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.

[r_towle]

A combined effort between a good tubing shop and someone like restoration design for stamping may make it a worthwhile thing to do....

[fixer34]

A combined effort between a good tubing shop and someone like restoration design for stamping may make it a worthwhile thing to do....

I'm in, but I don't have the facilities/skill to do it. I've been thinking about this for quite some time. Yea, stainless is nice, but mild steel and then get it coated would make it much easier to produce. The sheet metal heat exchangers (and the thru holes for the exhaust nuts) would be a little bit of work, but once you got the pattern done.
Just look on the VIN registry-there are a lot of 'real' sixes still out there, plus a bunch of conversions. They can't all be in SoCal where you don't want/need heat so you can run headers.

By the way, if anyone knows how to adjust the exhaust valves on a six WITHOUT removing the heat exchangers, or dropping the engine/trans slightly, I'm all ears. I've never been able to figure out how to get the valve covers off, let alone adjust the valves with removing them.

[rgalla9146]

A combined effort between a good tubing shop and someone like restoration design for stamping may make it a worthwhile thing to do....

I'm in, but I don't have the facilities/skill to do it. I've been thinking about this for quite some time. Yea, stainless is nice, but mild steel and then get it coated would make it much easier to produce. The sheet metal heat exchangers (and the thru holes for the exhaust nuts) would be a little bit of work, but once you got the pattern done.
Just look on the VIN registry-there are a lot of 'real' sixes still out there, plus a bunch of conversions. They can't all be in SoCal where you don't want/need heat so you can run headers.

By the way, if anyone knows how to adjust the exhaust valves on a six WITHOUT removing the heat exchangers, or dropping the engine/trans slightly, I'm all ears. I've never been able to figure out how to get the valve covers off, let alone adjust the valves with removing them.

Turbo valve covers cannot be removed with the engine mounted, unless you trim them.
Stockers, no problem.
I've adjusted the valves without removing the heat exchangers, not easy but do-able .
A lift makes it a lot easier switching from intake to exhaust.
Best to remove the wheels and lay under the car with your feet extended toward the side opposite the bank you're working on.
Rotating through the firing order will have you up and down many times. Or six times.
Remove the plugs to ease turning the crank, (use a medium length 19mm wrench at the pulley). The ignition rotor and the marks on the crank pulley will tell you where you are.
Later crank pulley ? AC pulley ? crank fire ? Remove the engine.
OR use a long stick (chopstick ?) to feel each piston come to the top of its stroke, verify clearance at both valves, adjust away !