Jason,
I know my engine guy has built a few Z11 and should have the flow numbers from them I will check with him and see
Z-11 vs BBC
- Thread starter jim_ss409
- Start date
I know my engine guy has built a few Z11 and should have the flow numbers from them I will check with him and see
Thanks Brian. Don't go through any trouble. It's just a curiosity thing.
Those have a kinda oval'd rectangular shape. I think the term "Roval" is used in the big block chevy world to refer to the Edelbrock and other manufacturers who have developed heads with ports in the oval port size & position, but with that shape.....almost square with rounded corners.
These things were way ahead of their time in my opinion.
Too valuable to ever do it, but it would be great to see what one would do with the stock displacement & compression, but stronger rods. Good induction and headers. If they made 540 to 550 on the dyno back when they were new with nothing but headers, I bet that they were easily capable of 700 HP with a better intake and a roller valvetrain with no other changes from stock.
Bev
Active Member
Jim Bev Bodkin here I bought your trailer a while ago. Read Smokey's book Sex Lies &Superspeedways he wrote just before he died.
He talks a lot about the mystery motor & the guy who did a lot of work on it Dick Kensith spelling? The heads are very similar to bb
But he complained they ruined his design when they released the bb. The mystery motor was designed for racing I think.
The bb went back to passenger car, truck, high performance, COMPROMISE! Sure would like to have achance to play with a mystery motor
head ! Saw a mystery motor at Woodward GM display. The heads are physically smaller than bb. I think that was the racing motor we
commoners missed out on !!!!
He talks a lot about the mystery motor & the guy who did a lot of work on it Dick Kensith spelling? The heads are very similar to bb
But he complained they ruined his design when they released the bb. The mystery motor was designed for racing I think.
The bb went back to passenger car, truck, high performance, COMPROMISE! Sure would like to have achance to play with a mystery motor
head ! Saw a mystery motor at Woodward GM display. The heads are physically smaller than bb. I think that was the racing motor we
commoners missed out on !!!!
I have to say, this is my first time reading this series of posts on the Z-11. I also have to say that I have been a member of other forums that have nothing to do with cars (.45 autos and WW1 Aviation), that had/have some very knowledgeable members. That being said, the knowledge expressed...... and experience that members have on this forum is stunning.
The Z-11, quite frankly, is my ultimate goal in 409 ownership and one that most likely will never happen. I would settle a Z-11 upper half on a high performance lower half, but that will probably never happen either. So, to that end, I read all the Z-11 posts like this with more interest than my "reading" of Playboy back in the day..... The openness and casual discussion of not only this topic, but all subjects presented for us on this forum, is incredible and has tremendous value to a novice like me.
I know as much about WW1 USMC Aviation as anybody I know, and was a "source" for helping others in their collecting in this extremely rare field. I was one of the go-to guys in this field. The preservation of the artifacts that still exist, in my mind, is paramount. The information found on this forum and the openness of those that are willing to help those like me who love these motors and cars, are to be commended for helping us to preserve these "artifacts"...... I wish I could sit down with all of you and have a beer and listen and learn.
Thanks Guys,
Dennis
The Z-11, quite frankly, is my ultimate goal in 409 ownership and one that most likely will never happen. I would settle a Z-11 upper half on a high performance lower half, but that will probably never happen either. So, to that end, I read all the Z-11 posts like this with more interest than my "reading" of Playboy back in the day..... The openness and casual discussion of not only this topic, but all subjects presented for us on this forum, is incredible and has tremendous value to a novice like me.
I know as much about WW1 USMC Aviation as anybody I know, and was a "source" for helping others in their collecting in this extremely rare field. I was one of the go-to guys in this field. The preservation of the artifacts that still exist, in my mind, is paramount. The information found on this forum and the openness of those that are willing to help those like me who love these motors and cars, are to be commended for helping us to preserve these "artifacts"...... I wish I could sit down with all of you and have a beer and listen and learn.
Thanks Guys,
Dennis
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I think the Stock Z heads flowed about 320 and Tony Schafer got them to 355. The first set of aluminum heads we ported flowed 363.
I ran my Z parts for many years but never wanted to port them, just to see what you could get out of them with a stock stroke.
Bob
I ran my Z parts for many years but never wanted to port them, just to see what you could get out of them with a stock stroke.
Bob
Dennis, what I know about the Z -11's I found out here. Something of interest, Fred Totten told me while he was racing somewhere in Califonia he raced and beat a Z-11 engined car. Fred ran a 11.95 with a stock stroke 409 in his 62 Impala "So Sadd" tuned by none other than Hayden Proffitt. The people that owned the Z-11 car were so upset that they killed the story somehow and Fred never got credit for that race. Fred showed me a picture of his car with the hood up at Hayden's shop. Not any relevance to this thread but a good Fred Totten story.
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Regarding Smokey Yunick, many years ago I had an occasion to visit with him one on one. He exuded his typical "I don't give a Sh-t attitude when I approached him. After "breaking the ice" a little, we began to discuss the Mystery Motor. He definitely was not happy with how Chevy treated him.
He drew out the valve design and where they should have been, how they were canted, diameter, etc. As I recall, while he liked the fact that the general design was better than the 409/Z-11, it could have been so much better. He was not happy with head bolt placement, valves, push rods and probably more based on his attitude. There was no doubt, with his engineering genius he believed what he wanted to do was far better than what they did. Then Chevy did the unthinkable.....they quit racing!!!!
While he was a wealth of info, it was crystal clear he was not happy with Chevy and he was through with me.
I politely thanked him and got out of "throwing distance".
He drew out the valve design and where they should have been, how they were canted, diameter, etc. As I recall, while he liked the fact that the general design was better than the 409/Z-11, it could have been so much better. He was not happy with head bolt placement, valves, push rods and probably more based on his attitude. There was no doubt, with his engineering genius he believed what he wanted to do was far better than what they did. Then Chevy did the unthinkable.....they quit racing!!!!
While he was a wealth of info, it was crystal clear he was not happy with Chevy and he was through with me.
I politely thanked him and got out of "throwing distance".
I think I read somewhere that Smokey wasn't happy with the way the BBC evolved from the mystery motor.
Apparently he thought the smaller main journals used on the 409 and mystery motor were better than the larger journals they used on the BBC and I think there were some changes he would have liked to have seen on the BBC.
Then again, I gather Smokey was a hard guy to please. When the Smallblock Chevy first came out someone from GM approached him about racing it and he almost turned them down.
When he first looked at it he didn't think it could ever be useful for anything more than hauling groceries, but after looking it over more carefully and looking at the relatively light weight of the 55 Chevy he figured maybe he could make it work,,, and the rest is history.
Apparently he thought the smaller main journals used on the 409 and mystery motor were better than the larger journals they used on the BBC and I think there were some changes he would have liked to have seen on the BBC.
Then again, I gather Smokey was a hard guy to please. When the Smallblock Chevy first came out someone from GM approached him about racing it and he almost turned them down.
When he first looked at it he didn't think it could ever be useful for anything more than hauling groceries, but after looking it over more carefully and looking at the relatively light weight of the 55 Chevy he figured maybe he could make it work,,, and the rest is history.
You can have all the Hp in the world, trick is getting it to the ground.
61 Bubble
Well Known Member
Now that "THE JIMS" have one of these that I can look at in person, I will see if that changes my mind. But I still think in a power/performance ONLY situation, the BBc still has an edge. Now if you put these Z-11 against the BBc "race oriented" engine, the ZLX and not the production L-88. LS-6 type motors, the performance can really get going in the BBc favor in my humble opinion, SORRY.
I just have a hard time, from solely power point of view that these rare and expensive motors and hang with the PRODUCTION BBc?? Example, I have a production ZL-1 going together that I'm hoping to have on a dyno by spring. Will run on pump gas, use GM block, heads AND INTAKE as Jim posted here in this thread, OEM dual-plane, and we are looking for OVER 800Hp. I have seen some impressive builds on here with Z-11 stuff that are up to 755Hp, but these are usually stroked engines and higher compression too. I know a 496 (1/4" stroked 454) with OVAL port heads has been in the 850Hp range. The pump gas version made 780Hp and in a 3580 Lbs of a friends, went 9.20's. Not to bad for pump gas and OEM oval ports.
BUT with this being said, I also think its the fact there has been more R&D on the BBc then the W motors in the last 20 years too. There still pretty stout these W heads, neat and cool for sure (that is why I'm buy a 409 too) but if I was going for just shear Hp or performance, I still think a BBc has the advantage and that's without the aftermarket heads, then it's a whole new ballgame the W's can even begin to close the gap on,
SORRY just my opinion, John
I just have a hard time, from solely power point of view that these rare and expensive motors and hang with the PRODUCTION BBc?? Example, I have a production ZL-1 going together that I'm hoping to have on a dyno by spring. Will run on pump gas, use GM block, heads AND INTAKE as Jim posted here in this thread, OEM dual-plane, and we are looking for OVER 800Hp. I have seen some impressive builds on here with Z-11 stuff that are up to 755Hp, but these are usually stroked engines and higher compression too. I know a 496 (1/4" stroked 454) with OVAL port heads has been in the 850Hp range. The pump gas version made 780Hp and in a 3580 Lbs of a friends, went 9.20's. Not to bad for pump gas and OEM oval ports.
BUT with this being said, I also think its the fact there has been more R&D on the BBc then the W motors in the last 20 years too. There still pretty stout these W heads, neat and cool for sure (that is why I'm buy a 409 too) but if I was going for just shear Hp or performance, I still think a BBc has the advantage and that's without the aftermarket heads, then it's a whole new ballgame the W's can even begin to close the gap on,
SORRY just my opinion, John
John,If I remember correctly ,the 63 Mystery Motor [the first rat] had close to a hundred hp edge with one carb. over the Z-11 with 2 carbs.I don't think that anyone here disagrees with your opinon,especially given the devlopement time on the rat motor.It's just that the rat dosen't have the cool factor of a 409.
I had no immediate dealings with a 409 as an impressionable teen, in '78 I was 16 and grew up reading super Chevy.409s and the hey day of the LS 454s had come and gone,but the legend of chevys W,the horsepower wars the era of the factory lightweights....the win on Sunday,sell on Monday, the writings of Doug Marion,tales of the first Stahl headers ever built,names like strickler,Jenkins,try to sneek this one by Lamar Walden,Vince Piggens(hope I got that one right)Hayden Proffit......this could go on and on......it was just a very captivating(romantic!!!!!!)time period.flat head Ford's dont make much for power,but I (Sorry jmo)find it and the 409 equally as sexy from a nostailgic perspective.now imagine being 16 in 1962(I can)
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