Author |
Message |
deprivation Samba Member
Joined: September 14, 2006 Posts: 1220 Location: Austin, Texas
|
Posted: Sat Mar 01, 2008 10:28 am Post subject: Maxi Pump VS Shadek Hi-Cap |
|
|
Does anyone out there know what the difference is between CB's Maxi Pump and the Shadek hi-capacity pump? From what I gather, the Shadek, while it moves more oil, does not give you higher OP.
Also, if I decide to add an external oil cooler, is one pump preferable over another in terms of moving the extra oil thru a bigger oil circuit?
THANKS! _________________ 1986 Westy 2WD auto a.k.a. "The Old Girl"
www.kittenfart.com |
|
Back to top |
|
|
tencentlife Samba Member
Joined: May 02, 2006 Posts: 10067 Location: Abiquiu, NM, USA
|
Posted: Sat Mar 01, 2008 11:58 am Post subject: |
|
|
You gathered right. A 30mm pump like the Schadek and others (they're all about the same; I can't see anything to recommend the Schadek over any other) are hi-volume, not high pressure. That is not the same thing, but people get fooled into thinking more volume will result in higher pressure. It will raise it a bit, but on the whole it's just not so. The extra volume will just take more power to move, while the relief valve dumps most of the excess back into the sump, heating and aerating it in the process. Hi-volume is for when you add a turbine or piston squirters or things like that, that bleed off a quantity of oil from the normal circuits. With those kind of additions there is a higher volume of oil leaving at the downstream end of things, so the extra volume needs to be delivered on the pressure side.
An external oil cooler is a closed loop, and doesn't constitute the need for more volume, as the oil just takes a longer, but closed, path to get to the same place. For this you need a pump and oiling system that can maintain adequate pressure, as the volume that needs to flow is basically the same. The nice thing is, whatever small drop in pressure is caused by the longer circuit thru the oil cooler, is more than made up for in the temp stability it gives. Temp stability is the best way to maintain good pressure output from the pump.
The CB Maxipump line is my first pick, because the manufacturing tolerances are very good, and most importantly the driven gear is keyed to the shaft instead of merely pressed on. That is a guarantee against slippage that occasionally occurs with pressed-gear pumps. Considering there is very little cost difference, the choice is a no-brainer. Just keep in mind that like all VW boxer oil pumps, there are two styles depending on which style of cam gear your motor has.
The other thing to consider to avoid pressure drop when adding a cooler is to use a stacked-plate cooler, like the Mesa line, instead of a cheaper finned-tube cooler. The stacked-plate will achieve more heat transfer with a smaller cooler, and the multiple parallel paths thru the plates will cause a much lower pressure drop across the cooler than the single-pass finned tube type. I also think the plate type are much more rugged.
Also, be sure that your oil cooler circuit incorporates thermostatic control. Cold oil is a poor lubricant! The Mocal type t-stat sandwich adapter achieves ths in a nice compact package that doesn't involve adding four more fittings like an external t-stat valve body requires. _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
|
Back to top |
|
|
Wildthings Samba Member
Joined: March 13, 2005 Posts: 50216
|
Posted: Sat Mar 01, 2008 12:28 pm Post subject: |
|
|
To add to what 10c said. Higher oil pressure and even volume do not translate into better lubrication. If you go to a higher volume oil pump you may actually want to run a thinner oil to drop your oil pressure back down. Oil that is being dumped through the relief valve does you no good at all, not only does it represent wasted energy, but it does not help remove waste heat from the bearing either. |
|
Back to top |
|
|
deprivation Samba Member
Joined: September 14, 2006 Posts: 1220 Location: Austin, Texas
|
Posted: Sat Mar 01, 2008 2:47 pm Post subject: |
|
|
Thanks 10cent and Wildthings.
I've heard people say they got a OP boost from the CB pump. I think Levi (may not have been Levi) said he got xtra 10lbs off a new CB Perf but I don't know if that's because his old pump was shot or what.
Also thanks for the info about tube vs mesa coolers. I may end up getting a mesa cooler and add on a fan for the Texas stop-and-go. It's friggin' hot down here. _________________ 1986 Westy 2WD auto a.k.a. "The Old Girl"
www.kittenfart.com |
|
Back to top |
|
|
tencentlife Samba Member
Joined: May 02, 2006 Posts: 10067 Location: Abiquiu, NM, USA
|
Posted: Sat Mar 01, 2008 4:49 pm Post subject: |
|
|
You've probably seen this, so just to put it here (and nuthin like pimpin my own, either...):
http://www.shoptalkforums.com/viewtopic.php?t=102662
I don't find that the OT gets up in traffic, where you're mostly revving pretty low (during the rare instants you're not idling). It seems like it's only sustained high revs, like highway cruising, that really get the OT to rise, and of course OP falls. I added my fans for climbing at low speed on the forest roads, as the load is pretty high and also the revs. But really it's just to augment the radiator, because roadspeed is low so no airflow. I also added a rad fan trigger at the same time I added fans to the cooler. _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
|
Back to top |
|
|
deprivation Samba Member
Joined: September 14, 2006 Posts: 1220 Location: Austin, Texas
|
Posted: Sun Mar 02, 2008 2:51 pm Post subject: |
|
|
tencentlife wrote: |
You've probably seen this, so just to put it here (and nuthin like pimpin my own, either...): |
Pimp away.
My new(ish) pump has a teeny leak so I'm going to pull it and re-do the job. The leak may be due to the fact that I was not able to run the engine for about two weeks after the pump was installed.
In any event, I am going to use Dirko sealant on the cover intead of the gasket as you've suggested. I've never used Dirko before so I'm not sure where to apply ot on the pump body.
What is your pereferred method? My main concern would be having the sealand clog the little channel.
_________________ 1986 Westy 2WD auto a.k.a. "The Old Girl"
www.kittenfart.com |
|
Back to top |
|
|
tencentlife Samba Member
Joined: May 02, 2006 Posts: 10067 Location: Abiquiu, NM, USA
|
Posted: Sun Mar 02, 2008 3:19 pm Post subject: |
|
|
I guess I'll go with envelope A, Bob.
It's good to keep sealant out of the groove there. As you can see, the groove is to collect any oil that seeps outward that far from the pressure chamber, and route it around to the suction side (where the groove tees and reaches the gear chamber). Having the cover really well-sealed renders the groove's function somewhat moot, but keeping the groove clear is the belt and suspenders approach.
It's important, though, to only omit the paper gasket once you have established that the gears in the housing have the right endplay, .002-.004" is the ideal range. If you have .002", and then add the gasket, the gears will end up having probably 6-10 thousandths total endplay, which is too much and it won't raise good pressure when oil is hot. But, if the gears have no endplay in the body, there needs to be something to establish that small amount that should be there, or the gears will just gouge out the cover right away. Pumps come from all kinds of suppliers so you do need to check this first, and make your decision whether to use a gasket or just sealant based on the dry endplay.
I have found that the CB pumps typically have a couple thou in the body, so I go with no gasket, only sealant, and end up with good tight pump endplay tolerances. But I still check every one. _________________ Shop for unique Vanagon accessories at the Vanistan shop:
https://intrepidoverland.com/vanistan/
Please don't PM here, I will not reply.
Experience is kryptonite to doctrine. |
|
Back to top |
|
|
deprivation Samba Member
Joined: September 14, 2006 Posts: 1220 Location: Austin, Texas
|
Posted: Sun Mar 02, 2008 4:44 pm Post subject: |
|
|
tencentlife wrote: |
I guess I'll go with envelope A, Bob |
Advance to the bonus round!
Thanks. _________________ 1986 Westy 2WD auto a.k.a. "The Old Girl"
www.kittenfart.com |
|
Back to top |
|
|
mattcfish Samba Member
Joined: October 24, 2006 Posts: 565 Location: Bellingham, WA
|
Posted: Thu Jan 20, 2011 10:33 am Post subject: |
|
|
tencentlife wrote: |
I guess I'll go with envelope A, Bob.
It's important, though, to only omit the paper gasket once you have established that the gears in the housing have the right endplay, .002-.004" is the ideal range. If you have .002", and then add the gasket, the gears will end up having probably 6-10 thousandths total endplay, which is too much and it won't raise good pressure when oil is hot. But, if the gears have no endplay in the body, there needs to be something to establish that small amount that should be there, or the gears will just gouge out the cover right away. Pumps come from all kinds of suppliers so you do need to check this first, and make your decision whether to use a gasket or just sealant based on the dry endplay.
I have found that the CB pumps typically have a couple thou in the body, so I go with no gasket, only sealant, and end up with good tight pump endplay tolerances. But I still check every one. |
$.10.....My Maxi pump has zero end play. Completely flush gears to body. The question is, which gasket to use. My pump came with a brown body to case gasket and two different pump to cover gaskets. One gasket is a white paper one, the other is a tranlusent material. Should the gaskets be aplied dry or with a sealer? There aren't any intructions with the pump. Also, do I use the allen screws supplied with the pump or do I use the studs in the vanagon case to mount it? _________________ 71 Bay Window
75 BMW 2002
76 BMW R90S
85 Vanagon with 2.2L upgrade |
|
Back to top |
|
|
Summers420us Samba Member
Joined: June 14, 2010 Posts: 759 Location: Amissville, Virginia
|
Posted: Fri Jan 21, 2011 8:42 am Post subject: |
|
|
mattcfish wrote: |
$.10.....My Maxi pump has zero end play. Completely flush gears to body. The question is, which gasket to use. My pump came with a brown body to case gasket and two different pump to cover gaskets. One gasket is a white paper one, the other is a tranlusent material. Should the gaskets be aplied dry or with a sealer? There aren't any intructions with the pump. Also, do I use the allen screws supplied with the pump or do I use the studs in the vanagon case to mount it? |
Did you figure out the answer to your question? I am pretty much in the same boat. |
|
Back to top |
|
|
mattcfish Samba Member
Joined: October 24, 2006 Posts: 565 Location: Bellingham, WA
|
Posted: Fri Jan 21, 2011 9:35 am Post subject: |
|
|
Summers420us wrote: |
Did you figure out the answer to your question? I am pretty much in the same boat. |
Nothing but crickets. _________________ 71 Bay Window
75 BMW 2002
76 BMW R90S
85 Vanagon with 2.2L upgrade |
|
Back to top |
|
|
Summers420us Samba Member
Joined: June 14, 2010 Posts: 759 Location: Amissville, Virginia
|
Posted: Sat Jan 22, 2011 9:00 am Post subject: |
|
|
bump |
|
Back to top |
|
|
klucz Samba Member
Joined: February 14, 2006 Posts: 1062 Location: Chicago, IL
|
|
Back to top |
|
|
|