Serpentine Belt Conversion

[minifridge1138]

Hello everyone,

Can someone recommend a good Serpentine conversion kit?
My 82 only has A/C, Power Steering, and Water pump.

I read that switching can give an increase of 30 hp and 25 trq.

Any advice will be appreciated.

Thanks!!

 

[KANE]

Hello everyone,

Can someone recommend a good Serpentine conversion kit?
My 82 only has A/C, Power Steering, and Water pump.

I read that switching can give an increase of 30 hp and 25 trq.

Any advice will be appreciated.

Thanks!!

Hmmmmm. Not sure about the HP increase from V-belts to serps... but moving to electric fans would give some increase in power to the engine.

 

[JohnZ]

You'd need NASA-level instrumentation to see any difference in power absorption between V-belts and serpentine belts; for a $1,000.00 belt conversion, you'll see ZERO benefit. You really need to stop believing the marketing hype in the Jeg's and Summit catalogs. Not flaming you, just pointing out the facts (which you're unlikely to see in their advertising).

 

[Crimson Thunder]

If the new serpentine conversion comes with underdrive pulleys you will see a horsepower increase but 25 HP seems a little optimistic.Just remember with underdrive pulleys your water pump spins slower(overheat in traffic?) and the power steering might not work as well.

 

[petes74ttop]

Too much madison avenue hype, and little truth to there claims. PG

 

[Vettehead Mikey]

If the new serpentine conversion comes with underdrive pulleys you will see a horsepower increase but 25 HP seems a little optimistic.

The flaw in all this advertising is that the engine accessories don't actually consume much power to start with. If the water pump and power steering only use 1 HP each, it's going to be pretty difficult to recover anything worthwhile.

 

[Evolution1980]

I agree with everyone so far. Those claims of increased power are bunk. Even underdrive pulleys likely don't give you claimed power. But I have 'em cause they look pretty. :L
If you go to a serpentine system, you'll have to get a new water pump as well, as the serp systems spin the water pump in the opposite direction of what currently is.

I personally am not keen on the serp system for my car because I don't like the idea of having a single point of failure for everything. I actually have redundant belts running to my water pump because that's the most critical part of the 'accessory' system. (Broke the belt one time and spun it off another time.)

 

[AKRAY4PLAY]

take a look at March Pulley. they have kits that are designed for the small block that utilize the standard rotation water pump. they run about $500 thru summit or jegs. the kits look great and work well. the only complaint i have with mine is the power steering cap is tucked under the waterpump mount to the block. i had to trim the cap to clear the waterpump. i do have an Edelbrock aluminum high volume pump, so it does have a little extra meat on the mounting legs compaired to the stock unit. but it worth mentioning. the other part of your question, as to power gain, is correct. underdrive kits do free up power to put to the ground, but it's not worth it. in order to get the 25 hp extra, you need to slow your power steering, water and alt pullies down about 35%. this is not good for street driven cars, so i'd stick closer to stock ratios. there are special kits thru March that slow down the power steering and alt, but speed up the water, or any combo of the fore-mentioned acc units. the kits don't cost any more, but are not really advertized. it would be best to call March and let them know what you want and get the real answer from the horse's mouth.

as for HP losses from the acc systems, it is large. look no farther than the old Gross HP ratings compaired to the Net HP ratings. the LT1 is a perfect example, same engine configs over several years that were rated under the both gross and net rating systems. the the biggest drop in HP was from running the acc systems under the net rating. also look at crate motors, they are still rated under the gross system, since they are not part of a car and do not have to have acc systems this leads to higher HP numbers. the same config engine in a production car has much lower numbers.

 

[Hib Halverson]

The idea of gaining 30hp from an 82 by converting to a serpentine belt system is laughable. You won't see much change, if any at all.

Most serpintine systems drive the water pump opposite the direction a v-belt system does, so you'll have to change water pumps. You'll also need to change cooling fans (because of the change of direction) or, better yet, swtich to electric fans.

Where a serpentine system will be a plus is in belt reliability/durability but you'll need to drive that 82 a long way to see the difference.

Lastly, don't put underdriven pulleys on that engine. The alternator already runs slow enough at idle and you won't have enough power steering pressure.

 

[Evolution1980]

Lastly, don't put underdriven pulleys on that engine....you won't have enough power steering pressure.

That caught my eye. (Obviously)

What exactly are the symptoms of a p/s pump without enough pressure? How can one easily measure the p/s pump pressure. Can it be easily done?

 

[Vettehead Mikey]

underdrive kits do free up power to put to the ground, but it's not worth it. in order to get the 25 hp extra, you need to slow your power steering, water and alt pullies down about 35%.

So you're saying to gain 25hp, you need to slow them down by 35%. That means that to run them at 100% speed would take 75hp? hnoes

Assuming that each of the three takes an equal amount of power, a non PS car should therefore have 25HP more available?

If you turned off all the lights and other electrical toys in a car to lessen the load on the alt, would that give you another 25hp?

Not picking on you but the assumption that it takes 75 hp to run the accessories is ummm, maybe stretched a little.

 

[Crimson Thunder]

I just reread the Chevy High Performance article that started this thread.The motor they tested the pulleys on was a 360hp(at the wheels)383ci small block.I'm wondering if the underdrive pulleys are more beneficial in a high HP car.I had underdrive pulleys on a 5.0 mustang once and hated them.The AC didnt blow as cold,the power steering took more effort,and the car ran a little hotter in traffic.Myadvice,find a HP gain elsewhere.

 

[AKRAY4PLAY]

So you're saying to gain 25hp, you need to slow them down by 35%. That means that to run them at 100% speed would take 75hp? hnoes

Assuming that each of the three takes an equal amount of power, a non PS car should therefore have 25HP more available?

If you turned off all the lights and other electrical toys in a car to lessen the load on the alt, would that give you another 25hp?

Not picking on you but the assumption that it takes 75 hp to run the accessories is ummm, maybe stretched a little.

it does not work quite that way. the water pump takes the majority of the power, mainly because it is hooked to the fan. the power steering, alt and a/c all take different amounts of power. you can test the parasitic losses two ways. find a dyno shop testing a motor and test it with and without accs. and the other way is when you decide to replace your acc belts, cut them off and drive it without any belts for a short rip down the street. then install belts and test under same conditions. anyone that has ever lost the acc belts while driving know how much power is gained in the short time when not turning the accs. i'll try and find some articles on the subject for you.

 

[Vettehead Mikey]

it does not work quite that way. the water pump takes the majority of the power, mainly because it is hooked to the fan.

Beg to differ. Most Corvettes have a clutch fan which -when operating correctly- allows the fan to virtually free wheel when not required.

When fully engaged (really hot engine), a typical fan will absorb ten HP, at engine red line. I don't know many people that frequently red line when their engine is hot enough to require the fan to kick in. The ten horsepower number came from actual dyno testing, results available at another popular Corvette website.


In another recent string here, the poster mentioned that his electric pump consumes 6 amps.

6 (amps) x 12(volts) = 72 watts.

72 watts = approx. 1/10th HP

Even if the GM pump is horribly oversized and inefficient, it would not be with a factor of 10.

For a parrallel example, most home swimming pools use a 1 HP (745 watt) pump. The flow and pressure from such pumps far exceeds any pump on a SB or BB engine if you've ever had an outlet hose come loose.

I did happen to lose my water pump belt a few years ago, good thing I was watching my temp gauge, there were no other signs...........

 

[JohnZ]

The difference between the old "gross" hp rating method and the later SAE "net" method has little to do with the accessory drive (the water pump requires 2.26hp at max flow, and a charging alternator requires less than 0.4hp - those are the only two accessory drive items mounted during the "net" test). The main differences result from using production exhaust manifolds, pipes, and mufflers instead of a power-extraction (zero backpressure) exhaust system, the production advance curve instead of advance settings optimized for each test rpm point, and production carburetor jetting instead of jets and rods optimized for each test rpm point.

All the hype about power increases due to the serpentine conversion is 99% marketing crap; the amount of power absorbed by the SAE "net" accessory drive is statistically insignificant. I think the same guys write the serpentine ads who write the ads for the "Tornado FuelSaver", the "Nuclear-Magnetic Clamp-On Fuel Molecule Straightener", and all the other useless junk out there designed to lighten your wallet. :eyerole

 

[minifridge1138]

My question has been answered.

Thanks everyone.

 

[Crimson Thunder]

This has been a fun thread.

 

[boss64]

Just ran across an article in this months CHEVY HIGH PERFORMANCE magazine. The article is titled "Dyno Proven Bolt-ons". The magazine did the dyno test with before and after figures for different products. The test on a serpentine conversion with underdrive belt produced 30 hp and 25 lb-ft peak. The average numbers were minus 6 lb-ft and plus 15 hp.