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Hello,
Wilson has an issue with heat. Not surprising, since I made some errors engineering the NA to Turbo conversion. I took him off the road after 3000 kms of driving for a variety of reasons, but one reason was to preserve the health of the engine. Well, now I'm in the mood to make things right. Also open to ideas based on the vast experience of RL'ers.
I just pulled the intake and turbo off. The concept of running the "crossover" pipe around the front to spin up the turbo, I think, is the #1 source of my heat problem. It's my intent to run the crossover pipe in a more conventional 951 manner. All the piping is custom and the turbo isn't a Porsche turbo. Not sure if I should buy oem Porsche exhaust manifold/crossover or just build it myself.
One problem I have is charge air cooler. I have the a/c condensor, radiator and aftermarket intercooler all sandwiched together in the front (which I understand is not great for cooling|). I can't run the 951 oem intercooler because I welded the hood pin mounts in such a position that the cooler doesn't fit.
One concept I am considering is a high quality electric water pump with PWM controller to replace the oem pump (though I'll keep the oem in place). I have to say, researching this companies product REALLY impressed me, though I'm a bit concerned about the oem 944 duel fan set up drawing a bit too much amperage, I guess I could wire in an extra relay (god I hate having all these wires and hoses everywhere... drives me nuts). https://daviescraig.com.au/product/e...er-12-24v-8001
So then I also started considering the concept -which is becoming popular; a water cooled heat exchanger in the intake manifold. Diesel engines are using it a lot more. BMW 4s & 6's are using it. Here's a cool 944 turbo powered mini with a custom intake.
Spencer,
When I ran the car as NA the temp needle was always at the middle point, even when driving it hard for hours and hours (subtle needle movement when the t-stat opened/closed). Now the needle is showing 3/4+ when on the boost. Even at high speeds. I think MGK944 suggested the coolant is boiling near the crossover where it touches the head. I can post a better photo. Even after adding an auxiliary rad, the needle is still too high.
So here is the 2.5" crossover very very close to the cylinder head and intake. Besides robbing power, its just no good. At this point where I built it I was just looking at getting the car running (...had too many things on the go with Wilson, and so many "what ifs")... figured get a rough tune going then at some point I'd be in a place psychologically to address the builders flaws.
I would move the engine temp sensor from the factory location. Since your cross over from headers to turbo is right next to it. Don't think the heat sheild and wrap can keep temps from overly heating sensor. You could also move turbo from current location and go headlight delete ,and have the turbo reside there. There's a few on the web with that setup. Or run 100% Evans coolant. Great to see up dates on Wilson!
Spencer, here is my current set up.
Shortyboy, thanks for your support brother. I considered the turbo on hotside approach. My biggest hesitation is : streetcar needs headlights and my turbo drain bung is on the driver's side so I'd need a oil transfer pump like STS turbo conversations use.
How do you have that auxiliary radiator that's mounted facing downward connected to the cooling circuit? It may actually be hurting your cooling. I'm used to seeing an auxiliary radiator take an existing path of the coolant flow and expand it to incorporate a radiator. An example would be to delete the heating core and send that coolant flow forward to a small additional radiator in an area that gets good air flow.
What's the current status of the primary rad and intercooler? Are they still in a > orientation? That little horizontal radiator is likely doing next to nothing running it like that as I can't see how any cool air is going to go through it. Is there an air conditioning condenser in there too?
Chrenan, the little boxter rad is plumbed in parallel series; spliced at both the upper and lower rad hoses. I ordered it based on measurement of length and width but was surprised at the small hose size it uses.
Well, now you have a plan of attack. Redesign your radiator and intercooler setup to make sure that air is being pushed through the fins. Ditch the air conditioning or find an out of the way place for the condenser. You could get a bigger radiator too, your metal work looks great so I'm sure you have the skills to make a big rad fit in there... just remember it needs air flow
Thank you Big J. Gonna try to make it right this time. This afternoon I'm building this log style exhaust manifold out of 14 gauge (I think) 3" exhaust pipe. It'll be non symetrical... Kind of like an intake manifold in reverse.
02-23-2020, 02:48 PM
Too much heat in engine bay
