Hayward and Scott 914-6 Heat Exchangers, Fitment Issues Options

[bluhun]

I purchased a set of the Hayward and Scott heat exchangers for my 1975 3.2 liter conversion several months ago. The conversion was performed 5 years ago and designed around the Billy Boat heat exchangers and muffler system. I was not happy with the B&B system because of the inadequate flow of hot air it delivered, and decided to give the H&S system a try. Attached is a picture of the H&S heat exchangers.

Unfortunately, and not surprisingly, we encountered significant fitment issues with the H&S heat exchangers. First of all, the exhaust primaries would not bolt up with the cylinder heads without enlarging the bolt holes on the exhaust flanges. Not a big issue, just enlarge the holes. The hot-air exit tube on the exchangers needs to be extended by several inches to bolt up to the heater-control valves. The collector end of the exhaust would not mate up with the B&B muffler, necessitating the purchase of a standard 911 banana-type muffler.

The most significant fitment issue, however, is that the system interferes with oil changes and exhaust-valve adjustments, requiring the exhaust to be removed in order to do an oil change or an engine service.

We reluctantly decided to retain the B&B system for the car, and new heater-control valves did significantly improve the hot-air flow. All-in-all, this has been a very expensive lesson.

The H&S exchangers come with 1-3/4" primaries and a 2" collector. The driver's-side comes with an O2-sensor bung installed. I am willing to sell them for considerably less than I paid for them ($2,900 including shipping). I will be posting an ad in the classified section.