Is there a High Output waterpump.

[colinr]

Having read the forum advice I was checking American ebay for a HO water pump. Some pumps on the ebay site were different prices so I asked were the dearer pumps the HO ones. No such things, all the same was the reply. My answer was wrong, wrong, do some homework and give your customers informed advice, Diesel Page, Heath and Kennedy Diesel all say there is. His answer was he runs http://howardstewartengineering.com/ and has been designing and selling waterpumps for 35 years and does know what he is talking about. Impeller and volutes on 6-2 and 6-5 pumps are all the same size, as are the internal passages, the only difference being angled different for CW and CCW rotation which are morror images. Don't beleive GM hype, the dual thermostat makes the difference, the pumps internally are all the same. Ebay site no. 220452338291, waterpumpwarehouse. The seeds of doubt have been sown and I'm out of my depth. He absolutely is sure. Can someone verify true or false.

[DmaxMaverick]

There are several very different pump options, OEM and aftermarket. All the pumps are compatible with all the 6.2/6.5 engines, depending on needs and individual additional hardware (V-belt vs. Serpentine, single vs. dual stats, etc.). Late 6.2 and all 6.5 are serpentine accessory belt driven (reverse rotation). 1997 model year got dual stats, and a higher volume pump. Early models (up to 88-91, depending on chassis models) had only one OEM choice, which is the original (low output) pump and V-belt. Peninsular Engines for years has offered a high output V-belt (normal rotation) pump for Marine and other applications.......Just to name a few.

So, whatever they are telling you is wrong. I suggest finding a seller who knows what they are talking about. If they are that ignorant, they don't know anything about the product they are selling.

[More Power]

The waterpump impeller used in the "HO" 6.5 water pump is both larger in diameter and wider than the earlier version. This was all settled in the late 1990's in an article I wrote on this very subject. In that article, I included photos of the impellers...... ;)

I have the three 6.5 waterpumps produced through the years sitting on my workbench as I type this. Tell him that there is serious money to be bet on the fact that the impellers are different, and that the 1997-98 "HO" pump uses a larger impeller than the original/earlier 1992-1996 version. By the way, the 1997-98 "HO" water pump has the letters "HO" cast into the pump housing... :)

Jim

[colinr]

Hi, hey, I told him this, quoted the 96 and earlier 87 gpm, later ones 130 gpm at 3000 rpm and was smug doing it. He's a nice bloke (maybe not as clever as he thinks) and came straight back with his website, drove a 6-5, 35 years experience and a warehouse full of pumps he sells for a living. As I said, I was out of my depth so when in doubt check facts. Had a quick look at the article in Vol II and never mentioned impeller size, havn't got any pumps to look at and used the scearch option on DP which didn't come up with much so I double checked with you. I'll tell him that he can put up or shut up, and by the sounds you'd put your house on it. Be interesting to see what he says.

[Yukon6.2]

Hi
I went through the same kind of thing a few months ago.I was trying to find a HO pump while i had the motor out of my tow truck.It's a 97 had dual tstats on it,but no HO on the pump.The donar motor was a 97 with EGR,had a single stat and no HO on the pump.I called all the parts house in the Big City of Whithorse,and nobody had any listings for the HO pump,listed the same pump for all 6.5's, i did get a pump from NAPA for a 98 hoping that it would be a HO pump,but there was no HO cast in it.I sent it backThe olny differance they had was the 2000 pump with the screw on fan hub.I left the donar on in place and am thinking of gettin one with the screw on fan hub.
Does anyone know if the screw on hub from a duramax will fit the 2000 6.5 waterpump?I did get a hub and fan from a 2001 duramax.
Thanks Thomas

[rogers]

I have replaced two pumps on my rig, both were the "HO" type but neither had the ho cast into the housing. You can tell the difference by looking at the impeller, the 87gpm has notches cut in the impeller disc and the 130 is a solid round disc without notches.