why no blowers in daily drivers?

bugsiegel

bugsiegel

Senior Member
I see some women wear their best diamonds when the leave the house but I never see a blown engine unless it's at a show.
It is price, wear, reliability, visibility, are they illegal, fuel economy, too much attention?
Do they have to be full on all the time?
Can they go the distance, will a blown engine make it across the country and back?
 
[FONT=&quot]Lots of good questions - I have a S.Co.T blown 59A Flathead in my stock bodied 35 Coupe.

For a higher performing flathead a blower aids in the bigger weakness of our beloved flatheads - breathing in an optimal fuel mixture under higher performance expectations - of course for reliability and performance - you don’t just plop a blower down on the intake side. As with any engine -all the aspects of the engine must be considered - i.e. each action has a potential reaction - so carburation, intake flow, valves, heads, ignition, exhaust and gearing must be considered for all to work well.

Cost is of course fairly steep for price of admission, and wear, economy and reliability are all a part of thoughtful full design, execution, maintenance and driver inputs.

At lower RPM the blower has minimal effect - as you get closer and closer to WOT the power climbs rapidly - so in a sense you can control economy with your right foot - and yes - they can they go the distance, and make it across the country and back many many times when consideration is given for all of the above.

There are many experts on this forum with far more knowledge and experience that I - so am sure will add much to your questions - perhaps oppisite of my thoughts - my comments are just my humble opinion as experienced running one on my little 3 Window Coupe.[/FONT]


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I do think this is possible and one of the tests I'll be preforming id just that. The Eaton blower is available at a very reasonable price they were available on Buick's since 1992 until the mid 2000 on their 3.9L engines. Unfortunately there isn't an intake available for them. These blowers work on a demand principle where the engine run under atmospheric pressures until Manifold vacuum drops below a predetermined value and you get max boost. This allow the driver a stock engine performance until he needs more power. I've built such a setup for testing and will pass along the results. These are also available from Magnason, They use a different blower , but operate on the same principal. Pics to follow.
 
I've got an A-V8 with a 6-71 GMC blower on it. I drive it on the street with no problems. I put a lot of thought into the set-up and it has turned out well. It has been together for about 20 years, and makes 12-15 lbs of boost max.
 
I've been thinking of putting a small blower on my '53 engine once it is done. However, I want to know the engine will hold up for a long time because I plan on driving the truck often. Something like a 3-71 or 4-71 I've been thinking about, with a small amount of boost. But if it means I'll have to upgrade a ton of internal parts and beef up the engine considerably I probably won't do it.
 
i have some blower experience and they can be reliable and long lived if done as a package. having said that ill never forgot what my dad taught me years ago,you can wear em out slow or you can wear em out fast,take your choice. rpms kill,my foot has a mind of its own.
 
Ol' Ron said:
I do think this is possible and one of the tests I'll be preforming id just that. The Eaton blower is available at a very reasonable price they were available on Buick's since 1992 until the mid 2000 on their 3.9L engines. Unfortunately there isn't an intake available for them. These blowers work on a demand principle where the engine run under atmospheric pressures until Manifold vacuum drops below a predetermined value and you get max boost. This allow the driver a stock engine performance until he needs more power. I've built such a setup for testing and will pass along the results. These are also available from Magnason, They use a different blower , but operate on the same principal. Pics to follow.
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Old Ron. The operating principle you describe is how the supercharger is setup on my engine (photo attached) in a daily driven car. Under normal street operation the engine runs naturally aspirated on the carb's primaries. As engine vacuum decreases the valve bleeding off the supercharger's boost closes at which time the 6#'s of boost is sent to the engine. The trick is maintaining engine RPM to stay on the torque curve without getting into it and making boost. (For some reason my 73 year old brain and legs don't communicate like they used to.) As you know CR, Cam design and Boost all play a role in making a supercharged engine street friendly. Another equally important element in balancing performance and fuel economy is getting the power to the ground. In setting up my car as a driver I used an automatic transmission with O/D and 3.73 gears. In retrospect I think any supercharged engine that produces good low and mid range torque coupled to an O/D trans a better compromise might be 3.54 gears. Just food for thought when you get around to the actual build.
 

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expavr said:
Old Ron. The operating principle you describe is how the supercharger is setup on my engine (photo attached) in a daily driven car. Under normal street operation the engine runs naturally aspirated on the carb's primaries. As engine vacuum decreases the valve bleeding off the supercharger's boost closes at which time the 6#'s of boost is sent to the engine. The trick is maintaining engine RPM to stay on the torque curve without getting into it and making boost. (For some reason my 73 year old brain and legs don't communicate like they used to.) As you know CR, Cam design and Boost all play a role in making a supercharged engine street friendly. Another equally important element in balancing performance and fuel economy is getting the power to the ground. In setting up my car as a driver I used an automatic transmission with O/D and 3.73 gears. In retrospect I think any supercharged engine that produces good low and mid range torque coupled to an O/D trans a better compromise might be 3.54 gears. Just food for thought when you get around to the actual build.
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Ya need to leave those shoes with the lead lined soles at home.... :D
 
I like your set up expavr, you take "Dare to be different" to a new level.
PeterC gives some good tips and I will expand on what he said. I have a 6-71 on an overhead (yes, it's a Chevy) but this discussion needs all the input it can get so I will add my 2 cents.
Any short block for a blower application should have a quality piston; I'd invest in forged pistons and a modern ring package, rebuilt rods done by a competent shop and pay close attention to bottom end clearances and the oiling system. In my case I run 8.7-1 compression, but it is an overhead, I'd keep a flathead in the 6.5 to 7-1 range. I run my blower at 15% underdriven and it is a bit on the loose side, never more than 7 lbs. boost and it has two 600 Holleys on it with direct linkage, not progressive. The total timing is set at 28* and I run a fairly conservative camshaft with .445 lift and 222* duration @ .050. Reliability has never been a problem, I have not driven cross country but have gone to Oklahoma City two times from the Chicago area and done numerous other long distance road trips and never had any problems.
Build a reliable short block, maybe with the L100 cam that many here like, add the blower and start up with a reasonable amount of total timing, sneak up on the best total advance, not too much right off the bat. I would probably go with a 600 carburetor, but even with two Holleys on mine and direct linkage I have no concerns. Mileage on the road has been 17.5 mpg with 3.36 gears and a 31" tall tire. The engine will run like a stocker at idle and in normal driving; only when you give it some serious throttle will it get enough air to build boost and at that point hang on! Read all you can, plan out a good combination, and build for the street- leave the hard core race stuff and gearing out of the picture and you will see that performance, reliability and mileage can be had in one package.
 
Thanks for the input, yes we need more people to address this kind of project. In my case the engine is stock and the boost will be in the 3-5 lb range the blower has a 2:1 overdrive, the same as the Buick.
 
These pictures were taken along tim ago at my other shop. I'll up date them when I install it on the present engine.
 

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Hi Everyone, I spotted this car on the field at the EFV8 National Meet in Hiawassee last summer. The day after I took the photos, I found myself having lunch with the owner, a really nice fella from Albuquerque. He has a restoration shop and they did the car and engine. He'd driven from ABQ to Georgia and was driving back. He said she'd do 70mph all day long and I don't doubt it. I don't recall the guy's name, but here's a couple websites for his shops. He had some good stories about the folks/fools who bring him cars to restore.

-VT/Jeff

http://www.worldwideautomotiveinc.com/
http://www.oldcargarageltd.com/

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Used a GM pulley and bored it to fit the ford crank. Have 2:1 and 3:1 OD. Blower Max RPM is 14K. Would like 3-5 lbs boost between 2500 and 3500 RPM. Engine is stock.
 
I like blowers, and I love flatheads, so this is what Im currently working on.
 

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Ol' Ron said:
These pictures were taken along tim ago at my other shop. I'll up date them when I install it on the present engine.
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Its hard to tell from the photos how the runners are setup on the intake manifold but with the carbs mounted to the back it seems like the front cylinders might run somewhat lean when the blower's boost is vented at cruising throttle settings. Have you noticed that happening?
 
Do you guy come across the little SC14 Toyota blowers.. Cheap N easy.. You cant rebuild them as such as the bearings are set and glued in.. The blades are basic and flat but if you dont rev them the're fine.
I used one on a 192 Ci inline 6 I had [Holden 186 red motor] with a 465 Holley [modified] Damn it went hard !!
Ive still got one under the bench and Im eyeing it off for the flattie..
 
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