Kurt R

I hate those stupid caps. They were never designed to hold up to cooling system pressure for a long time. I burned my hand last spring working on another guy's car, and I know at least one Rennlister who had the cap let go on his 944spec car, causing him to lose all his coolant and his head gasket shortly afterwards.

I'm running a hose.

16valver

Ladies and gentleman, we have an expert!

Van that makes so much sense! I didn't even think that I had the hoses mixed up. Since the return line has the control valve on it, I thought it was the other way around there for a second. Even though the line running above the exhaust is called the return line. Oops! Well that makes a whole lot more sense now! That also makes it sound like the return line nipple takes even less pressure than I thought.

16valver

Whoa, I may have to eat that prior statement.

Any other thoughts on this cap? I can't image that a hose would be that much more likely to not fail but I'm usually wrong... Heh

Van

That 1" cap from summit is at least as thick as a hose. I've had it on for a year with no problems... But maybe it's worth having a spare in the track box?

black944 turbo

I am not sure why you want to do this on a street car as the heater valve is not expensive and will allow you to keep heat.

Arominus

Its also in stupid easy spot to get to on a 16v car. Just replace all of your coolant hoses and you'll be fine. I run to 6800rpm all the time and since i replaced the valve and hoses before i started driving the car, i have no worries about it. I take 300+ mile day trips in it with zero fear of a coolant hose letting go.

Spend $100 for the hose kit and $20 on the valve if your worried about it, its a street car. Not a spec car.

xsboost90

i agree- replace the pieces that are broken....but if you are deleting the stuff under the dash anyways you can just do as Van said. Ive only replied to about ten or so threads of pple arguing that the coolant to the heater core is needed for head flow- not true- just branches off there to heat the car. Think about it- when the heat is off, the valve cuts flow to the heater core. I prefer to tap and plug the water pump since as stated above Sams car that i built had the plug blow off and after driving awhile it overheated and toasted the bottom end. You can use a small piece of coolant hose with a metal plug/bolt like a valve cover 8v plug clamped in the end works great. Everyone in spec and PCA runs their cars like this and im sure if there was any flow issues we would be first to know.

16valver

Last I checked, what I'm planning to do and why I'm planning to do it was not up for debate. The big question here is "how?". Let me be the judge of what my car does and doesn't need. No one said its not becoming a race car.

xboost90, would you mind elaborating on this slightly? Any pictures would be wonderful. I do agree that this is a spot that should not be skimped on.

mblaszak

Hey guys,

Sorry, late to the party but here is what we do at the shop

1) tap and plug the waterpump at the car. New waterpumps are always tapped prior to install to allow this in the future if needed. Tap is 3/8"NPT. Then plug hole with an allen head pipe plug. Secure plug with Loctite Hydraulic/Pneumatic sealant. This NEVER leaks and is a 100% fix... To do this with the waterpump ON the car is almost impossible. Porsche DOES sell a proper cap, it is shown on the Radiator drawing page and is used to cap off the radiator port on the passenger side on late model cars that use the water inlet line directly to the waterpump flange instead (non turbo) 944.106.103.02 is the part number. If it can hold the cooling system pressure at the radiator, please don't say it cant hold the same pressure at a fitting at the pump only 12" away.

2) at the back of the head we make a block-off plate from 1/4" aluminum and cut it approximately to match gasket shape. Material MUST be 1/4" thick or it will warp and leak. Alternative is to take factory pipe plate off, cut off the elbow pipe and:
a) tap the plate for an auxiliary temperature gauge sender or
b) weld the resultant hole over and reuse the steel plate to block head

Do you guys need a photo of the plug put into a pump? I suppose I could snap a pic later today by doing it to one of my pump cores here.

black944 turbo

16 valver people are just trying to help and from what you said in the beginning is that you had a leak and wanted to bypass the system. If you post things, expect to get opinions. A little respect can go a long way. Thanks and have a great day.

Cole

fWIW, I've personally used my heater quite a bit on the race track to help keep engine temps constant. Treating it as an auxiliary radiator.

16valver

Take it easy buddy, my initial post was more along the lines of "if it wasn't broken I would probably just leave it alone" but it leaks, I don't use it, and I'm going to want it out eventually. I'm sorry if that was harsh, but I just get annoyed by people telling me these things. Same thing happened when I went to de-power a power steering rack for the quick ratio and manual feel, delete the AC and get rid of the cruise control. I happen to love it that way, others don't. Each is their own I suppose. Apologies for the harsh retort.

mblaszak, pictures would be great!

This is a valid point. I think if I were running into over heating issues I would opt for a different/bigger radiator or some sort of stronger fan setup. This will be considered, though.

9turbo51

I'm with Cole, always have the heat on on track. If it is cold...feels good, if it is hot helps keep engine cool.

Cole

Fwiw, I also have a 3rd fan in front of the radiator, and still use the heater core to extract a little extra heat.

Van

Lol. I have just one fan - and frequently have it switched off. Just let the air going over the radiator cool the car. Then turn on the fan if there's a caution lap or something.