Waterpump Question For MK / LT1

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I am helping a guy long distance do a LT1 conversion and he has a question about hose routing looking at a drawing in your gallery. I remember the discussion on the old board before the turd burglars took it over.

Anyway you have a picture of a F body pump in your gallery that shows the third nipple hooking to the accumulator tank hose. Is that the current / latest thinking when using the F body pump. I have always used the Horvette pump, it does not have the extra connection.

Thoughts? Recollections?

You say that you have always used the corvette pump, How many have you done and what radiator have you been using? Unless you have a custom radiator with some sort of filler neck somewhere else in line what else would you use?

You have hoses with red and blue arrows. The one line you have with no arrows I have plugged with a cap and some fiberglass wrap (to make sure the cap doesn't expand and bust). I do have hot fluid running through the throttle body though which drains into the overflow tank which follows your un-arrowed hose.

Yup. Thats how I had my hoses routed for a while. Didnt know what to do with that extra outlet so I routed it to the inlet hose from the expansion tank. I should have just used the vette pump and rid myself of that extra hose though. I believe the most popular is to use a 944 turbo expansion tank with the 2nd nipple and that F-body hose goes to that. Have to have Paul (948) chime in here. I think thats how his is routed. But if you have the NA tank and F-body pump, thats the way as far as I know (thats what I did).

Regardless, I ended up installing an h-valve where the OEM porsche heater valve is to re-route hot coolant back to the pump instead of dead-heading it to the OEM valve. (This was a huge finding by "PORCH" back on PHB.com.....thanks again Porch....and RH must have agreed cause now its in their parts list ....non-credit giving thieving bastards!!!! ......AND....although autozone charges like 13 bucks for it, RH charges 30!).

PN# 5930 made by ready aire ... [You must be registered and logged in to see this link.] Also found at pretty much any parts house under this number.

Its already marked "in" and "out" on the valve so one hose comes off the pump and goes into the valve and another comes off the valve and into the reutrn side of the pump.

Better post this again ferya... [You must be registered and logged in to see this image.]

944-LT1 wrote:Regardless, I ended up installing an h-valve where the OEM porsche heater valve is to re-route hot coolant back to the pump instead of dead-heading it to the OEM valve.

Ditto on bypassing the interior heater cutoff in the event that the heater is turned off (which is most of the time). I just used two Y splitters/couplers, one right before the early cable operated valve shut-off (I have an '83) and a little bit of hose in between the two Y couplers to make the bypass.

Ooh. Also found a neat thread on these pumps ferya... [You must be registered and logged in to see this link.]

As 944-LT1(LS3) pointed out I have been through several layouts. The current and best is as follows:
- H-valve on heater circuit
- Lower left nipple out to secondary radiator core then on to heater circuit
- Upper left is the heater return
- Right nipple is now plugged/capped
- Upper rad hose has a tee that runs to the lower coolant tank nipple, NA tank not turbo
- 951 style radiator plumbed normally; the extra nipple on the pass side tank is closed.

I did have the turbo tank plumbed with the right side wp nipple but that was not needed with the added balance of the H-valve....

Edit: I rotated the nipples to suit my fitment needs, a little heat helps.....just put some hydraulic sealent on them to prevent the chance of leaks.

Just a test no offense meant. [You must be registered and logged in to see this image.]

HA! I tried to click cancel on that.