SWB heat ex question

[JCF]

In order to lower the hp on the 67 911 Normal a restrictor ring was placed on the heater/header dev for the S - until nov 66 when the cams were changed and the same heater/header was then used for both models.

Question: Anyone know if that ring can be removed ?

I have a pre Nov. model with the orig heat exchangers and want that 10 hp. I was thinking of going to SSI's but there are a few good years left in the orig ones and am wondering if there is another way out.

By the way - would the SSI's give me more hp? Are they the same as the early S he's ?

Thanks;

John

[304065]

Hey John,

Pull the muffler off and see if the ring is there. You'll probably destroy the copper gaskets and the bolts might be rusty so be sure to have extras handy. If the ring is there, this should be a conical-type ring mounted at the junction of the heat exchanger and the muffler inlet, pull it out with a pair of pliers. Given the history of your engine I would be surprised if it were there, however. I have never actually SEEN one of these rings so it could be the stuff of legend, but reliable sources say it's true.

SSI's are the same as the early S heat exchangers, and they are WAY more durable than the original steel ones. I would remove the original steel ones and save them for Concours purposes. If you wanted to appear super-original, you could have a set drop-shipped to Jet-hot and have them matte grey coated, or cheaper, get a can of Dove Gray paint from a certain Porsche dealer in Ohio whose name I cannot mention, and spray them with that, would be hard to tell the difference from original. I have SSIs on both of my cars and they are flat-out awesome.

Are you CERTAIN that you have the original cams? What is the valve lift at overlap TDC?

[JCF]

John;

Thanks.
The muffler was changed a few years ago so the ring could be gone if it is that easy to remove.
I'm not really concerned about the concourse thing and was looking at some SSI's about to go on a car the other day and they sure are nice.
More a matter of making my winter project list and spending priorities.
And of course that 10 hp.

The records I have on the car (ch# 305701 901/05 ) are pretty detailed as far as work done and there is no mention of a cam change. But I have not actualy pulled them.

It is almost due for a tensioner check so will see def. what I have then.

Thanks again;

John