452 CID 409 W/ Bob Walla Heads & Speed-Port 7000 Intake

[61 Bubble]

I'm new with these motors, so with people saying he did well, and the intake "looks" like it's doing well, I must conclude that this is pretty respectable.

I do know it "seems" to be down quite a bit from the "Sherman 434" that Jim's had?? I haven't compared specs, but I believe the the smaller 434 was quite the little motor. I myself use that engine as a "gauge" to where similar builds can be. I seem to think the SMALLER 434, with less bore diameter (to un-shroud the valve, therefore increasing flow), lesser heads, less compression lesser intake design, yet make considerably more then this????
I'm confused. Is the cam holding this 452 back that much??? There pretty close are they not. I would think this motor would have been in the 625+ range fairly easily???

 

[yellow wagon]

I too use the Sherman engine as inspiration for a future build. I have a stock bore 348 truck block sitting here and some other goodies. The plan will be to do a 434, big solid roller, Eagle H Beam rods, Diamond pistons etc. This project will be a ways out but I would be shooting for 600hp+ for sure. Aubrey's intake would be great for it. Would love to run Bob's heads on it but like usual my ideas vs. my wallet are continents apart so we'll see. I also had thought about doing a procharged, 333-headed motor too

 

[Don Jacks]

I'm also guilty of using that engine as a "benchmark" for what CAN be done.Especially when it comes to the 4 bolt main conversion in the early blocks.This engine didn't have it done [as far as I can tell from the article],yet after all the dyno testing,and a years worth of competion in Jims 55, at rpm levels of 7200 or so,Jim posted that there were no main bearing "fretting" issues in the engine.

 

[Dr Richard Kimble]

I bought one of these intakes last year , so I was very interested in the results . I haven't dyno'd mine yet , because of guys on this website , which persuaded me to swap out my flat tappet hydraulic cam , for a hydraulic roller , which I'm waiting on now .
I phoned aubrey , to see if he had more info that he could tell me about the combination that he just tested .
seems that he too , was quite disappointed with the results . they did run out of time to do any jet changes or anything , and apparently the engine went WAY lean above 6000 rpm , and actually bubbled the coating on the headers . he was concerned that there was a fuel delivery problem to the carb . was too late , day was over . in addition to that , he was disappointed with the lower rpm torque . The time they tested the 6000 intake , there was a much broader torque curve , that had substantially better numbers than the other intakes , throughout the entire rpm range of the pull . this one didn't really show up until 4500 .
well , he just had his pattern maker take about 3/16" tapered to 1/16" off the height of the intake runners , he figures this little bit , will be enough to improve velocity in the mid range , yet sacrifice nothing up high . I hope he's right , sounds like his foundry is in the process of doing a munch of castings now . his comment about this intake as it is , was that these first 19 7000's , are best suite to the big 480+ cubic inch engines .
one other thing , the talk of an intermediate port for the non stroker engines , sounds like the core boxes are already being prepared , and yes , it's called a 6500 . that one may be the answer for street cars

 

[Don Jacks]

The 6500 is what I'm going with for my 380.

 

[1961BelAir427]

I too use the Sherman engine as inspiration for a future build. I have a stock bore 348 truck block sitting here and some other goodies. The plan will be to do a 434, big solid roller, Eagle H Beam rods, Diamond pistons etc. This project will be a ways out but I would be shooting for 600hp+ for sure. Aubrey's intake would be great for it. Would love to run Bob's heads on it but like usual my ideas vs. my wallet are continents apart so we'll see. I also had thought about doing a procharged, 333-headed motor too

I'm also guilty of using that engine as a "benchmark" for what CAN be done.Especially when it comes to the 4 bolt main conversion in the early blocks.This engine didn't have it done [as far as I can tell from the article],yet after all the dyno testing,and a years worth of competion in Jims 55, at rpm levels of 7200 or so,Jim posted that there were no main bearing "fretting" issues in the engine.

Another thing about the Sherman engine build is that it really made the power they claimed and wasn't just a "happy dyno" magazine article number. It PROVED itself at the track in the '55.

 

[jim_ss409]

I think the best time I ran with that engine was a 10.37 I do recall that it was a fairly warm day. I figured that the car may have gone a tenth or two quicker on a cool day.

That engine did have quite a few little things that bumped up the power. Aubrey's engine was more streetable so it didn't have some of these things.
The Sherman engine had very thin, low tension rings and a vacuum pump. (that can be worth quite a bit of power on a high revving engine)
The heads were ported and so was the intake.
It also had a total of 3 inches of open spacers.
The cam was also bigger than the one Aubrey used. The specs in the article aren't quite right, I'll dig up the cam card tomorrow but I think it was 266/270 @.050 108 LSA. The intake lobe was an XHL series which is fairly aggressive and I think the gross lift was around .750"
Aubreys cam was..."Gentle ramp, street mechanical roller, .694" net lift, 260 / 264 @ .050"
The Steffs pan also had a kick out which is also good for some power on a high revving engine.
It also had an electric motor running the water pump.

All that stuff adds up. I think if you put the bigger cam, ultra light rings, vacuum pump and kick out pan on Aubrey's engine, it would probably make as much or more power.

Here's a link to the article on the Sherman engine...
I should also mention that the lifters listed in the article are not right. I can't remember the number of the ones it had off hand but they weren't the +.300 lifters listed.
http://www.hotrod.com/how-to/engine/hrdp-0911-chevy-w-series-engine-build/

 

[1961BelAir427]

You make some very good points Jim

 

[Dr Richard Kimble]

Jim , the vacuum pump? what effect does it have?

magazine / news articles ,
there's always a few bloopers

 

[Don Jacks]

The purpose of the vacuum pump set up is to remove the crank case pressure,thereby stabilizing the ring seal.A good set up for a dyno queen,or all out competition engine,but not very long lived such as a street engine would need.This engine might last two seasons before it would need the rings replaced.Another thing was that while Aubreys engine didn't tell us what size carb was used,this engine used 2x750 or 1500 cfm worth of carbs.Aubreys engine,while as you posted,was not jetted properly due to time constraints ,was designed as a street engine,while this one was more of an "Engine Challenge" type.Apples and Oranges comparison wise.If Aubreys engine had been able to have been jetted out properly,there was more than likely,25-40 more hp on the table.

 

[jim_ss409]

Here's a quote from Joe Sherman from the Speedtalk forum...

"Custon pistons with narrow, back cut rings and gas ports can be worth over 50 horsepower when used with a vacuum pump"

I'm guessing a 50 hp gain would be on a high revving engine in the 1,000 hp range, but I wouldn't doubt that the thin rings and pump could add as much as 30 hp to the stroked 348 he built.
I gather that installing a vacuum pump on a typical street engine will gain you next to nothing. Apparently the biggest benefit is to the vacuum is that it allows you to run ultra light piston rings.
The thin, low tension rings free up quite a bit of horsepower but without vacuum they won't seal well enough and the extra blow by will erase any of the potential gains.

The Sherman engine did have low enough compression to run on pump gas but it wasn't what you would call a street engine. It also wasn't a full race setup. I'd say it was a bracket race style engine. It's very close to what many of the 348/409 racers are running.

 

[1961BelAir427]

It would be very interesting to see the Sherman 434 with a set of max compression pistons like the Diamonds that Dan had made, another 10 to 15 degrees of duration, and a tunnel ram up top. I think it would be an easy 725 HP with no other changes.

 

[61 Bubble]

It would be very interesting to see the Sherman 434 with a set of max compression pistons like the Diamonds that Dan had made, another 10 to 15 degrees of duration, and a tunnel ram up top. I think it would be an easy 725 HP with no other changes.

I think that would be in the ball park.

 

[Dr Richard Kimble]

not without raised port heads

 

[61 Bubble]

Jim on these type of engines, I think IF you got 20Hp from a vac pump your doing good. On our NMCA Hot Street 360, the pump was worth 28/30 at 9300. But that was also with Q16 fuel and 0W2 oil. That little in-line Ford went from 862Hp to just over 880.

As well, the "typical" street style motor will gain NOTHING from a vac pump. Unless you build your motor FOR a vac. pump, it usually cost power to run the pump. The BIG motor draws about 20 lbs on an electric vac pump, but that's over 1900Hp N/A. Just know that these motors are built FOR the pumps and are purpose built for there intended usage.

Now to me, the problem with these motors seems to be intake track and low rev'ving? To make the upper power ranges that motor make today, they use RPM and lift. These motors do not seem to respond well to hi RPM????

 

[61 Bubble]

not without raised port heads

WHY? The "EDDY" heads made 650 NOW! So I think that motor might have picked up 30/40 or so with just the better intake, let alone compression and cam'ming to it's potential.

Check out Aubrey's post on the 6000 intake and what he made more then the EDDY intake then on his mild 409 in the wagon!!!

 

[Dr Richard Kimble]

Truly amazing, bubble... 637 and 656 HP with Eddy heads!
what I would give to study what was done to THOSE ports and intakes!
big a$$ carbs too
however , I believe that they have absolutely hit the wall , with how far a standard port location can go .

yes, of course I saw the old thread on the results of the speed port 6000 intake . I think much of the reason for those dramatic results , was that the severely ported small port heads , and conservative build , catered perfectly to the inherent limitations of the engine design . As you just mentioned , the big rpm is not necessaraly where these things want to go .
It was interesting to note just how stable and flat the torque curve was on that engine , even with that aggressive single plane intake . To me , it says that whatever was done to those heads , IS the way to do it .

 

[61 Bubble]

I agree, that Speed Port 6000 build was pretty good and seem to fit that intake perfectly.

As for Sherman motor, I think that those heads are pretty well max'ed out too. But I would have loved to see the Speed-Port intake on that motor for a comparison? I think it would have picked up quite a bit still. I still hold to the fact that another 70Hp "could" have been pulled out of that motor, but maybe 14-1 comp, BIG cam and the Speed-Port. But that's my thoughts.

BUT that is why I'm a little "miffed" by this 452? Made about what a stock LS-6 would make with headers and cam change. I also feel that EITHER of the BWR heads are superior to the Eddy's as well. 660-720 should be able to be had with the BWR heads, maybe even a bit more on a well thought out 440-480 inch motor.

 

[Ishiftem]

The Obsolete Missile II ran 9.80s at 3600 pounds and under 450 cubic inches. That was with his brothers modified 690 heads and a modified 881 intake. They did run original z-11 stuff and the 690s were faster, though I don't know how much was done to the z-11 stuff and the 690s were heavily modified. That was almost long enough ago to be considered a history lesson. I can't imagine what Tony could do with today's technology.

 

[BSL409]

I agree, that Speed Port 6000 build was pretty good and seem to fit that intake perfectly.

As for Sherman motor, I think that those heads are pretty well max'ed out too. But I would have loved to see the Speed-Port intake on that motor for a comparison? I think it would have picked up quite a bit still. I still hold to the fact that another 70Hp "could" have been pulled out of that motor, but maybe 14-1 comp, BIG cam and the Speed-Port. But that's my thoughts.

BUT that is why I'm a little "miffed" by this 452? Made about what a stock LS-6 would make with headers and cam change. I also feel that EITHER of the BWR heads are superior to the Eddy's as well. 660-720 should be able to be had with the BWR heads, maybe even a bit more on a well thought out 440-480 inch motor.

I doubt you will ever have 14.1 comp and a big cam in one of these W engines almost in possible