Smokey Yunick SY-1 Intake

[autogear]

Smokey would be proud to see the SY-1 with EFI bungs

[levisnteeshirt]

smokey talks about it in his book ,, he added some dams ,, its in the book ,,, I saw one run on a 406 in a vega ,,, it seemed to run well ,, against anything else ? don't know

[BlitzA64]

I ran one in the 80's on my circuit boat. I had issues at first, I called Smokey and told him the problems and he said "you have a spacer under the carb" He said it would not work correctly with anything other than a regular thin gasket. I had to grind a spot on the lid for the linkage and stagger jet the carb but after that it worked great, lots of mid range. I still have it on the shelf.

[Tuner]

I ran one in the 80's on my circuit boat. I had issues at first, I called Smokey and told him the problems and he said "you have a spacer under the carb" He said it would not work correctly with anything other than a regular thin gasket. I had to grind a spot on the lid for the linkage and stagger jet the carb but after that it worked great, lots of mid range. I still have it on the shelf.

Thank you for that important bit of information.

[RL]

I remember working on one and straight away I knew it wasn't great.

It's basically a cut in half squashed down tunnel ram that has to have double the plenum volume because it's two separate species mashed together.

Way too short runners - very high rpm work only -

And massive plenum that makes fuel distribution a problem at low rpm - modern sheet metal high risers have carb barrels lined up with the runners.

[Tuner]

I remember working on one and straight away I knew it wasn't great.

It's basically a cut in half squashed down tunnel ram that has to have double the plenum volume because it's two separate species mashed together.

Way too short runners - very high rpm work only -

And massive plenum that makes fuel distribution a problem at low rpm - modern sheet metal high risers have carb barrels lined up with the runners.

Apparently you missed the fact this manifold was designed for a specific racing class restricted to a single carb and stock appearing sedan hood line, such as SCCA Trans-Am in the early ‘70s. It only gets criticized by wankers who try to use it in a street application for which it was never intended and are too busy to read the instructions Smokey provided about carb selection and stagger jetting and adding some distribution dams in the plenum. People who are capable of following Mr. Yunick’s advice have good results.

[amc fan]

Their is one on Ebay now with bungs welded on for EFI aimed at ports for a little over $400.... under the listing SY1

[mtrhead]

Few things I haven found after I bought one (two) to try:
The #1 #3 port doesn't line up well on more than one intake I've had. The divider isn't lined up (casting shift?). I bought a second one because I thought something was wrong with the one I had. The port opening size is about felpro 1205 which is small for current crop of aftermarket heads. Fine for small cc hoeads or original double humps.
The ports go at the head off angle - surprised I've never seen anyone post on that. I did weld up the recommended redirection walls for reference. I have yet to finish because of the port mismatch and work required to get to a 1206 size exit. Maybe someday.

[RL]

Actually the runners are longer than I remember from 25 years ago. Looks like a 7500rpm on the 3rd

A customer bought one back then at a swap meet for $50, only because it had Smokey's name on it, and after working on high end sheet metals I knew straight away it wasn't good for what he wanted.

I can see that Smokey wanted something with longer runners, so as to use the more powerful 3rd harmonic, but it still doesn't explain the massive plenum. It's like he fell into the dyno trap where if you add more plenum volume you make more power, but didn't see that it just reduces driveability.

I'm sure it was the bees knees back in the 70's, but that probably because no one knew better at the time.

Apparently you missed the fact this manifold was designed for a specific racing class restricted to a single carb and stock appearing sedan hood line, such as SCCA Trans-Am in the early ‘70s. It only gets criticized by wankers who try to use it in a street application for which it was never intended and are too busy to read the instructions Smokey provided about carb selection and stagger jetting and adding some distribution dams in the plenum. People who are capable of following Mr. Yunick’s advice have good results.

It kind of proves my point if Smokey had to modify his own design to make it work.

Basically you can make it work with a lot of effort - injected would fix that plenum distribution problem - but from a performance stand point, why would you when nearly anything is better these days.

The sooner we bust the myths, the sooner we can advance.

[Tuner]

Actually the runners are longer than I remember from 25 years ago. Looks like a 7500rpm on the 3rd

A customer bought one back then at a swap meet for $50, only because it had Smokey's name on it, and after working on high end sheet metals I knew straight away it wasn't good for what he wanted.

I can see that Smokey wanted something with longer runners, so as to use the more powerful 3rd harmonic, but it still doesn't explain the massive plenum. It's like he fell into the dyno trap where if you add more plenum volume you make more power, but didn't see that it just reduces driveability.

I'm sure it was the bees knees back in the 70's, but that probably because no one knew better at the time.

Apparently you missed the fact this manifold was designed for a specific racing class restricted to a single carb and stock appearing sedan hood line, such as SCCA Trans-Am in the early ‘70s. It only gets criticized by wankers who try to use it in a street application for which it was never intended and are too busy to read the instructions Smokey provided about carb selection and stagger jetting and adding some distribution dams in the plenum. People who are capable of following Mr. Yunick’s advice have good results.

It kind of proves my point if Smokey had to modify his own design to make it work.

Basically you can make it work with a lot of effort - injected would fix that plenum distribution problem - but from a performance stand point, why would you when nearly anything is better these days.

The sooner we bust the myths, the sooner we can advance.

The sooner you quit making myth to suit yourself the better off all will be. Smokey had the distribution details in his design and Edelbrock deleted them after the first few because the foundry struggled with the casting. The details are in Smokey's book and several old magazine articles written in the era.

[RL]

Carb Cross Rams were all the rage in the 70's, but none of them lasted much past that.

It was a technical dead end, that's why they aren't used these days.

It doesn't take a genius to see what he did. He split a tunnel ram in half and squashed it flat, and then tied them together with a common plenum. And it was the large plenum spread flat that was the mistake.


Fuel distribution wasn't that well known back then, but that is totally accounted for these days - angled runners, split Dominators -


Smokey was fighting with what was an inferior engine compared to the opposition, so he tried to cover up the lack of flow with the old more plenum volume spacer trick. Unfortunately it looses driveability, hence the single plane became superior.

I was at Edelbrock when we made those.. they MIGHT have potential, but no one could seem to make it work very well.In my own experience, it did NOT drive well at low RPM ( below 4000 ) and was not any more power than the other manifolds we were making at that time.. Do not get too excited about it

JOE SHERMAN RACING

Joe had trouble with it, and he's a genius.

I was never able to get the Edelbrock cross ram 2 carb setup to run worth a crap on the street or the drags but I had no dyno back then either. That would have been approximately in the late 60s, jetting it right was a nightmare

More problems

It's about 50-50 just from this post, but no one was saying they were winning with it.

I'm sure I could get one running right - it needs injection or a lot of stuffers so stop fuel drop out, unless it only runs at 5000rpm+ - but why when I can spend less time on something better.

Even if you don't build a lot of manifolds, it's just common sense what's wrong.

It's the basic "The Half-Life of Facts" phenomena.
Stephen Hawking is a genius, but nearly everything the theorised has now been proven wrong.
It's normal to think things change with time as we learn more - even Smokey said that -.

[Tuner]

I agree with you, things are more like they are now than they ever have been and that includes how smart people think they are.

It's worth one more time on the hope it will sink in, the manifold was made to fit a racing rule requirement demanding a single 4-bbl and a stock appearing sedan hood line. Your argument for Dominators and a tunnel ram would not get you out of the scrutineers' paddock.

[crazyamc]

I vintage race my '69 Camaro ex A-Sedan car.... I always considered the '70 Trans Am season as the pinnacle year due to Chrysler joining the fray. In my first race, my car number was 30 (my age at the time).... and the Camaro is restored to the '70 TA specs, including a SY1.... I'm 51 now, the same 302 that started this craziness has been through one set of rings, bearings, and a fresh set of Brezynzski heads, all under the SY1.. It's strong, correct, fast, (not Cobra Automotive fast, they're crazy!) but will continue to run up against the 8K chip as it always has... and I fully expect it to continue to do the same in June at Indy with SVRA- that;s a winner in my book! Come out- you'll love it! Ken

[miniv8]

I have one of those, and if I were to use it I would build two tops for it and run it as two separate intakes on a single manifold, like so:

[BrazilianZ28Camaro]

I have a article here from back in the day called Smokey HI-Pressure 302. They claim about 500 HP with a Cross ram intake and two four barrels.

This another one is from a magazine, 482HP 302" FWIW:

http://www.hotrod.com/how-to/engine/ccr ... ro-engine/

Sooo looks like they make some power.

Tuner, don't be upset by few here, everybody knows your expertise and vast experience in carburation and induction systems.