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     V2win |
Ron, what pump would you recomend for a "healthy" street engine? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Mikej |
"make a quick way to get in the 150 club"  You sure know how to get someone's attention. Right now I've got to complete this project:  Sure liked the way that S2 sounded and ran though. Re: the flywheels, I know what I'm trying to say, but don't know the way to say it, but it has a lot to do with balancing the engine and other stuff. To me it's more of a felt-thing, seat of the pants sort of stuff. Years ago I rode two different bikes, both v-twins, both basically the same, except one was simply rebuilt and the other was balanced and then rebuilt by a shop in West Seattle, the two bikes felt and ran totally different, and the second one lasted a whole lot longer. Whatever I end up doing will be a complete integrated coordinated package, which is why I'm in no hurry to do it. Well, that and other issues that are in the way. Thanks for the follow ups and details. MikeJ (Might be for sale? Nope, don't think the $17 in my wallet will cover it, darn. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Peter |
Ron, "I have found the late model oil pumps to be junk and the root of many problems." What year did they start with those punps? PPiA | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blake |
1998 I think. Aaron has also speculated that the design is flawed. Apparently in trying to reduce breather pukage, the oiling was left compromised at the top end or elsewhere? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
That doesn't make sense to me. Wouldn't the way to reduce breather pukage be to improve crankcase scavanging by increasing oil pump efficiency? Russ | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
The '98 pump introduced the new scavenge inlet in the cam box, and they also started blocking the drain holes between the cam box and the crankcase. The idea is don't let that oil drain onto the flywheels and cause parasitic drag and get whipped into a froth. The main scavenge inlet is still routed to the bottom of the crankcase. Now it's entirely possible that there's something about this arrangement that I don't understand, but in my experience, you don't put two inlets on a pump unless you know both of them will always have fluid present. I can't help wonder what happens to the vacuum at one of those inlets if the other starts sucking air. Maybe the design of the pump is such that the effect is minimal, I don't know, but I wonder. The way it's done in S&S cases seems better IMO, they have a passage that takes cam box oil directly down to the cavity below the crankcase where the oil collects and the scavenge inlet is routed to. Another thing that doesn't sit quite right with me is the shaft through the middle of both sections has a flat side on it. So there's no seal between the scavenge and pressure sections, that flat side of the shaft essentially connects the two. What's to keep oil from just passing from the pressure side to the scavenge side and bypassing the motor entirely? Seems like this would not only lower oil pressure, but it could compromise actual scavenge capacity. Again, I don't understand it. It sure seems like there ought to be a sealed connection there. An interesting experiment would be to run one of these pumps on the bench with oil being fed into it's pressure section and some kind of restriction on it's outlet and see if anything comes out the scavenge side. They revised the pump again in '01, so apparently they still weren't happy with it, and that makes me wonder even more about these things. I haven't examined an '01 pump. So that's what little I know on these pumps. More confusion than conclusions. AW  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Doncasto |
AW: If you do find the time amidst all your other endeavors to examine the '01 pumps, would you please be sure to let us know if it would make any sense to do a '01 upgrade? Also, I recall the Wizard discussing a pump change on the RR/LSR engine. Do you (or anyone else) know of a bolt on after market pump that might eliminate the concerns you noted above? Thanks, Don (I know, its not like you haven't got enough irons in the fire already.)  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
Don: I suspect it probably would be worthwhile, but I don't have an '01 pump handy to disassemble and compare. Yeah, there are aftermarket pumps that work good, but they're a little pricey from what I hear. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
I second Don's motion, and in a big way. I'm on my second motor because the oil pump in my original '97 motor failed to scavange the crankcase, produced a "wet sump" condition, covered six lanes of Interstate with Hollywood quality blue smoke, and failed. The factory replaced the motor under warranty with a '98-spec unit. If the '01 oil pump is superior in some way, I'll gladly do the upgrade at my own expense. Russ | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
I would be willing to contribute to the purchase of an '01 oil pump for the proposed analysis. Are there others? Russ | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
I just went to look up some numbers to see what these things cost and saw something surprising. Take a look at these part numbers: '96-97: 26204-91 '98-99: 26204-98 '00-01: 26204-91A I was thinking they updated the pump again in '01, but the parts books seem to say it was '00. I don't have any '02 parts books. Anyhoo, from looking at those numbers, a person could infer that they reverted back to the old pump, with some minor modification. And of course, if that's true, a person could infer that maybe the '98-99 pump isn't a good solution. Hmm. Exactly what Mr. Wizard told us, imagine that. Now I'm *really* curious what got changed on this latest revision of the pump. Ron, do you know? Did they get rid of the cam box scavenge inlet by chance? Or seal between the two sections better? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
Oh, Don, let me retract that statement about upgrading. I'm under the impression (always dangerous) that '98-'99 cam boxes have no drain holes into the crankcase. If that's the "case" (hah, I kill me!), you better make sure you use an oil pump that has a scavenge inlet in the cam box. The 26204-91 does not. The 26204-91A, I don't know. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
Nice bit of research, Aaron. I'm wondering the same things as you, and in particular whether the -91A pump is compatible with '98-99 engines. Oil pumps being essential and single-point failure components (as I have previously discovered), we really need to get a complete understanding of this. Anything I can do to contribute to the effort, I will. Russ | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Court |
Aaron: Which oil pump would you like? Do you have the year Buell it was on or a P/N? Court | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Court |
'00-01: 26204-91A = $165.60 '98-99: 26204-98 comes up as obsolete and superceded by 26204-91A. If the 26204-91A is of any interest to get info from let me know and I can get one on the way pronto. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
The parts list for an oil pump is pretty small ...
No part numbers are shown for the main body or the lower housing. I assume you have to buy the complete pump to get those pieces. Sure looks like the -91A pump is the same internally as the -98 pump. The housing must be different??? Maybe they removed that cam box scavenge inlet? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
The -91A supercedes the -98 pump. Hmm. That implies either the cam box scavenge inlet is still there, or they never plugged those drain holes from the cam box to the crankcase on '98-'99 motors. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
What about those two fittings at the end of the list? What do they do? | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aaron |
Those just connect the hoses. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Peter |
OK. This is the nice new (I believe) oil pump fitted to the engine (now apart) from my just bought '98 S1W. Is that just the end plate number?  What's the thoughts on improving it all while it's apart? I have no problem with drilling and tapping holes in heads, cases etc with external plumbing to it all if needed. I sorta like the XR750 look.... (aka Volume 3. Issue 1. 1999. Battle2win. Pg 50-51) I will be fitting a flywheel scraper. PPiA | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Peter |
That made me curious, so I went down and took a pic of the one on the '00 M2. It's a bit hard to read, but it's the same number.  How can I tell which one I have for the S1W? PPiA | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ralph |
Peter, by the last two numbers. Both are '98 pumps. bighairyralph | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Peter |
'00-01: 26204-91A = $165.60 BHR, As my M2 is a '00 model, would the 26204-91A pump maybe still use the 26487-98 end plate? (I'm assuming that's what the number on both those pumps is for?) The oil pump in the top photo was only fitted in the last two months I believe. Maybe old stock though. PPiA | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
$165.60 for an oil pump that feeds two cylinders. Figuring $82.80 for the capability to properly lubricate each cylinder, then an oil pump for a Chevy 350 should cost about $662.40. What a racket. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Blake |
Ara: A pump is a pump. Same number of moving parts. One might be a little bigger and/or completely different. Basing a comparison on number of cylinders might not be valid. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ralph |
Pete, you know I don't know nothin', but as I understand it the end plate is the identifier for the pump. Like others, I have not seen an '01 pump, I assume (that's dangerous) that it would be marked -01 or -91A. Both your '98 S1WL and '00 M2 would have been originally fit with the -98. Earlier models the would use the -96. I would very much like to see a '01 to see what changes they made. From what I understand they basically went back to the -96, from there, I don't know. The -98 pump does not turn me on. I think it was Jose who pointed out that since it was sucking through two orificaces (orifie?) it would basically compare to trying to drink with two straws in your mouth. One in the drink, the other in air. Not very good. There are also supposed to be changes in the cases, as Aarroonn noted. It seems that may not be the truth. Any one feel like loaning me their '01 bike so I can tear the motor out? Ara, rather than compare cost to cylinders, try cost to pressure. My Blazer idles at fourty pounds and S1 at eleven. Which is good by the way. bighairyralph | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Jmartz |
I beleive Hoser once mentioned that the difference between the '98 and '01 pumps was the location of the "timing" holes in the body. All other parts as posted above are the same. I have on ocassion attempted to empty the "sump" in my motor while changing the oil by runnig the starter and routing the return hose into a bucket. That SOB has lots of pressure. I'm fully aware that if I'm sucking a milk shake with two straws and one come off the fluid I will be unable to continue. How this pump works is a mystery. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
Thanks, Ralph, you prove my point - that the H-D oil pumps are vastly overpriced. That notwithstanding, here I am with a '98-spec motor in my '97 S3 which suffered a catastrophic engine failure due to poor scavanging of the crankcase by the oil pump, the '98 pump has been superseded, and it's been superseded by a pump that appears to be very, very similar to the '97 design that cost me a motor. Catch 22?  Russ | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ralph |
Russ, I didn't prove diddly. I was just having some fun. You can not compare the price for small block Chebbie parts to motorcycle parts. Get a grip, dude. How many small block Chevy pumps have been made, for how long, with no changes? Compared to a tiny company like Harley? No way. Chevy uses more pumps in a year than Harley has made Evo motors. By the way, if you think Buell parts are expensive I would suggest you take a look at the cost of Japanese factory parts  Buell parts are cheap. As far as your sumping problem....no clue. I ran the same '98 pump in my S3 for twenty thousand miles, after using the stock '96 for the first ten thousand. No problems with sumping with either one. Two years of production of Buells run that same pump. No problems (at least none connected to the pump in an endemic fashion). If I actually knew something I could give a conclusive "phooie", but, darn it, I don't. So I'll just have to say that I don't think it's a problem because there haven't been more people whos pump "cost them a motor" bighairyralph | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Ara |
Ralph - Oh yeah, I know about the Japanese Big 4 parts. Kawasaki is famous for extravagantly priced parts, but the others are not slouches either. And I take your argument about volume production. I guess I just showed a little attitude, and attitudes are a dime a dozen - a lot cheaper than oil pumps!  Russ |
