How's your heat with 993 HEs?

Maxhouse97 · 11-13-2014, 04:42 PM

Was thinking of installing these on my 3.2, but one anecdote (Jeremy in FL) said the heat was barely enough to demist the windshield. Not good when you live in Cincinnati and polar vortex is a regular occurrence (where's the global warming?!?). Anybody have better heat with 993 HEs?

Maxhouse97 · 11-15-2014, 04:48 AM

Bump

arrivederci · 11-15-2014, 05:42 AM

I have them on my 3.6 conversion but have not plumbed for heat yet. My guess is that they will provide plenty of heat but might not have enough air being pushed through them. Add footwell blowers maybe?

sc_rufctr · 11-15-2014, 05:42 AM

I would have thought the 993 headers would have provides excellent heat
considering it's the last of the air cooled cars and therefore the most refined.

But like anything you'd have to do this properly minimising leaks.

BTW: A 12 volt hair dryer if set-up properly can demist your windscreen so maybe "Jeremy in FL" was exaggerating a bit.

JeremyD · JeremyD's Garage

Not known for exaggerating - but hey knock your lights out.

BTW - this only tells part of the story - I had HE that were only drawing heat through the footwell blowers (and on a cabriolet). If I did it again - I'd probably go the bilge blower route.

sc_rufctr · 11-15-2014, 06:12 AM

No offence intended Jeremy.

Maxhouse97 · 11-15-2014, 06:40 AM

Hey Jeremy what exactly is a bilge blower? Something in addition to the stock blowers on my 3.2?

I recently backdated my heat and took off my engine compartment blower but could reinstall it if needed.

911pcars · 11-15-2014, 10:38 AM

Many owners who have transplanted 993 HEs onto earlier engines often have no-op cabin hot air. It takes an extra effort to gather the right pieces and integrate. Please confirm the system heat path is intact. If backdated properly, it should be no worse than early 911s and better with Carreras who also have two fan assemblies up front.

Sherwood

Elombard · 11-15-2014, 12:03 PM

One thing that may be affecting it, the 3.6 motors fan is much less powerful than the earlier fans, but also much quieter. On a 3.2 I would bet you would be fine. As mentioned above you have to do all the backdate parts, oil lines, ducts etc. If it was not enough you could add the engine compartment blower and/or the foot well blowers.

Dont forget I think you have to have the header flanges rotated on one side of the exchangers.

ALEX P · ALEX P's Garage

I recently stuck 993 h/e on my car and only run it with a pair of sill blowers and I absolutely couldn't be happier with the amount of heat they give.

My Ti exhaust project

I don't really get the thinking behind this - if 993 heat exchangers were no good don't you think we would have all heard about it by now with all the 993 owners complaining???

RarlyL8 · RarlyL8's Garage

Fans are important to the function. The 993 had multiple heater fans where early 911 had none. Lots more surface area in an early 911 exchanger than a Bischoff 993 exchanger.

$ Short · $ Short's Garage

I run 993 HE's in my 3.2 (backdated heat) and I have plenty of heat. This is central Texas though.

Maxhouse97 · 11-16-2014, 05:53 AM

Thanks Brian that's my concern.

To clarify, I have all the stock 87 blowers in place (foot wells, standard engine, I think that's all) except for the engine mounted aux fan. This is what I refer to when mentioning an heater backdate. I bought the left side tin to replace the duct you loose when removing the aux fan.

The reason I am concerned is that after doing the backdate, I have lost some heating capability. It's still ok, but it used to be a furnace before (and heated up much quicker). Therefore I was concerned about degrading my heating performance any further, and wanted to know how 993 HEs would play into this. I like heat because I want to use my car in the winter (seriously, if I had no heat and no a/c, I'd be able to drive my car 4 months out of the year ... where's the fun in that)?

I am interesting in seeing how people hooked up their heating hoses to the 993 HEs. Is an issue in determining the amount you get? Most of the pics I have seen are without (before) the heating hoses. Thanks!

JeremyD · JeremyD's Garage

Bilge blowers from a boat - have heard of several folks using them successfully.

Rule Marine In-Line Blower

Maxhouse97 · 11-17-2014, 11:06 AM

BTW found a good post on IB that describes great heat coming from an 993 HE conversion (and has a wonderful step by step process). Seems like it can work well.

Fitting 993 Heat Exchangers to 3.2 Carrera - Exhaust: Gas and Heat - Impact Bumpers