Good read as always

Thanks Ryan

Your threads are the most interesting on this site. Not that others are boring it just that I love the technical and empirical aspect of building engines. In another life I would love to do the work you do.
Thanks

Ryan, the 364" W-5, was that a Quick Fuel carb?

Ryan, thanks for the pics and post always very imformative.

Pfft, only 4 dyno sessions in one post? Geez- when are you going to post something of interest on here

Great post and info Ryan. Other than the execution I don't see anything wrong with those headers, they actually look like they're designed pretty good. I build anti-reversion into my headers at the flange/tube. But, I wonder if that is adequate? I would like to look up the peice Larry Mieux posted on speed talk. Where shall I look? This must be Hamacher's (spelling?) motor for the Valiant?

Ryan, every board member should thank you for devulging this type of information. Very few engine builders would ever do this---most want to keep their work "Black Magic".

I just want to make a comment about headers and W7/W8 heads. We ran them for years on dirt engines. And we built most of the headers too. Never use anything smaller than 1 7/8". We also found those heads didn't like 2" either. We found our engines(from 358" to 410") perferred 1 7/8" to 2" STEP headers. But the 1 7/8" section out of the heads shouldn't be too long---around 8-10" worked best. Schoenfield produced the best "store bought" header for the W7 and W8 heads.

We also built Tri Y headers---and they work! But, their design is very critical and only use the very best "Merge" collectors. Our best Try Y header used 1 7/8" primary, 2" secondary merging into a 2 1/8" with both merging merging into a 3.5" collector. A lot of trouble to build but does help a small engine.

All of this is a little ancient history since our last W8 engine was about seven years ago. We use only P7 stuff now and we only race in Nostalgia events.

this is some really interesting info.
I just want to say youre the man Ryan.

im not lookin for the golden knee pad award,but ryans threads are killa...also knowing my 59deg stuff made the power it did compared to w7 makes me just know i went to the right source and will continue too

I have seen similar results with custom headers myself. One example a 331 cube Ford Windsor that ran faster with the exhaust on, and a 340 Chrysler that was just down on power.
After trying jet and timing changes, changing carbs, even lash while we were at it on the Ford engine we threw on a set of off the shelf headers with the same primary size and diameter collector. Picked up around 30hp. Bolted the custom headers back on and added some length to the very short collectors and picked up most of the gain made with the shelf headers.

The 340's headers just plain had the wrong sized collector which we were able to make custom collector extensions for to get a reasonable number out of it.

Those custom headers shown and Ryan's dyno headers have a look at how different they are, especially note how the tubing exits off the head.

& here is same motor with the TTI W2 header on, this is how was ran in the car, went 9.87 @ 137 @ 3260 LBS. This is probably about same HP loss as AWBDART is seeing with his 1 7/8 TTI's on his INDY head 440. 25-30 HP. & then bolt on full exhaust out the back of car... dunno how much more that would kill... probably another 10-15.

Been there done that with the header comparison . Went from 1 7/8s tti's to 1 7/8s hedmans and gained a consistent tenth and 1.5 mph. Its true...

ok, so what off the shelf w2 street car style header makes the best power? i'v been using the 1 7/8 TTI,but been thinking about getting something different. i'v had two pairs of TTI's and when looking into the collector notice on both pair the tubes to be different lengths where they come together in the collector. does'nt look right. every pair of hookers i'v looked in are all even.

Finally looked at this. So, you saw visible reversion evidence in the intake of the freshend engine? I ask this, as usually, an A, B, A, comparison, is the benchmark of diagnostics. Not trying to be an A S S. I have an invested interest, as my intake manifold and exhaust side shows heavy reversion.
Thanks,
Leigh