Has anyone here used these pulleys on an early small block. I just got a set that underdrives the crank and waterpump. I am gonna use a standard alternator pulley. Has anyone heard or experianced cooling system or charging problems. Any advice is apprectiated

All the ones ive installed before have had problems charging the battery when the head lights or other loads where on and power steering can suffer when you make u-turns.

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70 camaro 307 (350soon) /350th

I'm running a set on my '68. Three groove crank, two grove w/p and alternator. I had to space my p/s pump forward better than an 1/8" to align it with the crank pulley. I tried two different sets to get it this close!!

The power steering is definitely a little sluggish at idle speeds and the charging voltage goes low as well. (the "GEN" light never comes on but the voltage is down to about 12.5V!) I have a Comp 305H in my engine so, it really doesn't idle that great below 1000 RPM anyway!! I have converted to the integral regulator alternator, and even idling at 1000 RPM it's shoveling S*&T against the tide with these pulleys.

I haven't had any cooling system problems, most people believe that the stock engines ran the water pump too fast anyway! I also have a radiator on my small block big enough to cool a 502!! (heat is not your friend in traffic!!)

The March stuff is super high quality and I've never thrown a belt since installing them but, their applications guide is all f'd up and you will definitely lose some accessory performance at low speeds.

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Paul D.

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68RS, 331, 10.5:1, 4spd, 3.90 9", lowered, 245-45-16's all 'round

[This message has been edited by PDQUICK (edited 11-29-2001).]

Everyone that I know who used them had cooling problems but it does get hot where I live. If the weather is not to hot in the summer you might get away with it.

[QUOTE]Originally posted by chevyboy68:
[B]Has anyone here used these pulleys on an early small block.

All:

New user here. Never posted before. Hope new people welcome. Underdrive works ok in Arizona, but I have twin electric fans sealed to an Aluminum radiator. My opinion is "try it". What the heck, we only live once (atleast here on earth right). I have a proposal for anyone interested, I'm seriously considering selling the Meziere electric water pump (in box still) and the associated March Alternator mount (drivers head) which accomodates the Jayco PS setup. I ordered a procharger kit and must use standard water pump for the belt routing. Let me know if anyone is buying themselves a Christmas present....

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1966 Chevy II

I have March crank pulleys on both my cars and dont have any problems. My 91 has a volt guage and it does go below 12vts when it idles low 600rpm, but I idle it at 800rpm and its at 14vts http://www.camaros.net/forum/biggrin.gif

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67RS CAMARO - STREET CAR, 502 PUMPGAS, HYD. ROLLER, TH350 w/ATI 10" 12-BOLT w/373 ET= 10.47@129 60FT=1.55 ~ ON MOTOR, ET-STREETs w/MUFFLERS
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DAILY DRIVER: 91 B4C CAMARO, 305TPI, TREMEC 5-SPD, 342 GEARS, K&N, CRANK PULLEY, EDELBROCK HEADERS, FLOWMASTER, ET=14.1@98 60FT=2.06
SOON TO BE 383 W/ SUPERRAM

I have to chime in here on this subject, I have reseached and written articles on this very subject and even designed and currently manufacturing a line of products in this area. WE have dynoed this very subject matter and can back it up with paper and other corroborated articals from other sources.

First of all, the claims of major hp gains with underdrive pulley is bogus to most extent. High quality components are not the horsepower eaters of yesteryear's and a typical underdrive set will only reduce a fraction of a hp at best!!! Take a Stewart Components high flow waterpump for example, it only takes around 2 hp at full tilt and a typical alternator will only eat up a little over a hp at full rpms under most circumstances. You risk losing cooling capacity (more flow is better in all cases...there is no such thing as too much flow) and also electrical generation at slow and idle is severely hampered. Most alternators put out less than 25 amps at idle (1750rpms shaft speed at least) and slowing them risks slow cruising battery discharges.....I have seen a lot of them personally with underdrives. And actually, you should be overdriving your waterpump for the street for the maximum cooling effort and the prevention of hot spots especially.

Go to http://streetrodstuff.com/Articles/March_2001/Top_Ten_Cooling_Tips.php for more no nonsense information on cooling and if you want more try what I think is another excellent site at http://www.stewartcomponents.com/tech_info.htm .

The bottom line is that there is no reason for underdrives anymore and for those of you that have them don't go rushing off to change just for the sake of change, especially if you are cooling okay. Actually, a switch to a hi performance afterrmarket pump such as Edelbrock, Stewarts, or Tuffstuff will add more hp to the engine than the switch to underdrives.

I will hand it to March....there stuff looks great and is well made, but there claims of all this hp savings is a real push.

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STEVE JACK
ConceptOne Pulleys and Brackets
http://streetrodstuff.com/Products/pics/thumb_198_1.jpg

[This message has been edited by HOTRODSRJ (edited 11-29-2001).]

They look nice but the only vehicles that I've actually seen a performance improvement on is on smaller motors (imports). Also the part about flowing too much coolant can be a problem because it can scavenge for coolant at high RPM's and that can cause it to run hot. It doesn't happen on all cars but it does happen on some and sometimes it is better too have an underdrive pulley to lower the speed of the water pump so it can still flow at high RPM's. Just my thoughts on the way I see things. Everyone has their opinion and thats mine.

RYANMAN.....I don't know what you mean by "scavenge for coolant at high RPMS"?

If you mean that cavitation can take place at high RPMS (which is literally sucking until the pressure is so low on the suction side that it forms air......that has all to do with the internal design of the cooling system, the pump and moreover the working pressure the system is carrying. Alot of poorly designed systems and pumps will do this if not watched carefully. Most high performance water pumps today with a minimum of 14lbs of pressure will not cavitate until well over 8000RPMS.....mainly due to design.

I do agree that if you are a circle track driver and constantly turning over 7500RPMs there is a wanted feature of "underdrive" technology that you might want because of possible cavitation and the formation of air and hot spotting. Otherwise, for the purpose of pure cooling, the more flow the better, esp on the street. Of course there will be a point of no return if you get high enough rpms obviously, but racing pump designer and NASCAR engineering legend Howard Stewart even recommends http://www.stewartcomponents.com/techtip1.htm a full 35% overdrive on all of his high performance pumps. They WILL NOT cavitate with that recommendation.......I have tested them at that.

Now I don't know if that was what you were talking about, but that's not uncommon for me...? IF not ....nevermind, but your explanation of what you really mean has peaked my interest.

Thanks for the reply ahead of time.

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STEVE JACK
ConceptOne Pulleys and Brackets
http://streetrodstuff.com/Products/pics/thumb_198_1.jpg

[This message has been edited by HOTRODSRJ (edited 12-02-2001).]

Cavitation is what I meant. I got my words mixed up. I was half asleep when I did that post.

It may not happen with a good pump but on my 92 Eclipse it happened to me until I did get an underdrive pulley and I noticed during a high speed run down the highway that it does run cooler than with the stock pulley. It also turns alot more RPM's than a typical small or big block does. I do agree with you about poorly designed systems and also about the new pumps now manufactured in this day and age. They are getting better and better every day.

ok, here go's. I bought the march serpentine system for my small block driving the alt., water-pump, crank, and pwr steering. the brackets put the pwr steering below the alt on the drivers side with one belt running it all. at this time I had a flex fan on the water-pump pulley. started it up and at about 3k rpm the water-pump completely shattered around the shaft, the fan and pulley came off at high speed and ate the alluminum radiator and the crank pulley. after four more water-pumps and two more pulleys, ( talking with March each time) they told me of an idler pulley that allowes less tension by giving more belt wrap but I had to ask for something like that before they told me they had it. of course, this was the first time they had heard of this with their kit so I got to pay roughly twice as much for the parts and repairs by the time it was back together. I wasn't happy with what they told me.

Hi All,

I currently have the March underdrive setup on my BB 69. I am also currently having problems with charging and power steering. I don't think I have to say more. Take care, Paul

I'm with Steve - they may look "cool", but functionally, they're a disaster, and don't gain you any power either. All you get for your trouble is idle cooling, charging, and power steering problems. Huge waste of money if you're looking for power gains - it just isn't there, and the tradeoffs are unacceptable. It's a "Marketing" thing, not a "Performance" thing.

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JohnZ
'69 Z28 Fathom Green

I installed a set of their pulleys on a friends honda civic about a month ago and since then we've replaced the alt. twice and his pwr. steering is getting worse every day.

67rsmoneypit.....man o man I am sorry to hear that you did all that and paid March to do it. You are not alone in this, I have heard many a story!

March pulleys are made of high quality aluminum and the parts themselves are very good. However, the inherent design of their systems are lacking in certain areas. I would never use them in a "performance" arena. Anything with fairly high revs is at risk.

Their system of putting idlers and tensioners on the belts is a science in-and-of-itself. I don't think they get it. If you talk to the GM or Ford engineers on their factory serpentine systems, the one thing that they recognise is that there are inherent resonant frequencies in the belt drive system that exacerbate themselves in belt problems, including high speed "walk off" and assorted other ills. Take a high speed shift for example, going from 1st to second (6500rpms to 4000rpms)...the inertia that the belt(s) have at that speed is tremendous (think of a 8 foot belt traveling at 10,200+ feet/minute or 170 feet per second (at 6500rpm) and now slowing to a difference of over 3900+ feet/min or 65ft/sec in just a quarter of a second....that's like hitting a wall at 45mph head on...)and when they literally stop in the shifting process the inertia (literally thousands of pounds of force) tries to stretch the belt in some places and compresses it in others and resonant slack appears and therefore belt tension goes away at a certain point in the system and voila...the belt walks. The idlers and tensioners are supposed to take up this inertia caused slack, but if they are not designed to be in the right place at the right time, with the right amount of spring resonance then ooooops...there goes the neighborhood! This is what is wrong with the March systems. They just put there idlers and tensioners in the places where it "looks" like it should go and moreover dictated by "engineering wrap" for a certain device rather than taking the whole system in tune.


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STEVE JACK
ConceptOne Pulleys and Brackets

Steve, thanks for your sympathy. Marchs stuff does look very good, but I have spent many frustrating hours dealing with the pulley system and regret that I didn't look at other options before going with what looks cool. from what you are saying, I think the high rpm vibration I can feel and hear on my new motor is probably coming from the serp belt. factory equip is much less problematic - spend your $ on other stuff!

The factory equipment is generally less problematic as it's better engineered! I have owned one Chevy with a 'clunker' accessory drive system! My '85 IROC-Z with the TPI engine had 4 belts!! This was a year or so before they went serpentine. The AC belt used to resonate like a mother at idle and at 3000RPM when the compressor was on.

Moral: there's more science involved in properly designed pulley/belt systems than meets the eye!!

PDQUICK.......you have hit the preverbial nail on the head!!!!Many don't think of it that way. GM has a whole section of engineers dedicated to hanging accessories on the engines. DUH?

ConceptONE, coincidentally has been in the racing business for circle trackers pulleys and brackets for years. This technology was not perfected overnight and especially with NO TENSIONERS OR IDLER pulleys in our systems. We have dyno tested these suckers to over 8000rpms and flogged them to death.

You will see that Scoggin-Dickey, CCI and The Paddock will start to advertise our products. We are not just staying with engine accessories either. We have billet shifters for Hurst shifters that are so cooooool.




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STEVE JACK
ConceptOne Pulleys and Brackets