[GTS Dean]

Time for another update:

The cold reality is that when you're hunting parts for a low production volume, 26 year old vehicle, you have to start every parts search with a 2-4 week + delivery window. Some things can take 2 months, or 2 years. The good thing is that is IS just a Dodge. If you're willing to spend the time and money, you can often find things that can be adapted to refresh your worn out parts.

The factory supplier of water pumps was Airtex and they are still very much in business. They just aren't making G2 pumps. The G1-2 Viper motor architecture was largely the Magnum series V-6,8,10 blocks and accessories. The 488 is basically a 360 with 3/16" more stroke and 2 more cylinders on the back. Bore spacing is the same. Front cover accessory drives are quite similar.

The G1 Viper and iron block truck V10s use the same bolt pattern for the pump housings. The shafts vary in length by 1/4" - trucks being shorter. The belt drive pulley is pressed onto the truck shaft and it sits 1/4" further back than the bolted pulley. Impellers are the same. The "snail" section of the pump snout is the same, the water inlet is very similar, but the heater hose and t-stat jumper are different. With the exterrnals so similar, I expect the bearings, seals and impellers are nearly identical from what I've observed from external observation. The earlier pumps thru at least '98 have a 12mm impeller diameter, (FlowKooler Green) and a 5/8" shaft pilot diameter for later ones (FlowKooler Orange).

Now, it's time to start disassembling them all and comparing the guts!

 

[Marks GTS]

Boy what a long journey! Following since at 61k miles, no idea if the current one on my 2000 GTS is OE or been replaced.

 

[GTS Dean]

Pressing and pulling... Sorry for my image editor rotation. This site doesn't like it.

 

[GTS Dean]

I wonder how well the FK impeller works since it is a Vortex (recessed ) type. Not sure on what the stock one is as the pictures I seen are just the back with the pump off. Did FK copy the design and add extra impellers?

Here's the aluminum 8-vane impeller on the G1 pump. The plastic one looks just the same, only smoother. The FK piece has 10 longer vanes for more pressure. You will not be able to salvage the plastic impeller - period. I'm not sure the Al impeller will come off undamaged, but I'm going to try tooling up for it. I will tell you one thing - all that shit is pushed together TIGHT!!! You ain't gonna casually disassemble these with ordinary tools and pullers.

 

[85vett]

I've got a press if you want to use it. I'm assuming you've got one too but calling it out just incase.

Best of luck.

 

[GTS Dean]

Thanks, but I have currently disassembled 3 pumps today.

 

[RobV]

If tight, could they have used extreme cold to contract the shaft?

Not sure if they could heat the impeller looks like casted.

 

[GTS Dean]

When we have to install high interference bearnings, we sometimes pack the shaft in dry ice for a few hours. For the outer, we heat a pot of geear oil with a rosebud torch to about 350F, then immerse the other part for a few minutes to expand. Get them both ready and assemble firm and quickly.

 

[GTS Dean]

I got the car up and running last week. Happy to report that the bearing/shaft swap from the Gen 1 fits perfectly and if desired, can use the 12mm FlowKooler impeller. For an ordinary duty rebuild, you can just pull the hub off the font, press the bearing/impeller assembly out the back and go straight into the Gen 2 housing. It is a very tight interference fit coming out and back in. The impeller vanes should have a clearance of 0.030" to the housing. I measured mine with a standard feeler gauge. Be careful to note the distance from the hub face to the back face of the pump housing. If you press the hub on the new shaft too far, the pulley could rub and cut the cam sensor plug - it's really close and that's not something you want to have happen. The truck bearing assembly is a little shorter and will also work, but the hub placement is EXTRA-CRITICAL.

If you don't feel comfortable tackling this on your own, Mike can set you up with a reman done right for a fair price with either impeller.

 

[Brickhead]

As time marches on do you think someone like Ipsco or another might start fabbing up routine replacement items for our aging hoopties considering he already produces some great stuff now? Unless these folks are in tune with some sites they may not know the types of replacement parts that were routine are becoming unicorn wings.

Not like it's going to get better moving forward. It's great to have a member here that collects & has some items for us but these will go away sooner more than later for typical wear out parts.

 

[RobV]

The only reason was that flowkooler lost the person or company that was rebuilding them for them but people were interested in the impellers so they said we can sell you that.

 

[GTS Dean]

I drove to SA and back late today and after dark. Ambient was in the low 80's. Going in, the Interstate was showing very slow in Maps, so I ran a 45mph 2-lane roughly parallel about halfway. Temp gauge was running steady at about 185 in 4th/5th gear. The hottest it got in slow traffic was ~210. I was not running the AC. So far, I'm well pleased with the new impeller's performance. Stock 2-row brass radiator, stock early fan module, I think I bought a stock replacement t-stat from NAPA for engine rebuild. When I hit the track again in June-September, that's the real test.

 

[85vett]

I've also been real happy with my new pump. My gauge stays right around the 190 mark now unless I hit bad traffic with the AC on. Real test will be the 95+ days but in the 80-90 range I'm not worried about overheating anymore.