I have a 914-6 with a 2.7 liter engine and the original heat exchangers are rusty and
the headers are alittle too small for the 2.7 heads. Has anyone tried the Billy Boat 1-3/4 heat exchangers?
thanks
zac

Not personally, but over the years I have met a bunch of people locally that tried them and complained about poor heat and fitment.
However they are the only one that makes 1 3/4" heat exchanger, so i have seen people with 3.6 engines add an external fan to push more air through them.
I ran stock 914-6 heat exchanger's with my 3.2 and then when MB911 made his 1 5/8" heat exchangers I swapped them out and sold the stock ones. There was a noticeable difference between the stock heat exchangers and Bens. See if Ben will make you a set of his heat exchangers. There was no noticeable difference between Ben's heat exchangers and the stock heat exchangers.

factory duplicate 914-6 heat exchangers work great on the 2.7 and readily available

Cost and hassle wise, I would just get a set of the new factory duplicates. However when I ran a 2.7S with 40ida webers, I preferred 1 5/8" heat exchangers over the factory heat exchangers.

I went with Hayward and Scott 1.75, take a look at their website for the 914-6.

Todd

@T.Rick6 - Have you installed and run the Hayward & Scott exchangers? How do they fit and perform?

Curious. I’ve heard mixed reviews.

Guys lets clarify some things here. I know that I am not involved with any exhaust products any more but the knowledge has not left the building lol. Stock heat exchangers are absolutly ideal for a street/track car up to 3.0. if you go to 1.625/1-5/8'' then you will lose considerable low end. that is where a street car spends 80% of the time.

I want to note this is not anecdotal information but information I have gathered over 20 plus years of doing this. The other thing that happens with to large of primary is that the idle circuit will not support a nice smooth idle. when I was doing 1.625 heat exchangers Richard Parr called me a few times asking me to stop making them as his small displacement customers were having major issues with the cars idling. I kindly let him know that I just sold the product and was not in charge of what engine they put it on. this happened a few times over the many years I was involved with those heat exchangers

B&B is known to crack on a pretty regular basis and have very poor heat. I rebuld stock heat exchangers all the time and post them here, FB , and instagram. I take the rusted ones and fab new shroud areas as needed and even replace tubing as needed. They turn out pretty nice and much cheaper then new at $3500 and up. I typically can rebuild a set for under $800.

914-6werkshop.com is my instagram

I sold a few sets of the B&B and could not recommend them. Fit is a typical problem, and the heat shells are too small.

@mb911 I sent you a note

Replied



Everyone remember this. Larger primary gives more power up top and less down low so let’s say like 5k and above. Then ask yourself are you willing to give up all the TQ down low for that 1500 worth of rpm that you use what 5% of the time?

Guess I am lucky. Have had them on my 6 for a long time without any issues. Don't drive it when really cold so have no comments on the heat. Doing the Concours thing with it soon so bought stock headers from a member here.

I personally have never tried to use the B&B heat exchangers. But I have encountered them on a car.

The late Wes Hildreth had a six conversion in his shop years ago. The customer had bought B&B heat exchangers and wanted Wes to put them on. I helped him get them mounted to the heads. Once on the car, there was a 4" difference in the rear height of the pipes. Meaning the muffler, if you could have fitted it, would have been angled to the right. Wes took them off and told the customer to send them back.

Hope that helps.

Clay

On my 6 number 41

Factory Heat Exchangers with ceramic coating with extensive custom Heat Exchangers work by PMB Performance mated to a Dansk modified muffler in polished stainless with 2 in 2 out, O2 sensors on the heat exchangers for my fuel injection.

Best Bob B
Click to view attachment

WOW thanks for all the great replies makes the decision so much easier
zac

Running stock HE's on my 2.7 with CIS, 964 cams, bumped compression and slightly larger valves. Seems fine and I really like the heat stock HE's produce.

I can't believe how expensive these have become. Over $3K for a set and shipping in most places now.

don't buy new. buy used. I make a good part time living refurbishing the used units. just have to shop. I have one side on my website right now pretty cheap www.914-6werkshop.com