61 Bubble
Well Known Member
So very true. That is why I AM getting a '09 for my '61 still.
What all the other posts get "likes" but MINE DIDN'T lol.
Z-11 vs BBC
- Thread starter jim_ss409
- Start date
So very true. That is why I AM getting a '09 for my '61 still.
What all the other posts get "likes" but MINE DIDN'T lol.
Took the words out of my mouth well except in '78 I was 5.
That's very impressive!
You certainly wouldn't match that with a Z11. 
I guess the thing I was thinking about when I started this thread was that the W motor and the Z11 in particular had a lot of untapped potential.
It would have been neat to see where they could have taken this engine with a little more R&D. A better intake manifold would have done wonders for the Z11.
I don't think that it would have come close to matching the BBC's potential, but I would have loved to see what they could have done with the 409.
The BBC sure is the smart way to build big power for drag racing these days. There's almost no limit to the power you can make with those engines.
I feel like if you took a Z11 built to stock specs EXCEPT a roller valvetrain and better intake and compared it to a crate bbc such as the ZL1/L88/LS6/LS7 with no other changes to it except the same roller/intake upgrade. All other parts remaining OEM......I bet the difference would not be that great. I am not talking about "blueprinted" engines such as Super Stock efforts where they can run 10's with a 2 barrel 327 with "stock" parts either.
My uncle has a 70 Monte Carlo with it's original LS6 in it.It was using some oil at about 50,00o mi.in 1978,so I pulled and rebuilt it with ALL GM parts.Given that I can't leave well enough alone,it was "blueprinted" to exact factory specs,including degreeing the cam.This engine makes 515 hp at 6200,with open 2 in. headers .With a modern roller cam,and improved intake,I could see an easy 600 hp here.We have to run av gas,or race fuel in the thing now due to the compression,and the original cam,but it'll blow the tires off when punched at 60 mph.
It went back into the car with the stock manifolds and looks just like the way it did when new. When new,it was clocked at Tallegada at 162 mph with a 3.31 gear,it's faster now,but I don't know by how much.
It went back into the car with the stock manifolds and looks just like the way it did when new. When new,it was clocked at Tallegada at 162 mph with a 3.31 gear,it's faster now,but I don't know by how much.
Funny, when we all went to Clay City Kentucky, the original 348/409 Fred Totten race. I remember some of the locals didn't exactly welcome us with open arms and had very little regard for the 409's that were there. During the time trials however some of our very first 348/409.com members handed those locals their ass. It did change a few guy's opinions that day. I remember one guy in a 57 Chevy Belair with a big block that was particularly ornery. He actually tried to run me down in the pits. Remember guys?
Yes, I remember that. It was a nice looking car with a brand new 502 but the guy was a dick.
I like to think us 348/409 guys change opinions wherever we go.
I just dug up an article from the Aug. 2008 Super Chevy. (the same issue that Aubrey's car was featured in)
http://www.superchevy.com/how-to/engines-drivetrain/sucp-0808-nhra-stock-eliminator/
Anyway, a blueprinted stock eliminator L88 BBC made 650 hp.
They are allowed to use headers and any cam duration as long as they stick to the stock lift,,, .560/.580 in this case.
The heads must be unported but a better three angle valve job is allowed. The stock compression must also be used. A little over 12.7 to 1 in this case. With the overbore and stroke allowance this engine would be about 44o ci.
This engine went into a Corvette that ran the quickest pass ever clocked in stock eliminator at that time, (9.747) so this is obviously a good example of the potential of a factory BBC.
So if this 440 ci BBC made 650 hp, what could a fully blueprinted 440 ci Z11 do??? Keep in mind that you're allowed headers and any cam duration, gapless low tension rings etc.
Would it make 550hp? or maybe 600?
I'm sure the Z11 wouldn't make as much power as the L88 but I think it would do better than many people would think.
I agree Jim. Also, if you were to take that Stock Eliminator L88's heads off (even though they are built to spec and un-ported) and swap on a pair of out of the box from GM heads for that L88 - or even a pair of old unported ones that have been rebuilt at the local machine shop with a 3 angle valve job - it would drop a lot of horses off of that 650 HP number. Even though those heads are blueprinted and unported, there are so many "tricks" they have. That is why a pair of heads built to "Stock" specs will cost you a major chunk of change compared to just new castings or rebuilt heads.
Is he saying that the "heads like the Z11" that were later issued for Nascar use and only used on 409's were not the same castings, but just similar heads? That doesn't sound right. I'm probably just interpreting it wrong.
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That's interesting stuff Pat. 
I'm guessing he was referring to the Z11 style heads.
Here's a picture of one of the single carb Z11 style intakes. I think they're very rare.
I'm guessing he was referring to the Z11 style heads.
Here's a picture of one of the single carb Z11 style intakes. I think they're very rare.
Below is the Chevrolet document out of the engine plant Tonowanda, NY. Notice the recap is dated from 8-20-62 through 7-31-63 and captures all of the engines they built for the various assembly plants. There are obviously more engines than jus these. I chose the page with the Z-11 engines. Here you can see the total of 50 Z-11 engine assemblies shipped for installation in the 50 cars, not 57.
There were additional cars that raced as Z-11's but they were built by ordering the components from a Chevy dealership.
There were additional cars that raced as Z-11's but they were built by ordering the components from a Chevy dealership.
This page shows 20 Z-11 half motors built and were sent to the National Chevrolet Parts Warehouse for subsequent replacement parts for the 50 cars that were built. I do not know how many heads, intakes, valley covers, water pumps, etc. were built. While no one really know we can see there were only 70 engines or partial engines built. No matter, the number remaining is incredibly small.
Hope this helps in some way.
Hope this helps in some way.
Oh, interesting to note on the list of engines built for some reason Tonawanda built 2 1962 RPO 587 409/409 engines.
I remember back in the 1960's while working at a Chevrolet dealership in Ft Worth, Texas we would get in a stripped car, interior, engine, transmission, etc. sometimes the insurance would pay for the rebuild if it had not been stripped too bad. I imagine these 1962 409/409 engines would have been special order engines to fulfill such an order. There would be no reason to order a 409/409 when the 409/425 had just been released. Can't think of any other reason.
Just thought this was interesting.
I remember back in the 1960's while working at a Chevrolet dealership in Ft Worth, Texas we would get in a stripped car, interior, engine, transmission, etc. sometimes the insurance would pay for the rebuild if it had not been stripped too bad. I imagine these 1962 409/409 engines would have been special order engines to fulfill such an order. There would be no reason to order a 409/409 when the 409/425 had just been released. Can't think of any other reason.
Just thought this was interesting.
All these heads, intakes and valley covers that were pre Z-11 were different part and casting numbers. When Chevy launched the RPO Z-11 option for 1963 they applied different part numbers. Most of the pre stuff was the "0" casting numbers, very limited production.
I think I am sure I have shared before, but I was talking to a retired Chevy Engineer and mentioned to him how I had a couple of sets of "0" casting heads and top ends. He immediately went from being very engaging and informative to combative!!! He told me in no uncertain terms that no "0" casting parts were ever to be released to the public and they were for experimental and testing purposes only! He then began to ask me where I got them, how long I have had them, where did the other person get them and on and on. I immediately began to politely end the conversation! While I admire his loyalty and wanting to preserve what they had developed internally, I did not have the heart to tell him that all that pre-Z-11 stuff had actually been shipped to the drag racers of the day as part of their agreement to race for Chevy. Obviously he was following the corporate line, but everyone else was out to win races, no matter how!
As for the single 4 intake, I can check the casting date, I'm positive it was a 1962 casting
I think I am sure I have shared before, but I was talking to a retired Chevy Engineer and mentioned to him how I had a couple of sets of "0" casting heads and top ends. He immediately went from being very engaging and informative to combative!!! He told me in no uncertain terms that no "0" casting parts were ever to be released to the public and they were for experimental and testing purposes only! He then began to ask me where I got them, how long I have had them, where did the other person get them and on and on. I immediately began to politely end the conversation! While I admire his loyalty and wanting to preserve what they had developed internally, I did not have the heart to tell him that all that pre-Z-11 stuff had actually been shipped to the drag racers of the day as part of their agreement to race for Chevy. Obviously he was following the corporate line, but everyone else was out to win races, no matter how!
As for the single 4 intake, I can check the casting date, I'm positive it was a 1962 casting