Blower Question

jrvariel48

jrvariel48

Well-known member
I have a Camden 9" blower and I would like everyone's opinions on installing it on a stock motor. I'm not looking to get full performance out of it, just a little.
I'm thinking 2-3 lbs. of boost? I'd like to know if this is do-able or if I'm asking for trouble. I've read some books that say it's possible, but I'd like to hear from the experts.
The motor is a 1946 59 with very low miles. It runs excellent with no smoke and the compression is at 100 lbs. or above on all cylinders. The blower is set up with a 600 cfm carb which I think will probably be to big for a stock application.

Please chime in.

Happy Father's Day to all the Dad's out there!

Thank you,

Joe
 

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I say go for it.
How's your compression ratio? Below 8ish to 1 will be fine with 2-3 lbs. I think that carb may be ok, it's a vacuum secondary so should be able to be calibrated to work fine, probably. You gotta remember the required air flow of a blown engine is higher than a naturally aspirated engine. Would look loads better with a pair of 94 or 97's or a early Rochester 4jet or WCFB.
Cast pistons will be fine with with that tiny amount of boost, as would the ignition. 2-3lb I feel won't require any "blower motor required" changes from a stock engine.
Just don't forget the oil line to the blower on they Camden huffers.
Martin.
 
Scooder, thanks for your response, it sounds very promising! I do have a pair of 94's I could add. I'm only guessing that my compression ratio would be the stock ratio. From what I've read, it's about 6.75? As far as ignition goes, it is necessary for a boost retard module to control detonation or will this not be a factor because of the low boost?
How about the stock fuel pump? I've run the dual 94's on an Edelbrock Slingshot on the stock pump.
Thanks again.
 
The CR of a stock 59 is probably 6:1 maybe even less. So I think you're golden. Now, besides the blower gearing, you'll have to do something with the ignition advance and maybe a hotter spark. Good luck, keep us posted.
 
If you have access to machine equipment to make some of the drive system components and such, it makes these mods more do-able. The 600 CFM is big. Somewhere around 400 CFM like the Holley 390 may be better.

The 9-inch blower seems kind of small according to their website. Most of the info is for Mazda rotary engines and 4-bangers so it doesn't tell you it's design capability like the GMC blower numbers do. It would be better to have one that can handle needs of a 240 to 290 CID engine without driving it too fast and I can't tell if the 9-inch Camden is in that category or not. The faster you drive them the quicker they wear out. You might check out Roadrunner Engineering's or H&H's stuff. Some of it is expensive but some isn't bad. The problems are always in the little details.
 
You should probably shoot for 5 lbs of boost or so - that will make a noticeable performance difference and won't hurt your engine at all. Flatheads really respond to superchargers - so you'll love it. The original SCoT blowers put out about 5 lbs - potentially 7 at times . . . and they were originally designed as a bolt on accessory for stock flatheads. I'd put a good exhaust system on the engine (headers), make sure you have a good hot ignition and set the advance a bit lower - I'd probably start with about 15 before TDC and go from there.

The 600 cfm carb will probably be too big - I'd go with a Holley 390 if you want to stay with a 4 barrel . . . or a couple Stromberg's. The easiest 'traditional' carb to use would be a Stromberg style - as they don't have vacuum operated power-valves. If you run the Holley 390, you may need to boost-reference the power valves - so they actually enrichen the mixture at the right time. Here is a little quote to think about:

The issue is at part-throttle, not WOT. The positive displacement supercharger will make pressure in the engine when there is vacuum between the carbs and blower intake.

The reason for boost reference is at part-throttle there can be pressure below the blower and vacuum above it. The power valve closes any time the pressure difference (vacuum) across the diaphragm and spring is great enough. Rig a vacuum gauge above the blower and a pressure/vacuum gauge below it and see for yourself. When the cylinders are seeing boost but the carbs are still seeing vacuum and PV’s are closed is when the “blower sneeze” occurs. The good thing with boost reference PV’s is when there is pressure, it pushes them open so they cannot partially close as vacuum climbs with RPM.


Here is a link to modifying a Holley for boost referenced power valves on typical Holley 4 barrels - can't say I've tried this on a Holley 94! :)

http://www.motorsportsvillage.com/modifycarb.html

The one thing you don't want to do is run it too lean, so pay attention to your jetting and if you can hookup an AFR meter for tuning, they can be a big help. Under full boost and load, aim for an AFR around 12.5 or so to 1. The last thing you ever want is detonation - it is the killer of engines (especially ones with cast pistons).

Once you're comfortable with the tune, then you might try to work with the timing and potentially lean it out just a bit (paying attention to the plugs and detonation) - maybe getting closer to 13 -1 - again under wide open throttle and full-boost.
 
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Ol' Ron said:
The CR of a stock 59 is probably 6:1 maybe even less. So I think you're golden. Now, besides the blower gearing, you'll have to do something with the ignition advance and maybe a hotter spark. Good luck, keep us posted.
Click to expand...

Ron, thanks for responding.
Will I need a boost retard module to control detonation?
Right now I'm running a crab distributor with a Pertronix set-up.
Can I get the advance & hot spark I need with this?
 
Dont forget to get three or four new sets of head gaskets. A friend of mine had this set up and he got real good at changing a head gasket.
 
I'll have more info after Horrelll's engine is on the road as far as ignition timing. He's running ab Edelgrock 500 modified for a blower, but I have no idea what they are, I think your in a learning curve. Be nice if you had an AF meter to go by. I have a bUICK 3.8 Blower on a homemade intakebut have never tried it.YET!!!
 
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Blower size,
The Camden 9" blowers capacity is 144 cu,
Weiand 142 and B & M 144 are same size,
Roadrunner regular set up uses the 142 Weiand.
So your ok there.
Ignition,
at your desired 2-3 psi, nudging the timing back a couple of degrees should be all that's needed. You could run a boost retard device and stock timing if you wanted. These retard the timing 1-2 degrees per lb of boost, I don't think you'll need it. The above mentioned SCOT used stock ignition.

Carb size,
I'd be surprised if your Holley couldn't be calibrated to work very well.

Boost reference power valve.
If you've got the 335 hp Joe abbins book, he dyno tested Holleys blower calibrated carb, that has a boost reference power valve. And reported no real difference on the dyno. His kits don't use these carbs. These boost reference carbs are a relatively new thing. I do fully understand the idea behind this, but can't dismiss the fact that before maybe 10-20 years ago this was a very rare modification,
thousands and thousands of blown motors didn't/don't use blower/boost reference power valves/metering rods. It would allow you maybe to run a leaner mixture at idle and cruise. Obviously this power valve talk is irrelevant to a 97 with its mechanical power circuit. This does make the 97 desirable as it doesn't sence load to bring in the power circuit, just your foot stomping on the gas has its power valve open till you get off it.

In conclusion,
With your desired 2-3 lb, in my opinion these "blower motor" modifications arnt needed. I'm not saying that they're a bad idea, these are well thought out ideas. I just don't think they're needed on your setup.
I do agree with Dale that 5-7 lb would be much more noticeable, like the original SCOT setup. Which didn't have boost reference power valves or boost retard. Using these boost referencing modifications along with an ignition that has both mechanical and vacuum advance taped into below the blower, will allow you to run more advance at cruise and a leaner fuel mixture. Which should deliver better mpg, which is always nice. We have to remember we're talking low boost street use here, we're not "pushing the envelope".
If you haven't got Joe abbins second book (the 335 hp flathead one" you should get it. Lots of relevant info in the book. Sure his dyno appears to be a very happy dyno, but as he uses the same dyno on all the test, the results are relative.

Think I've waffled long enough.
These are my opinions, not arguing, just discussing.

Martin.
 
scooder said:
Damn! That's a long post!
Sorry about that.
Martin.
Click to expand...

You and I suffer from the same disease . . . we tend to "over communicate"! What the Hell, I think it is better than under communicating - but some might disagree. :)

Always good to share ideas, experiences and knowledge - as best as we can.

B&S
 
Boost Referenced Power Valves: Just a few more comments to add . . .

The whole purpose of the power-valve fuel circuit was to monitor the vacuum signals coming to the carb and when the vacuum saw a heavy drop (like when you're under heavy load), then the power-valve circuit would open up and enrichen the circuit. What makes this more complex for a blower (or even a multi-carbed setup) is getting the right power valve settings (they are based on vacuum numbers) for the particular engine, cam and induction system - so they match up.

When you 'boost reference' a power valve, you're basically using the boost to force the power valve open - such that it enrichens the fuel at the right time.

There are other methods that were used before boost-referencing (with Holley carbs)

a) Take the power valves out (especially in the secondaries) - then one puts in bigger jets. This results in a much richer fuel mixture - ALL the time. While this will prevent detonation at partial throttle (as it is rich), it does result in less power (at partial throttle) and poor gas mileage.

This is what most folks did for racing situations - as they cared about WOT the most and didn't want to lean it out under boost . . . so solve the problems with jetting and get the dang power valves out of the picture.

b) Put High Number Power Valves In: Which essentially causes them to open up any time the vacuum drops much at all. This is kind of a work-around . . . as like the bigger jets, just enrichens the fuel a lot more of the time and with the right numbered valve, you ensure it is open when you're under WOT.

The bad part of BOTH of the above methods is that you end up with a situation where the engine is overly rich . . . too much of the time. The whole purpose of the power-valves are to have a load-sensing method that delivers the extra fuel . . . only when needed.

C) Do Nothing - Use the Power Valves That Come in the Carbs: This would be the most common thing that somebody who didn't know how to tune would do. In the end, the power valves are not open when they should be . . . so the 'solution' would be changing jets until it was rich enough. The 'fix' would not help you at partial throttle, but as long as it was rich enough at WOT, then the motor would not be hurt.
 
"Take the power valves out (especially in the secondaries) - then one puts in bigger jets. This results in a much richer fuel mixture - ALL the time. While this will prevent detonation at partial throttle (as it is rich), it does result in less power (at partial throttle) and poor gas mileage.

This is what most folks did for racing situations - as they cared about WOT the most and didn't want to lean it out under boost . . . so solve the problems with jetting and get the dang power valves out of the picture."

I have this setup on a Holley 4150 blow thru carb which uses a boost referenced fuel pressure gauge to enriched the A/F mixture as boost increases and vacuum disappears. For the proposed use of this supercharger running 2#'s of boost on an essentially stock engine is detonation really an issue? Missing from this build discussion is the OEM cam design which I wouldn't think would have the right profile to take advantage of a supercharger. It seems like the cam profile should be the starting point in a discussion of putting a supercharger on any engine. JMO.
 
The stock cam works well with a blower on a stock engine. With the short ex timing, there is no blow down at low rpms and the small amt of boost you have at 1500-2000RPM does more work. For this reason I like the the Eaton by blower, which is what the Magnasom system uses. On the 294 engine we have 300Ft/lbs of torque at 3000. Yhis should make an interesting ride. Boost is limited to 5 lbs.
 
expavr said:
I have this setup on a Holley 4150 blow thru carb which uses a boost referenced fuel pressure gauge to enriched the A/F mixture as boost increases and vacuum disappears.
Click to expand...

Just as an FYI, the boost referenced fuel pressure regulator in a blow-through carb setup (which is what I think you meant to say) - doesn't enrichen the A/F mixture as it really has nothing to do with that. The 'boost referencing' in this case is so that the regulator can actually do it's job (regulate) when there is boost pressure inside the carb. (It needs to overcome the pressure - usually at a 1/1 ratio with boost lbs). Otherwise you can get into a situation where the float needle is open and the boost is pushing air BACK into the fuel line - not good.

On an EFI setup, the problem is much the same, the boost pressure in the manifold is "pushing back" on the fuel coming out of the injectors and fuel rails, so additional fuel pressure needs to be added to compensate for this.

In both cases, the boost referenced regulator isn't richening the A/F ratio - more like making sure the fuel supply is consistently available under all vacuum and pressure/boost situations.

Hope my babble makes some sense. :rolleyes:

B&S
 
jrvariel48 said:
The blower is sitting on an intake for an 8BA. Can I install this intake on a 59 motor?
Click to expand...

Yes, though you may want to revisit the crankcase ventilation setup of the 59AB - and change the 8BA intake to match (oil fill at the back, fuel pump stand and pump off a 59AB, plug the side mounted breather tube on the 8BA manifold).

This isn't a super big deal, plenty of guys have ran 32-48 manifolds on 49-53's - and visa-versa, but I believe the crankcase ventilation systems on both engines are designed to work a certain way - and one should consider the breathing differences between the two designs.

With that said - there has to be thousands of flatheads that swapped manifolds back and forth and didn't worry about the crankcase breathing . . . and they worked just fine.
 
Bored&Stroked said:
Yes, though you may want to revisit the crankcase ventilation setup of the 59AB - and change the 8BA intake to match (oil fill at the back, fuel pump stand and pump off a 59AB, plug the side mounted breather tube on the 8BA manifold).

This isn't a super big deal, plenty of guys have ran 32-48 manifolds on 49-53's - and visa-versa, but I believe the crankcase ventilation systems on both engines are designed to work a certain way - and one should consider the breathing differences between the two designs.

With that said - there has to be thousands of flatheads that swapped manifolds back and forth and didn't worry about the crankcase breathing . . . and they worked just fine.
Click to expand...

With putting the oil fill from a 59 onto the 8BA manifold, which fuel pump rod will work with this set-up?

Thank you,
Joe
 
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