Kitcat Posted July 29, 2010 Share Posted July 29, 2010 (edited) It has been suggested that a quick/cheap way of remedying my chronically low oil pressures wld be to shim the pressure relief valve (so as to allow greater pressure build up). My question is, therefore, where is the valve and how is it accessed? I see the oil pump hanging off the side of the engine, oil filter below, etc. But does anyone have a blow-up or schematic of how it all fits together and where the pressure valve & spring are and how they are accessed? Are there any tricks to it (hidden clips that have to be removed, etc.)? I have the book:"Ford Kent Crossflow Engine", P & V Wallage. It shows the pump, but no details as to location of the relief valve. Or, should I just buy the Dave Bean upgraded oil pump (for a mere $750.00), and be done w/it? Thx. Mike Edited July 29, 2010 by Kitcat Link to comment Share on other sites More sharing options...
bball7754 Posted July 29, 2010 Share Posted July 29, 2010 Mike - I think I would go for the High Pressure/High Capacity (part no. FP200a) option from Burton's first: https://www.burtonpower.com/product_main.aspx?prodLanding.aspx?CCode=PC090 Another thought. Given the poor reliability/accuracy of the electrical sender, are you sure the pressure is really low? What if the gauge is not displaying the actual oil pressure, and is understating what it is? Steve Link to comment Share on other sites More sharing options...
TheDingo8MyBaby Posted July 29, 2010 Share Posted July 29, 2010 Mike, Dave bean has a spring kit for $8. I know because I just ordered one this week. You can also shim the spring to get more pressure, but I'd rather pay $8 so I don't have to take it apart again if it's wrong. I figure I'll put it in if I ever decide to sell it - so the prospective buyer isn't concerned with the oil pressure. The spring is accessed from the block side of the pump. If you buy bean's spring, they'll send you a catalog that has exploded views. Keep in mind, there's nothing wrong with 5psi idle/ 25psi 3000 rpm. The crossflow likes good flow, not necessarily pressure. Formula Fords run these pressures all day (and the ones running the lower pressures make more power). Another thing to consider is more pressure may mean more oil leaks... Link to comment Share on other sites More sharing options...
Ian7 Posted July 29, 2010 Share Posted July 29, 2010 As above, but more detail if you need: pop the pump off the block (three bolts iirc); on the face of the pump that was against the block you will see a small metal disc about 3/8" to 1/2" dia with a small hole in the center, pressed in to a recess in the pump face, the spring is under there; DON'T STARE RIGHT AT THE DISC, IT'S SPRING LOADED! pull the disc out slowly, ready to catch the spring; put a shim on top of the spring, push down HARD, reinstall disc into recess; ... and if all goes as usual, hunt around for the spring, disc, and shim on the floor somewhere and keep trying :-) Link to comment Share on other sites More sharing options...
Kitcat Posted July 30, 2010 Author Share Posted July 30, 2010 Thx all. After calling Dave Bean, I learned the replacement pump was $80, not $750, so i ordered it. I will give it a try, if pressure doesn't move, BBall is right. If it does, and I start springing (more) leaks, Dingo is right. The engine does make nice power and if it was a really big problem, it seems unlikely that I wld have logged 27K miles. Still it makes me nervous to see 28 lbs of pressure at 6500 RPM's, after all is nicely warmed up. Mike Link to comment Share on other sites More sharing options...
Off Road SHO Posted July 30, 2010 Share Posted July 30, 2010 (edited) Shimming the pressure relief spring (so that it is tighter) will only increase your oil pressure if the valve was actually bypassing oil at the time. Shimming doesn't increase oil pressure, it raises the point at which it opens and passes some of the oil back to the pan, bypassing the oil galleys all together. Let's say you are running flat out at 5000 rpm's and your oil pressure is 65 psi. It might be 65 at 5000 because that is the result of the pump's ability to push oil and the mechanical's ability to leak it out, or it might be that the pump's ability to push the oil exceeds the mechanical's ability to leak it and the relief spring is opening up another "leak" back into the pan. If you have low oil pressure at low rpm's it's not because of the pressure relief valve, which we should really call the OVER pressure relief valve, but because the pumps worn out or the mechanicals are and leak too much. Tom Edited August 5, 2010 by Off Road SHO Link to comment Share on other sites More sharing options...
locost7018 Posted July 30, 2010 Share Posted July 30, 2010 Kitcat let me know how the new pump works for you. I run about 20-25 at idle and about 30 at 5600 redline on my 1300cc xflow. 6500 RPM!!!!! Man I have never taken mine past 5600. WOW!!!! Russ Link to comment Share on other sites More sharing options...
Ian7 Posted July 31, 2010 Share Posted July 31, 2010 Shimming the pressure relief spring (so that it is tighter) will only increase your oil pressure if the valve was actually bypassing oil at the time. Shimming doesn't increase oil pressure, it raises the point at which it open and passes some of the oil back to the pan, bypassing the oil galleys all together. Tom Good point, but mine must be bypassing, as I appear to have "over-shimmed", and result is 90psi at idle, over 100 with tiniest throttle tap, so shims coming out obviously. Link to comment Share on other sites More sharing options...
Off Road SHO Posted July 31, 2010 Share Posted July 31, 2010 Good point, but mine must be bypassing, as I appear to have "over-shimmed", and result is 90psi at idle, over 100 with tiniest throttle tap, so shims coming out obviously. Ian, What do you have for an engine? I just can't imagine a car manufacturer making an oiling system where the pressure relief valve was always in bypass to some degree. I don't understand why they would do it. Anticipated wear of the rubbing parts? Tom Link to comment Share on other sites More sharing options...
TheDingo8MyBaby Posted July 31, 2010 Share Posted July 31, 2010 Ian, What do you have for an engine? I just can't imagine a car manufacturer making an oiling system where the pressure relief valve was always in bypass to some degree. I don't understand why they would do it. Anticipated wear of the rubbing parts? Tom If you only knew what it is like to own a crossflow... My guess would be oil leaks. For some reason the kent just doesn't like to stay sealed... Link to comment Share on other sites More sharing options...
Ian7 Posted August 1, 2010 Share Posted August 1, 2010 Ian, What do you have for an engine? I just can't imagine a car manufacturer making an oiling system where the pressure relief valve was always in bypass to some degree. I don't understand why they would do it. Anticipated wear of the rubbing parts? Tom Running a wet-sump Kent with a stock pump. Faulty electric Caterham oilP guage scared me into shimming the pump, but substituting a Racetech mechanical gauge now reveals the 100+psi mentioned above. Link to comment Share on other sites More sharing options...
Kitcat Posted August 5, 2010 Author Share Posted August 5, 2010 New pump = lower pressures, not higher(:. Next step-get an accurate measurement of actual oil pressure as BBall's theory is looking more plausible. Link to comment Share on other sites More sharing options...
Croc Posted August 5, 2010 Share Posted August 5, 2010 Go for it - the mechnical oil pressure gauge was one of the better improvements I invested on my car. Also easier than expected to install once I purchased the right bits and bobs. Link to comment Share on other sites More sharing options...
Off Road SHO Posted August 5, 2010 Share Posted August 5, 2010 New pump = lower pressures, not higher(:. Next step-get an accurate measurement of actual oil pressure as BBall's theory is looking more plausible. Kitkat, can you explain why a new pump would give you lower pressures and not higher? Tom Link to comment Share on other sites More sharing options...
Kitcat Posted August 7, 2010 Author Share Posted August 7, 2010 Tom-my mechanical "skills" are limited mostly to checking the dipstick to see if the engine has adequate oil (it does). The new pump was added by my trusty mechanic, who was baffled (no pun intended). So someone else will have to offer thots and theories on my oil pump conundrum. I will have the actual pressure accurately measured next week and we'll go from there. Once all is resolved I will post an update here. Mike Link to comment Share on other sites More sharing options...
Kitcat Posted August 10, 2010 Author Share Posted August 10, 2010 With the mechanical gauge: cold idle 40, warmed up,on acceleration, 60, warm idle 25. And this w/the new oil pump that produces less, not more, pressure than the old unit that came w/the car. So who makes a mechanical bolt in oil-pressure gauge for a Caterham? Mike Link to comment Share on other sites More sharing options...
bball7754 Posted August 11, 2010 Share Posted August 11, 2010 Mike - The Mocal gauge is often recommended, partially because it sort of looks like the Caterham gauges. Gauge and fittings are available from British American Transfer (BAT). http://www.batinc.net/mocal-central.htm Hoping you'll keep track of all the fittings you'll need - and then let me know so I can do the same on my Xflow. Steve Link to comment Share on other sites More sharing options...
Kitcat Posted August 11, 2010 Author Share Posted August 11, 2010 Steve: Will do. For now I am just going to add 30 to whatever the gauge says:). Mike Link to comment Share on other sites More sharing options...
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