Blk63Vette

Hello
I have a friend that has a SY1 intake on his 1967 Camaro. He has a 327 Chevy block out of a 1968 Corvette. He has a 850 Holley carburator on top of it. I like the way the intake looks. He LOVES this intake and swears by it. He says its for higher RPM this intake was designed for..I was wondering is this a good "street" intake? I was thinking of putting one on my 327 300hp Corvette maybe with a 750 Holley carb..

Im sure at least a couple of the forum brothers have opinions about this intake...Good idea or Bad idea??

Thanks

wmf62

just a 'rule of thumb'; anything that is 'good for high rpms' is usually not good for normal street use, whether it be cams or intakes..
Bill

mechron

hi blk63, wmf is right. i have an origonal SY1 i bought several years ago off fleabay. i bidded to the moon and payed the outragious price of $370!! a good deal today. i haven't run it on my car yet as i'm doing a body off resto-mod right now. the "bling-wow factor" was worth the price.

the SY1 is basically a cross ram manifold. there are 2 flavors of this manifold, the few origonals cast up by smokey (the one that i have). and the later offenhauser ones (they bought the rights to produce it), they are pretty much identical except that the smokey manifolds are rough on the outside and the offenhouser ones have a big "offenhouser" like 2-3 inches cast into the drivers side top plate.

these manifolds are not street friendly as smokey designed them for NASCAR and road racing. the huge plenum will kill low speed torque but will shine at higher RPMs. the rumored Z-28 cross ram manifolds that were (alledgely) delivered in the trunks of the first cameros as a racing option (john Z, what's the real story???) were they an offsoot of the sy1. i have never seen a a Z-28 racing manifold in real life but have seen pics, it looks like a copy of the SY-1.

i'm going with smokey's origonal manifold and am working around the the loss of low speed torque by going from a 327 to a 383 stroker high compression engine with 64 CC alumium heads.

if you can find one of the SY-1 manifolds you better be good at crose jetting that holley. after haveing tuned hollies to different manifolds for decades i have got pretty good at it.

i'm so confident i can make the SY1 work on the street that i gave away my C3BX to asstrodokk (watch out asstrdokk, i may break in your garage door and kill you and steal my manifold back)

anyway, asstrodokk is coming over today (sat) and hopeferily bring over his camera and take pics of the SY-1, the origonal cast sy-1. i think you would like to see it

aworks

I'm putting the Offy one on my 69 vette. I'm using the dual quad top like the Z28's. On a stock 300 hp you may make ok low end with that intake.Your cam is pretty short on duration. I'm depending on gears to make up the low end. I have a few high winding small blocks so I can live with the low end torq. You can buy the Offy new and still get the single quad top. Much better than trying to find a good orig. Smokey one. I wish I had one, even if I didn't use it.

MikeM

A friend here ordered a new '68 Z-28. Dark Green/blk vinyl top. Cross ram and factory headers.

He came up short on cash so the dealer had the car on the showroom floor for a short while. The headers and cross ram WERE in the trunk and best I remember (don't take this to the bank) the price of the cross ram and headers was listed on the window sticker. Or, it could have been listed on a supplementary sticker. In any case, the price for the two options was clearly visible.

As far as the stuff being in the trunk, it seems likely to me the intake setup and headers came through the parts department and added to the car trunk at time of delivery. The parts were placed loosely in the trunk when I saw them.

Blk63Vette

Well, Im not that good at tuning Holley carbs. I know there is alot of history with this manifold and alot of mixed reviews and questions.

I was thinking a 750 Holley on it...My friends says nothing less than a 850 Holley..I want it to be somewhat street friendly. Be able to use todays gasoline at the pump. I LOVE the way it looks. Im a Smokey Yunick fan.

thanks
Pete

P.S Yes I would like to see a picture of it...I was wondering if it will fir under the stock hood of a 1963 Vette

silver67

Im sure at least a couple of the forum brothers have opinions about this intake...Good idea or Bad idea??

I had a borrowed SY1 on my 69 Z28 302 with an 850 holley double pumper and a 1 inch spacer. No problems except not a lot of vaccum for repeated power brake stopping. I modified inside the chamber with some 1/2 inch walls for lack of better terms per some article of the day. I think it was supposed to keep the fuel from sloshing around while cornering. Definetely a high RPM manifold though. With a 373 rear had no problem taking the speedo up to MPH. It was fine on the street, it was my daily driver. The 302 was not known for low end grunt and I wouldn't put that combo in front of an automatic. I use to just wind it up and feather the clutch. Has a lot of Cool Look Factor.

Blk63Vette

there is that cool factor. I read that it is not a "streetable" intake. That it would "bog down" with my 327 300hp 4spd and only mod was lil more radical camshaft in it. I never actually torn down my engine to see whats exactly in it. The previous owner of the car told me what was inside my engine. So, when it comes time to rebuild I will have a better idea what Im dealing with. Also hood clearance issues im concerned about on a stock 63 Corvette hood. I was hoping someone already had one in their Corvette and tell me the "ins" and "outs" with this type of manifold.

mechron

pete i don't think it will fit under a stock 63 hood, i glassed up a cowl induction hood scoop on my 64 hood to pull cool high pressure air in from the base of the windshield. i am going to use a 750 holley on mine, so your 750 holley guess is right on... i also plumbed in a nitrous system to get more HP. i will try to get astrodokk to post some pics tonight of my setup along with pics of his 383 stroker build we are doing.

edit--> my car is a 4 speed, 4.11 car as is dokks. so low speed torque is not that much of an issue.

Astrodokk

Hey Blk63Vette,

I'll be taking pics of mechron's setup today and post later this evening. I always thought his intake looked awesome, and now I know why. Anyway, good for me since he then gave me his Edelbrock C3BX dual plane to replace my Torker. Although we've been told that it is way old school, the price is right for now.

Ron, burglars are gonna have to get past my neighborhood watch nosy old ladies, then my outdoor wireless security system, then my indoor alarm system, then my cat, then my locked and bolted bedroom door, then my Mossberg 500 shotty, then my 357 Magnum, then my Bowie knife, then my hand to hand combat before they can take anything. Besides, we're all dead anyway. The next life will be the good one!

PS If you ever want the intake back, just ask and that will give me the excuse to put the Torker back on and get a wilder cam for better race trim rather than polite street vehicle.

Blk63Vette

I want to see your setup when its all done...I was thinking a 750 holley carb..Mine has 3.73 and is also a four speed...I have the SY1 intake..But, I think it needs a gasket and some studs with nuts..

Cool

Astrodokk

Ron's Smokey Yunick 1 intake manifold:

L79vette

The Offy is a close copy of the Z/28 manifold. The Z/28 manifold was engineered by Chevrolet. The SY1 has much shorter runners than the Z/28. I sold the Offys for a few years through an Ebay store. Summit now stocks them.

Here's a decent article with pictures of the Offy and GM manifolds:
http://www.camaros.org/crossram.shtml

I have an Offy on my 327 under a stock small-block hood. A little manifold lid machining was required, and had to trim one of the hood support ribs a bit.







I have a 235-degree @ 0.050 cam headers, 4.11 rear end w/wide ratio Muncie. These things all help make the manifold work. Two 390-cfm double pumpers - you want to keep the carbs small. 780CFM of total flow is way more than enough for my engine. It works well, but is a project to set up for sure.

L79vette

Notice also how the SY1 has a taller but narrower plenum. The GM & Offy pieces hang over the valve covers a bit.

It's pretty clear they were designed with different philosophies. The Z/28 guys say the runner length on the GM manifold was designed to give a resonant ram effect at 7200RPM. The SY1 runners are so short that I don't see how they can resonate at any reachable RPM. I don't doubt that it works OK, just don't understand the science behind it. Notice the ridges cast into the base of the GM and Offy manifolds - they are to even out fuel distribution.

Found an interesting article on a build of a 333CI small-block with AFR heads and cross-ram:
http://www.superchevy.com/technical/...dyno_test.html

Another good historical article on the GM stuff:

http://www.yearone.com/enthusiast/re...amz28/z-28.htm

JohnZ

The headers (if ordered with the car) were delivered in the trunk (in '67-'68 only), and were also available over the parts counter. The cross-ram setup, however, was ONLY available over-the-counter as a complete kit in a single box; it couldn't be ordered with the car, and was never stocked at the factory.

MikeM

Were the headers listed on the MSRP supplied windown sticker?

The car I saw had the headers just laying loose and there was the intake box in there also. It was all just laying loose.

JohnZ

Yes, if the headers were ordered with the car and supplied from the factory - they showed as RPO Z283 on the sticker. The cross-ram kit was P/N 3940077.

Headers for Norwood-built cars were made by Kustom Equipment Co. in Flint, Michigan, and headers for Van Nuys-built cars were made by Bill Thomas Race Cars and Douglass Mufflers in Anaheim, California.

jerrybramlett

Edelbrock had an installation instruction sheet that they included with each "Smokey Ram" when it sold new. I got a xerox of one from Edelbrock when I lived in California during the eighties. The sheet included carb advice down to jetting suggestions. You might be able to find one posted on-line now.

There was also a good article about the introduction of the Smokey Ram in a 1968(?) edition of Hot Rod magazine. I've got that somewhere too, but I don't remember if it has any tuning suggestions. I do remember Yunick's comment from that article though. It was something like: "This manifold will gouge the eyes out of the other designs if you set it up right". I always thought that was a strange way to put it. I think he was implying it was a performance turd in the hands of a beginning mechanic.

wmf62

Smokey was a strange man....
Bill

Blk63Vette

This one has some modifications inside like u are talking about on each side inside of the manifold I bought this off of Flea bay.