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Author Topic:   throwing belts help!
jamHxs
Dirt Roller

Total posts: 17
posted June 13, 2005 08:08 PM  
we have a midwest 355 and we can not keep the belts on it we have changed every thang on the front even the balencer twice and steel throes the belts both of them water pump and ps pump. we have no more ideas we thout of serpenten set up or deep grove pullys any sugestions. he runs 6500 to 7000 and he does not want to chang gear he is happy with the gear but i dont now whatto do thanks

sideways
Dirt Forum Champ
Total posts: 715
posted June 13, 2005 08:11 PM  
Deep grove pulleys.

hobby39
Dirt Maniac

Total posts: 112
posted June 13, 2005 09:10 PM  
A friend of mine had the same problem he always uses a belt that has groves on the outside that create air turbulance and push the belts into the pulley's. One night he got into it a little and had to borrow a standard belt and sure enough he lost it in the main. he got mad and started looking really close and the shaft on the PS pump was bent just slightly. Not sure what those belts are called but when I asked another racer he said he ran them also. I've also seen a water pump shaft go bad and start wobbling. I was told that autozone carries them but checker dosen't, not sure who else might have them. also itr might be just one belt going and taking the other one with it.

eaton89
Dirt Freak

Total posts: 268
posted June 13, 2005 10:31 PM  
I had exact same problem. Same motor. Tried everything. Only would throw them at about 6500 or more. Replaced everything(water pump, alternater,alternater bracket, balancer and stock pulleys) from top to bottom, no change. Tried several different belt types and brand, still did it. Finally spent $100 for 1 to 1 deep pulleys and cured the problem. No more heating problems and turned up to 7200 with no problems. Highly recomended. I would never ever do it any other way again!!

merlinmech2
Dirt Maniac

Total posts: 131
posted June 14, 2005 08:00 AM  
I agree, deep groove pulleys. You can try running a 3/8 belt. It will sit down in the pulley.

marshalr
Dirt Maniac

Total posts: 148
posted June 14, 2005 09:55 AM  
Gates or dayco belts only. The Dayco "topcog" seem to work the best.
The deep groove pulleys help too, but key is to get the pulleys properly aligned, use washers and shims to get em perfectly aligned. You can buy spacer shims that go behind the water pump pulley.

------------------
Some People Race For A Living; I Live To Race

jamHxs
Dirt Roller

Total posts: 17
posted June 14, 2005 01:04 PM  
thanks we will be trying all of this weekend

istock59
Dirt Forum Champ
Total posts: 501
posted June 14, 2005 01:55 PM  
I have friends that swear by the Gates "green" belts. I believe they are an Industrial type. And yes, they're green colored.

Me, I prefer my KRC serpentine pulley setup over a v-belt any day.

eaton89
Dirt Freak

Total posts: 268
posted June 14, 2005 09:18 PM  
I dont know what it is but when you have the wrong combo it doesnt matter what you do it doesnt seem to fix it. I moved things around by shimming them used a straight edge and it didnt make any difference. I could crank that motor up to 6500 and up in the shop and watch the belts **** down into the pulley and make the belt loose until it would fall off. Maybe if the pulleys were all new original stuff they would work but nothing and I mean nothing would work for "me"! Spend the money and buy deep 1 to 1 pulleys and spend the time you save screwing around with it for making the car faster!! Just my 3 cents worth

racer2
Dirt Freak

Total posts: 352
posted June 15, 2005 07:20 AM  
deep groove pullies

Jeep83
Dirt Roller

Total posts: 9
posted June 16, 2005 08:53 PM  
Are you running a solid blade fan? If so you may need to flatten the blade pitch a little bit. Too much drag from the fan will cause the belts to peel off, been there ... done that. It was a hard problem to figure out, I did all the same stuff you did with no avail, finally an old timer told about the fan thing, worked the first time out.

Just something to try if all else fails.

Good luck

DangerZoneRacing
Dirt Maniac

Total posts: 176
posted June 16, 2005 09:49 PM  
I started running the serpintine style off the late 80's metric cars (the kind that go on the crank, water pump, and alt., and still runs v-belt on power steering pump). I had nasty problems last year with throwing belts and it cost me the championship. I had a guy from one of the wrecking yards suggest this so I put it on and no problems now. I also am turning more RPM's then I did last year and still no problems. (no im not saying im turning more R's cuz of the pulleys lol) I wont ever go back to the v-belts now.

bncars10sen
Dirt Roller

Total posts: 23
posted June 18, 2005 07:13 AM  
You need to slow down the belt speed....use the smallest crank pulley you can.....use a pulley from a 305 or a 283...that will stop your throwin problem..

fastow
Dirt Maniac

Total posts: 168
posted June 19, 2005 02:20 AM  
bncars10sen You are right on track. I have read alot of post on cooling and belts here and it seems everyone has forgot why the reason for the underdrive pulley system. 1st with a smaller crank pulley it slows belt speed witch in turn is not going to cause near the problems throwing belts, making pulley alignment, fan drag and pulley depth less of a concern. 2nd the more underdrive can be run ie: smaller crank pulley vs: accessory pulleys the less horsepower loss to the engine.

Mr. Badboy
Dirt Full Roller

Total posts: 29
posted June 20, 2005 06:40 PM  
I did not hear what kind of power steering pump you were running. If it is stock, and when the motor is turning at high rpm's, and when the wheels hit full travel to one side or another, that will cause backlash on the power steering pump and throw belts. If you have a power steering pump made for racing, and throw belts, I am like the others on the use of a deeper groove pulley.

sc1 racing
Dirt Freak

Total posts: 419
posted June 20, 2005 11:43 PM  
1 quick fix is if you are running a stock water pump get a 3/8 bolt and a few washers. put the bolt in the water pump by pulley and find a socket the will barely touch the belt. tighten it down and your problem is solved.

i dont think id mess with the fan blades they are designed for max air flow.

and only belts we have had problems with are the ones from auto zone. we always run the napa belts

sideways
Dirt Forum Champ
Total posts: 715
posted June 21, 2005 12:39 PM  
quote:
Originally posted by sc1 racing:
1 quick fix is if you are running a stock water pump get a 3/8 bolt and a few washers. put the bolt in the water pump by pulley and find a socket the will barely touch the belt. tighten it down and your problem is solved.

i dont think id mess with the fan blades they are designed for max air flow.

and only belts we have had problems with are the ones from auto zone. we always run the napa belts


I agree with the autozone belts and using napa been there threw those autozone belts.I am sticking to napa belts(gates).


Magic82
Dirt Full Roller

Total posts: 34
posted June 24, 2005 05:54 AM  
Just my Canadian two cents....I had this problem once and it turned out to be the thrust washer at the back of the crankshaft. It was worn beyond it's allowable tolerance and it let the crankshaft walk in and out just enough to throw the belts at high rpm. I am not sure if your crank is new but it's something to look at.

powerglides
Dirt Freak

Total posts: 374
posted June 24, 2005 06:43 AM  
Are you running both belts around both the water pump and crank? If so you need to be running the same brand belts (I use NAPA also) otherwise you can have the pulleys trying to spin at different speeds due to one belt running deeper in the groove. This can also be caused by different size pulleys on the same shaft. If all else fails run one belt around just water pump and crank and one belt around just ps pump and crank. Try different brand belts to get one to fit properly between crank and water pump.

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