mechanical oil pressure gauge I, I mean my source uses to test engine oil pressure definitely has an 1/8-27 on it and doesn't pop out or leak when inserted into engines from various continents. I would look up one 1/8 27 and one 1/8 28 switch that trip at a reasonable oil pressure. Buy them for $3 on rockauto-amazon-partsgeek and for $6 you will have one that is perfect and one that isn't quite perfect, and when the first one eventually fails, replace it with the second. Best. | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 369 Registered: 4-2015 |
Ross... Oops...and forgive my error with your name. Ross, not Russ. Christian | ||
| ross kowalski Prolific User Username: cdfpw Post Number: 120 Registered: 11-2015 |
If Russ is the worst thing I get called, I consider that a pretty good day. | ||
| David Hughes Frequent User Username: wedcar Post Number: 59 Registered: 7-2004 |
Dear All Perhaps reading the article on this link may help. https://www.valvesonline.com.au/references/threads Regards David | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 372 Registered: 4-2015 |
Mark... Forgive me for flogging this, but I am still confused as to what the thread is on the early Shadows for the oil pressure light sender, and am confused by your statements that: 1) "On my S1, I had to fit a BSP 28 tpi to NPT 27 tpi adapter" 2) "Crewe part UE 33647 appears to be fitted to all Shadow 1 and therefore I presume all cars are 27 TPI NPT", and 3) "The sender for the oil pressure gauge where fitted appears to be BSP!" Questions: On #1: I assume by S1, you mean Shadow I, rather than the S1 Bentley, but in either event, are you saying that the fitting was actually BSPT and you fitted an adapter in order to use the NPT sender? On #2: Is that Crewe part specified as being 1/8x27 NPT and indicated as being proper for all Shadows which leads you to conclude that all Shadows are the NPT thread? If so, this does not seem to correlate to #1. On #3: Are you confirming that the thread on your oil filter housing for the oil pressure gauge, rather than the oil pressure light, was actually BSP, or both senders were BSP? In either event, this does not seem to correlate to the conclusion in your #2 statement that all Shadows are NPT. Can you clarify? Again, what I am trying to determine is the threading for the oil pressure sender unit on the oil filter housing on the earliest Shadows...BSPT or NPT. Your three statements seem to contradict each other, and are thus not conclusive. Thanks!! | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 341 Registered: 10-2008 |
Christian, By S1 I meant my Bentley S1.The link http://rrtechnical.info/SY/spare/6580_4/IMAGES/k/K11.pdf shows the pressure switch Ud33647 , which is now UE33647 at FS.The original pressure switch from my 1975 Shadow is 27TPI and my advice would be to check the thread on your switch. The pressure gauge blanking plug is BSP. Mark | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 373 Registered: 4-2015 |
Mark... Thanks for those clarifications. Yes, I have saved the original sender and someday as time allows will verify the threading. It would appear however that odds are that it will indeed be the NPT. The concern was born from the realization that anything can be the norm on RR cars of that era, especially following on the radiator drain petcock event, and as interestingly indicated by your disclosure that the oil pressure sending unit (or blanking plug where no sending unit is installed) is indeed BSPT!! Two adjacent holes where one is NPT (for the pressure light) and the other BSP (for the pressure gauge). Go figure! I am however still unclear the circumstances under which you found it necessary to install the BSP to NPT adapter on your Shadow. Was it perhaps that you wanted to install an oil pressure gauge, but instead of using a Crewe BSP sending unit and gauge (probably pricey), used the adapter to insall an aftermarket sender and gauge? |
