Board index Flathead Power-Technical Questions, Answers, and Suggestions Big Twin Flatties CHP oil pump

CHP oil pump

Post Fri Jun 26, 2020 5:36 am

Posts: 1731
Location: Interlaken, NY USA

Greetings,
Been awhile since this thread was active. Ended up not trying the extra oil return trick, bought the valve, just never got 'round to it".
Went a different way. Bruce Argetsinger built a prototype gearrotor pump 7 or 8 years ago and then dropped the project. I'm using the prototype on my "88" BTSV with good results. I don't know how the rotor size compares to the CHP unit however.
I was satisfied with how the '72 sporty pump system worked WRT keeping my engine alive and healthy, Thousands of miles and no undue wear. I was looking to achieve engine wear one would expect from a Knuck or Pan, and I achieved that. BUT, keeping the oil on the inside was always a problem. As Gallo J. mentions the early screw valve covers were a necessity. I converted them to "O" rings throughout with a small grove Ala K style covers between the sliding parts. Also "O" ringed the tappet bodies like the Sporty as the valve gear area was a constant source of leaks. Likewise mating the pump to the engine case for a leak free mount. But I digress.
At one point I did put valve seals on the guides, machined down the end to take Panhead or Shovelhead seals, don't remember which, the ones that required the least machining to fit :D They worked, but the real problem was worn guides. Once new properly clearanced guides were installed, it wasn't a problem.
I also had a problem when I went with the gearrotor pump in that the stock return pump could not keep up and I got oil out the breather. I had added a shutoff valve in the supply line to prevent wet sumping, so that wasn't the issue. This was only on startup, as Woody had noticed, after warming up, it kept up just fine. I resolved the issue by tapping the pressure relief oil from the pump and "y"ing it to the standard return line to the oil tank. I put a piece of clear line temporarily to observe how this worked out, and saw no issues. Blowoff was set at 40psi. When oil is warmed, pressure settles down to 20PSI. this with full flow pinion and piston squirters. Alas, I haven't put Bruce's prototype on the test stand to measure the output, so I don't know what flow rates are to compare to the CHP unit.
I have these comparisons to share: The 72 sporty pump return gears are about 20% larger than the stock UL pump. The stock UL pump just handles Bruce's pump, so maybe it outputs 20% less than a sporty pump???
Just speculation. I did modify the breather tower to sporty timing spec's.
My personal research led me to using piston squirters to cool the pistons at what I observed their point of failure, that being the area closest towards the valves, with pistons crumbling from the heat or cylinder walls/pistons failing from carbon deposits in this area. The cylinder heads also showed this area being hotter than any other part of the combustion chamber.
However, with the addition of the "ULR" heads to my machine, this hot spot disappeared. My takeaway, the shelf design of the ULR head changed how combustion occurred and toned down this "hot spot". So, my current thoughts on BTSV are to first and foremost, fit the ULR heads as an engine prolonging modification. Then of course, add more oil, but perhaps the 4 vane mod to the stock pump may be all that's needed.
Keep in mind, I've only observed this on my personal motor, so it's a sample of one. Not too scientific I grant, but the difference in the visual evidence in my engine is dramatic.
On the 4 vane conversion, I have used it on 3 builds now, mostly because I am reluctant to build and motor and sell it when I can keep the oil on the inside! So I chose not to use sporty pumps on them. Two motors are for friends so I can keep an eye on how they hold up with the 4 van setup. Neither have 10k on them as yet, so it's early days. I'd be interested to hear how your motor(s) fare Gallo J.
I do the conversions myself, using the stock rotor and modifying springs and vanes to fit.
My test jig shows twice the output of a stock pump, making it about 1 qt/4 minutes.
Enough. Just wanted to share my thoughts/experiences, not looking to make any exclusive claims to knowing the "right" way to modernize a BTSV. Anything to keep 'em on the road is a good thing.
DD

Post Fri Jun 26, 2020 5:39 am

Posts: 1731
Location: Interlaken, NY USA

Greetings,
Been awhile since this thread was active. Ended up not trying the extra oil return trick, bought the valve, just never got 'round to it".
Went a different way. Bruce Argetsinger built a prototype gearrotor pump 7 or 8 years ago and then dropped the project. I'm using the prototype on my "88" BTSV with good results. I don't know how the rotor size compares to the CHP unit however.
I was satisfied with how the '72 sporty pump system worked WRT keeping my engine alive and healthy, Thousands of miles and no undue wear. I was looking to achieve engine wear one would expect from a Knuck or Pan, and I achieved that. BUT, keeping the oil on the inside was always a problem. As Gallo J. mentions the early screw valve covers were a necessity. I converted them to "O" rings throughout with a small grove Ala K style covers between the sliding parts. Also "O" ringed the tappet bodies like the Sporty as the valve gear area was a constant source of leaks. Likewise mating the pump to the engine case for a leak free mount. But I digress.
At one point I did put valve seals on the guides, machined down the end to take Panhead or Shovelhead seals, don't remember which, the ones that required the least machining to fit :D They worked, but the real problem was worn guides. Once new properly clearanced guides were installed, it wasn't a problem.
I also had a problem when I went with the gearrotor pump in that the stock return pump could not keep up and I got oil out the breather. I had added a shutoff valve in the supply line to prevent wet sumping, so that wasn't the issue. This was only on startup, as Woody had noticed, after warming up, it kept up just fine. I resolved the issue by tapping the pressure relief oil from the pump and "y"ing it to the standard return line to the oil tank. I put a piece of clear line temporarily to observe how this worked out, and saw no issues. Blowoff was set at 40psi. When oil is warmed, pressure settles down to 20PSI. this with full flow pinion and piston squirters. Alas, I haven't put Bruce's prototype on the test stand to measure the output, so I don't know what flow rates are to compare to the CHP unit.
I have these comparisons to share: The 72 sporty pump return gears are about 20% larger than the stock UL pump. The stock UL pump just handles Bruce's pump, so maybe it outputs 20% less than a sporty pump???
Just speculation. I did modify the breather tower to sporty timing spec's.
My personal research led me to using piston squirters to cool the pistons at what I observed their point of failure, that being the area closest towards the valves, with pistons crumbling from the heat or cylinder walls/pistons failing from carbon deposits in this area. The cylinder heads also showed this area being hotter than any other part of the combustion chamber.
However, with the addition of the "ULR" heads to my machine, this hot spot disappeared. My takeaway, the shelf design of the ULR head changed how combustion occurred and toned down this "hot spot". So, my current thoughts on BTSV are to first and foremost, fit the ULR heads as an engine prolonging modification. Then of course, add more oil, but perhaps the 4 vane mod to the stock pump may be all that's needed.
Keep in mind, I've only observed this on my personal motor, so it's a sample of one. Not too scientific I grant, but the difference in the visual evidence in my engine is dramatic.
On the 4 vane conversion, I have used it on 3 builds now, mostly because I am reluctant to build a motor and sell it when I can't keep the oil on the inside! So I chose not to use sporty pumps on them. Two motors are for friends so I can keep an eye on how they hold up with the 4 van setup. Neither have 10k on them as yet, so it's early days. I'd be interested to hear how your motor(s) fare Gallo J.
I do the conversions myself, using the stock rotor and modifying springs and vanes to fit.
My test jig shows twice the output of a stock pump, making it about 1 qt/4 minutes.
Enough. Just wanted to share my thoughts/experiences, not looking to make any exclusive claims to knowing the "right" way to modernize a BTSV. Anything to keep 'em on the road is a good thing.
DD

Post Fri Jun 26, 2020 9:31 am

Posts: 10
Hello Frankenstein,
After rereading my post I would like to clarify that at no time I wanted to depreciate the CHP oil pump. Like any other industrial product made there, the oil pump is of incredible quality. Really well done, with attention to detail, moves oil with incredible volume and pressure. My personal impression is that it may be oversized for an engine close to factory specs, like mine. A highly modified stroker engine will need it, or something like your conversion to the sportster oil pump. As for the engine I use on the bike I ride the most, I use a pair of cylinders from flatheadpoverty made by Anders (flatheadpoverty.com), a 4 3/8 crankshaft made by order from T&O, not to take advantage of the engine with stroke of the piston increased, its almost stock stroke, just to bring the piston top closer to the head to keep the squish in the range of 40 thousand( I bought it second hand from Jeffrey Diamond aka Panic or kitabel). Medium compression iron heads, Everything else is plain stock, except for using PEEK seals on the intake manifold, and a Mallory electronic ignition with modified advance for sidevalves (because they always come in XL specs). I don't have cars, just some bikes, so I need to eventually pull some heavy transport, hence the need to keep the compression ratio at lower levels. My two U bikes have a similar configuration and I use them almost daily, always with 0.3% fully synthetic smokeless 2t oil in the gas, because I don’t have Marvel Mistery Oil where I live. Also, I use round slide Mikunis 34mm, carefully jetted for more fuel because we have 25% ethanol added to the gas down here in Brazil. The pump I use have some mods. I did those mods myself using a Dremel and patience, the cavity where the vanes scrape the oil has been slightly enlarged, as well as the channel and orifice that bring the oil into the inlet cavity the then rotor. The passage for the cavity that receives the oil scraped by the vanes has also been slightly increased in length, but not in width. I blocked the low rpm bypass circuit, because it is there for the simple reason that the factory only managed to develop reasonably efficient oil control rings in the mid-1950s. I use full flow to the crank. I ordered three kits of 4 vanes rotors from Paul Friebus, so I have one spare and in two in use. At that time Barbara Friebus was still alive, and at the head of the business, or so I thought. Things seem to have changed but I prefer not to comment further on respect. Personally I have always been very happy dealing with them in the past. Like I said before the configuration is for an almost stock bike, not a performance ported, flowed, hi-compression long stroker. What I do works for me, it depends on what you want to achieve. My bikes work just fine this way. Oil gets a lot hotter than the regular baby bottle warm, so it works somehow. The heat is from the pistons and cylinders walls washed with air-oil moist, obviously. Haven't done any highly controlled flow test, but an old oil flow meter borrowed from a friend in the return line gives a lit bit three times than stock.

Post Fri Jun 26, 2020 6:41 pm

Posts: 10
I forgot a detail, there's an oil filter from Earl's Performance in the oil supply line. Don't want to open a can of worms about filters on feed lines, right? It's a non restrictive reusable steel mesh 100 micron filter and can be used there NO PROBLEM. Before it I tried to use a similar one from Moroso but the steel mesh holes were wide enough to let a rhino pass through it. I'd like to thank all you guys who willingly share your knowledge on the lubrication system, specially Frankenstein. I try my hardest to study through manuals but forums like this, and others, are a precious source of info from people who really like to wrench and ride these oldies. Thank you very much.

Post Fri Jun 26, 2020 6:59 pm

Posts: 1731
Location: Interlaken, NY USA

Gallow J, No, didn't think you were disparaging the CHP.
If your system is "delivering the goods" with top end oil and the modified pumps, great. Having a hot oil tank is a good sign, for sure.
My approach was a little heavy handed, cause I've been in love with this motor for damn near 50 years and frustrated for the first 35. I was going to make it so I could ride it with no special treatment, like "oh, roll off the throttle occasionally, or "well don't ride them hard too long", or "you can only get 10K miles on a flatty top end".
B.S. So, I may have gone a little overboard in the oiling department. :D
I met Paul F and Barbara at the first Rhinebeck many years ago. Had dealings with him and talked with him many times since. Smart guy and really loves Flatheads. His reputation has taken a beating recently on the web.
Last week I sold a project 47UL to a fellow who knows and works with Paul occasionally. He reinforced my good opinion of Paul.
Anyway, glad to hear you've got two BTSV's and keeping them in the wind. It's a beautiful motor and I love the way they run.
just read your latest post re filters, with the sporty pump I was able to run a filter on the supply line as well. I ran supply pump out to cooler to filter to motor. If Detroit and twin cam harleys can do it , so can flatheads.
Good call.
DD

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